Sewer Thermal Energy Network Blog

Why Heat Pump Manufacturers Must Lead in the Sewer Thermal Revolution

Mon, 06 Apr 2026 18:29:09 GMT

From Vendor to Infrastructure Partner with STEN Membership

For heat pump manufacturers, the next frontier isn’t in the air or the ground - it’s in the pipes. As urban centers scramble to decarbonize, Sewer Heat Recovery is emerging as the most stable, efficient, and scalable thermal resource available. By utilizing wastewater, which stays at a near constant temperature year-round, manufacturers can offer systems with a Coefficient of Performance of 4.0 or higher, even in the dead of winter. However, capturing this market requires more than just high-quality hardware; it requires a seat at the table where infrastructure is designed.

The Massive Opportunity: Data Centers & Urban Cooling

While heating is a primary focus, the most explosive growth opportunity for heat pump manufacturers lies in Data Center Cooling.

The Sink: Data centers generate immense waste heat. In urban environments where traditional cooling towers are restricted by space or water-use regulations, sewers act as a massive thermal sink.
The Solution: Large scale water-source heat pumps can reject this heat into municipal sewer lines far more efficiently than air-cooled systems.
The Market: Manufacturers who develop specialized units for this heat rejection application are positioned to dominate the tech-sector infrastructure market.

Why Join STEN? Go From Vendor to Infrastructure Partner

Membership in the Sewer Thermal Energy Network (STEN) is the strategic bridge that moves manufacturers from being simple equipment vendors to essential partners in thermal energy networks. Specifically, membership can provide:

Direct Pipeline to Anchor Projects: STEN is the primary hub for municipalities like Syracuse , Toledo and DC Water that are actively mapping their wastewater assets.
Member Benefit: STEN connects you directly with city planners and utility directors. This allows you to get your hardware specifications baked into the feasibility and design phases of massive developments like the National Western Center .
Solving the Dirty Water Engineering Gap: The biggest barrier to adoption is the ick factor - biofouling and clogging from raw sewage.
Member Benefit: STEN provides technical lessons learned from global leaders. Members can collaborate with specialized heat exchanger firms like Huber Technology or Teralba Industries to create integrated systems that combine advanced filtration with high-efficiency heat pumps.
Influencing Policy & Funding: Manufacturers rarely have the bandwidth to lobby for regulatory changes needed to tap into municipal sewers.
Member Benefit: STEN advocates for legislative wins - like those in Connecticut , Oregon and Massachusetts - that incentivize utilities to pivot to thermal networks. By joining, you help create the very market that buys your equipment.
Precision Market Intelligence: Where should you deploy your sales team? STEN knows...
Member Benefit: STEN provides heat mapping services that identify exactly where high-flow sewer mains intersect with high-demand building clusters or data center zones. This data allows for surgical R&D and sales targeting.

Strategic Advantage: Traditional Air Source vs Sewer Source

Transforming Wastewater into a Valuable Resource

The US DOE estimates that enough heat is flushed away annually to power 30 million homes. As a manufacturer, you can either watch utilities and municipalities build these networks with your competitors' specs, or you can join STEN and lead the design of the next generation of urban energy. As a STEN member , you’ll join a group of the most influential professionals in the industry - leaders and decision-makers who are working together to shape the future of sewer heat recovery solutions - and you’ll have access to resources that will help you unlock the potential of this growing market. Click to contact us today and learn more about becoming a member of Sewer Thermal Energy Network.. .

The Role of Sewage Thermal Energy Use (STEU) In Data Centers

Tue, 10 Mar 2026 16:12:19 GMT

How Can We Make Data Centers Less Wasteful of Local Resources?

Data centers are a part of our modern life, a necessary component of our current infrastructure space. They have been around for a long time too, first referred to simply as Server Farms, then later The Cloud and now as AI. With each step comes the next level of development and as with most infrastructure, the NIMBY (not in my backyard) effect applies. People want the benefit of a specific asset but do not want it in their neck of the woods. One of the main reasons stated for opposition to its local development is that they use too much electricity and water. It is reasonable to expect a new infrastructure project to be a good neighbor but is it reasonable to expect the laws of physics to be abandoned? Hence the need for compromise and creative thinking. How can we make data center use less wasteful or at least more acceptable?

Water Is at Epicenter of the Environmental Impact of Data Centers

To develop the framework in which to compromise, it important to know more about how the systems work and to clearly define objectives. The construction of data centers requires capital, which they have received, and to date they are performing in the financial space. This is not a reflection of the long-term viability of the ventures but clearly, they are currently able to pay for the water and electricity they use. This is having a measurable effect on the overall cost of electricity and the economy in general. They are also performing in their technical mission helping to fill the expanding need for such services. So, what remains is the environmental impact.

Not only do data centers use a lot of electricity to do their IT work, but they also need additional electricity to keep the equipment cool enough to operate and control humidity. What the facility does with that heat after it cools the servers is the concern in this post. Heat can be removed from the building cooling system via air or water. Water is 4,000 times better at heat transfer than is air, so as one might imagine, the cooling of data centers is a water centric process.

Evaporative Cooling Is Powerful, But It Permanently Consumes Water

In most cases the overall system cooling is achieved via the thermodynamically beneficial effect of evaporation. Cooling water by evaporation consumes a vast amount of heat, which is the objective of the system. It takes 970 BTU to evaporate one pound of water. If one were to heat one pound of water from 32 F to 212 F that would take 180 BTUs. Evaporating water consumes more than 5 times as much energy as it takes to heat it. However, once that water is evaporated it is discharged into the atmosphere and blows away. Evaporative cooling is powerful, but it permanently consumes water. If water is of value to the community, then evaporative cooling becomes a conflict point.

Evaporative cooling consumes even more water than it takes to evaporate the waste heat. The cooling system needs to discharge a certain amount of water (blow down) to keep the water quality of the cooling stream in the appropriate range. Therefore, some water conservation methods are focused on reclaiming and treating the blow down water so that less water is used in the system overall, but evaporation still takes place.

One could choose to find an alternative supply of water other than the local potable water utility. If that source is ground water, then the data center is still pulling water out of the local potable water supply. However, on could approach the local wastewater authority and their plants, what are often referred to a water resource recovery facility (WRRF). The effluent of these WRRFs can be treated to a high enough quality to be used as the cooling water. In this scenario, the WRRF becomes the source of cooling water reducing stress on the local potable water supplier. Water is still being consumed (discharged as vapor to the air) just not potable water.

Data Centers & Thermal Energy Network Utilities Working Together

Better yet, the waste heat can be discharged into a sewer by heat exchanger so that evaporative water is not needed. A flowing sewer has a tremendous amount of thermal capacity, both to give up heat and to accept heart . Again, water (sewage is over 99.5% water) is 4,000 times more effective at heat transfer than air.

For example, at the Naval Air Station Oceana, Dam Neck Annex , their data centers add heat to a base internal loop (a meso-temperature loop). This loop provides heat to all buildings, year-round, with each building having its own heat pump to remove heat from the loop. However, in the summer and when there is too much heat, it dumps the excess in Hampton Roads Sanitary district’s Atlantic plant effluent. The plant effluent is the systems thermal sink. There must be sufficient flow of wastewater to absorb this excess heat.

If this scenario is explored, the expelled heat can be retrieved downstream of the exchange point. The sewer system itself becomes a conveyor of heat, a community capital asset, utilized for more than waste conveyance.

A Framework of Compromise & Creative Thinking

The highest value use of data center waste heat is to supply a local heat loop so that excess heat could be used in a Thermal Energy Network (TEN). In this way a separate third party TEN utility could make beneficial use of that energy selling it as a method to help people reduce their carbon footprint and in many cases helping the local building stock electrify. The main reason this is not happening is that the operators of data centers are focused on meeting a growing demand under high stakes pressure. While third party TENs, with less access to capital, are looking to be profitable over the long run while providing a service to a community.

Considering the use of sewage thermal energy will increase the acceptance rate of data centers and allow for their inclusion in more densely populated areas, where there are large sewers. Developing a relationship with the local wastewater utility and the inclusion of a Thermal Energy Network will proved the framework of compromise.

Transforming Wastewater into A Valuable Resource

Do you want to do more to help the world utilize clean energy, but don't know where to begin? The Sewer Thermal Energy Netwo rk is all about professional planners who understand the potential of heat recapture. As a member of STEN , you’ll join a group of the most influential professionals in the industry - leaders and decision makers who are working together to shape the future of sewer heat recovery solutions. We are eager to hear your thoughts, concerns and hopes for this promising approach to making our energy systems more sustainable. We invite you to send a message to begin a conversation that will give you the answers you need…

Value Proposition: Wastewater Heat Powered Data Centers

Tue, 09 Dec 2025 18:09:47 GMT

Integrating Data Centers with Sewer Thermal Systems

Paul Kohl and Nick Meeten met with a Mid-Western Utility recently to discuss the advancement of sewage thermal energy use. The meeting went well but excitement reached a pitch when the conversation moved to sewer heat exchangers and the value proposition around the potential of wastewater systems , specifically associated with data center development.

Economic Potential of Wastewater Heat Recovery

Data centers use a lot of electricity and produce steady, continuous waste heat, which is of value to local communities if they are able to capture and reuse it. Once data centers, municipal entities and even district energy companies get into a mutually supportive conversation, solutions can be produced. This thermal surplus is often viewed as a liability requiring large cooling plants, but in a sewer-coupled model, it becomes a resource. This makes the economic potential of wastewater heat recovery a key driver for all participants.

From Waste to Resource

The convergence of high heat output from server racks and consistent flow in sewers offers a unique synergy. The Sewer Thermal Energy Network (STEN) is a leading innovator in wastewater heat recovery solutions. STEN has been established to provide advocacy, education, information dissemination, capacity building, and networking opportunities for cities, municipalities, and wastewater utilities as well as other interested entities such as data centers. We are a membership class organization with various levels of participation and benefit. Become a member of STEN today and let's continue this important conversation.

Data Centers & Sewer Thermal Energy: Turning Sewers into Climate Allies

Wed, 15 Oct 2025 20:18:26 GMT

What a Sewer Heat Powered Data Center Future Could Look Like

One of the most underappreciated opportunities lies literally beneath our feet - the thermal capacity of the water in sewers . By pairing high-density, energy-hungry data centers with the untapped thermal potential of sewer systems, we can reimagine urban heat systems, reduce emissions, and turn waste into utility.

Integrating data centers with sewer thermal systems promises multiple wins: lower energy costs, lower carbon emissions, and smarter urban thermal infrastructure. The exponential growth of artificial intelligence, cloud services, and edge infrastructure is driving data centers to consume ever more electricity. As those loads climb, cooling management becomes even more critical and increasingly expensive - not just operationally but environmentally.

STEN positions sewer thermal energy as a form of energy recycling, tapping into waste streams to supply heating or cooling. This is a sustainable activity, reducing the amount of primary energy expenditure and therefore reduces greenhouse gas emissions while achieving the heating and cooling needed within the built environment. The convergence of high heat output from server racks and consistent flow in sewers offers a unique synergy.

How Sewer Thermal Energy Works

To understand the marriage of data centers + sewers, it's useful to review how sewer heat recovery is typically structured:

Continuous Flow : Sewer systems are a reliable, continuous, reasonably temperature-stable source of thermal energy - both warmer than the air in the winter, and cooler than the air in the summer. This paradigm is referred to as Sewage Thermal Energy Utilization (STEU) .
Heat Extraction: A heat exchanger interfaces with the wastewater stream in the sewer, capturing thermal energy from the fluid.
Heat Pump Upgrade: Because the temperature from sewage is relatively low grade, a heat pump is used to ratchet the thermal energy to useful levels for heating or for cooling.
Distribution & Reuse : The upgraded heat can be supplied to buildings for space heat or hot water, district heating systems, or reused for cooling in the summer.

Why Data Centers Are Good Partners for Sewer Thermal Systems

Here are some reasons why data centers and sewer heat make strategic sense together:

High Heat Density + Continuous Operation - Data centers produce steady, continuous waste heat. This thermal surplus is often viewed as a liability requiring large cooling plants, but in a sewer-coupled model, it becomes a resource.
Proximity Synergy - Data centers are often located near urban infrastructure including sewer lines. If the sewer network already exists nearby, the distance between the data center and heat exchange point can be minimized.
Seasonal Complementarity - In colder months, the sewer’s warmer than air temperature can supplement heating demand. In warmer months, the sewer can absorb waste heat, alleviating the burden on cooling systems. While both the sewer and the data center can be supply nodes for a distributed energy system with sewers offering a modulation effect.
Emissions & Cost Reductions - By tapping an existing thermal resource, the net energy required (and thus emissions) for heating and cooling can be reduced. A well-designed reuse scheme can improve a data center’s overall efficiency, reducing system costs and emissions relative to conventional data centers. Recycled heat is a benefit to society.
Economic Value for Both Stakeholders - Sewer utilities or municipalities can monetize their thermal resource. Data center operators can reduce operational costs while a third party such as a municipality, can sell the surplus. Most likely through a district energy system which allows great access to this common good. This makes the economic potential of wastewater heat recovery a key driver for all participants.

Vision: A Sewer Heat Powered Data Center Integration

Here’s a conceptual pathway for how this integration might roll out in urban settings:

Heat Potential Mapping : Using GIS and sewer flow data, map sewer segments for their thermal potential and identify heat opportunity zones. Members of STEN already do this work.
Site Pairing: Place or retrofit data centers in proximity to promising sewer segments ideally located or within short piping distance.
Hybrid Heat System Design: Combine sewer heat exchange + heat pumps + thermal storage + distribution to cooling and heating loads.
Heat Integration: Use recovered heat to serve building heating, hot water, cooling refrigeration loads, or neighboring district heating systems.
Feedback / Load Flexibility: In times of low computing load, reduce heat extraction; in times of peak, maximize. The data center could even coordinate with the energy grid for flexible cooling and heat swapping as part of a smart ecosystem.
Scaling & Multiplier Effects: As multiple data centers, buildings, and utilities interconnect, the sewer network becomes an integrated thermal backbone for urban climate systems.

Practical Challenges

No solution is without headwinds. A general review of waste heat recovery in data centers highlights that these barriers are not insurmountable, but adoption is still early. One of the main challenges in implementing data center + sewer thermal systems is the capital cost and financing. Upfront investments in heat exchangers, pumps, piping, and controls can be a lot and the payback period needs to justify it. Another challenge includes the regulatory and institutional barriers. Water/sewer utilities and data center operators often belong to different regulatory domains. Coordinating incentives, cost sharing, and responsibilities can be complex.

Alignment of Recent Trends & Market Pressure

The explosive growth in AI and computational demand has data centers under pressure not just to expand capacity, but to do so sustainably or be at risk of regulatory, reputational, and cost constraints. Meanwhile, policy regimes in many jurisdictions are beginning to require that new data centers evaluate heat reuse potential or justify rejecting waste heat.

As data centers proliferate into more urban and distributed locations, aligning them with local thermal systems becomes more feasible and attractive. Sewer-based thermal recovery presents an especially appealing path because it leverages existing infrastructure in the city’s sewers rather than building entirely new geothermal systems.

From Waste to Resource - A Path Worth Pursuing

The proposition is elegant . . . instead of fighting heat, data centers should embrace it and turn it into value. Sewer thermal energy offers a grounded, real-world means to do exactly that. While some institutional and financial hurdles remain, the alignment of trends makes this a moment ripe for experimentation and deployment. As the number of pioneering data centers partnering with sewer utilities grows, and proves the economics showing the reliability, this model could scale rapidly - turning lots of what we now consider “waste” into a core building block of sustainable urban thermal systems.

Sewer Thermal Energy Network - A Rare Combination of Expertise

The Sewer Thermal Energy Network (STEN) has been established to provide advocacy, education, information dissemination, capacity building, and networking opportunities for cities, municipalities, and wastewater utilities as well as other interested entities. Discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment, from a single building to a whole district. STEN is a membership class organization with various levels of participation and benefit. It is made up of member cities and the professionals that serve them. We invite you to send a message to begin a conversation that will give you the answers you need...

Wastewater Heat Recycling Projects Status in Germany

Wed, 09 Jul 2025 18:37:44 GMT

Wastewater Heat Recycling Achieving Sustainable Growth in Germany

Evidence of this commitment to progress is the signing of a new policy initiative in the German state of North Rhine-Westphalia . The state has now launched this new program to further accelerate the pace of the heat transition using this previously underutilized source. According to current state estimates, around 800 sewerage projects will be needed to achieve the targets for the expansion of wastewater heat in the region by 2045.

Interactive Projects Map

This map shows the locations of 20 wastewater heat recycling projects in Germany which are currently in various stages of development. These projects range from those newly announced, in the planning phase, in construction or completed and in operation.

To utilize the interactive map, first choose Language /English in the top right corner. In the Source Category field, choose Wastewater to filter other sources. More information on each project can be found by hovering your cursor over the dot and also by clicking the respective dot on the map.

MassDEP Announces Their Newest Program

Mon, 23 Jun 2025 19:26:59 GMT

Wastewater Energy Recovery Pilot Program Offers Incentives

The Sewer Thermal Energy Network is a mutual benefit organization focused on expanding the market for sewage thermal energy use (STEU). To that end, it is our pleasure to inform you of a Massachusetts Department of Environmental Protection 's (MassDEP) announcement of their newest program. Included below is a link offering more explanation and connection. The program will start by mid-summer 2025.

New Program Can Provide Funding Assistance in 3 Project Phases

The state of Massachusetts is promoting sewage thermal energy use (STEU), what they call Wastewater Energy Recovery (WWER), an apt name. This is a pilot program offering incentives, in the form of grants. These incentives are in three phases and the amount of subsidy for each phase increases. The pilot program grant structure is as follows (all limits and conditions must be confirmed by MassDEP).

Study Phase (Energy Assessment) grant - up to $15,000
Design Phase Assistance - up to $100,000
Construction Phase - up to $750,000

STEN feels it important to note that these funds are state authorized, meaning the current uncertainty of federal funding is not a concern. The current program fund total is $5 M. The pilot project grants (WWER Grants) are being offered by the Clean Energy Results Program (CERP), a collaborative program in partnership with MA DOER and the Mass Clean Energy Center.

For more information feel free to contact Michael DiBara , the program head at MassDEP directly. STEN, as a mutual benefit organization, has members that can provide assistance with services in each of the three program phases. Rest assured STEN will keep you informed of program updates and clarifications. We invite you to send a message to begin a conversation that will give you the answers you need.

Prospective Benefits of Wastewater Heat Recovery

Wed, 02 Apr 2025 16:37:11 GMT

What Is the Broader Impact of This Innovation?

As the world searches for more sustainable alternatives to improve energy efficiency, wastewater heat recovery has emerged as a promising technology. This process captures and repurposes the heat from wastewater, reducing energy consumption and lowering greenhouse gas emissions. Let's explore the potential impacts of wastewater heat recovery.

Environmental Benefits

One of the most significant advantages of wastewater heat recovery is its ability to reduce energy consumption. Traditional water heating systems require substantial energy, often sourced from fossil fuels. By utilizing heat from wastewater, buildings and industrial facilities can reduce their dependence on non-renewable energy sources. This, in turn, leads to lower carbon emissions, contributing to climate change mitigation.

Additionally, wastewater heat recovery can decrease thermal pollution. When wastewater is discharged into natural water bodies, it can raise temperatures and disrupt local ecosystems. Recovering heat before disposal helps maintain the natural balance of aquatic environments.

Economic Savings

Implementing wastewater heat recovery can lead to substantial cost savings for homeowners, businesses, and industries. By preheating water using recovered energy, facilities can lower their utility bills. In large-scale applications such as wastewater treatment plants and district heating systems, the savings can be even more significant. Moreover, reduced energy demand may translate into lower operational costs and improved system efficiency.

Energy Efficiency & Grid Stability

By integrating wastewater heat recovery into energy systems, municipalities and industries can optimize energy use, leading to greater overall efficiency. A more efficient energy system reduces the strain on power grids, particularly during peak demand periods. This not only helps prevent blackouts but also supports the transition to renewable energy by making the grid more resilient and adaptable.

Challenges & Considerations

Despite its benefits, wastewater heat recovery faces some challenges. There is an initial investment for installing heat recovery systems which are slightly higher than air source heat pumps, yet their operating cost is significantly lower. Additionally, system compatibility with existing plumbing infrastructure must be carefully assessed if changing from a fossil fuel system to a heat pump system. However, technological advancements and carbon reduction goals (and other incentives) can help overcome these hurdles, making wastewater heat recovery more accessible.

Start Recycling Wastewater into a Valuable Resource Now!

Wastewater heat recovery presents an exciting opportunity to enhance energy efficiency, reduce emissions, and lower costs. As more industries and municipalities adopt this technology, its potential benefits will only grow. Investing in wastewater heat recovery is a step toward a more sustainable and energy-efficient future.

Transforming Wastewater into A Valuable Resource

Do you want to do more to help the world utilize clean energy, but don't know where to begin? The Sewer Thermal Energy Network is all about professional planners who understand the potential of heat recapture. As a member of STEN , you’ll join a group of the most influential professionals in the industry - leaders and decision makers who are working together to shape the future of sewer heat recovery solutions. We are eager to hear your thoughts, concerns and hopes for this promising approach to making our energy systems more sustainable. We invite you to send a message to begin a conversation that will give you the answers you need…

Mapping the Potential of Sewage Heat Recovery

Tue, 18 Mar 2025 18:30:55 GMT

Why Map Sewage Heat Availability?

As cities seek sustainable and efficient energy solutions, one often-overlooked resource is wastewater. Utilizing sewage heat recovery for heating and/or cooling buildings is one of the most exciting opportunities available for cities. They can quickly and easily take big steps in stopping fossil fuel use and reducing carbon emissions, saving precious drinking water, improving air quality, and reducing noise pollution.

Most significantly, is that the city already has their sewage network in the ground, and they already have the heat energy flowing within those pipes, ready and waiting to be utilised. By mapping the available wastewater heat within a city, municipalities can strategically plan for its integration for use in buildings, industries, into district heating and other energy networks.

Sewage Heat Availability Mapping

Mapping the thermal potential of a city’s sewage system visualizes the flows and pinpoints high-potential zones within the network. This can help improve cost-effectiveness by prioritizing locations where heat recovery investments yield the highest return. In turn, this will support sustainability goals by reducing carbon footprints and reliance on conventional heating sources.

Key Steps in Mapping Sewage Heat Availability

1. Data Collection & Analysis

Expert analysis of the data is required to assess technical risks, establish upper and lower thresholds and generate forward looking scenarios. All of this work then allows modelling of the thermal capacity available at any location within the network. Mapping sewage heat starts with gathering a variety of data such as:

Wastewater temperature
Flow rates
Treatment processes
Wastewater characteristics
Topography
Climate
Infrastructure layout
Policy regulations
Planned infrastructure changes
Urban expansions or intensifications

2. Information System (GIS) Mapping

This modelling information can be presented using Geographic Information System (GIS) to show the locations of the heat energy.

Heat Maps show where the heat flows are located.
GIS map layers can be added to existing GIS data or be the basis for its own series of layers.
The most common information presented is the heat energy capacity of the sewer segment which is the result of an analysis of flow temperature and thermal limits of removal.

3. Identifying High-Potential Zones

By overlaying thermal capacity data onto urban maps, planners can pinpoint optimal locations for heat recovery installations. These may be locations where wastewater network ‘hot spots’ coincide with high thermal demand zones within the city. Examples of these that often present the best opportunities may be:

High-density urban areas
Hospitals
Commercial districts
Industrial zones
Community aquatic facilities

4. Feasibility Assessment & Implementation

Technical and economic feasibility studies help refine site selection by assessing:

Energy demand vs. available sewage heat
Infrastructure modification needs
Non-financial benefits such as: noise reductions, air quality improvements, water savings, legionella risk reductions, seismic risk reductions
Cost-benefit analysis and return on investment

Future Outlook of Sewage Heat Recovery

With rising urban energy demands, sewage heat recovery is poised to play a crucial and significant role in sustainable city planning. By leveraging the hidden energy potential in wastewater, cities can take a significant step toward decarbonization while enhancing energy resilience. Mapping sewage heat availability is not just a technical endeavor—it’s a pathway to a cleaner, more efficient future. STEN is a network of the scientific and engineering community, the municipal utility community and the governance community with membership for all.

Objective of the Sewer Thermal Energy Network

Sewer Thermal Energy Network 's objective is to promote the use of sewage thermal energy for the benefit of our collective lives and the environment by making development more sustainable. One of the main objectives of STEN is to provide an interactive capacity between entities that allows for the development of this useful resource. This information will help bridge the information gap between a little known but vast resource and the development community.

Peer to Peer Networking with STEN

The idea of energy recycling is a new, dynamic idea that will require rethinking by all participants in society. Not only does a bridge between groups need to be built, a community also needs to develop within that space to change the world. STEN hopes to provide a place for all members of this coalition to meet and exchange information: Engineers, Educators, Researchers, Developers, Policy Makers, Regulators. We invite you to send a message to begin a conversation that will give you the answers you need.

Unlocking the Potential of Sewer Thermal Energy for Wastewater Heat Recovery

Thu, 20 Feb 2025 18:57:20 GMT

Unlocking the Potential of Sewer Thermal Energy for Wastewater Heat Recovery

As the world seeks innovative ways to reduce carbon emissions and improve energy efficiency, one often-overlooked resource is gaining attention - Sewer Thermal Energy . Wastewater, which constantly flows through sewer systems, holds an immense amount of thermal energy that can be harnessed to heat and cool buildings, reducing reliance on fossil fuels and lowering energy costs.

What Is Sewer Thermal Energy?

Sewer Thermal Energy refers to the heat contained in wastewater, including residential, commercial, and industrial effluents. This energy comes from showers, dishwashers, washing machines, and industrial processes, maintaining relatively stable temperatures throughout the year. With the right technology, this heat can be recovered and repurposed for sustainable heating and cooling applications.

How Wastewater Heat Recovery Works

The process of capturing and utilizing sewer thermal energy typically involves the following steps:

Heat Exchange: A heat exchanger extracts warmth from the wastewater.
Heat Pump Integration: A heat pump upgrades the extracted thermal energy to a usable temperature.
Distribution System: The recovered heat is distributed to buildings for space heating, domestic hot water, or industrial processes.
Cooling Applications: In warm months, the same system can be reversed to remove heat from buildings, transferring it to the sewer system.

Benefits of Sewer Thermal Energy Recovery

Energy Efficiency - Wastewater temperatures are relatively stable, offering a reliable heat source.
Lower Carbon Footprint - Reducing the need for fossil-fuel-based heating and cooling systems.
Cost Savings - Decreased reliance on traditional energy sources translates to long-term financial benefits.
Scalability - Can be applied to residential buildings, commercial properties, and industrial facilities.

Real-World Applications

Cities across the globe are already implementing sewer thermal energy projects. For instance, Vancouver, Canada has integrated a wastewater heat recovery system in its False Creek neighborhood, significantly reducing greenhouse gas emissions. Another large scale sewage thermal energy system has just started in Toronto, Canada. It is used to heat and cool a hospital. Similarly, European countries like Switzerland and Germany are investing in large-scale wastewater heat recovery initiatives. In the US, there are two systems in Washington DC currently in operation and a new system is going "online" in Seattle, Washington.

Future of Sewer Thermal Energy

With increasing urbanization and the push for sustainable energy solutions, wastewater heat recovery is poised to become a key component of modern heating and cooling strategies. Innovations in heat pump technology and smart energy systems will further enhance the feasibility and efficiency of sewer thermal energy recovery. By tapping into the power of wastewater, cities can create a more sustainable and resilient energy infrastructure, paving the way for a greener future while also providing economic benefits to industries and communities.

Connect with the Experts at STEN

Do you want to do more to help the world utilize clean energy, but don't know where to begin? The Sewer Thermal Energy Network is here to help you get started. As a member of STEN, you’ll join a group of the most influential professionals in the industry - leaders and decision makers who are working together to shape the future of sewer heat recovery solutions. We invite you to send a message to begin a conversation that will give you the answers you need.

What Is Sewer Thermal Technology?

Thu, 10 Oct 2024 20:25:40 GMT

Sewer Thermal Technology Explained in Non-Academic Terms

In short, sewer thermal technology is like turning a source of waste heat into something useful and environmentally friendly, making our energy systems more efficient and sustainable.

What It Is

Sewer thermal technology uses the heat that's already present in our sewer systems to help heat or cool buildings. Think of it like harnessing the warmth from the pipes below our streets.

How It Works

Heat Source: Sewers carry wastewater, which is often warmer than the surrounding ground. This warmth comes from things like hot showers or industrial processes.
Energy Extraction: Special systems can capture this heat from the sewers and use it to warm up buildings.

Why It’s Good

Eco-Friendly: It’s a sustainable way to use energy that’s already being produced, which helps reduce our reliance on fossil fuels and cuts greenhouse gas emissions.
Cost-Effective: By using the heat from sewers, we can lower energy bills because we're utilizing a resource that’s already available and doesn’t require additional energy to produce.
Reduces Waste: It makes use of a byproduct (wastewater) in a useful way, which helps in managing resources more efficiently.

Real-World Impact

Energy Savings: Imagine your building or home being heated with energy that would otherwise go to waste. It’s like getting free heating from the infrastructure we already have.
Environmental Benefits: By cutting down on the need for other heating sources, we’re reducing pollution and our carbon footprint.

What Are Some Basic Ways of Learning About the Environmental Benefits of Sewer Thermal Technology?

By using these basic methods, you can gain a broader understanding of the introductory concepts of environmental benefits of sewer thermal technology.

Informational Websites:

Wikipedia : Look up sewer thermal technology or waste heat recovery to get a general overview of how it works and its environmental benefits.
Environmental Organizations: Visit websites of organizations like the Environmental Protection Agency (EPA) or the World Resources Institute (WRI) which might have accessible summaries or articles on related topics.
STEN: A non-profit focus on developing the marketplace for sewage thermal energy use.

Educational Videos:

YouTube : Search for videos explaining sewer thermal technology and its benefits. Look for content aimed at a general audience that simplifies complex concepts.
TED Talks : Watch talks on sustainable energy or waste heat recovery that might touch on sewer thermal systems.

News Articles:

Local & National News: Find news articles that cover recent developments or projects involving sewer thermal technology. They often highlight the environmental benefits in an accessible way.

Infographics & Fact Sheets:

Infographics: Search for visual representations that explain sewer thermal technology. Infographics can illustrate how it works and its positive environmental impacts.
Fact Sheets: Look for fact sheets from environmental or energy organizations that summarize the benefits and key points about sewer thermal technology.

Brochures & Public Information Documents:

Local Government Publications: Check out brochures or public documents from local municipalities that may have implemented sewer thermal projects and detail their environmental benefits.

A Sustainable Path Forward

Discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment. Wastewater heat recovery presents a compelling opportunity to enhance energy efficiency, reduce costs, and promote environmental sustainability across various industries and applications. By harnessing the untapped thermal energy present in wastewater streams, organizations can make significant strides towards a more resource-efficient future. With careful planning, implementation, and maintenance, wastewater heat recovery systems can deliver long-term benefits for both the bottom line and the planet. The Sewer Thermal Energy Network (STEN) invites you to send a message to begin a conversation that will give you the answers you need…

Heat Pump Project Cost Compared by Heat Source

Wed, 21 Aug 2024 18:15:06 GMT

Large-Scale Wastewater Source Heat Pumps Have Considerable Market Potential

We at the Sewer Thermal Energy Network are frequently asked how much a wastewater heat recycling system costs compared to other low carbon options. The answer is that every project is unique and so generalizations are difficult to make. However, the chart below demonstrates the results of research done in Germany on investment costs for large-scale heat pump projects.

The cost of wastewater source heat pump projects are shown as being in the lowest three cost options. The bars indicate the total unit cost of investment needed to build the system, with six components of the total cost indicated by color. Although the cost of wastewater heat and air source heat pump projects are similar, the continuing efficiency of wastewater heat pumps are far superior, making them less expensive to operate.

Saving Tax Dollars by Rethinking Wastewater Management

So, in this research example, it is clear that wastewater source heat pump projects are extremely good value. The Sewer Thermal Energy Network (STEN) is a member supported network that provides advocacy, education, information dissemination, capacity building, and networking opportunities for cities, municipalities, and wastewater utilities as well as other interested entities in the use of freely available heat in sewage for heating and cooling for the built environment, from a single building to a whole district. We invite you to contact us to begin a conversation that will give you the answers you need.

Impact of the Heat Source & System Components on Investment Costs of Large Scale Heat Pump Projects

Wastewater Heat Recovery in Urban Areas

Fri, 12 Apr 2024 16:59:55 GMT

Wastewater is an Overlooked & Undervalued Existing Asset

In urban environments, where the demand for energy is high and resources are often stretched, innovative solutions like wastewater heat recovery are gaining attention for their potential to enhance energy efficiency. One of the most overlooked and undervalued assets many cities already have, is their wastewater network(s). Explore the concept of wastewater heat recovery , its benefits and its implications for sustainable urban development.

Existing Heat Energy Resource Already at Our Disposal

Wastewater heat recovery involves capturing thermal energy from wastewater (showers, sinks, or industrial processes) before it is discharged back into the environment. This recovered energy can then be repurposed for various applications, such as space heating and cooling, water heating, or industrial processes. Typically, up to 35% of total housing energy and up to 40% of the commercial & industrial energy is used to make hot water – water which is used once and then discarded into a city's sewers. An urban wastewater network collects of all this warm water and brings these thousands of flows together in the existing system of pipes. This heat energy is nicely contained, well distributed and is ready and waiting to be recovered and recycled.

Benefits of Wastewater Heat Recycling

Energy Conservation: By harnessing the otherwise wasted heat from wastewater, cities can significantly reduce their reliance on traditional heating sources like natural gas or electricity.
Cost Savings: Utilizing recovered heat can lead to substantial cost savings on energy bills, particularly for large-scale facilities or multi-unit buildings.
Reduced Environmental Impact: Wastewater heat recovery contributes to lower carbon emissions and less reliance on fossil fuels, aligning with environmental sustainability goals.
Resource Optimization: Instead of treating wastewater solely as a waste product, this approach transforms it into a valuable resource for thermal energy.

Implementation Challenges & Solutions

While wastewater heat recovery presents clear advantages, several challenges must also be addressed:

Infrastructure Compatibility: Retrofitting existing buildings and sewage systems to incorporate heat recovery technologies can be complex but is feasible with strategic planning and investment.
Regulatory Considerations: Regulations and standards related to water quality and heat exchange must be navigated to ensure safety and compliance.
Public/Private Partnerships (P3s): These partnerships are designed to can provide a range of solutions that can help municipalities manage the financial and technical challenges of operating these complex facilities.
Public Awareness & Acceptance: Educating the public about the benefits of wastewater heat recovery is crucial to gaining support for these initiatives.

No Need to Wait - Start Recycling Existing Heat Energy Now!

As cities continue to prioritize sustainability and energy efficiency, wastewater heat recovery is poised to play a vital role in urban infrastructure. Advancements in technology, coupled with favorable policies and investments, will drive further adoption and innovation in this space. Wastewater heat recovery represents a compelling opportunity to maximize energy efficiency and reduce environmental impact in urban areas. By harnessing this untapped energy source, cities can move closer to their goals of sustainability and resilience in an increasingly resource-constrained world.

Become a Member of the Sewer Thermal Energy Network (STEN)

Do you want to do more to help the world utilize clean energy, but don't know where to begin? STEN is here to help you get started . There is enough heat capacity available to power highly efficient electric heat pump systems to heat and cool many large buildings. Allowing them to quickly transition from fossil fuels and make a real meaningful decarbonization difference very quickly. So don't wait another moment - the time is now. Take the leap and unlock the potential. We invite you to send a message to begin a conversation that will give you the answers you need…

The Basics of Wastewater Heat Recovery

Wed, 27 Mar 2024 20:30:38 GMT

Understanding Wastewater Heat Recovery to Maximize Energy Efficiency

In the quest for sustainability and efficiency, industries and municipalities are increasingly turning to innovative methods to harness every available resource. One such method gaining traction is wastewater heat recovery. This process involves capturing and utilizing the thermal energy present in wastewater before it is discharged, thereby reducing energy consumption and environmental impact. In this article, we will delve into the basics of wastewater heat recovery, exploring its benefits, applications, and key considerations.

What is Wastewater Heat Recovery?

Wastewater, often generated from industrial processes or municipal facilities, carries a significant amount of heat energy, which would otherwise go to waste. Wastewater heat recovery is founded on the principle of Sewage Thermal Energy Utilization (STEU) - a concept goes beyond the traditional view of sewage as waste heat. By recognizing its dual capability as a source for productive heating and cooling applications and by implementing heat recovery systems, this energy can be salvaged and utilized for residential space heating and cooling, water heating, as well as industrial processes.

Key Components of Wastewater Heat Recovery Systems

Heat Exchangers: Central to wastewater heat recovery systems are heat exchangers, which facilitate the transfer of thermal energy from the wastewater to a separate fluid loop. These exchangers come in various designs, depending on the specific application and requirements.
Heat Transfer Fluid : A secondary fluid, often water or a specialized heat transfer fluid, circulates within the heat exchanger to absorb the recovered thermal energy. This fluid then carries the heat to where it is needed, such as heating systems or industrial processes.
Distribution & Utilization Systems: Once the thermal energy is transferred to the secondary fluid, it is distributed and utilized according to the specific heating requirements. This may involve circulating the fluid through radiators, boilers, or other equipment to provide space heating and cooling or hot water.
System Design & Sizing: Properly sizing the heat recovery system and selecting appropriate components are crucial for maximizing efficiency and performance. Regular maintenance and monitoring of the system are also essential to ensure optimal operation and longevity.

Benefits of Wastewater Heat Recovery

Energy Efficiency: By capturing and repurposing thermal energy that would otherwise be wasted, wastewater heat recovery systems significantly improve energy efficiency, leading to reduced utility costs and environmental impact.
Cost Savings: The utilization of recovered heat can result in substantial cost savings on heating expenses, particularly for industries with high energy demands or municipalities operating large wastewater treatment facilities.
Environmental Sustainability: Wastewater heat recovery aligns with sustainability goals by reducing reliance on fossil fuels and lowering greenhouse gas emissions associated with conventional heating methods.

A Sustainable Path Forward

Discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment, from a single building to a whole district. Wastewater heat recovery presents a compelling opportunity to enhance energy efficiency, reduce costs, and promote environmental sustainability across various industries and applications. By harnessing the untapped thermal energy present in wastewater streams, organizations can make significant strides towards a more resource-efficient future. With careful planning, implementation, and maintenance, wastewater heat recovery systems can deliver long-term benefits for both the bottom line and the planet.

Connect with the Experts at The Sewer Thermal Energy Network (STEN)

Wastewater Heat Recovery is a potent solution in the sustainable energy landscape, transforming waste into a valuable resource. As engineers and professionals in related fields, it's crucial to continue exploring and promoting such innovative technologies. STEN is all about helping planners and professional understand the potential of heat recapture. We are eager to hear your thoughts, concerns and hopes for this promising approach to making our energy systems more sustainable. STEN invites you to send a message to begin a conversation that will give you the answers you need…

Harnessing the Economic Potential of Wastewater Heat Recovery

Mon, 18 Mar 2024 21:28:34 GMT

Strengthen the Bottom Line & Contribute to a More Sustainable Future

Wastewater heat recovery, once seen as a mere byproduct of sewage treatment, is now being recognized as a significant untapped resource with immense economic potential. As industries and municipalities seek sustainable solutions to reduce energy costs and carbon footprints, wastewater heat recovery presents itself as a promising avenue. This article delves into the economic dimensions of wastewater heat recovery, exploring its benefits, challenges, and the evolving landscape of investment and policy.

The Economic Value Proposition

At its core, wastewater heat recovery involves capturing the thermal energy embedded in wastewater and repurposing it for heating or cooling generation. This process can significantly reduce the energy consumption of facilities, leading to substantial cost savings. Moreover, by utilizing a resource that would otherwise go to waste, organizations can enhance their sustainability credentials and reduce reliance on fossil fuels.

Industries such as food processing, manufacturing, and data centers, which generate substantial amounts of warm water as a byproduct, stand to benefit immensely from wastewater heat recovery systems. By integrating these systems into their operations, companies can lower their energy bills, improve efficiency, and gain a competitive edge in an increasingly sustainability-focused market.

Municipalities are also realizing the economic advantages of wastewater heat recovery. By harnessing the heat from sewage, cities can reduce the energy demands of wastewater treatment plants and adjacent facilities such as swimming pools, hospitals, and residential buildings. This not only cuts operational costs but also alleviates pressure on the grid during peak demand periods.

Challenges & Considerations

While the economic benefits of wastewater heat recovery are evident, several challenges hinder its widespread adoption.

Investment Requirements - One key obstacle is the upfront investment necessary to implement these systems. Despite the potential long-term savings, many organizations may be deterred by the initial capital outlay.
Development of Efficient Heat Recovery Systems - Furthermore, the variability in wastewater flow and temperature presents technical challenges. Engineers must develop solutions that can adapt to fluctuations in flow rates and temperatures to ensure consistent performance.
Regulatory Landscape - While some regions offer incentives and subsidies to encourage the adoption of renewable energy technologies, others lack supportive policies or regulatory frameworks. Policymakers play a crucial role in incentivizing investment in wastewater heat recovery through favorable tax credits and grants.

Emerging Trends & Opportunities

Despite these challenges, several trends indicate a growing momentum towards wastewater heat recovery.

Technological advancements , such as improved heat exchangers and innovative system designs, are making these solutions more cost-effective and efficient.
Climate change awareness and the imperative to reduce greenhouse gas emissions are driving companies and municipalities to explore sustainable alternatives. Environmental harm caused by traditional energy sources has become more apparent which is strengthening the economic case for wastewater heat recovery.
Collaboration between the public and private sectors is also fostering innovation in this space. Partnerships between utilities, technology providers, and government agencies are facilitating the deployment of large-scale wastewater heat recovery projects and driving down costs through economies of scale.

Unlock the Full Value of This Renewable Energy Resource

Wastewater heat recovery holds immense economic potential, offering cost savings, energy efficiency, and environmental benefits. While challenges remain, concerted efforts from stakeholders across sectors can overcome these barriers. By embracing wastewater heat recovery, industries and municipalities can not only bolster their bottom line but also contribute to a more sustainable and resilient future.

The Sewer Thermal Energy Network (STEN) is a leading innovator in sewer heat recovery solutions. STEN has been established to provide advocacy, education, information dissemination, capacity building, and networking opportunities for cities, municipalities, and wastewater utilities as well as other interested entities. As a member of STEN , you’ll join a group of the most influential professionals in the industry and you’ll have access to resources that will help you unlock the potential of this sustainable energy source. We invite you to send a message to begin a conversation that will give you the answers you need…

Benefits of Wastewater Heat Recovery for the Environment

Wed, 13 Mar 2024 18:28:58 GMT

Harnessing the Power of Thermal Energy for a Greener Future

Wastewater heat recovery is a promising technology that offers significant environmental benefits by harnessing the thermal energy present in wastewater . As societies strive to reduce their carbon footprint and transition towards sustainable energy sources, this innovative approach presents an opportunity to utilize a readily available and often overlooked resource. In this article, we will explore the environmental advantages of wastewater heat recovery and its potential to contribute to a cleaner and more sustainable future.

Energy Efficiency

One of the primary benefits of wastewater heat recovery is its ability to improve energy efficiency. Wastewater contains thermal energy from various sources, including industrial processes, household activities, and natural heating. By capturing this heat before it is discharged into water bodies or treatment facilities, it can be utilized for heating buildings, preheating water for industrial processes, or even generating electricity through heat exchangers and heat pumps. This reduces the reliance on traditional energy sources, such as fossil fuels, and helps to mitigate greenhouse gas emissions associated with energy production.

Reduction of Greenhouse Gas Emissions

By utilizing the thermal energy present in wastewater, heat recovery systems can help reduce the demand for fossil fuels and the associated emissions of greenhouse gases. Traditional heating methods, such as boilers and electric heaters, often rely on non-renewable energy sources that contribute to climate change. In contrast, wastewater heat recovery offers a renewable and sustainable alternative that significantly reduces carbon dioxide emissions, thereby mitigating the environmental impact of energy consumption.

Conservation of Natural Resources

Wastewater heat recovery promotes the efficient use of resources by tapping into a continuous and abundant source of thermal energy. Instead of allowing this energy to dissipate unused, heat recovery systems capture it and repurpose it for various applications, such as space heating, water heating, and industrial processes. By maximizing the utilization of existing resources, wastewater heat recovery helps to conserve natural resources and minimize the environmental footprint associated with energy production and consumption.

Water Conservation

In addition to its thermal energy content, wastewater also contains a significant amount of water that has been heated through various activities. By recovering heat from wastewater, not only can thermal energy be utilized, but the water itself can also be recycled for non-potable uses, such as irrigation, industrial cooling, or toilet flushing. This promotes water conservation and reduces the strain on freshwater resources, particularly in regions facing water scarcity or drought conditions.

Promotion of Enhanced Sustainability

Overall, wastewater heat recovery contributes to enhanced sustainability by transforming a waste product into a valuable resource. By capturing and utilizing the thermal energy present in wastewater, heat recovery systems help to close the loop on energy consumption and waste generation, moving towards a circular economy model. This not only benefits the environment by reducing pollution and resource depletion but also offers economic advantages through energy savings and resource efficiency. It sets an example encouraging broader adoption of environmentally friendly technologies and practices.

Connect with the Experts at Sewer Thermal Energy Network STEN

Overall, sewage thermal energy utilization holds tremendous potential for addressing environmental challenges and promoting sustainable development. As governments, industries, and communities seek to transition towards cleaner and more sustainable energy solutions, wastewater heat recovery stands out as a promising option for realizing a greener future. Implementing wastewater heat recovery demonstrates a commitment to sustainable practices and resource management. By harnessing the thermal energy present in wastewater, these systems contribute to a greener, more sustainable future while also providing economic benefits to industries and communities. As a member of STEN , you’ll join a group of the most influential professionals in the industry - leaders and decision makers who are working together to shape the future of sewer heat recovery solutions . We invite you to send a message to begin a conversation that will give you the answers you need.

The Business Case for Recycling Heat from Wastewater

Mon, 04 Mar 2024 22:01:12 GMT

Unlocking Profit + Sustainability

In the pursuit of sustainable and economically viable urban development, city authorities are increasingly turning to innovative solutions. One such solution that has gained traction in recent years is the recycling of heat from wastewater. This forward-thinking approach not only addresses environmental concerns but also proves to be a lucrative investment for city authorities. In this article, we delve into the reasons why recycling heat from wastewater is good business for city authorities.

Energy Efficiency

Recycling heat from wastewater is a prime example of harnessing energy that would otherwise go to waste. Wastewater from urban areas and industrial facilities carries a significant amount of thermal energy. This heat energy is all collected and contained within the sewer pipe network and the energy flows right through cities, where it can be used by the buildings located there. By capturing and utilizing this heat, cities can enhance their energy efficiency, reducing reliance on traditional energy sources and minimizing their carbon footprint. This not only aligns with sustainability goals but also results in long-term cost savings for city authorities.

Cost Savings & Revenue Generation

Cities that invest in heat recycling systems can benefit from substantial cost savings over time. By utilizing the captured wastewater heat for heating buildings, water, or other processes, city authorities can reduce their reliance on conventional heating methods. This, in turn, leads to lower energy bills and operational costs. Moreover, surplus heat from the wastewater flows can be sold back to businesses, creating an additional revenue stream for city authorities. The dual benefit of cost savings and revenue generation makes recycling heat from wastewater an economically attractive proposition.

Environmental Impact

Beyond the economic considerations, recycling heat from wastewater aligns with the global push towards sustainable practices. Traditional heating methods often involve the combustion of fossil fuels, contributing to air pollution and greenhouse gas emissions. By adopting heat recycling technologies, city authorities can significantly reduce their environmental impact, contributing to cleaner air and a healthier living environment for their residents. This environmental commitment can also enhance the city's reputation, attracting eco-conscious businesses and residents.

Job Creation & Economic Development

The implementation of heat recycling projects requires skilled labor for design, installation, and maintenance. As city authorities invest in these initiatives, they contribute to job creation and economic development within their community. Skilled professionals in engineering, technology, and maintenance are in demand, fostering a growing and sustainable job market. Additionally, the emergence of new technologies and services in the heat recycling sector can attract private investments, further boosting the local economy.

Future-Proofing Infrastructure

Investing in heat recycling technology is a strategic move for city authorities looking to future-proof their infrastructure. As the world transitions towards cleaner energy sources and more sustainable practices, cities that embrace heat recycling position themselves as leaders in innovation. This not only attracts environmentally conscious businesses and investors but also ensures that the city's infrastructure remains relevant and resilient in the face of evolving energy trends.

A Sustainable & Lucrative Path Forward with STEN

Recycling heat from wastewater is not just an environmentally responsible practice; it is a sound business decision for city authorities. The economic benefits, including cost savings, revenue generation, job creation, and enhanced infrastructure, make it a compelling investment. By prioritizing heat recycling initiatives, cities can achieve a harmonious balance between economic prosperity and environmental stewardship, setting a positive example for the future of urban development.

The Sewer Thermal Energy Network (STEN) is dedicated to helping municipalities and nonprofit institutions understand how sewer heat recycling works and how to unlock the potential profit as well as the sustainability factor. As a member of STEN , you’ll join a group of the most influential professionals in the industry - leaders and decision makers who are working together to shape the future of sewer heat recovery solutions . And you’ll have access to resources that will help you unlock the potential of this sustainable energy source. We invite you to send a message to begin a conversation that will give you the answers you need.

Technologies Behind Wastewater Recovery

Mon, 26 Feb 2024 21:06:24 GMT

Unveiling the Future of Water Treatment

As global water scarcity and environmental degradation become increasingly pressing issues, the role of efficient wastewater recovery has never been more critical. This article delves into the evolving world of wastewater treatment, highlighting both traditional methods and groundbreaking innovations, with a particular focus on the sophisticated technologies employed in heat recapture , a crucial aspect of sustainable water management.

Traditional Wastewater Treatment Methods

Traditional wastewater treatment encompasses a series of processes to remove contaminants. The initial stages involve physical separation methods to remove solids, followed by biological processes targeting organic matter. The concluding phase typically employs advanced purification techniques, like sophisticated filtration and disinfection. While these conventional methods form the foundation of wastewater treatment, they often struggle against modern pollutants and are generally resource intensive.

Innovations in Wastewater Treatment

Recent advancements are transforming the wastewater treatment landscape:

Heat Recovery from Wastewater: Innovative technologies are now being used to capture and reuse heat from wastewater .
~One such technology is the use of heat pumps which extracts thermal energy from wastewater. This system uses a heat exchanger to transfer heat from the wastewater to a refrigerant, which is then compressed to increase its temperature. The heated refrigerant is used to warm up water or air for heating purposes in buildings.
~Another method involves the use of large-scale wastewater heat recovery facilities, like those in Vancouver, Canada, which utilize advanced filtration and heat exchange systems to extract heat directly from the municipal wastewater stream.
Membrane Bioreactors (MBRs) , such as those by Kubota Membrane USA Corporation, merge conventional biological treatment with advanced membrane filtration.
Advanced Oxidation Processes (AOPs) , like APTwater's HiPOx system, use reactive species to break down contaminants resistant to traditional treatments.
AI & Machine Learning in Wastewater Treatment: Systems like Xylem's Wastewater Network Optimization are revolutionizing treatment processes, enhancing efficiency and cost-effectiveness.
Adoption of Nanotechnology for targeted pollutant removal, bioelectrochemical systems, and algae-based treatments also signifies major progress in this field.

Case Studies & Applications

Globally, these technologies are being effectively implemented. Cities like Tokyo and Vancouver are leading the way in using wastewater heat recovery systems, such as the SHARC Energy System, to provide heating for urban buildings. Singapore’s NEWater plants and Stockholm’s Hammarby Sjöstadsverket are prime examples of the integration of advanced treatment technologies, including MBRs and AI-driven optimization, into urban water management systems.

Challenges & Future Directions

The sector continues to face challenges, such as managing high energy consumption and emerging contaminants. The future vision includes the development of energy-neutral or positive wastewater treatment plants, focusing on sustainable energy sources and innovative technologies. For more in-depth information, resources like The Water Research Foundation and The International Water Association offer comprehensive insights into these technologies, providing case studies and detailed analyses.

Join with the Experts at the Sewer Thermal Energy Network (STEN)

The advancements in wastewater recovery technologies, especially in heat recapture, are pivotal in our journey towards sustainable water management. Integrating time-tested methods with innovative solutions like heat recovery and AI optimization is key. Our collective efforts in innovation, investment, and implementation of these technologies will shape the future of water treatment. STEN can help you discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment, from a single building to a whole district. We invite you to send a message to begin a conversation that will give you the answers you need…

U.S. Policy Towards Sustainability & Energy Independence

Mon, 12 Feb 2024 22:20:51 GMT

Sewage Thermal Energy Use - A Practical Solution to Fossil Fuel Independence

Liquified Natural Gas (LNG) is in the news again with the Biden Administration's recent decision to pause the permitting of new natural gas production facilities in the United States. This is a calculated move because it reflects a long-term vision towards sustainability and energy independence. The U.S. policy is not just a reaction to current events, but a deliberate step towards addressing the broader challenges posed by our reliance on fossil fuels. However, this action has caused concern in European markets, especially in Germany where the US constitutes 80% of their LNG imports. It is important to note that current US exports are increasing, and new LNG terminals are coming online with new ones being built. This temporary pause is for those in the approval process.

A significant portion of energy consumption in North America and Europe – about two-thirds – is for heating and cooling. In broad terms, if this energy could be recycled, then the need for primary fuel would decrease. Sewage Thermal Energy Use (STEU) is just such a technology. If two thirds of Germany’s need for LNG was reduced itself by two thirds. It would be like increasing their imports by 45%. Recapturing heat from sewage using a water-to-water heat pump with an easy to achieve COP of 3 or above is equivalent to reducing primary energy by 2/3.

Technologies like sewer thermal recapture is not just environmentally sound; it represents a practical solution to reduce our fossil fuel dependency. Utilizing all the heat we already produce (and not just flushing it down the drain) could enhance energy security and economic resilience. This approach aligns with a broader vision of energy independence, where we are not only more sustainable but also less susceptible to geopolitical tensions and supply disruptions.

The recent policy changes by the Biden administration, including the temporary pause on LNG exports to non-FTA countries, are part of this larger strategy. While primarily aimed at evaluating environmental impacts, these decisions are inherently tied to an emerging global energy narrative. They reflect a commitment to balancing immediate energy needs with long-term climate goals and geopolitical considerations. The U.S., as a major LNG exporter, plays a crucial role in supporting Europe, especially in reducing reliance on Russian gas. However, this role must be balanced with the need to transition towards more sustainable energy sources.

For Germany, reducing its reliance on LNG, whether sourced from Russia or the United States, is essential. One viable approach is to harness the potential of wastewater reservoirs. By tapping into this underutilized resource, Germany can move towards a more balanced and self-reliant energy mix.

Selling to European markets is obviously good for American producers, but diversification is good for producers too. The United States has an opportunity to expand its energy market and offerings. Through innovation, the U.S. can reduce costs and enhance the effectiveness of these technologies. Such advancements not only further domestic energy objectives but also position the U.S. as a leader in the growing sustainable energy sector.

As we have been saying for more than half a century - current energy challenges highlight the need for a strategic rethinking of our energy policies and practices. We need a holistic approach that promotes a balance of energy choices. Investing in sewer heat recapture is an important step towards a more sustainable, secure, and independent energy future. When we stop wasting heat, we will reduce the vulnerabilities associated with our carbon-fuels.

Connect with the Experts at The Sewer Thermal Energy Network (STEN)

Sewer heat recovery stands at the forefront of innovative solutions for sustainable urban development. By leveraging the untapped warmth beneath our streets, cities can reduce their reliance on non-renewable energy sources, paving the way for a more sustainable, resilient, and environmentally friendly future. Sewer heat recovery promises to play a crucial role in shaping the energy landscapes of tomorrow's cities, and STEN stands ready to help municipalities launch the journey in the right direction. Discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment, from a single building to a whole district. We invite you to send a message to begin a conversation that will give you the answers you need…

Public-Private Partnership (P3s) & Sewer Heat

Fri, 09 Feb 2024 21:40:41 GMT

Sewer Policies Among the Crucial Issues Facing Communities Today

In their 2017 report titled “ Understanding America’s Water and Wastewater Challenges ”, the Bipartisan Policy Center observed:

The nation’s water and wastewater utilities are victims of their own success. Americans have become accustomed to receiving clean water when they turn on their taps and having waste disappear down their pipes. Yet, the public's understanding of the complicated and costly systems required to deliver these services is minimal. For example, the United States has 1.2 million miles of water-supply mains, equating to 26 miles of water mains for every mile of interstate highway. That figure only accounts for the drinking water system, with nearly an equal number of sewer pipes in existence.

Little has changed in the past seven years. Sewer policy remains largely out of sight and mind. However, with 16,000 sewage treatment systems serving over 50,000 communities nationwide, it's time for a serious conversation about modernizing our sewer systems. While it may not seem like an agenda item that captures votes, sewer policies are among the most crucial issues facing communities today.

As the town manager in a small Rhode Island community, I lived through a weeks-long drinking water contamination crisis. The experience taught me the importance of understanding the mechanical, chemical, and biological principles at work in our water and wastewater systems. Knowing how the systems work is crucial for the local officials – both appointed and elected – who oversee these systems.

Private Sector Plays a Vital Role in Wastewater Management

Protecting public health is the foremost priority for water and wastewater service providers. However, a deeper understanding of water utilities can also reveal revenue opportunities and save tax dollars. When local officials are well-versed in their systems, they are better equipped to ask the right questions and make cost-saving decisions without compromising public health.

Private firms including investor-owned utilities, with their expertise and resources, can effectively address issues like infrastructure renewal and cost management. Public-private partnerships (P3s), co-ownership arrangements, and system acquisitions provide a range of solutions that have aided many communities in maintaining safe, clean, and reliable water services.

Examples of P3 Arrangements:

P3s, for instance, can vary from contracts for new facility construction to the complete transfer of water systems to private entities. These arrangements can offer immediate financial relief and technical expertise to municipalities, particularly those facing urgent infrastructure needs or compliance mandates.

In Norwalk, Connecticut, SUEZ North America was awarded a contract to operate and maintain the city's wastewater system. This agreement includes managing an 18 million-gallon-per-day wastewater treatment facility, 210 miles of sanitary sewers, and 25 pump stations, providing services to Norwalk's residents and businesses, and bringing in new technology for asset management and process monitoring.
SUEZ North America also entered into a 20-year contract with the Springfield (Massachusetts) Water and Sewer Commission to operate and maintain the city’s wastewater treatment plant and combined sewer overflow system. As part of this agreement, SUEZ is partnering with AECOM to upgrade the treatment process, enhancing energy efficiency, system reliability, and biosolids dewatering. The Springfield Regional Wastewater Treatment Facility serves a population of 250,000 across seven municipalities, treating an average of 40 million gallons of wastewater daily.
Veolia Water : A major player in this sector, Veolia Water manages wastewater treatment facilities for numerous municipalities across the country, offering services such as operational management, maintenance, and efficiency improvements.
American Water Works Company : Through its subsidiary American Water, this company provides services to various municipal wastewater systems, including operation and maintenance, and in some cases, involvement in financing and construction.
Severn Trent Services : As a global company, Severn Trent Services has provided operational services for wastewater treatment plants in the United States, offering operations and maintenance, and system upgrades.
J acobs Engineering Group : Having acquired CH2M Hill, Jacobs Engineering Group is involved in the operation of several wastewater treatment facilities in the United States, focusing on technological upgrades and operational efficiency.

These partnerships are designed to help municipalities manage the financial and technical challenges of operating these complex facilities. The specifics of these arrangements can range from short-term contracts for specific services to long-term agreements covering operations, maintenance, and capital investment.

Learn How Sewer Heat Recycling Can Be Politically & Commercially Viable

For local officials, finding ways to reduce the taxpayer-funded costs of managing these facilities is essential. One innovative approach is harnessing and commercializing the thermal energy generated by these plants, creating a revenue stream that can help finance P3 agreements. For communities where commercial operators manage wastewater facilities, exploring ways to monetize sewer heat can be particularly beneficial.

The Sewer Thermal Energy Network (STEN) is dedicated to helping municipalities and nonprofit institutions understand how sewer heat recycling works and how to make it politically and commercially viable. As a member of STEN , you’ll join a group of the most influential professionals in the industry - leaders and decision-makers who are working together to shape the future of sewer heat recovery solutions. And you’ll have access to resources that will help you unlock the potential of this sustainable energy source. We invite you to send a message to begin a conversation that will give you the answers you need.

The Energy Potential in Wastewater

Mon, 05 Feb 2024 19:49:33 GMT

The Essentials of Wastewater Heat Recovery

Wastewater systems carry a remarkable amount of energy. A typical municipal treatment plant can harness enough energy to significantly contribute to local heating and cooling demands. The specific energy content varies, influenced by factors like wastewater flow and temperature. Wastewater Heat Recovery (WWHR) stands out as a particularly transformative technology because most of the infrastructure we need to make it work is already in place.

What is Wastewater Heat Recovery?

Wastewater heat recovery involves capturing heat from wastewater typically discharged from domestic or industrial sources. This process allows the reuse of heat energy that would otherwise be lost, contributing to heating, cooling, and hot water supply systems while reducing environmental impact. This reuse can be considered energy recycling.

A Potent Solution in the Sustainable Energy Landscape

In a typical municipal wastewater treatment plant, there is a lot of heat energy. Such a facility might handle tens of millions of gallons of wastewater daily. The temperature of this wastewater generally ranges from 10°C to 30°C (50°F to 86°F), which is significantly higher than the ambient temperature, especially in cooler climates and is cooler than the rejected heat of air conditioning.

The energy potential can be roughly estimated by considering the heat capacity of water. For instance, the heat capacity of water is about 4.18 joules per gram per degree Celsius. If a sewage thermal energy unit removed 5°C from one million gallons of sewage, this would represent almost 80,000 megajoules of heat energy. In other words, the heat value of sewage is 80,000 megajoules per million gallons. A 10 MGD plant would be equivalent to a 9-megawatt thermal energy plant.

Qualitatively, the energy in wastewater is reliable and constant, unlike many renewable sources like solar or wind energy. It's also relatively low-grade heat, meaning it's not at a high temperature, but it's ample for applications like space heating, space cooling and water heating. This consistent, low-grade thermal energy is particularly useful in district heating systems, where it can provide a steady supply of heat to multiple buildings or facilities.

Moreover, the energy in wastewater is inherently sustainable and eco-friendly. By harnessing this energy, we are essentially recycling a waste product, reducing the need for fossil fuels and decreasing greenhouse gas emissions.

The Energy Content in Wastewater Is Influenced by Various Factors:

Wastewater Volume: Larger volumes of wastewater contain more thermal energy. Hence, big cities with more significant wastewater outputs have higher energy recovery potential.
Temperature: The temperature of the wastewater depends on several factors, including geographic location, season, and the source of the wastewater (industrial, residential, etc.). Warmer wastewater carries more thermal energy for heating.
Efficiency of Heat Recovery Systems: The technology used for heat recovery also plays a crucial role. More advanced systems can extract a higher percentage of the available thermal energy.

Contemporary WWHR Techniques

Modern WWHR systems employ two methods for heat capture from sewage. The choice between these methods depends on project-specific requirements and environmental guidelines. It is important to note that sewage itself if never used in the building heating or cooling process. Neither of these methods uses sewage directly in a building. Heat is removed from the sewage, nothing more.

In situ Heat Exchange: Utilizes a heat exchanger installed within the sewer to facilitate heat transfer between wastewater and a separate clean water circuit. This method is preferred for its lower operating cost, and reduced maintenance, once it is installed it works.
Direct Heat Exchange: Involves the transfer of sewage from sewer to the heat exchange, from there it is returned to the sewer. It is more efficient but necessitates screening to reject contamination that would foul the heat exchangers.

Transforming Waste into A Valuable Resource

Of all the sustainable energy solutions available today, Wastewater Heat Recovery (WWHR) is a potent solution in the sustainable energy landscape. As engineers and professionals in related fields, it's crucial to continue exploring and promoting such innovative technologies. There is enough heat capacity available to power highly efficient electric heat pump systems to heat and cool many large buildings. Allowing them to quickly transition from fossil fuels and make a real meaningful decarbonization difference very quickly.

No Need to Wait - Start Recycling This Heat Energy Now!

Do you want to do more to help the world utilize clean energy, but don't know where to begin STEN is all about professional planners who understand the potential of heat recapture. We are eager to hear your thoughts, concerns and hopes for this promising approach to making our energy systems more sustainable. So don't wait another moment - the time is now. Take the leap and unlock the potential. We invite you to send a message to begin a conversation that will give you the answers you need…

Why Sewer Heat? The Essentials of Wastewater Heat Recovery

Mon, 29 Jan 2024 19:02:47 GMT

A Potent Solution in the Sustainable Energy Landscape

Of all the sustainable energy solutions available today, Wastewater Heat Recovery (WWHR) stands out as a particularly transformative technology because most of the infrastructure we need to make it work is already in place. Wastewater heat recovery involves capturing heat from wastewater typically discharged from domestic or industrial sources. This process allows the reuse of heat energy that would otherwise be lost, contributing to heating, cooling, and hot water supply systems while reducing environmental impact. This reuse can be considered energy recycling.

The Evolution of WWHR

The concept of WWHR can be traced back to the early 20th century, though it was not as sophisticated or widely recognized as it is today. Early examples of utilizing waste heat can be found in industrial applications, where waste heat from manufacturing processes was repurposed, albeit not specifically from wastewater. These initial efforts laid the groundwork for understanding heat recovery's potential.

A notable early instance of heat recovery from wastewater, though in a rudimentary form, occurred in parts of Europe and North America during the mid-20th century. These systems primarily focused on using heat from large industrial effluents or municipal sewage systems to provide supplemental heating for nearby facilities. However, these early systems were limited by technology of the time – they were often inefficient, had high maintenance costs, and were limited in scale and application.

Significant Strides in WWHR Are Due To:

Technological Advancements: Modern WWHR systems benefit enormously from advances in heat exchanger technology, improved thermal efficiency, and more robust filtration systems. Innovations in materials science have led to heat exchangers that are more efficient and less prone to fouling. Advanced control systems now enable more precise management of heat recovery processes, optimizing efficiency and adaptability to varying wastewater characteristics.
Increased Focus on Sustainability: The late 20th and early 21st centuries have seen a growing global emphasis on sustainable energy practices. This shift in mindset has been a critical driver in adopting WWHR systems. As the impacts of climate change and the need for sustainable energy solutions have become more apparent, WWHR has emerged as a valuable tool in reducing greenhouse gas emissions and improving energy efficiency.
Economic Viability: Recent advancements have made WWHR systems more cost-effective. The initial investment is offset by significant energy savings over time, making these systems financially attractive. Additionally, government incentives and policies supporting renewable energy and energy recovery have also played a role in promoting WWHR systems.
Integration in Urban Planning: Modern WWHR systems are now considered integral components of urban energy and sustainability planning. Cities like Vancouver and Oslo have demonstrated how WWHR can be seamlessly integrated into urban infrastructure, providing heating and cooling solutions on a large scale while reducing the environmental footprint.

Global Successes in WWHR

The adoption of WWHR has seen successes worldwide. In Vancouver, the Neighbourhood Energy Utility utilizes wastewater heat to serve local communities. Oslo's implementation of WWHR contributes to heating most of the city's buildings, exemplifying the system's efficacy and environmental benefits. There have literally been thousands of successful applications of WWHR techniques implemented in the last decade.

Connect with the Experts at The Sewer Thermal Energy Network (STEN)

Wastewater Heat Recovery (WWHR) is a potent solution in the sustainable energy landscape, transforming waste into a valuable resource. As engineers and professionals in related fields, it's crucial to continue exploring and promoting such innovative technologies. STEN is all about help planners and professional understand the potential of heat recapture. We are eager to hear your thoughts, concerns and hopes for this promising approach to making our energy systems more sustainable. Discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment, from a single building to a whole district. STEN invites you to send a message to begin a conversation that will give you the answers you need…

The Rise of Sewer Heat Recovery

Mon, 22 Jan 2024 21:25:41 GMT

Leveraging Sewer Heat as a Renewable Energy Source

Sewers are not only conduits for wastewater but also vast sources of heat that often go wasted in today’s municipalities. Heat that can be used. Energy that can even be a revenue source. This article will explore the concept of sewer heat recovery, showcasing how forward-thinking cities and industries are harnessing the energy that already exists beneath the streets of virtually every city in the world. From district heating systems to creative urban planning, the possibilities and challenges of leveraging sewer heat as a renewable energy source are discussed here.

The Hidden Potential of Sewer Heat

Sewers, usually viewed as mere waste conduits, contain vast amounts of renewable energy. Sewer energy recovery involves either extracting the latent warmth from wastewater AND/OR using the relatively cool water as a heat sink. This process taps into a consistent and often abundant energy source that flows beneath our cities. The technology to do this already exists and is widely used. Simply put, a sewer system can essentially be turned into a geothermal city-wide heating and cooling system.

Pioneering Cities & Applications

Across the globe, pioneering cities are implementing sewer heat recovery systems, but few municipalities are taking a city-wide approach. While one-off projects installed throughout a city are a great start and way to demonstrate the technology, large scale systems like district heating systems powered by sewer heat offer an eco-friendly alternative to traditional heating methods, reducing carbon footprints and energy costs locally and worldwide.

Urban Planning Challenges & Sustainability

Incorporating sewer heat recovery into urban planning represents a step towards more sustainable and resilient city infrastructures, but most municipalities are lacking the tools and experience to approach sewer energy recovery on a city-wide scale. Despite its potential, sewer heat recovery faces challenges such as the need for significant initial investment and integration with existing infrastructure. Getting started can be overwhelming, but as technology advances and awareness grows, these obstacles are gradually being overcome. That is where the Sewer Thermal Energy Network (STEN) becomes involved.

A Sustainable Path Forward

Sewer heat recovery stands at the forefront of innovative solutions for sustainable urban development. By leveraging the untapped warmth beneath our streets, cities can reduce their reliance on non-renewable energy sources, paving the way for a more sustainable, resilient, and environmentally friendly future. Sewer heat recovery promises to play a crucial role in shaping the energy landscapes of tomorrow's cities, and STEN stands ready to help municipalities launch the journey in the right direction. Future prospects include enhancing the efficiency of heat extraction and expanding the application of this technology in various urban contexts.

Connect with the Experts at The Sewer Thermal Energy Network (STEN)

Do you want to do more to help the world utilize clean energy, but don't know where to begin? STEN is here to help you get started. We are a non-profit established to provide advocacy, education, information dissemination, capacity building, and networking opportunities for cities, municipalities, and wastewater utilities as well as other interested entities. Discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment, from a single building to a whole district. We invite you to send a message to begin a conversation that will give you the answers you need…

Support for Sustainable Waste Heat Recycling by Policy Makers

Fri, 05 Jan 2024 20:10:54 GMT

What Policymakers Should Be Doing in 2024 to Support Sustainable Waste Heat Recycling

As we step into 2024, there's a growing imperative for policymakers to bolster the momentum in sustainable waste heat recycling. Here are key areas where focused policy action could make a significant impact:

Enhanced Financial Incentives: Policymakers should prioritize the development and implementation of robust financial incentives, like tax rebates or grants, to encourage the adoption of waste heat recovery systems. This move would help offset initial installation costs and make these systems more financially accessible, especially for small and medium-sized enterprises.
Standardization & Certification: A critical step for 2024 should be the standardization of waste heat recovery technologies. Implementing certification processes for these technologies ensures their efficiency, reliability, and safety, ultimately fostering trust among users and stakeholders.
Streamlining Regulatory Processes: The complexity of current regulatory frameworks can be daunting. Simplifying approval processes for waste heat recovery installations, while maintaining rigorous security, safety, and environmental standards would expedite their adoption.
Integration into Building Codes: Including waste heat recovery requirements in building and energy codes would be a strategic move. This policy change could promote the integration of these systems in new constructions and significant renovations, amplifying their impact across urban landscapes.
Public-Private Collaboration: Strengthening partnerships between government entities, technology developers, and facility operators will be pivotal. Such collaborations can drive innovation, limit risks, and share benefits. Greater collaboration would accelerate the deployment of waste heat recovery solutions.
Educational Campaigns & Awareness Programs: Awareness and understanding are key to adoption. Policymakers should launch educational initiatives to inform the public and industry professionals about the benefits and potentials of waste heat recovery, dispelling misconceptions and highlighting success stories.
Research & Development Support: Continued support for R&D in waste heat recovery technologies will be crucial in 2024 and beyond. Investing in research can lead to more efficient, cost-effective, and adaptable solutions, catering to a broader range of industrial and municipal applications.

Share Your Insights & Join the Discussion

As we set our course for 2024, policy makers have an opportunity to significantly contribute to a more sustainable and energy-efficient future by focusing on waste heat recycling. Let's amplify this conversation: What other policy initiatives could be key in championing sustainable waste heat recycling this year? We invite you to send a message to begin a conversation...

Reframing Our Perception of Wastewater Networks

Wed, 29 Nov 2023 20:41:35 GMT

Act With the Urgency That the Limited Time Requires

Planet Earth, we have a problem - the Intergovernmental Panel on Climate Change (IPCC) and many other climate assessment reports state very clearly that TIME is now absolutely critical in the fight against climate change. The time to act is now because time is quickly running out. Waiting is not an option!

A good analogy to our current situation is the famous scene from the Apollo 13 film, where CO 2 levels in the spaceship were reaching dangerous levels. The managers at Mission Control pulled their engineers into a room, threw onto a table a collection of items that astronaut crew had available to them up in space, and told them to come up with a solution to fit the square filter into a round housing. Critically, both time and energy were extremely limited. They had to get the CO 2 levels down and conserve limited energy in order to get the astronauts back to earth.

It's the same situation here on our spaceship (Earth) where CO 2 levels are reaching dangerous levels (albeit not toxic like in the Apollo capsule). The collection of resources we have available on our table are people, equipment, existing infrastructure, and money. And like in the movie, energy and time are limited. Unfortunately, unlike Tom Hanks & crew, we do not have a safe base that we’re trying to reach. Therefore failure is not an option!

Reframing Perceptions of Wastewater Networks

One of the most overlooked and undervalued assets many cities already have, is their wastewater network(s). Why is this so? Ask most people what they think of when sewer networks are mentioned and you’ll likely hear the negatives like smelly, dirty, disgusting, polluted, disease ridden etc. But let’s reframe our thinking and look at things in a positive way…

Wastewater = 99% Water : The Food & Agriculture Organization (FAO) definition of wastewater is 99.9% water and 0.1% pollutants. So, let's focus on the 99.9% which is simply water. We know that water is a fantastic conductor of heat energy as it has the highest specific heat of any substance on earth.
Existing Heat Energy Resource Already at Our Disposal : Typically, up to 35% of total housing energy and up to 40% of the commercial & industrial sectors, is used to make hot water which is used once and then goes into a city's sewers. The wastewater network collects of all this warm water and brings these thousands of flows together in the existing system of pipes. This heat energy is nicely contained, well distributed and is ready and waiting to be recovered and recycled.

Wastewater is an Overlooked & Undervalued Existing Asset

So, we need to wring every bit of potential out of the energy and resources we already have at our disposal. We do not have the luxury of time to wait for a magic solution that doesn't exist because while we procrastinate, time just keeps ticking away. Like the astronauts, we will likely need to adjust our lifestyles. But we cannot allow the tiny window of time we have available to be wasted.

Courage is required by politicians and policy makers because they are our Mission Control. John Mauro, former sustainability manager for Auckland City once said , "We have to push and maybe we get a little scared. We are not going to transform the city (to a better Auckland) by pleasing everybody." There’s no time le ft to procrastinate. Mission Control needs to step up, be brave and do the right thing. Not everybody will be pleased, but it’s the right thing to do.

Connect with the Experts at The Sewer Thermal Energy Network (STEN)

STEN is a non-profit established to provide advocacy, education, information dissemination, capacity building, and networking opportunities for cities, municipalities, and wastewater utilities as well as other interested entities. Discover the potential of unused resources with the utilization of freely available heat contained within a sewer system for heating and cooling of the built environment, from a single building to a whole district.

No Need to Wait - Start Recycling This Heat Energy Now!

Do you want to do more to help the world utilize clean energy, but don't know where to begin? STEN is here to help you get started. There is enough heat capacity available to power highly efficient electric heat pump systems to heat and cool many large buildings. Allowing them to quickly transition from fossil fuels and make a real meaningful decarbonization difference very quickly. So don't wait another moment - the time is now. Take the leap and unlock the potential. We invite you to send a message to begin a conversation that will give you the answers you need…