NYC's Energy Future Isn't Electric: It's Thermal
NYC sits atop a potentially 157 trillion kBtu thermal energy battery while policymakers fixate on an overburdened electric grid that still burns fossil fuels for 85% of its power.
This post draws from an interview conducted by Range NYC on March 26 with Tony Amis and Jason Hertz of Endurant Energy (an industry-leading firm in energy-pile foundations).
(Cerro Prieto Geothermal Power Station, Baja, Mexico, 2012)1
Discussions about New York City's energy future focus on clean electricity generation while ignoring the most obvious untapped resource: thermal energy. While politicians chase offshore wind projects and solar incentives, they've overlooked the city's most viable large-scale energy source—the enormous thermal mass beneath our buildings that could store and shift gigawatt-hours of energy seasonally and run highly efficient ground-source heat pump systems. This oversight isn't just a missed opportunity; it's a fundamental policy failure that threatens to undermine the city's decarbonization goals.
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Key Points
NYC's climate policies prioritize electrification while ignoring geothermal thermal storage, which could provide 30% of the city's energy needs and reduce emissions equivalent to removing 2 million cars.2
Thermal energy storage costs $15-20/kWh versus $200-400/kWh for lithium batteries, yet building codes actively penalize geothermal systems despite their demonstrably lower carbon footprint.3
Converting new building foundations to energy piles (225,000 annually) would meet our 2050 carbon goals, yet we continue pouring concrete without thermal capacity.4
We must stop myopically focusing on the electric grid and instead develop an integrated "energy grid" approach in which thermal networks and electrical systems work together in hybrid or tandem with legacy systems when and as it makes sense.
The Ground Beneath Us Is More Valuable Than the Air Above
The thermal energy capacity of New York's underground strata dwarfs what lithium-ion batteries could ever provide. A building with an energy foundation can store heating and cooling seasonally, dramatically decreasing the need for source energy for heating, cooling, and domestic hot water production.
How does it work? Energy piles and high-mass foundation elements contain a circulating pumped fluid that passes through heat exchangers to deliver energy to heat pumps for space heating, cooling, and hot water production. This is called a ground-source heat pump (GSHP):
In the summer, during space cooling, relative cold is extracted from the GSHP system to cool the interior environment, and heat is extracted from the building’s interior and rejected to the ground.
In the winter months, the cycle flips. During space heating, relative heat is extracted from the GSHP system to heat the interior environment, while cold is extracted from the building’s interior and rejected to the ground.
The building’s foundation and surrounding strata are used as a thermal bank replenished and depleted annually between the heating and cooling seasons. The following image is a graph showing this annual cycle:
(Image courtesy of Endurant Energy)
An analysis of a 1.5mn GSF new-construction residential building in Brooklyn conducted by Endurant Energy and Range NYC found that a single 406x energy-pile foundation could provide 85% of the building's heating load and 35% of its cooling load—substantial figures translating to approximately 54% of total building energy demands for a large multifamily apartment building.5
Energy foundations are already deployed and operating in NYC today. For example, Hines recently installed a full energy pile foundation for its commercial office development at 555 Greenwich Street. The following quote is taken from the Hines webpage for 555 Greenwich Street.6
555 Greenwich represents the next level of high-performing buildings and will be a benchmark for future development in New York City. The 270,000-square-foot, 16-story addition to the thriving Hudson Square Properties campus will set a new standard for sustainable and responsible development in the Hudson Square neighborhood. The design will ensure compliance with New York Local Law 97 so that the building (and the tenants) will not be liable for future fines.
The energy efficiency and carbon-associated costs at 555 Greenwich are estimated at a 1.2% hard cost premium, which will be negated through energy efficiency-associated OpEx savings, regulatory fine mitigation, and incentives, including a $2.7m grant from utility Con Edison.
The estimated return is $220k per annum or ~$3m in reduced OpEx over a 15-year span, which at an exit yield of 5.50% could impact the exit price by $4 m. This has been achieved with incentives that make the additional CapEx cost-neutral.
The scale of this opportunity is staggering. NYC's annual thermal energy demands total approximately 523.5 trillion kBtu, with each resident using 59.4 million kBtu annually.2 If energy foundation systems addressed just 30% of this load, the result would be 157 trillion kBtu of clean energy generation and 8-10 million metric tons of CO₂ equivalent reduced annually, roughly equivalent to removing 2 million cars from NYC’s streets.
(Image showing an energy-pile installation run as a proof of concept. Courtesy of Endurant Energy)
Rather than seeing the ground as static, we should reconceptualize it as a dynamic thermal reservoir. The constant temperature of the earth at depth—roughly 55°F year-round in New York—provides an ideal baseline for energy exchange. Thermal storage costs approximately $15-20 per kWh of capacity, compared to $200-400 for lithium-ion systems, and can maintain seasonal energy balances with minimal losses over months, not hours or days.7
NYC's Regulations Actively Penalize Thermal Thinking
The irony of New York's energy policy approach is that it actively discourages thermal storage solutions. For new buildings, the city's energy code offers two paths to energy code compliance:
The Prescriptive Path - This approach involves meeting specific requirements for each building component, such as insulation R-values, window U-factors, and HVAC equipment efficiencies, as laid out in the energy code.
The Performance Path (also called the Energy Cost Budget method)—This approach allows more flexibility by demonstrating that the proposed building's annual energy cost will be equal to or less than that of a baseline building meeting all the prescriptive requirements.
The misaligned incentive arises in the Performance Path (or Energy Cost Budget method). Because the performance path is based on energy cost and not actual energy usage, when comparing a new building with a ground-source heat pump (GSHP) system to a standard baseline building that would pass under the Prescriptive Path, the GSHP system is penalized relative to a baseline building system with a water source heat pump coupled with a fossil fuel boiler. The baseline system results in a lower annual energy cost based solely on the typical electric and gas utility rates. At the same time, other metrics, including Source Energy, Site Energy (EUI), and Carbon, all show a benefit from the ground source system.
Rephrased: the relative affordability (based on utility rates) of burning natural gas makes a less efficient system (from a physics perspective) perform better when evaluated by NYC’s building energy code.
The NYC DOB could correct this perverse incentive in the NYC energy code by adopting other efficiency metrics, such as source-energy usage instead of cost. A recent analysis revealed that ground-source-heat-pump (GSHP) systems would be penalized by approximately 1% in energy cost calculations despite showing 11.2% site energy reduction and 6.3% carbon reduction compared to conventional systems3.
This misalignment persists because energy models currently emphasize operating cost, where fossil fuels artificially appear cheaper, over carbon impact. Despite Local Law 97 penalties looming at $268 per metric ton of CO₂ over the limit, private developers must choose between code compliance today and tomorrow's carbon compliance.
From Electric Grid to Energy Grid: The Myopia of Our Current Approach
New York's climate policies suffer from a fundamental conceptual error: they frame decarbonization exclusively around electrification rather than energy optimization. This electricity-first mindset ignores the massive potential of thermal networks that could operate alongside the electrical grid.
That said, Certain geographies within the ConEd district steam network use grid-scale thermal energy directly from the utility.
The Manhattan district steam system is the world's most extensive commercial steam system, and Con Edison operates it. It has been in continuous operation since 1882. It serves over 1,700 commercial and residential customers throughout Manhattan, from Battery Park to 96th Street on the west and 89th Street on the east. The system consists of approximately 105 miles of steam pipes running beneath New York City streets, distributing steam that's produced at multiple plants throughout the city.8
Consider the following: electricity is a high-quality energy form ideal for powering electronics and motors, but inefficient for low-temperature heating and cooling. Using precious electrons to generate 75°F air (even using a high COP heat pump) when geothermal resources can provide it directly onsite and without line loss represents a fundamental misunderstanding of energy hierarchy. Reframing building source energy from offsite grid electrification to onsite thermal energy:
Eliminates the need to convert source energy to usable space heating/cooling and production of domestic hot water.
Eliminates enormous infrastructure investment to move electrons from Point A to Point B.
Eliminates line loss from the point of source energy generation (electricity: power plant vs. onsite thermal: energy foundations).
Eliminates single-point-of-failure legacy systems in the form of centralized electrical power plants.
Instead, we need an integrated "energy grid" approach where thermal networks operate for heating and cooling, electrical networks serve computing and motors, and both work in concert through intelligent systems. Countries like Denmark and Sweden understand this intuitively; they've built district energy systems to store summer heat for winter use. They dramatically reduce strain on their electrical infrastructure while converting their consequently smaller grids to fully renewable hydropower.9
You can feel this intuitively: using thermal energy for thermal demand makes sense; using electrons for electrical equipment loads and lighting similarly makes sense; and to the extent that the energy density of natural gas can peak shave (addressing only the coldest cold hours/days) to allow for much more efficient capex and infrastructure deployment we should be deploying that resource as well. Different building systems have different “energy languages” that most naturally fit their demand profiles. Rather than taking a one-size-fits-all approach, our systems should speak to systems in their natural “languages” to align the highest and best use of technologies with demand.
NYC's Tale of Two Grids: Why Electrification Isn't Enough
The discussion of New York's energy future becomes even more troubling when examining the stark contrast between NYS’ downstate grid and the upstate system. As of 2022, the downstate grid that powers NYC was approximately 85% powered by fossil fuel-emitting source energy, primarily natural gas burned in 24 aging power plants scattered across the five boroughs.10 In sharp contrast, the upstate grid derives about 91% of its electricity from clean sources, including hydroelectric, nuclear, and wind power.
This disparity persists mainly because there aren't sufficient transmission lines to bring clean upstate power to NYC. While the state has ambitious targets to generate 70% of electricity from renewables by 2030, downstate New York—including NYC—remains tethered to fossil fuel generation. Even as new renewable projects come online, the physics of the situation remains unchanged: NYC will continue relying on gas-fired generation until substantial transmission capacity is built.
The irony is palpable. City policies like Local Law 9711 and Local Law 15412 mandate building electrification, while the grid they connect to is overwhelmingly fossil-fuel-powered. This creates a shell game of carbon emissions—moving them from building-level combustion to grid-level combustion without meaningful reduction. When a residential building converts from gas heating to electric heat pumps in NYC today, it's primarily swapping onsite natural gas for offsite natural gas. Electricity is generated by burning natural gas elsewhere in the city, often in less efficient peaker plants.
(Map of median annual energy costs from NYC.gov. Note the overlap between the most affordable energy in Manhattan and the ConEd district steam grid.)13
This reality makes the case for geothermal thermal even stronger. By tapping into the earth's constant temperature rather than drawing additional load from an already carbon-intensive grid, energy pile foundations offer a pathway to genuine carbon reduction rather than carbon displacement. Every building that installs thermal energy storage isn't just reducing its emissions—it's directly relieving pressure on NYC's strained electrical infrastructure and eliminating the need to fund massively costly deployments of electrical infrastructure that energy consumers are ultimately penalized for in the form of much higher electrical rates.
Toward A Thermal-First Building Energy Grid
To address 30% of NYC's thermal demand, we would require approximately 5.65 million energy piles.14 With NYC constructing an estimated 225,000 new foundation piles annually, converting all new piles to energy piles would address about 4% of our 30% target annually. This means that through new construction alone (without any retrofit and based on today’s anemic pace of new construction in NYC), we could reach this goal in about 25 years, perfectly aligned with our 2050 carbon neutrality target. If we start to fix the artificial throttles we impose on the supply of new “land” through a morass of restrictive zoning, imbalanced incentives, and punishing taxation of density, the upside of energy-foundation deployment could be enormously beneficial to resiliency, utility infrastructure modernization, and reduction of carbon-intensive power generation.
A coordinated approach combining new energy foundations with retrofitted borehole fields, horizontal ground loops under parks, and district-scale systems could dramatically accelerate this timeline. Every foundation constructed today without geothermal capability represents a missed opportunity that will last for generations.
Without this paradigm shift, NYC will continue investing billions in electrical infrastructure upgrades while ignoring the thermal goldmine beneath us. Every thermal watt we extract from summer to use in winter is a watt that doesn't require new transmission lines, new generation capacity, or new carbon emissions. That's the revolution we're ignoring, and it's time we dug deeper.
Ever upward.
*This Substack is a work in progress that will endeavor to improve over time. If you are reading this, thank you for making it to the end of the post — you are a part of the community that can improve this content. Please comment, share, and send feedback that can improve future posts. What was left out of the above? How could the argument be taken further? Was the post true to Range NYC’s stated objectives in A Note on Content? Send a message with your thoughts.
From Edward Burtynsky’s website: Edward Burtynsky is regarded as one of the world's most accomplished contemporary photographers. His remarkable photographic depictions of global industrial landscapes represent over 40 years of his dedication to bearing witness to the impact of human industry on the planet. Burtynsky's photographs are included in the collections of over 80 major museums around the world, including the National Gallery of Canada in Ottawa; the Museum of Modern Art, the Metropolitan Museum of Art, and the Guggenheim Museum in New York; the Reina Sofia Museum in Madrid; the Tate Modern in London, and the Los Angeles County Museum of Art in California.
The 157 trillion kBtu figure in the subheadline comes from an analysis of New York City's thermal energy potential. Here's how I calculated it:
First, I estimated NYC's total annual thermal energy demands:
Total cooling load: 184 trillion kBtu
Total heating load: 259 trillion kBtu
Total domestic hot water load: 80.5 trillion kBtu
Total thermal energy demand: 523.5 trillion kBtu
Then, based on analysis conducted with Endurant Energy for a new ground-up project in Brooklyn, where energy pile foundations could provide approximately 54% of the building's total energy demands, I calculated a more conservative 30% potential contribution for geothermal systems citywide: 523.5 trillion kBtu × 0.3 = 157.05 trillion kBtu
This represents the estimated annual thermal energy that could be provided through geothermal systems like energy pile foundations across NYC.
Sung Valley Power and Light: Comparing Lithium-Ion, Thermal, and Hydrogen Storage Technologies; Institute for Renewable Energy: Energy Transition and Storage Costs; University of Michigan: Geothermal Factsheet
NYSERDA: Large-Scale Thermal
Proprietary analysis conducted by Endurant Energy
Hines: 555 Greenwich Street
Sung Valley Power and Light: Comparing Lithium-Ion, Thermal, and Hydrogen Storage Technologies; Wikipedia: Seasonal Thermal Energy Storage; International Renewable Energy Agency (IRENA): Innovation Outlook Thermal Energy Storage
Wikipedia: New York City Steam System; ConEd District Steam: Steam Service
Nordic Energy Research: The Nordics: Flexibility from heat; Research Gate: Large-scale solar district heating plants in Danish smart thermal grid: Developments and recent trends; CIBSE Journal: Danish District Heating - The heat of the moment
NYC Mayor’s Office of Climate & Environmental Justice: Systems Building a clean, resilient, and affordable energy system; New York State Energy Research and Development Authority (NYSERDA): New York City Renewable Energy
NYC Mayor’s Office of Climate & Environmental Justice: Systems Building a clean, resilient, and affordable energy system
Excellent points made, especially the irony of pretending that electrically-powered heating in NYC (via heat pumps) has less carbon impact than onsite consumption of natural gas, just because the gas used to produce electricity is “out of site, out of mind” at inefficient local power plants.
But take all this great analysis a step further: What if the earth under buildings, both existing and new, could be used to provide heating and cooling largely without running compressors, which are needed in conventional geothermal systems and consume most of the power the system uses? This is entirely possible using BTES, Borehole Thermal Energy Storage, type geothermal. BTES requires a smaller footprint, less wells, and work by super cooling one set of wells in the winter to temperatures low enough to provide direct cooling in summer without running compressors in a typical refrigeration cycle. The other set of wells is super heated in summer so it provides heating in winter, also without running compressors. This is the future of geothermal. It’s the most important new design solution I have seen in my career and I see it as a true game changer that I am excited to help implement.
As NYC transitions to electrically driven heating, if heat pumps alone are used, then the power consumption will be similar what we now see in Summer. What happens when we see blackouts and brownouts in WINTER!? Losing AC in power outages in summer is extremely uncomfortable. But losing heat in winter power outages could easily result in burst pipes through-out a building, and could even be deadly in a residential occupancy. Is the already-stressed local grid ready to give us the reliability we need in Winter with the added loads of heating?