One Java Street is a new Brooklyn residential development designed by Marvel that will utilize geothermal energy.
Lendlease and Marvel One Java Street is a new Brooklyn residential development designed by Marvel that will utilize geothermal energy.

In the basement of a New York skyscraper, the future of building sustainability is being dug into the Manhattan soil, quietly and without fanfare. Using water jets to drill 4½-inch diameter holes into the ground—described by an engineer as “sticking a toothpick into a birthday cake”—high-tech equipment from Armonk, N.Y.-based building energy company Brightcore seeks to go 500 feet deep, roughly the height of the Washington Monument, where the temperature is a cool 55 degrees Fahrenheit. It’s the company’s latest geothermal retrofit, which transfers renewable and sustainable heat between bedrock and a building via water circulated through newly dug wells to cool or warm the interior. It’s also an opportunity to, ideally, change the way the industry thinks about energy use.

“The operating system of these buildings has to change,” says Mike Richter, president of Brightcore, referring to the status quo of heating and cooling practices in buildings today.

Digging wells isn’t radical new technology: Roman baths used deep wells to provide radiant heat. But the growing demand for sustainable buildings and retrofits, modern drilling capabilities, and the catalyzing impact of the 2022 Inflation Reduction Act’s subsidy for this technology have supercharged the efforts of early adopters and startups. As a new generation of buildings start to open their doors, including a critical mass of apartments, affordable housing, and offices in New York, developers see geothermal energy becoming a mainstream method of cutting the carbon footprint of new and existing buildings.

“I don’t think that the technology has gotten significantly [more] advanced,” says Michelle DeCarlo, associate partner at JB&B, a New York engineering firm with extensive experience in geothermal energy. “I think there’s more attention being paid to energy conservation and carbon reduction, and owners are more motivated to be more innovative.”

A 16-story office tower from New York-based CookFox Architects, 555 Greenwich, was completed late this spring. It uses geothermal technology paired with building electrification and artificial intelligence controls. Designers expect to achieve 40% energy reduction compared to similar office buildings.

And the forthcoming One Java Street project on the Greenpoint waterfront in Brooklyn, N.Y., a 2.6-acre site with 834 residential units set to open in 2025, will have the nation’s largest multifamily geothermal system, employing 320 boreholes. While the construction of such a pioneering system will add 6% to the upfront cost of a typical building, it promises to cut emissions by 53% compared to a standard residential project and quickly recoup costs with operational savings.

“You’re creating a project that’s highly investable, and for many, the geothermal system will be the most valuable aspect of the project,” says Layth Madi, director of development management and operations for integrated real estate company Lendlease, which built One Java Street.

Changing light bulbs or installing building sensors offers a sensible, but relatively small, emissions impact. Heating, ventilation, and air conditioning, the primary system powered by these large-scale geothermal projects, makes up roughly 60% of a building’s emissions. The wells function as temperature regulators in the winter, pumping up hot air, and heat sinks in the summer, absorbing hot air. It’s a mostly passive system that requires a lot less energy than traditional fossil fuel systems to heat, cool, and circulate air, and because it achieves significant efficiency, it doesn’t need to wait for the strengthening of the electrical grid to make an impact on emissions. If builders are already going to be drilling or digging to lay a foundation or supports during the construction process, adding boreholes is not a huge shift.

“When we’ve looked at doing renewable energy or sustainability on-site, it doesn’t line up very well,” says Nat Felder, AIA, an architect at CookFox. “Doing wind or solar on-site just attacks a portion of the energy needed. Geothermal is something that’s oriented toward being used in an urban environment.”

These systems work well at temperature extremes, and don’t require as much mechanical equipment that inevitably needs replacing, which is key to their operational efficiency. A geothermal energy retrofit is akin to swapping out an old gas car with an electric model; fewer moving parts mean less wear and tear and lower costs, offering efficiency as well as an environmental benefit.

“It’s one of those win-win-wins. It pencils out so well,” says Myrrh Caplan, national vice president of sustainability at Stockholm-based construction company Skanska, which has done numerous geothermal projects, including ones on university campuses such as Wake Technical Community College in Raleigh, N.C., and Dartmouth College in Hanover, N.H. “We’re talking about this with a lot more clients.”

Legislative efforts to incentivize geothermal energy have given a greenlight to developers seeking to employ the technology. The IRA offers a 40% subsidy, numerous state subsidies provide benefits, and local building emissions regulations, such as New York’s Local Law 97 or Boston’s BARDO, underscore the case for geothermal retrofits to avoid fines for emissions. Programs such as the Western Governors Association’s Heat Beneath our Feet initiative are promoting exploration and investment. All of these efforts are helping the United States catch up to Canada and the Nordic countries, where such technology is more advanced and accepted.

For architects, the addition of geothermal energy to a project doesn’t radically alter design, though digging boreholes does take more planning in the early construction stages. Many designers call such systems “mostly invisible” to building tenants. Having fewer mechanical systems, and no necessity for rooftop AC and HVAC systems, can make more interior space available for amenities, and open up rooftops for additional appealing features like decks or pools—or solar panels for additional sustainable benefits.

“The primary difference between a typical multifamily building and one that adopts geothermal is the design of the mechanical rooms,” says Lendlease’s Madi. “Specifically, the geothermal system eliminates the need for traditional cooling towers and boilers, which allows for flexibility around the placement of the central mechanical equipment.”

Technology like Brightcore’s smaller drilling rigs and mini drills also points to the significant potential the industry sees in retrofitting older buildings. A vast majority of the buildings in New York, or any other major metropolitan area, will probably still be standing in 2050, and geothermal can help achieve emissions reductions without costly façade replacements. Geothermal energy offers a truly long-term investment—boreholes don’t need to be re-dug—and can be used for more and more buildings, with its capital investment outweighed by significant operational savings over time. Brightcore’s tech can work at odd and obtuse angles within bedrock. Brightcore’s chief administrative officer Dan Bengyak says most of the geography from North Carolina to Maine, including a majority of New York, could tap into geothermal energy depending on the distance to bedrock.

“This [investment] was future-proofing the building,” says Nicholas Pasquenza, director of development and construction at Bethesda, Md.-based LCOR, which is currently building the 1515 Surf residential development on Coney Island in Brooklyn and has a handful of other geothermal projects in the works. “It adds real value when you consider the long term.”

Part of that value is the degree to which this technology can scale. Developments can quickly be redesigned to incorporate geothermal energy, and the ability to create neighborhood-scale geothermal systems means not every building needs to be perfectly positioned for drilling wells (a Boston-area utility provider, Eversource Energy, is currently developing a neighborhood geothermal system connected to more than three dozen buildings). The greenest building is the one that’s already built, and one of the easiest ways to bring it up to contemporary sustainability standards is drilling geothermal wells.

“If you’re attempting to increase the sustainability for your project, geothermal makes the most sense,” Madi says.