SHARC International Systems Inc. and partner Egg Geo, LLC have created the world’s first combined wastewater energy transfer (WET) and geothermal system in two multiresidential towers in the Bronx in New York City.

The system will provide 100 per cent of the heating, cooling and hot water for 316 affordable housing units in the 20-storey towers.

St. Petersburg, Fla.-based Egg Geo is collaborating with the Amalgamated Housing Cooperative (AHC) and EnPower Group under the New York State Energy Research and Development Authority’s Empire Building Challenge program. As one of 16 other partners, the aim is to cut energy use emissions in the two towers from 2,741 tonnes of carbon to zero.

SHARC Energy’s (SHRC-CN) technology — utilizing either a SHARC or PIRANHA system — recycles thermal energy from wastewater which can then be used in heating, cooling and hot water production for commercial, residential and industrial buildings.

The SHARC is intended for district energy, large commercial or industrial use, while PIRANHA is ideal for apartments, hotels or commercial uses.

In the case of the Egg Geo collaboration, a SHARC system will be used.

SHARC and geothermal

SHARC Energy chairman and CEO Lynn Mueller said he's been working with fellow CEO Jay Egg on the project for the last three years. AHC, totalling 15 buildings, is the largest and oldest co-op project in New York City. Its decarbonization project began with these two towers.

Mueller and Egg have known each other since around 2015, having originally met at a geothermal conference in Kansas City. Over the next seven years, they stayed in touch trying to find the right project on which to collaborate. 

“When we were able to present our case to combine the thermal capacity of the sewage with the thermal storage capacity of the geothermal, (it) was just a match made in heaven,” Mueller said. “It allowed the system to do 100 per cent of the carbon reduction and provide all of the energy for the 20-storey buildings, with a reduced number of (geothermal) boreholes, so it saved millions of dollars in drilling costs.”

SHARC's systems are installed where wastewater exits. They extract heat from the wastewater to preheat the water fed into the customer’s hot water tank or boiler.

Thanks to the extensive work being done on the Bronx towers, it was easier for SHARC Energy to implement its WET system. Mueller also stated the hybrid system is about 45 per cent cheaper than a full geothermal setup – not counting possible tax credits depending on the location.

“What we had to do, which was outside of the normal realm, was catch the leaving sewage so we could put it through the SHARC system and transfer the energy into the loop. Basically, we had to dig a hole to … bury a 10,000-gallon tank.”

SHARC Energy CFO Hanspaul Pannu previously told SustainableBiz that for every dollar of electricity which is used, the company’s systems draw about $4 of energy output. He attributed this to the consistent availability of wastewater compared to air source units, for example.

The project will be completed in 2024.

Future of the hybrid system

SHARC Energy is also working with Egg Geo on two other projects in New York City, incorporating both SHARC and PIRANHA systems. The potential for these systems is vast; Mueller highlighted that in New York City alone around 1.4 billion gallons of sewage is produced per day.

He pointed out a unique problem the hybrid technology solves – that in dense, urban cities like Manhattan, there simply isn’t a lot of room to drill boreholes for geothermal.

In August, the company signed a joint sales and marketing agreement with Santa Ana, Calif.-based Salas O’Brien, an employee-owned engineering firm. The relationship is multi-disciplinary, Mueller said, but specializes in geothermal design.

He said SHARC Energy, Egg Geo and Salas are working together to make geothermal technology more available and widely used.

“I spent many years in the business and 45 years ago, when I put in my first geothermal system, the loop system would get too cold in the winter. But now over the last 40 years, that has completely shifted to where the loops are getting too warm in the summer.

“So rather than just putting in more and more boreholes, using the sewer to take that load off has made geothermal economically feasible again.”

Founded in 2011, Vancouver-based SHARC Energy went public in 2014.

Previously, the company had stated its 2025 goal was to have a sales pipeline of $100 million. With the new hybrid technology, Mueller calls that a conservative estimate.

“It should have a huge impact on our sales pipeline, and the sales pipeline is growing daily,” he said. “”Over the next three to five years, you're going to see SHARC and geothermal just continue to grow in double digits.”