Research Project Information

Research Project Summary Information

Residential Renewable Energy(16713)



All residences have three energy-based needs: heating and cooling, electricity for lights and appliances, and hot water. There are four main renewable sources for that energy: solar electric, solar thermal, geothermal heat pumps and biomass (primarily wood). Each of these sources has its own relative advantages for different uses, but only solar electric generates electricity. In places like the Northeast U.S., however, the unsubsidized cost of a solar electric system to supply the electricity needed by a household is prohibitive. Adding the capacity to produce electricity to existing or new solar thermal, biomass and geothermal installations could increase the efficiency and cost effectiveness of these installations.

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Project Description

This contractor aims to develop a product offering that can produce electricity from non-solar electric residential renewable energy sources by using the organic rankine thermal cycle and its patented Trochoidal Gear Engine (TGE) technology. The renewable energy source will be used for different hot/cold temperature combinations, with particular focus on biomass/ambient air and solar thermal/geothermal.


The tally of annual installations for wood pellet stoves, geothermal heat pumps, and solar thermal hot water systems are 200,000, 50,000, and 80,000 respectively. Having the ability to link one kW of electricity production to each of these systems could reduce the need for typical annual electrical generation between 95-150 GW. This would enable 85 technical jobs to be created within five years at the contractor’s facility. In addition the technology will provide a low cost alternative to another funded NYSERDA micro-CHP development. The experimental test results indicate isentropic efficiencies of less than 90%, compared with conventional turbines at less than 80% in the 1-100 kW output range.

Project Results

TGE expander technology was demonstrated to be versatile and have high isentropic efficiencies in the temperature range (170-240 deg F) at load supply range (100 W-5 kW), typical in residential HVAC systems. Most expanders increase in efficiency as they get larger; this TGE device defies that by maintaining a roughly 90% isentropic efficiency when tested on a 100 W output device using three different pressurized gases: argon, nitrogen and air, as well as the refrigerants. The ORC provides electricity from a temperature differential, therefore the larger this temperature differential, the greater the electrical output. Conducting an experiment using different refrigerants, with different thermal properties (R134A, R236FA) to test this concept, proved that R134A yielded higher kW outputs, along with higher system efficiencies. This is relevant and beneficial because residential boilers and solar thermal collectors can produce more electricity using the R134A with a lower temperature heat source, than the R236FA can. Both of these systems mentioned operate better at lower temperatures (i.e., 180 deg F provided by the R134A) and remaining well below the boiling point of water, which avoids pressure and safety issues. Avoiding the boiling point of water while generating electricity enhances the commercial prospects of this technology.


17 Fern Avenue
Rotterdam, NY 12306

Principle Investigator

Ted Eveleth

Universities Involved


Project Type:

Product Development

Technologies Types:

Energy Power Supply
Micro CHP

NYSERDA Contact Information

Gregory Pedrick


R&D -Transport & Power Systems

Contract Details

Start Date: 6/15/2010
Project Status: Active
Contract Number: 16713

Last Updated: 9/23/2014