Generators for Small Electrical and Thermal Systems

Distributed Energy Resources

Release Date:
Project Count:

Program Description:

The GENSETS program aims to develop transformative generator technologies to enable widespread deployment of residential combined heat and power (CHP) systems. These small, natural gas-fueled systems can fulfill most of a US household’s electricity and hot water needs, and if widely used could increase the overall efficiency of power generation in the US, and reduce greenhouse gas emissions.

Innovation Need:

In 2013, centralized US power plants had an average electricity generation efficiency of only 33%, wasting 67% of primary energy as heat and emitting 2 billion tons of CO2, about 38% of the US total. Further, 6% of electricity is generally lost during transmission and distribution from the power plant to the customer. An alternative to centrally produced power is distributed generation, in which electricity is generated at the point of use. Residential CHP systems can use natural gas to produce electricity for a home while also generating heat that can be used for space and water heating. These systems offer increased efficiencies by utilizing the waste heat of the generator that is produced when the fuel is burned. In fact, the combined efficiency of primary energy usage for CHP systems can reach more than 80%. Since about 75% of the electricity generated from centralized power plants is consumed by the residential and commercial sectors, CHP use in these sectors could have a significant impact on both energy savings and CO2 emissions. However, adoption of small CHP systems is limited by the high price, low efficiency and short lifetime of systems currently on the market. Since roughly 70 million US homes (61%) have access to piped-in natural gas, availability of long-lasting, low-cost CHP systems could result in their widespread deployment. To this end, the GENSETS program seeks to develop 1 kW (electric) CHP generators that have high fuel to electricity generation efficiency, long life, low cost, and low emissions. GENSETS project teams will develop and test advanced generators in four technology areas that offer the potential to meet these goals: Stirling engines, internal combustion engines, microturbines, and solid state devices (thermal to electrical converters with no moving parts).

Potential Impact:

If successful, innovations created in the GENSETS program will facilitate development and commercialization of economical, efficient, and durable CHP systems for residential use. These advancements support progress toward ARPA-E’s overall goals as follows:


Innovations developed in the GENSETS program could help households and businesses become more energy self-reliant and less susceptible to energy-related outages through distributed, local generation of power and heat.


Widespread adoption of high-efficiency residential CHP systems could decrease overall primary energy consumption and therefore reduce CO2 emissions associated with electricity generation by up to 10%.


Cost-effective natural gas-fueled residential CHP systems could offer consumers lower electricity and heating costs.


Program Director:
Dr. David Tew;Dr. William Horak;Dr. Ji-Cheng Zhao
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Project Listing

• Aerodyne Research - Single-Cylinder Two-Stroke Free-Piston Internal Combustion Generator
• Air Squared - High Efficiency Generator System
• American Superconductor (AMSC) - Sustainable Economic mCHP Stirling (SEmS) Generator
• Brayton Energy - 1kW Recuperated Brayton-Cycle Engine
• MAHLE Powertrain - Advanced Lean Burn Micro-CHP Genset
• Metis Design Corporation (MDC) - Advanced Microturbine Engine for Residential CHP
• Mohawk Innovative Technology, Inc. (MiTi) - High-Speed Microturbine with Air Foil Bearings for Residential CHP
• NanoConversion Technologies - High-Efficiency Thermoelectric CHP
• Sencera Energy - Hybrid Engine Generator for Residential CHP
• Sunpower - Free Piston Stirling Engine Based 1kW Generator
• Tour Engine - High Efficiency Split-Cycle Engine for Residential Generators
• West Virginia University Research Corporation (WVURC) - Advanced Stirling Power Generation System for CHP
• West Virginia University Research Corporation (WVURC) - Oscillating Linear Engine and Alternator
• Wisconsin Engine Research Consultants (WERC) - Spark-Assisted HCCI Residential Generator