Breakthrough Flow Battery Cell Stack

United Technologies Research Center (UTRC)
Transformative Electrochemical Flow Storage System (TEFSS)
Graphic of UTRC's technology
ARPA-E Award: 
East Hartford, CT
Project Term: 
09/09/2010 to 09/30/2013
Project Status: 
Critical Need: 
Our national electric grid has limited ability to store excess energy, so electricity must constantly be over-generated to assure reliable supply. Though wind and solar power are promising clean alternatives to fossil fuels, their natural unpredictability and intermittency present major challenges to delivery of the consistent power that is necessary to operate today's grid. The U.S. needs technologies that can store renewable energy for future grid-use at any location. Flexible, large-scale storage would create a stronger and more robust electric grid by enabling renewables to contribute to reliable power generation.
Project Innovation + Advantages: 
UTRC is developing a flow battery with a unique design that provides significantly more power than today's flow battery systems. A flow battery is a cross between a traditional battery and a fuel cell. Flow batteries store their energy in external tanks instead of inside the cell itself. Flow batteries have traditionally been expensive because the battery cell stack, where the chemical reaction takes place, is costly. In this project, UTRC is developing a new stack design that achieves 10 times higher power than today's flow batteries. This high power output means the size of the cell stack can be smaller, reducing the amount of expensive materials that are needed. UTRC's flow battery will reduce the cost of storing electricity for the electric grid, making widespread use feasible.
Impact Summary: 
If successful, UTRC's redesigned flow battery cell stack would enable energy producers to store power and balance intermittent energy production from renewable energy sources, transmitting it to regions that need energy at any given moment.
A more efficient and reliable grid would be more resilient to potential disruptions.
Electricity generation accounts for over 40% of U.S. carbon dioxide (CO2) emissions. Enabling large-scale contributions of wind and solar power for our electricity generation would result in a substantial decrease in CO2 emissions.
Increases in the availability of wind and solar power would reduce fossil fuel demand, resulting in reduced fuel prices and more stable electricity rates.
ARPA-E Program Director: 
Dr. John Lemmon
Project Contact: 
Mr. Michael Perry
Clipper Windpower Technologies
Pratt and Whitney Rocketdyne
University of Texas