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Craig Evans


The Winds are Changing: Shifting the Economics of a Texas Microgrid with Long-Duration Energy Storage
Wednesday 23 May 2018 15:45 – 17:00

Mr. Evans is the President and CEO, and a founder of ESS Inc. Having started ESS from his garage in 2011, he led the company to the commercialization of the Iron Flow Battery system in 2016. Prior to ESS, Mr. Evans was the Director of Design & Product Development at ClearEdge Power Inc. His team designed the ClearEdge5, a 5kW combine-heat-and-power fuel cell system, which was successfully commercialized in 2010. This product received both CSA International certification in North America and KNREC certification in Asia. Mr. Evans began his career at United Technologies Corporation (UTC) where he held technical leadership positions in their Fuel Cell business and, prior to that, as a project engineer in the Pratt & Whitney aircraft engine business. In 2006, Mr. Evans was awarded the distinguished George Mead Award, the highest honor for individual engineering achievement at UTC.

Mr. Evans has authored over 15 patents and patent applications. He holds a BS in Aerospace Engineering and a MS in Mechanical Engineering from Clarkson University, a MS in Finance from Rensselaer Polytechnic Institute and a M.B.A from Carnegie Mellon University.

Abstract Outline:
The increasing use of renewable generation and DERs is adding strain and uncertainty to the aging U.S. electrical grid. This uncertainty is only multiplied in a place like Texas, where wind farms regularly face periods of negative pricing throughout the day due to imbalances in electricity supply and demand. Short of another solution, wind projects, such as the grid-connected Group NIRE microgrid in Lubbock, are typically forced to curtail this excess energy.

In late 2017, ESS, Inc. offered a solution. The iron flow battery manufacturer joined forces with the Advanced Research Projects Agency-Energy (ARPA-E) to install a 50 kW, 400 kWh Energy Warehouse (EW) battery at the microgrid to complement the existing wind turbine + solar PV installation. The long-duration (4+ hour) battery performs renewables shifting to smooth out the imbalance in supply and demand, enabling the microgrid to function independent of the grid even after the sun sets and the wind dies down. In addition, the EW is capable of providing behind-the-meter demand charge management as well as wholesale ancillary services, which establishes a stronger use case for the EW over a more limited, shorter-duration lithium-ion solution.

Flow batteries are still a relatively new technology in the marketplace, but they are increasingly viewed as the best alternative for long-duration requirements. Thus, while ESS Inc.’s EW is able to switch the economics of the microgrid in favor of the facility, Group NIRE is serving as a proving ground for long-duration flow batteries to demonstrate their compatibility with and added value to a combined wind + solar PV system. This case study presentation will further analyze the Group NIRE microgrid components to evaluate the economic payback of adding a long-duration energy storage system to the existing system.