The first project, Elwood Energy Storage Center, will be situated on Pilsen Road in West Chicago.
The second development, Jake Energy Storage Center, will be located on Brandon Road in Joliet.
BYD America will deliver the lithium iron phosphate battery storage modules for the two projects, which will have the capability to store 7.8 megawatt-hours of energy.
RES Americas will develop and provide the energy storage control and dispatch systems.
Construction on both the projects is expected to start this winter with planned completion by August 2015. RES Americas expects each center to operate for about 10 years.
RES Americas acquired the projects that were in development phase from Glidepath Power in September 2014.
The projects will provide real-time frequency regulation service to the PJM ancillary services market and are interconnected to the local Commonwealth Edison (ComEd) electric grid.
RES Americas vice president of energy storage Victor Babbitt said: "The Jake and Elwood Energy Storage Centers represent commercial installations of cutting-edge energy storage technology.
"These projects will increase the reliability and quality of ComEd’s grid in these communities which, in turn, may help attract new business that demands a high-quality & reliable electricity supply."
RES Americas has energy storage projects in Ohio and Ontario apart from the planned systems in Illinois.
