The aquarium installed a one-megawatt lithium battery weighing 30 tons on May 26. It’s the largest lithium-ion battery installed in any aquarium or zoo in the U.S.
The goal is to cut the aquarium’s energy use in half by 2020. It's part of Shedd's Master Energy Roadmap plan, a green initiative started in 2012. In addition to the installation of the giant battery, the plan calls for replacing 75 percent of the aquarium’s lights with high efficiency LED lights and implementing enhanced automation systems that can adjust electricity use based on real-time shifts in electricity pricing.
The $2 million battery will generate revenue for the Shedd by maintaining the area's electrical grid at a frequency of 60 hertz for the regional transmission organization PJM, which manages the grid. For example, if it's a cloudy day and the city's solar panels aren't generating enough electricity, the battery will distribute extra power. It will also serve as emergency back-up power for the Shedd.
The massive battery is visible to visitors from the loading dock outside or through the south Abbott Oceanarium window inside.
The battery, along with an adjoining transformer and inverter skid, were funded in part by a $500,000 grant from the Illinois Department of Commerce and Economic Opportunity (IDCEO) and installed by Schneider Electric. The remaining $1.5 million cost was covered by the Missouri-based company EaglePicher, which built the battery.

Lithium-ion Battery