While solar and wind are proving to be viable forms of energy generation that are coming closer in costs to fossil fuel generation, one big issue remains: What to do when the wind’s not blowing or the sun’s not shining? It’s a question of energy storage. A new energy 20 megawatt electric storage project, which aims to address that issue, will be undertaken by AES Corp. in Johnson City, N.Y.

In some places, like the southwestern United States, solar thermal energy-based power plants can store excess energy in the form of heat. But in most of the U.S. the lack of excess power storage and need for extra generation still means reliance on fossil fuels—for now. The Obama Administration is investing billions of dollars in energy storage technologies, as is the Department of Energy.

The AES storage project is one such example. It will use lithium-ion batteries developed by Pennsylvania-based A123 Systems, Inc. to provide battery storage and power conditioning. It got a significant boost last week when the Department of Energy (DOE) announced that it would support the project with a $17.1 million loan guarantee, which should help AES find funding for the project.

While such systems can be used to provide backups to solar generation, this system would just increase grid stability. DOE spokesperson Stephanie Muller said “The system utilizes properties of storage batteries to absorb excess power from the grid and provide it back as demand fluctuates, thereby improving system reliability and power quality.” 

Power conditioning, or frequency regulation, is critical to making sure the grid is reliable and must be adjusted moment to moment, according to Mueller. “The demand for frequency regulation is expected to increase as more renewable energy sources are integrated into the grid, specifically wind and solar. These renewable energy supplies are subject to intermittent and rapid changes in supply levels, which require greater frequency regulation than traditional fossil fuel energy supplies,” she said.

In a press release, DOE Secretary Steven Chu said, "The AES project helps reduce carbon emissions and strengthens our energy infrastructure by allowing for more renewable energy sources like solar and wind to contribute to the electrical grid."

As an alternative to frequency regulation through fossil fuel-fired power stations, the AES system could help reduce carbon emissions by 70 percent and by providing storage rather than extra generation, it could regulate grid frequency for less, the DOE said.
 

Image courtesy of A123