Large-scale batteries are integral in shift to renewable energy
At Turkey Hill Dairy in Lancaster County, the secret ingredient in its ice cream is wind.
Along with conventionally derived power used to make its sweet treats, the dairy is the sole customer of a nearby wind farm, built in 2010, that provides 25 percent of its electricity.
“That's honestly all we need,” said company spokeswoman Andrea Nikolaus.
Relying on wind for bigger operations, or to power the grid, is a different matter. As critics of renewable energy are quick to point out, the wind doesn't always blow — or it does when customers don't need it — and the sun doesn't always shine on solar panels.
But tougher environmental rules are prompting more interest in solar and wind power as the government looks to change a national electrical grid that gets most of its power from traditional sources — 39 percent from coal, 27 percent from natural gas and 19 percent nuclear.
Finding a cheap, reliable way to store electricity generated by renewables — energy resources that are abundantly available and environmentally friendly — is the hope of many researchers, government officials and power producers.
“The main issue is cost,” said Gabriela Hug, an assistant professor of electrical engineering at Carnegie Mellon University. “There's not one technology that has been decided, ‘That's the winner, that's the one we should go after.' ”
Many people are focusing efforts on making batteries commercially viable.
“Batteries have not traditionally been designed to be installed and used in a large scale,” said Ted Wiley, vice president of production at Aquion Energy, a Lawrence-ville-based company that is working on solving bulk storage for solar and wind power. “Everything is small-scale, or an existing type that has been repurposed.”
The types of non-battery storage that exist require unique geological features such as elevation for pumped water storage or caverns for compressed air storage. Or, they are expensive or require construction, experts said.
Aquion's battery, developed at Carnegie Mellon, is powered by lithium salts, cotton and activated charcoal and other chemicals. They can be charged and discharged thousands of times, said Wiley. And, because those materials are abundant, the cost of the battery is fairly low.
Southern California Edison, a utility that serves about 14 million people, is testing a collection of 600,000 lithium-ion battery cells to see if they can store power generated by 5,000 nearby wind turbines for later use.
Aquion is competing to get batteries to communities and power suppliers in California and New York, where Wiley said the grid is under stress.
“In Pennsylvania, the system isn't broken,” he said. “In California, the renewables that are already on the grid are adding to the mismatches on the grid.”
Nearly one-quarter of energy produced by California's three largest electricity providers comes from renewable resources, according to the California Public Utilities Commission.
Another company, Axion Power in New Castle, has created a lead-carbon battery for energy storage. Though corporate officials said they could not comment because of restrictions associated with a recent incorporation filing for the Securities and Exchange Commission, product specifications say the battery has a faster recharge rate and is more environmentally friendly than lithium-based batteries.
While both companies try to optimize more common battery technologies to large-scale storage, pilot projects funded by the Department of Energy will look at new battery technologies:
• In Harlem, Urban Electric Power is funded by the DOE's Advanced Research Projects Agency-Energy program to build a zinc/manganese oxide-powered rechargeable battery that could withstand the rigors of the electrical grid.
• ARPA-E also is funding two flow batteries — an iron-based system that uses two tanks of liquid that flow back and forth to charge and discharge the battery, and an organic battery that uses carbon compounds from oils and foods to store and release energy.
With the focus on storage, Hug, the Carnegie Mellon engineer, cautioned: Stored energy dissipates.
Researchers are working on how to best transmit electricity to meet demand, and how to make sure usage doesn't stress the grid.
“Storage may be the one you think about immediately,” Hug said, “but how to coordinate demand response and storage? You don't generate energy when you store. You're always losing a little.”
Bloomberg News contributed to this report. Megha Satyanarayana is a Trib Total Media staff writer.