Those skeptical of renewable energy as a viable power source often note that the wind doesn’t always blow nor does the sun always shine.
But advancements in battery technology are helping keep energy flowing on those dark, windless days.
“It’s happening at a record pace,” said Lisa Salley, vice president and general manager of energy and power technologies at Underwriters Laboratories, a Northbrook, Ill.-based independent safety consulting and certification organization.
The goal is to increase the usability of renewable energy, which currently accounts for 21 percent of all electricity generated worldwide but just 11 percent of consumption, according to the Energy Information Administration.
“One of the areas that’s been neglected in the past has been the storage component of renewable energy sources, and that includes wind and solar, of course,” said Tom Granville, CEO of Axion Power International.
That, however, is changing. Power, chemical and material science companies, locally and elsewhere, are investing heavily in battery technology. Some are improving existing technology while others are developing new chemistry to create entirely new battery structures.
The development is driven by a variety of factors. Battery technology got a huge boost from the mobile device boom of the past 20 years as one of the biggest complaints about high-tech smart phones is short battery life. Those same chemistries used to improved mobile device batteries can be scaled to store renewable energy.
Government action — either by mandate or incentive — has increased the demand for energy storage. The state of California is requiring that its utilities develop 1.3 gigawatts of energy storage by 2020, which has helped spur development in the industry. And federal solar credits have increased demand for solar panels, which in turn have increased the need for storage.
Similar mandates and incentives for smart grid technology, which modernizes electrical grids to act more immediately, have spurred the battery market.
New Castle-based Axion Power developed PowerCube, a large-scale energy storage unit that can send power to or receive power from the electricity grid. PowerCube, which can send up to one megawatt of power for 30 minutes or 100 kilowatts for 10 hours, is about the size of a semi-truck trailer.
The company recently sold four 500-kw PowerCube to a New Jersey-based solar installer for $1.1 million, its largest order.
Unlike the two leading chemistries used in large-scale batteries — lead acid, first developed in the 1800s, and lithium ion, which emerged on the commercial market in the past 25 years — Axion’s PowerCube is based off activated carbon technology.
Lawrenceville-based Aquion Energy developed its Aqueous Hybrid Ion battery using saltwater electrolyte, manganese oxide cathode, carbon composite anode and synthetic cotton separator. Its battery, like Axion’s PowerCube, can be used to supply power and receive power from the grid. It also can be incorporated into micro-grids to service locations that are otherwise unconnected to the electric grid.
Aquion Energy received $5 million in federal grant money to help develop its Aqueous Hybrid Ion battery as part of smart grid development.
The company, which spun out of Carnegie Mellon University in 2009 and began pilot production in 2010, has produced more than two megawatt hours of batteries in its manufacturing facility this year, and one line at the facility has the capability to produce 200 megawatt hours of storage per year.
Ted Wiley, vice president of product and corporate strategy for Aquion, said while production is fast-paced for the industry, it might seem slow compared to other technological innovations. Computer processors typically double their performance level every 18 months. That type of evolution is not possible for batteries, which require material science development.
Both Axion’s and Aquion’s batteries are more costly than lead acid batteries — sometimes twice as expensive. But they last nearly four times as long.
Solvay, a Belgian chemical group that recently acquired Plextronics of Harmar, is using the conductive ink technology Plextronics developed to help increase the battery life and capacity of lithium ion batteries.
“There are hundreds of competing technologies, and every day I hear of one more,” said Ms. Salley of Underwriters Laboratories, adding it is hard to predict which technology will emerge as an industry standard.
Since a lot of battery development is based on developing new chemistries, safety is a big component, she said. The firm recently opened a battery lab in Taiwan to test new components as well as entire systems connected to battery technology.
Battery failure can be catastrophic, she said, sometimes even leading to fires and explosions.
“How do we ensure that the technology is safe, how do we make sure that tech is validated in independent and safe ways?” she said. “Having a collaborative push on that is really, really powerful for the good of the common movement of renewables as a whole.”
But all agree that battery development is essential to growing renewables.
“I think the renewables are going to be easier to deploy and integrate more readily to the regular grid if they are coupled with energy storage,” Mr. Wiley said, adding it will give renewable energy sources the same type of reliability as traditional electricity generation sources.