Renewable energy is the wave of the future, but it won’t be practical if you can’t store the energy. The catch is storage needs to end up in low-cost batteries.
Right now there is a new kind of battery that could make the grid more efficient and allow communities to run on solar power around the clock.
Aquion, the startup that developed the battery, finished installing its first commercial-scale production line at a former Sony television factory near Pittsburgh, and is sending out batteries for customers to evaluate. It recently raised $55 million of venture capital funding. The money will help it ramp up to full-speed production by this spring.
The battery will cost about as much as a lead-acid battery, which is one of the cheapest types of battery available, but will last more than twice as long, said Jay Whitacre, the Carnegie Mellon professor of materials science and engineering who invented the new battery.
While lead is toxic and the sulfuric-acid electrolyte in lead-acid batteries is potentially dangerous, the new battery is made of materials safe enough to eat. Nontoxic materials are also a good fit for remote areas, where maintenance is difficult.
By providing an affordable way to store solar power for use at night or during cloudy weather, the technology could allow isolated populations to get electricity from renewable energy, rather than from polluting diesel generators. Combining solar power and inexpensive batteries would also be cheaper than running diesel generators in places where delivering fuel is expensive.
The batteries could allow the grid to accommodate greater amounts of intermittent renewable energy. As Aquion scales up production and brings down costs, the batteries could also see use to balance supply and demand on the grid. When recharged using renewables, the batteries don’t need fuel, so they’re cleaner than the natural gas power plants.
In some places, concerns over pollution make new natural gas plants hard to build, which could create an opening for Aquion’s technology, even if it’s somewhat more expensive.
The battery consists of inexpensive materials including manganese oxide and water. In concept, it operates much like a lithium-ion battery, in which lithium ions shuttle between electrodes to create electrical current. The new battery, however, uses sodium ions instead of lithium ones, which makes it possible to use a salt water electrolyte instead of the more expensive — and flammable — electrolytes used in lithium-ion batteries.
The trade-off is the batteries store less energy by weight and volume than lithium-ion batteries do, so they’re not practical for cars or portable electronics. But space isn’t as much of an issue for stationary applications, where batteries can stack in warehouses or shipping containers. For storing large amounts of power from the grid, success is “all about cost,” Whitacre said.