Aquion has started production of a low-cost sodium-ion battery aimed at making renewable energy viable.

A former Sony TV factory near Pittsburgh is coming to life again after lying idle for four years. Whirring robotic arms have started to assemble a new kind of battery that could make the grid more efficient and let villages run on solar power around the clock.

Aquion, the startup that developed the battery, has finished installing its first commercial-scale production line at the factory, and is sending out batteries for customers to evaluate. It recently raised $55 million of venture capital funding from investors including Bill Gates. The money will help it ramp up to full-speed production by this spring.

Jay Whitacre, the Carnegie Mellon professor of materials science and engineering who invented the new battery, says it will cost about as much as a lead-acid battery—one of the cheapest types of battery available—but will last more than twice as long. And while lead is toxic and the sulfuric-acid electrolyte in lead-acid batteries is potentially dangerous, the new battery is made of materials so safe you can eat them (although Whitacre says they taste terrible). Nontoxic materials are also a good fit for remote areas, where maintenance is difficult.

Most importantly, 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 (see “How Solar-Based Microgrids Could Bring Power to Millions“).

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 be used instead of a type of natural gas power plant—called a peaker plant—often used 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.