New Water-Based Battery Could Help Store Solar and Wind Energy
A group of researchers at Stanford University have developed a new type of battery using water and salt that they hope could be used to store energy produced from wind and solar farms, increasing the effectiveness of renewable energy sources.
The two fastest-growing forms of energy generation in the world today are wind and solar, and both have the same fundamental limitation. They're subject to the weather, and routinely go for hours or days without generating any electricity at all. Energy companies relying on these generation methods need some sort of backup while their solar farms and wind turbines are offline.
Researcher Wei Chen with a prototype of the new battery. JINWEI XU
There aren’t too many options for these energy companies, and most simply turn to fossil fuels like coal or natural gas which significantly undercuts the benefits of green energy in the first place. An alternate solution—and one being trialed in places like Australia—is battery storage, so that excess power produced from renewable energy can be saved for later.
But batteries have their own problems. Most utility-scale battery systems are expensive to build, and there’s a limit to how long they last. Typically, rechargeable batteries have a lifetime of around a decade before they can no longer effectively hold a charge and need to be replaced.
The new battery developed by researchers at Stanford solves these problems with a cheap, long-lasting battery perfect for utility-scale energy storage. The battery is a manganese-hydrogen battery, and it’s made by dissolving manganese sulfate, a common salt, in water.
When electricity is pumped through the solution, it triggers a chemical reaction, creating manganese dioxide and pure hydrogen gas. That hydrogen gas can then be stored and later burned as fuel whenever excess electricity is needed. The battery itself can be recharged with more electricity and the process repeats.
There’s still a long way to go before this type of battery starts seeing widespread use. The researchers have only tested a small prototype in the lab, and there’s no guarantee that the design will perform as well out in the field. But if the battery is as cheap and long-lasting as it seems to be, we could start seeing this type of storage showing up everywhere.
More importantly, cheaper, better batteries could increase the number of utilities building solar and wind plants. After all, a cheap battery would eliminate the biggest downside of renewable energy. Perhaps some good battery technology is all we’ll need to help us against climate change.