Gigantic Batteries Could Fix Renewable Energy's IntermittencyRenewable energy has a problem. Unlike traditional fossil fuels, most types of renewable energy are based on the environment. Unfortunately, this means that power generation fluctuates. The wind blows and then dies down, the sun sets, the tide retreats.
Batteries are the solution, but they have a problem: no one has ever built a truly large one. Most battery banks are based on collections of smaller batteries networked together. This is costly and inefficient. But someone might have finally beaten the scalable battery problem.
Donald Sadoway is a renowned professor of materials chemistry at MIT. A bit of research he and his team has performed has earned him a fair bit of recognition. They managed to make an entirely new style of battery, one that uses layers of molten metal and salt. This new approach has the distinguished honor to be the only battery technology that can be scaled up to a level useful by utilities.
In case you weren’t aware, our current power grid isn’t exactly efficient. Ignoring all the talk of the smart grid for a moment, the only way to compensate for increased energy demand is to bring another power plant online. The only way to deal with less energy demand is to take more power plants offline. This induces enormous waste into the system, in addition to needing far more power plants than is strictly necessary. Take, for example, a situation where you have two power plants of equal capacity. Say the power demand exceeds what the first can produce by a couple of percent. The utilities would have to spin up the other power plant, despite only a fraction of the possible output being used.
Sadoway made a TED talk on the subject, which has garnered hundreds of thousands of views. His research has also earned him and his team $13 million in funding from both the government and interested companies. He has some fairly prominent backers; Bill Gates watched Sadoway’s classroom lectures through MIT’s OpenCourseWare initiative, and half the money put forth to commercialize the technology has come from him.
The prototypes are still very small. The first was the size of a hockey puck, while the second was the size of a small pizza. But the thing about these is that they get more efficient as they scale. Unlike traditional batteries, which lose efficiency when they heat up--a natural side effect to their functioning, and one that limits the size at which they can be built--Sadoway’s gets more efficient, to a point. In fact, it simplifies the design. Larger batteries generally require an active cooling system. Once you start Sadoway’s battery, you shouldn’t need any form of active heating or cooling. So the battery is simpler, cheaper, and uses less electricity to maintain its energy production. This means that there are fairly few size restrictions to the battery that we know of right now. It also means, and this is a big one for solar, that the battery can operate in the desert with little worry.
There is still a lot of work to do on the technology, but so far everything has been immensely promising. If this technology takes off, we could be looking at a world of cheaper electricity, more efficient batteries, and renewable energy.