Hook up your solar panels to a giant rhubarb battery

CleanTechnica

Yes, all you rhubarb fans take note. A new energy storage breakthrough is under way at Harvard University, and it is based on a common little molecule that is almost exactly the same as one found in rhubarb. The rhubarbesque molecule is part of a group called quinones, which are used to store energy in any number of green plants as well as petroleum.

The Harvard breakthrough battery itself is a flow battery, an emerging technology that frequently pops up on our screen because it is ideal for storing intermittent forms of energy, namely wind and solar. However, the rhubarb angle is new to us.

Rhubarb (cropped) by Kathy McGraw.

Flow Batteries And Intermittent Energy Storage

Loosely speaking, flow batteries generate an electrical charge from the interaction of a liquid flowing past something else, either another liquid (MIT is working that angle, for example) or a solid (see Stanford for more on that).

Either way, the liquid(s) are stored in separate tanks where they are inert until a current is needed. That means a flow battery can be idled for long periods of time and brought online very quickly when needed, making it ideal for intermittent energy storage.

That also means a large flow battery has the potential to be relatively cheap, since to scale up the infrastructure all you need is a bigger tank and more powerful pumps.

The sticky wicket is the high cost of the metals, including vanadium and platinum, that drive the electrochemical reaction in conventional flow batteries.

That’s that’s where the Harvard team seems to have struck gold.

Quinones are cheap and abundant in nature — so abundant, in fact, that the research team ran 10,000 different quinone molecules through a computer model searching for the best candidates to adapt to flow batteries.

We Built This Next-Generation Flow Battery!

So far the Harvard battery has achieved about 100 cycles without significant degradation. Thousands of cycles are needed for commercial application but the research team already has its eye on improvements.

If that pans out go ahead, pat yourself on the back. The three-year research project is partly funded by the Department of Energy’s ARPA-E (Advanced Research Projects Agency – Energy) arm, which is modeled on the Department of Defense’s cutting edge technology funder, DARPA.

Partnering in the project is a Connecticut company called Sustainable Innovations, LLC.

Meanwhile, some folks are not waiting around for flow battery technology to catch up, as pumped hydro, next-generation lithium batteries, and other forms of utility scale intermittent energy storage are already coming into mainstream use.

Source: Clean Technica. Reproduced with permission.