Germany expects 40 to 45% of the electrical power consumed in Germany to be generated from renewable resources by 2025. That number is anticipated to grow to 55 to 60% by 2035. That’s good news for greening the electrical grid, but renewables still require some form of storage medium, such as a batteries, in order to compensate for the fact that the output from solar panels and wind turbines is not as constant and predictable as generators turned by burning fossil fuels.
There are many theories about how best to store electrical energy from renewables. They include dragging a train filled with rocks up a mountain every day and letting it generate electricity as it rolls back down at night. Others prefer to pump water uphill during the day so it can turn turbines when it flows downhill later.
Others favor battery storage, but that idea has split people into two camps — those who favor using new batteries and those who believe it makes the most sense to repurpose batteries from electric cars when they reach the end of their useful life. An EV battery may not be able to deliver the bursts of power needed to accelerate an automobile, but may still have the ability to store electricity from the grid and feed it back later.
In Germany, the world’s largest second use battery facility is taking shape. When completed by the end of this year, it will use 1,000 former EV batteries, most of them from Smart EVs, to store up to 13 megawatt-hours of electricity. The project is a joint venture between Daimler, The Mobility House, and GETEC. A fourth company, REMONDIS, will step in to recycle the repurposed batteries once their storage capability has been completely exhausted. The batteries are expected to last an additional 10 years after being removed from the electric cars they started life as part of.
Not everyone is convinced that using old EV batteries for grid storage is good idea. Tesla CTO JB Straubel told a conference last month that it is better to use new batteries with the latest chemistry rather than batteries that were state of the art a decade ago but are now hopelessly out of date.
There is yet another school of thought that thinks the key to electrical energy storage is using the rays of the sun to create molten salt and use that stored heat to make steam to turn conventional turbines after the sun goes down. Advocates say concentrated solar power is one tenth the cost of grid scale battery storage. It will be interesting to see which of these theories comes to dominate the marketplace in a decade or so.
