Grid-scale battery storage for renewable energy still problematic


California is mandating utilities invest in renewable energy storage. However, no one yet knows how or if this will work. Renewable energy is by nature unpredictable yet the grid must always be in perfect parity between supply and demand. Storing energy for future use sounds like a solution. However, it’s costly and battery technology to handle such massive loads doesn’t yet exist.

PG&E is testing two battery storage units in Vacaville. They are the size of moving vans, cost $10 million, and can store energy from two large wind turbines operating for seven hours. Sure, this is still experimental but that hardly seems cost-effective if done on a grid scale.

Nobody really knows how the batteries can best smooth out the irregular power supply from wind and solar power.

Batteries waste about 25 percent of the energy in the process of being charged and discharged. These sodium-sulfur batteries need to be heated to 600 degrees Fahrenheit to work.

Yikes. Those batteries sound seriously potentially dangerous, certainly not the kind of thing you want in residential neighborhood switching stations, that’s for sure.

Battery technology has not advanced much in the past hundred years. Flywheels and stored hydro can also store energy, however they will be small in comparison to what batteries will have to be able to do soon.

Batteries will find some role, but they are still very expensive. Strauss says for batteries to succeed, the technology needs the kind of revolution that brought down the price of solar panels by about 75 percent over the past decade.