NYTimes - Why a Big Utility Is Embracing Wind and Solar

[hunter]

5. Batteries? Are you kidding?

Batteries are used to fill in the gaps between the wind or sun cutting out and the fossil fuel plants spinning up. Big battery installations are useful wherever the local fossil fueled power grid is sluggish and unable to cope with fluctuating inputs of wind and solar. The energy storage capacity of huge battery instalations is often measured in minutes, not hours or days. This is especially true in places like Australia where three-quarters of the electricity is generated in coal plants.

The limitations of battery storage are true at any scale, from an RV parked out on the desert to a regional electric grid.

Every affluent person's off-grid solar house I've seen has a "backup" fossil fuel source covering a third and usually more of the home's total energy budget, fossil fuel use far in excess of most humans.

Wind power or not, Iowa still relies heavily on coal. Batteries are not going to make that go away. Natural gas might.