Building the level of renewable generation and storage necessary to reach California’s goals would drive up costs exponentially, from $49 per megawatt-hour of generation at 50 percent to $1,612 at 100 percent. And that's assuming lithium-ion batteries will cost roughly a third what they do now
Similarly, a study earlier this year in Energy & Environmental Science found that meeting 80 percent of US electricity demand with wind and solar would require either a nationwide high-speed transmission system,which can balance renewable generation over hundreds of miles, or 12 hours of electricity storage for the whole system. At current prices, a battery storage system of that size would cost more than $2.5 trillion.
Using batteries for electrical storage runs into real problems. The authors of a 2016 study found steeply diminishing returns when a lot of battery storage is added to the grid. They concluded that coupling battery storage with renewable plants is a “weak substitute” for large, flexible coal or natural-gas combined-cycle plants, the type that can be tapped at any time, run continuously, and vary output levels to meet shifting demand throughout the day.
Read the rest of the story, HERE