The challenge of 33% renewables on the California grid

California plans to have 33% renewable energy by 2020. Jim Detmers helped create the California Independent System Operator, which operates most of the state’s wholesale transmission grid. He was right back then when he predicted a calamity was coming. He’s worried now too.

Here’s why. Traditional forms of electricity generation like coal, natural gas, and hydro produce alternating current. and automatically adjust themselves to whatever tiny fluctuations may be happening in the grid in terms of frequency and voltage.

PV solar and wind produce direct current. It goes through an inverter before entering the grid. But the inverter can not adjust its power to match the grid like alternating power and thus could, in effect, pump “bad” electricity into the grid, destabilizing it.

But a bigger problem might be politicians making decisions about the grid rather than those who know something about how it operates.

The challenge is keeping “supply and demand in balance on the grid around the clock,” as well as “managing the 53,000 megawatts of electricity currently on California’s grid.” Detmers is concerned that decisions are being made by legislators about how much — and how fast — renewable energy is to be introduced.