California Grid Operator Asks Geothermal to Help ‘Feed the Duck’

Greentech Media | By Herman K. Trabish | Link to article

By 2015, the need for grid support will double.

California’s 33-percent-renewables-by-2020 mandate is becoming a reality, and the state’s electricity system operator wants the geothermal industry to help keep the grid stable as more generation comes from variable resources.

By 2020, due largely to solar, a graph of the change caused by variable renewables in the state’s grid ramping up will look like a duck, California Independent System Operator VP Karen Edson told industry leaders at the Geothermal Energy Association National Geothermal Summit.

Instead of the present maximum ramp in demand from 19,000 megawatts to 25,000 megawatts, Edson said, the ISO could need the capability to ramp from 11,000 megawatts to 25,000 megawatts by 2020.

The biggest needs will come in what Edson called the “shoulder months,” when excess wind and hydro create overcapacity and early sunsets cause solar generation to drop off before peak evening demand periods end.

(complete article)