By Editors of Power Engineering
The California Independent System Operator is now curtailing more renewable generation due to an oversupply, Platts reported.
Mark Rothleder, ISO’s vice president for market quality and integrating renewables, said ISO curtailed 60,000 MW/h in February and 80,000 MW/h in March, up from 21,000 MW/h and 47,000 MW/h one year earlier.
So far this year ISO experienced curtailments in 31.1 percent of its market intervals this year so far, up from 21.1 percent in 2016, 15.9 percent in 2015 and 9.6 percent in 2014.
Rothleder said ISO had underestimated the amount of behind-the-meter solar that would be added in California, with 5 GW of rooftop solar installed to date.
As the system has 10,000 MW of nuclear, hydro and other qualifying facilities “you can’t move,” renewables were curtailed in low load periods.
The system was able to export up to 2,000 MW of renewables to other states rather than curtail them.
Three weeks ago, ISO began issuing oversupply forecasts so market participants can better prepare.
A massive growth of solar generation has caused power prices in the state to fall, sometimes to negative levels.