CALIFORNIA—For the first time, the California Independent System Operator (CAISO) accounted for almost 40 percent of net grid power produced during the hours between 11 a.m. to 2 p.m., showing almost 50 percent growth in utility-scale solar photovoltaic installed capacity in 2016 indicated the Energy Information Administration (EIA) website.

Large amounts of sunlight can produce too much electricity around the middle of the day during winter and early spring, where demand can reach it’s annual minimum. Energy and environmental policies initiatives are driving electric grid changes. According to the California ISO, these include 50 percent of retail electricity from renewable power by 2030.

Managing a green grid presents challenges, including an oversupply risk; where more electricity is supplied than needed to satisfy the real-time electricity needs.

The Los Angeles Times reported that the $300-million plant closed indefinitely, just 15 years into an expected 30 to 40 year lifespan. The power it produced is no longer needed, in part because state regulators approved the construction of a plant just 40 miles away in Colusa that opened in 2010.

According to ISO, during oversupply times, wholesale prices can be very low and even go negative in which generators have to pay utilities to take the energy. The market often remedies the oversupply situation and automatically works to restore the balance between supply and demand.

“An unexpected combination of oversupply of natural gas and a boom in solar and other renewable energy has depressed power prices and threatened the viability of natural gas plants that sell power into the Golden State’s electricity market,” Reuters stated.

Michael Picker, President of the California Public Utilities Commission, indicated in an interview on the Interchange podcast that he believes the state should consider liberalizing its retail electricity market in order to broaden customer choice.