California’s All-Renewable Moment Shows the Future of the Power Grid
On the last day of April, California hit a milestone: For a brief spell during a sunny Saturday afternoon, renewable sources met 99.87% of electricity demand. Power systems outside the U.S. have reached this target before (Denmark with wind power and South Australia with solar alone last year). But California’s main grid, which serves 80% of the state, is far bigger than those examples.
Related Knowledge Center: ENERGY BASICS: renewables
Renewable energy sources — once the fuel of the future, then practical in specific, narrow applications — are increasingly economic mainstream sources of power generation. Hydropower was long the mainstay of U.S. renewable electricity generation, although wind power surpassed hydro for the first time in 2019, and solar continues its rapid growth. The continued growth of wind and solar, with their fluctuations, is tied in part to improvements in storage technology: batteries.
Related Knowledge Center: ENERGY BASICS: electricity
Electricity is a secondary energy source: it is generated through the conversion of primary energy sources such as natural gas, coal, solar, hydropower, and wind. Electricity’s versatility is not cost-free: a substantial amount of energy is lost in its generation and the cost of storage is high, compared with fuels such as coal, oil and natural gas. The economics of battery technology hold the key to expanded use of renewable sources to generate electricity.