California sets clean energy record as it pushes toward climate change goals

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.

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.