By SAMMY ROTH | LA TIMES

Sometime next summer, there’s a decent chance a heat wave will bake the American West, and California’s power grid will again be stretched to its limits.

As the sun sets, solar panels will start generating less electricity even as temperatures remain high. Power plants that burn natural gas will fire up as quickly as possible, in a race to keep air conditioners blowing and avert the need for rolling blackouts.

But the fossil fuel won’t be alone in riding to the rescue.

As power supplies tighten, lithium-ion batteries — some connected to sprawling solar farms in the desert and others tucked away in household garages — will dispense electricity produced during the afternoon sunlight. A small but growing number of household batteries will be part of coordinated networks, discharging in unison as dictated by the needs of the grid.

Meanwhile, millions of people will cut back on electricity use in their homes, in some cases because state officials asked nicely and in others because they’re getting paid to conserve. Many will have agreed in advance to have their air conditioners automatically turned down a few degrees, or their refrigerators briefly powered down.

As California works to build a future without fossil fuels, electricity generation isn’t just getting cleaner — it’s getting smaller and nimbler. Big power plants and far-flung transmission lines are increasingly being joined by programmable thermostats, solar-charged batteries and even electric cars as key tools for balancing supply and demand.