Last week, Californians were hit with a scorching heat wave, and as households blasted their air conditioners in the afternoons to keep cool, it placed extreme stress on the state’s power grid. So, for the first time, Californians received an emergency text alert asking citizens to conserve electricity to avoid blackouts. And it worked. Marketplace’s Kimberly Adams speaks with Severin Borenstein, who researches energy markets at University of California, Berkeley’s Haas School of Business.