How Gift Cards Keep the Lights On When Power Is Short

When extreme heat or bitter cold threaten to overwhelm fragile power grids in places like California and Texas, there’s an effective, old-school tool to avoid a shortfall: turn the lights off. But how to make that happen? The key may be “demand response” -- voluntary conservation programs that kick in during critical hours. In many cases, civic-minded citizens are doing their part, simply opting not to use appliances when the grid is most stressed. But others are being enticed with big financial carrots -- as well as gift cards.

It’s an umbrella term for a variety of short-term, voluntary efforts that encourage homes and businesses to reduce electricity during hours when grid operators fret power supplies may not meet heavy demand. Getting consumers to switch off is a critical tool for helping California avoid blackouts during a mounting heat wave this week, as temperatures soared above 110 degrees Fahrenheit (43 degrees Celsius) in some regions. It’s also sometimes called “power shaving,” and can, in a way, be considered a form of rationing.