The sun sets behind power lines and poles in Rosemead, California, on July 9, 2018 (Photo by Frederic J. Brown/AFP/Getty Images)

During last July's heat storm, parts of Los Angeles sustained lengthy power outages, along with a shortage of information about when they would end. The Twitter rants from Angelenos kept (literally and figuratively) in the dark were as heated as the asphalt melting in the streets.

The Department of Water and Power is now rolling out a new service intended to close the power outage information gap, but to get alerts, you have to opt-in.

Instructions are in this video, but the brief version is to sign in to your customer account at www.ladwp.com and click the "Outage Alerts" tab on the left side of the screen and follow the instructions.

Customers can get email or text alerts in English or Spanish about outages in up to three different parts of L.A. Say, one for yourself, and the others for your family or your workplace.

The system also sends updates on expected repair times and when the power is back on.

In the past, LADWP has used social media to inform the public of outages. It posts an outage map online, too. People could also call in to ask when repairs would be completed. But this is the first messaging app that pushes the information directly to customers.