National Grid, one of the largest utility companies in the world, decided to put its network of data to good use. The company knows the peak times energy is being produced and consumed, information that is valuable to its consumers.

The company, with Edelman U.K., developed a smart light bulb, the “Green Light Signal,” that receives information from National Grid servers in Great Britain and turns green during the most eco-friendly times to put appliances and devices to work.

The campaign distributed 750 bulbs to influencers and politicians, including Prime Minister Boris Johnson—who installed them outside of his office on 10 Downing Street. The effort was accessible to other users, who could buy compatible light bulbs to set up a “Green Light Signal” of their own or use the campaign app to be alerted of best times for energy use.

The campaign saw a total reach of 237.8 million and its website, which features instructions on installing your own bulb, registered more than 18,000 visitors.