Arizona Public Service Co. saw its biggest year for solar in 2021, with more residential systems being installed than ever before in the utility’s history.

The utility saw 141 megawatts of residential solar installed during the year, along with another 7 megawatts of commercial solar to set a record as the most ever in a single year, utility officials said.

APS is the state’s largest utility and serves the bulk of its 1.3 million customers in the Phoenix area. It has a goal to have all its generation done by carbon-free sources by 2050.