Stem Inc, a Millbrae, California-based provider of energy storage solutions, has secured US$80 million in a Series D financing. The round was led by Activate Capital and joined by Ontario Teachers’ Pension Plan and Singapore’s Temasek. Founded in 2009, Stem’s technology pairs artificial intelligence with energy storage to help reduce electric costs for businesses. Last year, the company had more than 1,100 sites operational or in construction, with an average system size of 500 kilowatt hours, located in the United States, Canada and Japan. Stem, Inc.