By the numbers
(c) 2013, The Washington Post.
_ Has more than 400 employees and 90 energy utility clients.
_ Reaches 22 million homes in the United States and Britain.
_ Has saved customers more than $350 million to date.
Pepco (Maryland, District of Columbia)
_ Saved more than 2.4 megawatts of electricity between January and the end of June, partly because of Opower. (One megawatt is enough to power 1,000 homes for an hour.)
ComEd (Chicago area)
_ Spends about $160 million each year on energy-efficiency programs.
_ Has been using Opower for two years, crediting it for about 2 percent of its annual energy savings.