ARLINGTON, Va.--(BUSINESS WIRE)--Opower (NYSE: OPWR), a leading provider of cloud-based software for the utility industry, today announced its financial results for the first quarter of 2015. The company ended the quarter with revenue of $33.4 million, an increase of 17 percent year-over-year. “Opower is off to a strong start in 2015, delivering first quarter results that beat our expectations for revenue and the bottom line,” said Dan Yates, chief executive officer of Opower. “We expect to bui