Sunrun Inc (NASDAQ:RUN) shares are surging Wednesday after the company reported better-than-expected financial results for the second quarter and announced a partnership with Tesla Inc (NASDAQ:TSLA) to support Texas’s power grid. Q2 Revenue: $523.866 million, versus estimates of $515.167 millionQ2 EPS: 55 cents, versus estimates for a loss of 31 centsSunrun reported customer additions of 26,687 in the quarter. The company had 984,000 customers as of June 30. Storage capacity installed totaled 264.5 megawatt hours in the second quarter, up 152% year-over-year. Solar energy capacity installed ca…