The Sunnyside Powerhouse powered San Francisco's first electric streecar line, the San Francisco and San Mateo Electric Railroad. It was built by the Joost Brothers, Behrend, Isaac, and Fabian primarily to make their extensive real estate holdings in the Sunnyside neighborhood more accessible. The line opened in April 1892 and ran from the foot of Market Street to Colma's Holy Cross Cemetery (with a transfer near 30th and Chenery) and was later extended to South San Francisco, still later to downtown San Mateo.
By the end of May 1894, the SF & SM Electric Railroad had gone into receivership due to mounting debt and a poor safety record. Sales of Sunnyside lots didn't prove as popular as the Joosts had hoped.
In 1896, bondholders sold the line to a group of investors headed by Adolph B. Spreckels. The line was renamed the San Francisco & San Mateo Electric Railway.
In 1902, the railway and powerhouse was sold again, this time to a syndicate of east coast investors which became known as the United Railroads. They consolidated many of the transit lines in San Francisco, and by 1904 (the date of the two large images here) the Sunnyside Powerhouse was not used. Power for the line was generated at the Geneva Powerhouse at San Jose Avenue and Geneva.
1938 aerial photos still show remnants of the powerhouse and condensing pond. By 1941, housing finally started being developed on the block.
A special thank you to the SFMTA Photo Archive for the two great photos here (used with permission). The SFMTA collection of United Railroad images is amazing and the staff is continuing to digitize negatives.
Please visit http://sfmta.com/photos.