For 15 years following its construction in 1990, this was the largest commercial solar power plant in the world, generating around 160 megawatts at its peak. It is one of three separately owned sites within 40 miles of one another, that make up the nine solar fields in the Solar Electric Generating System (SEGS #1 and 2 are at Daggett, and #3 through 7 are at Kramer Junction). Harper Lake was the last of these built, and is designated as SEGS #8 and 9. It is still online, but has been surpassed by other newer facilities, including the Mojave Solar Project, which is being built next to it, and is expected to produce 280 megawatts when it goes online in 2014.