Massive downtown power hub breaks ground

LS Power Grid California broke ground on May 20 on the Power Santa Clara Valley and Power the South Bay projects, starting a Bay Area transmission buildout that includes new equipment and connections at PG&E’s San Jose B substation in downtown San Jose. The company said the broader “Power the Bay” program carries a $2 billion price tag and is designed to strengthen grid reliability across Santa Clara and Alameda counties. California ISO documents show the San Jose B portion was expanded in 2024 to allow 1,000 megawatts of injection, up from 500 megawatts previously planned. (caiso.com) (sanjoseca.gov) The project has drawn attention because San Jose officials have tied new transmission capacity to growth in advanced manufacturing, artificial intelligence, data centers and transportation electrification. City Manager Jennifer Maguire said in a March 24 city release that “a modern, resilient energy grid is foundational” to the city’s role as an innovation center, while Mayor Matt Mahan said the expansion would be judged against standards for environmental protection, community impact and public value. ### What exactly is being built near Station B in downtown San Jose? (prnewswire.com) California ISO said the modified Metcalf–San Jose B project will increase power injection at San Jose B to 1,000 megawatts, change the AC-side voltage at the converter station to 230 kilovolts, and add a 230-kV switchyard and a 230/115-kV transformer at San Jose B. Those changes were approved by the ISO board in November 2024 after load forecasts in the San Jose area rose from earlier assumptions. LS Power said the Power Santa Clara Valley project will use high-voltage direct current technology to connect two new terminals in San Jose through a new 12-mile underground line. (sanjoseca.gov) The company described that technology as unusual in the United States and said it would give the state grid operator more control over power flows. ### Why did the project grow from 500 megawatts to 1,000? November 2024 ISO planning documents said the scope changed because of “significant increases in the load forecasts” in the San Jose area after the original projects were approved in 2022. (caiso.com) The ISO said the revised plan reflected technical discussions with PG&E, Silicon Valley Power and LS Power Grid California, and was intended to meet reliability needs under a more robust long-term plan for the South Bay. The City of San Jose said on March 24 that the transmission investments would improve redundancy and enable bidirectional power flow between critical substations, helping residents and businesses during peak demand or unexpected outages. (prnewswire.com) The city also said the added capacity would support electrification of buildings, transportation and industrial operations. ### How much electricity does this add, and how much of that is downtown? LS Power said the Power the Bay projects will be capable of transmitting 1,000 megawatts of electricity, which it described as roughly enough to serve 750,000 homes. (caiso.com) That figure differs from some local coverage that described the San Jose-area upgrades more broadly as enough for about 1 million homes, but the ISO documents are specific that the San Jose B injection was increased to 1,000 megawatts from 500. Engineering News-Record reported in April that San Jose’s agreement with LS Power covered projects expected to add about 2 gigawatts of transmission capacity across the region. (sanjoseca.gov) That wider figure reflects multiple linked projects, not just the downtown San Jose hub at Station B. ### Who approved it, and what are local officials getting in return? The City of San Jose approved a franchise agreement with LS Power on March 24 to allow construction of the transmission projects in city rights-of-way. The city said the work includes a 12-mile underground power line along Monterey Road to downtown San Jose and about two miles of additional power lines in north San Jose along Los Esteros Road. (prnewswire.com) TD World, citing the city agreement, reported that LS Power will also install about three miles of shadow conduit that San Jose could use later for fiber-optic cable. (enr.com) LS Power said the broader Bay Area projects are expected to create about 300 union construction jobs and more than $650 million in local and state tax revenue over coming decades. ### What happens next, and when is the power hub supposed to be online? March 24 city materials said construction would begin in spring 2026 and be completed by December 2028. (sanjoseca.gov) California ISO said when it selected LS Power Grid California in March 2023 that the expected in-service date for the San Jose-area projects was June 2028, though later city materials describe the broader construction schedule running through the end of 2028. April 17 brought another related award from California ISO, which selected an LS Power affiliate to build a new 7-mile underground 230-kV line connecting Silicon Valley Power’s Northern Receiving Station to PG&E’s San Jose B substation. (tdworld.com) LS Power said that line will build on the Power Santa Clara Valley and Power the South Bay projects, which it expects online in 2028. (lspower.com) (sanjoseca.gov)