The renewable energy system that powers Stanford University and its hospitals will undergo a major expansion over the next two years to allow it to keep pace with a growing campus and a warming climate while minimizing the risks of building cooling shutoffs like the ones that disrupted teaching and research in summers 2017 and 2019.
As part of the expansion, the Stanford Energy Systems Innovations (SESI) will nearly double its chilled water capacity by adding two new cooling towers that will allow its novel heat recovery chillers to operate when needed, as well as three new permanent chillers and cooling towers and an extra backup chiller in case one of the others is offline. The chillers and cooling towers work in tandem to extract waste heat from buildings. The upgrades will boost SESI’s maximum permanent chilled water capacity to 28,500 tons – or nearly double the summer 2019 capacity of 14,500 tons.
“There are three main drivers of this expansion: campus growth, curtailment risks and climate change. We feel very confident that with this upgrade, SESI will be able to handle predicted energy loads through 2028,” said Jack Cleary, the associate vice president of Land, Buildings and Real Estate (LBRE) at Stanford.
The expansion is expected to cost $85 million and to finish by June 2022, although Cleary notes that delays related to COVID-19 could push that date back by a few months. Fortunately, temporary chilled water capacity installed in June 2020 nearly matches the planned expansion, so there should be no lapse in coverage in the interim.
The decision to expand SESI was based upon a detailed statistical analysis of future campus energy needs, conducted by an advisory committee that included Stanford researchers in disciplines ranging from physics to energy resources engineering. The team considered the possible impact of warming in local weather and developed a model that can be updated based on actual weather trends over the coming years.