San Jose residential tower
Designing a 25-story all-electric residential tower as an active, grid-responsive part of California’s energy system.
The challenge
The redevelopment of an existing San Jose property created an opportunity to design the energy infrastructure from the ground up. The planned 531,557-square-foot development would introduce 388 residential units with substantial year-round demand for cooling, ventilation and domestic hot water. Meeting San Jose’s all-electric requirements was only the starting point. The energy concept needed to limit the tower’s grid dependence by recovering energy within the building and shifting demand to better align with grid conditions.
The system approach
URBS developed an integrated all-electric concept centered on a shared hydronic network and multi-stage heat-pump plant. The system can produce heating and cooling simultaneously, allowing thermal energy to move between building uses before being rejected. Energy recovered from wastewater, ventilation exhaust and cooling is reused to serve domestic hot water and other thermal loads. Geothermal boreholes and ambient air provide additional energy sources and sinks, while water tanks and the building’s pool provide thermal storage. Rooftop solar and battery storage complement the thermal system by reducing peaks and shifting electricity use. Together, the thermal and electrical strategies allow the tower to respond to grid conditions and time-of-use pricing rather than operating as a fixed load.