Adele Peters, writing for Fast Company:
At a construction site on Google’s new Bay View campus–a few miles from its headquarters in Mountain View, on NASA-owned land near the San Francisco Bay–cranes lift tubing high in the air and drop it into holes that descend 80 feet into the ground. It’s a step that will allow three new office buildings to heat and cool themselves without fossil fuels, setting apart from nearly all existing offices, which use enormous amounts of energy to manage the temperature in their spaces.
The system uses geothermal heat pumps, relying on the steady 65-degree temperature of the ground to absorb and reject heat. Excess heat from the buildings can also be sent into the ground to be stored until it’s needed.
It’s one piece of an overall design for the campus that aims for LEED Platinum certification, the highest level possible in the sustainability rating system for buildings. Outside, 20 acres of open space will be planted with native species. Stormwater will be collected and treated for reuse in on-site ponds. (Materials will be vetted through Google’s healthy materials requirements.) The windows–which fill the space with natural light–are treated with a pattern that helps birds avoid crashing into the glass. The windows can also automatically shade themselves and darken at night to reduce light pollution. Electricity use, as in other Google campuses, will be offset by renewable energy. By using heat pumps, the company will reduce its carbon footprint even further.
Kudos to Google for making sustainability, resilience and building performance such high priorities in their building program. By the numbers:
- Heat pumps will provide 95% of cooling for the buildings, the other 5% will be made up by a cooling tower
- Ground temperature at the site tends to stay around 65 degrees, but by concentrating heat from the pumps, the interior temperature can be raised
- 2,500 of 4,500 of the piles supporting the foundation will serve a dual purpose as “energy piles”
- To pull this feat off will require 69 miles of tubing, making it the largest heat pump system in North America