Geothermal heating and cooling: Renewable energy’s hidden gem
Yale Climate Connections reports:
Often described as a giant tower of Jenga blocks, Boston University’s Center for Computing and Data Sciences shows no outward signs of leading the race to sustainable energy design. No rooftop wind turbines grace its heights; no solar panels are mounted on the multiple roof decks jutting out from the building’s core.
What makes this building unique lies deep underground, where water circulating through 31 geothermal boreholes will supply 90 percent of its heating and cooling needs when the building opens, as scheduled for later this year. Through a process called geothermal heat exchange, water pumped from 1,500 feet underground will draw upon the near-constant temperature that prevails beneath the earth’s surface – 50 to 60 degrees Fahrenheit year-round. Even on the coldest New England days, water prewarmed by the earth will be circulated through heat pumps that will further raise its temperature to deliver heat where needed. On warmer days or in heavily occupied spaces where heat builds up even in winter, the heat exchangers will draw on the earth’s cooler temperature to provide air conditioning.
Dennis Carlberg, associate vice president for university sustainability, was a key player in preparing BU’s Climate Action Plan, which set 2040 as the target date for achieving net carbon neutrality. That goal is to be met by phasing out gas-fueled heating systems, stepping-up energy efficiency, and investing in on-campus renewable energy sources like the data center’s geothermal plant. The university already draws its electricity from renewable energy, via a power purchase agreement with a South Dakota wind farm. [Continue reading…]