PORTLAND — Drivers who use a new parking lot at the Portland International Jetport won’t notice, but their vehicles will be atop more than 11 miles of plastic tubing.
If they could slice open the earth, they would see 120 loops extending 500 feet into bedrock. And if they could peer through the tubing, they would see fluid circulating at 500 gallons a minute.
Drill rigs will run every day for the next month to turn the land under the new parking lot into a giant heat exchanger. The fluid will absorb some of the earth’s stored heat in winter and help warm a new addition at the jetport. The process will be reversed in summer, with heat being dumped into the cooler earth.
When the jetport’s $75 million expansion opens in 2012, it will be heated and cooled by Maine’s largest geothermal system. The system is expected to cut the amount of oil that would otherwise be used for the new terminal by 90 percent — nearly 102,000 gallons a year.
Click for the rest of the story by Tux Turkel in the Portland Press Herald.