Better All The Time Thanksgiving Dispatch #6
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"Black Friday" has arrived, the most media-covered shopping day of the year, if not actually the biggest. If you've decided to start your holiday shopping today, don't worry that you'll be missing anything. We'll keep tracking the good news, and it will be here for you when you get back from the mall.
Item 6
How
Geothermal Heat Pumps Could Power the Future
A geothermal heat pump (sometimes called a ground source heat pump) can work anywhere.
If you've ever touched the tubes on the back of a working refrigerator, you know that it is pulling heat from the inside and radiating it to the rest of the kitchen.
A heat pump is like a refrigerator run backwards. It pulls heat from outdoors (as if it were trying to cool the outside) and releases it indoors.
In both a fridge and a heat pump, a system of tubes circulates a refrigerant fluid that becomes hot when compressed and cold when expanded.
To heat a home, the hot compressed fluid is typically passed through a heat exchanger that warms the air that feeds into a duct system. This "spent" fluid is then cooled through expansion and brought into contact with a ground source, so it can "recharge" with heat.
Although pumping the fluid requires electricity, a geothermal heat pump is more efficient than any alternative heating system. In fact, current models can produce as much as 4 kilowatts of heat for every 1 kilowatt of electricity. This is because they are not generating heat, but rather moving it from the outside.
The Good News
These systems can work anywhere. (Well, okay, the linked article says "anywhere but Antarctic.") To heat an average-sized house, you need a hole that extends 150-200 feet into the ground or, if you have some land available, a small network of horizontal pipes buried about six feet deep. Geothermal systems can provide air conditioning, too.
Such systems will initially be more expensive than conventional heating systems, but they will pay for themselves with the savings they provide. Imagine a hybrid system in which a non-carbon-emitting power source such as solar, wind, or nuclear provides the electricity, and then geothermal provides the heat or cooling. Very nice!
Live to see it!
