Monday, January 04, 2010

“Waste Heat” a Potential Threat to the Climate

A new paper argues that cutting greenhouse gas emissions, switching to nuclear or geothermal power, and even sequestering carbon in the earth won’t stave off massively disruptive climate change. Greenhouse gases are less a threat to stable climate than is the excess heat produced when fuel is burned to create energy, say Swedish researchers Bo Nordell and Bruno Gervet.
About half of the energy that humanity creates becomes waste heat. Depending on the method of energy creation or manner in which it’s used, such as to raise the temperature of water, waste heat can be as high as 70% or 80%. In terms of electricity usage, even extremely efficient devices, appliances, and gadgets give off a lot of warmth in their operation. This is why your laptop needs a fan and why a car that’s been turned off is still hot to the touch after it’s been driven. But most of this excess thermal activity comes from energy generation itself: the burning of fuel to create electricity. It’s commonly believed that this excess heat escapes into space, but that’s only true at very high temperatures, Nordel and Gervet contend. Read Entire Article