Putting Waste Heat To Use

I was standing next to the external vent of our gas heater a while back and noticed there was an awful lot of heat issuing forth; heat that would have been better off inside – without the carbon monoxide of course.

When we think of waste, what usually springs to mind is tangible waste – but one of the biggest waste products of our society is heat. For example, the combustion engine of a car is, even now, terribly inefficient – so much energy is lost as waste heat rather than being used for mechanical work.

Another example is the incandescent light bulb, currently being phased out in many countries. Around 90% of the electricity consumed by an incandescent light bulb is emitted as heat.

I’ve often also wondered if all the heat generated by our machines and gizmos is a contributor to climate change.

What if we could capture some of this waste heat and put it to use?

It is already happening to a degree, with some factories capturing heat and recycling it for manufacturing purposes or to heat offices.

New technology is also being developed at Oregon State University to capture and use waste heat from cars and diesel generators. The “thermally activated cooling system” prototype is converting 80 percent of every kilowatt of waste heat into a kilowatt of cooling capability. With air-conditioning systems in vehicles stealing from a vehicle’s power (and therefore gas), such a system might not only help address the heat issue, but crude oil consumption as well.

The same system when applied to electricity generation only achieves around 15-20 percent, but the researchers point out it’s better than wasting the energy potential of all of the heat.

The system could be scaled up for factories and also be incorporated in clean energy technologies, such as solar or geothermal.

You can learn more about Oregon State University’s efforts in putting waste heat to work here.