Monthly Archives: July 2014

There Ain’t No Such Thing As A Free Lunch

I’ve been thinking lately about the impact of renewable sources of energy. Now please understand that I absolutely favor shifting from dirty, non-renewable energy sources to clean, green, renewables. But at the same time I am also aware that there are environmental impacts of these sources as well. As the Laws of Thermodynamics assure us, there ain’t no such things as a free lunch.

Consider solar energy, for example. A certain amount of energy is transmitted from the sun to the earth at every moment. Some of the energy is reflected back out again, and the rest is absorbed in various ways. Some of the absorbed energy is radiated away, and some stays on earth in various different forms. There is a balance between the energy reaching the earth and the energy leaving the earth, the result of which is a fairly constant ambient temperature. That temperature has been rising as a result of our release of CO2 and other greenhouse gases, but it still represents a balance. 

Solar panels trap some of the incoming energy and convert it to electricty. This conversion of sunlight into electricity will have an impact on the amount of free energy on the earth. The immediate effect of this would be to lower the ambient temperature of the earth, and that seems like a good thing. Right? But has anyone tried to figure out how much electrical energy we would have to remove to have a noticeable impact? Or to lower the ambient temperature enough that we experience a serious decrease in ambient temperature?

But wait. There’s more. A lot of that electricity will be converted into heat. If more of the sun’s energy is being trapped than had been the case previously, then could an initial lowering of absent temperature actually be followed by a net increase?

Or again, we are beginning to remove energy from the wind and even from the tides. But there are plants and animals that depend on the wind and tides for their very existence. At what point would we be doing environmental damage by tapping these resources?

I am sure we are very far from any of these impacts, but aren’t they questions that we should consider? After all, we got into this environmental mess by failing to consider the long term impact of our energy use. Are we willing to risk making the same mistake?