Energy Return on Investment
It takes energy to get energy. Drilling a natural gas well, stringing a power line or erecting a wind farm all require energy. One popular measure of how much energy we get for the energy we use in development is called the “Energy Return on Investment.” For each unit of energy spent to develop the following resources, you could get back…
- 10 to 100 units of energy from petroleum
- 70 to 80 units from coal
- 30 to 35 units from wind
- 15 to 20 units from natural gas
- 15 to 20 units from nuclear
- About 5 units from solar PV
- About 5 units from Canadian tar/oil sands
- A bit more than 1 unit from biodiesel or corn ethanol
Note that the source of these calculations is American Scientist: Revisiting the Limits to Growth After Peak Oil (2009)
The U.S. has clearly been spoiled by coal and oil! These energy resources, for all of their other costs and problems, are incredibly dense in energy and have historically been easy to extract. As traditional oil reserves have dwindled and we turn to unconventional formations, the Energy Return on Investment calculation may change.