The energy profit ratio is
developing as a way of looking at which options are likely to emerge as
replacements for oil. The energy profit ratio looks at the energy output
compared to the energy input that is required to make the energy. There are a
number of assessments of these ratios, which invariably are different based on
what they include or exclude. However the best estimates we have found are set
out in the table below.
Process
Energy Profit Ratios
Non Renewable
Oil and gas (domestic
wellhead)
1940s
Discoveries>100
1970s
Production 23, discoveries 8
Coal (mine mouth)
1950s
80
1970s
30
Oil shale
0.7 to 13.3
Coal liquefaction
0.5 to 8.2
Geopressured gas
1.0 to 5.0
Renewable
Ethanol (sugar cane)
0.8 to 1.7
Ehtanol (corn)
1.3
Ethanol (corn residues)
0.7 to 1.8
Methanol (wood)
2.6
Solar space heat (fossil
back up)
Flat-plate collector
1.9
Concentrating collector
1.6
Electricity Production
Coal
US average
9.0
Western surface coal
No scrubbers
6.0
Scrubbers
2.5
Hydropower
11.2
Nuclear (light water
reactor)
4.0
Solar
Power sateliite
2.0
Power
Tower
4.2
Photovoltaics
17 to 10.0
Geothermal
Liquid dominated
4.0
Hot dry rock
19. To 13
Peter Newman, Tim Beatley, and Heather Boyer | hmboyer@gmail.com
