Energy Values

1. Energy Values

Energy is neither created nor destroyed. Rather, it loses its potential to do work. Humans lower stores of potential when they want work done. A wood burning fire is an example. Fissioning a nucleus is another. Energy loss is usually associated with the outflow of heat.

Energy stores come in many shapes and sizes. As well, we have different methods of applying the energy’s potential. when it comes to providing energy, we aim for a method that provides more than the effort in making its provisions. We can represent this as a ratio. The following table shows some ratios.

Source R3 Energy Ratio.

(output/input)

Input % of
lifetime output
Hydro Uchiyama 1996 50 2.0
Held et al 1977 43 2.3
Quebec Gagnon et al 2002 205 0.5
Nuclear (centrifuge enrichment) see table 1. 59 1.7
PWR/BWR Kivisto 2000 59 1.7
PWR Inst. Policy Science 1977* 46 2.2
BWR Inst. Policy Science 1977* 43 2.3
BWR Uchiyama et al 1991* 47 2.1
Nuclear (diffusion enrichment) see table 1. 21 4.8
PWR/ BWR Held et al 1977 20 5.0
PWR/BWR Kivisto 2000 17 5.8
Uchiyama 1996 24 4.2
PWR Oak Ridge Assoc.Univ. 1976* 15.4 6.5
BWR Oak Ridge Assoc.Univ. 1976* 16.4 6.1
BWR Uchiyama et al 1991* 10.5 9.5
Coal Kivisto 2000 29 3.5
Uchiyama 1996 17 5.9
Uchiyama et al 1991* 16.8 6.0
unscrubbed Gagnon et al 2002 7 14
Kivisto 2000 34 2.9
Natural gas – piped Kivisto 2000 26 3.8
Natural gas – piped 2000 km Gagnon et al 2002 5 20
LNG Uchiyama et al 1991* 5.6 17.9
LNG (57% capacity factor) Uchiyama 1996 6 16.7
Solar Held et al 1997 10.6 9.4
Solar PV rooftop Alsema 2003 12-10 8-10
ground Alsema 2003 7.5 13
amorphous silicon Kivisto 2000 3.7 27
Wind Resource Research Inst.1983* 12 8.3
Uchiyama 1996 6 16.7
Kivisto 2000 34 2.9
Gagnon et al 2002 80 1.3
Aust Wind Energy Assn 2004 50 2.0

* In IAEA 1994, TecDoc 753.
Source is here.
All these ratios come with lots of assumptions and considerations. Compare the above to the following table’s values to see this.
Heinberg in his book “The Party’s Over” provides similar ratios which he defines as net energy. His values (which he attributes to others) follow.

&nbsp Process Energy Profit Ratio
Nonrenewable Oil and gas (domestic wellhead, 1940s) Discoveries > 100
Oil and gas (domestic wellhead, 1970s) Production 23
Coal(mine mouth) 1950s 80
Coal(mine mouth) 1970s 30
Oil shale 0.7 to 13.3
Coal liquefication 0.5 to 8.2
Geopressured gas 1 to 5
Renewable Ethanol (sugarcane) 0.8 to 1.7
Methanol (wood) 2.6
Solar space heat, flat-plate collector 1.9
Electricity Production Coal, US averagetd>

9
Hydropower 11.2
Nuclear (light-water reactor) 4.0
Solar, power tower 4.2

However, these ratios only consider the application of energy by humans to obtain energy for humans. Precious little consideration or value gets considered for any loss of energy capture by autotrophs. A mine lays waste thousands of hectares and may take hundreds to thousands of years to return to a pristine state. The ratios don’t include this consideration.
Fence