Controversies
The concept of emergy has been controversial within several academic communities including ecology, thermodynamics and economy. Emergy theory has been criticized under the assumption that it fosters an energy theory of value to replace other theories of value. This criticism may miss the fact that the goal of emergy evaluations is to provide an "ecocentric" value of systems, processes, and products as opposed to the anthropocentric values of economics. Thus it does not purport to replace economic values but to provide additional information, from a very different point of view, which public policy might benefit from.
While energy quality has been recognized, somewhat, in the energy literature where different forms of fossil energy are expressed in coal or oil equivalents, and some researchers have even expressed electricity in oil equivalents by using 1st law efficiencies, many researchers have been reluctant to accept quality corrections of other forms of energy and resources. The idea that a calorie of sunlight is not equivalent to a calorie of fossil fuel or electricity strikes many as absurd, based on the 1st Law definition of energy units as measures of heat (i.e. Joule's mechanical equivalent of heat). Others have rejected the concept as being impractical since from their perspective it is impossible to quantify the amount of sunlight that is required to produce a quantity of oil. This latter issue results from a concern about the uncertainty involved in such quantification. In combining systems of humanity and nature and evaluating environmental input to economies, mainstream economists criticize the emergy methodology for disregarding market driven values as determined by willingness to pay.
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