CORRECTION: I apologise for my post on this topic last week. It contained errors.
The table compares environmental warming by a coal station, with a solar panel and a wind turbine, which have equal capacity to convert and transfer electrical energy.
All input energy ends up in the environment, whether absorbed, converted or used.
Energy conversion efficiency E is electrical output/total energy input.
Different energy sources and technologies can be compared with equal electricity output as environmental energy input, or warming, in the table below. Relative environmental warming per unit of electricity produced is the reciprocal of conversion efficiency 1/E. It is ‘inefficiency’ of conversion, or input for output.
After subtracting 10% for reflection due to albedo or whiteness of a panel, typically 15-30% of incident solar energy is converted (0.15-0.30).
* Environment warming would be reduced when the solar panel is installed on a roof above a cooled interior.
Assume efficiency of rotary multi-blade turbine is 30% or 0.30.
Assume station thermal efficiency = 40% or 0.40
Coal would have a 25% lower environment warming effect (3.33-2.50)/3.33 X 100. A renewable energy technology could warm the environment more than coal. A technology of lower thermal efficiency is more thermally polluting. It is one of several important factors such as cost to be considered before installing it to replace a more efficient technology.
Renewal of energy input is ultimately from the Sun, for solar and wind, or by combusting coal. The heat flows from hot to cold, cooling down to ambient temperature, ending up as heat warming the environment as entropy: heat that cannot be used. For technologies having low efficiency, the amount of ambient warming is significant. This thermal pollution could be sufficient to disadvantage individuals of many species, locally and globally.
No amount of warming has been included from an Enhanced Greenhouse Effect, due to CO2 and CH4. I am not convinced that the postulated mechanism exists and I would need a method I can use to calculate any effect.
It is claimed burning fossil fuels to produce electricity or heat is responsible for roughly half of global warming (Google, April 13, 2014). Installing solar panels and erecting wind turbines to replace coal may not reduce warming and could increase it.