BP and the International Energy Agency (IEA) measure the contribution of renewables to the global energy mix in terms of primary energy consumed while the World Bank estimates it in terms of final energy consumed. All three give different results, with BP estimating a total renewables contribution of 9.5% in 2015 compared to IEA’s 13.7% and the World Bank’s 18.1%. The BP/IEA differences become larger when contributions are segregated by source (BP estimates almost three times as much energy from hydro as as IEA and IEA estimates four times as much energy from “other renewables” as BP). This post documents these discrepancies while making no attempt to say who is right and who is wrong – that would have to be the subject of another post. But it does raise the question of whether we really know how large a contribution renewables are making to the world’s energy mix.
The BP and IEA “primary energy” estimates
It’s important to establish exactly what primary energy is before proceeding. Fortunately there is general agreement on how to define it:
OECD: Primary energy consumption refers to the direct use at the source, or supply to users without transformation, of crude energy, that is, energy that has not been subjected to any conversion or transformation process.
United Nations: Primary energy should be used to designate energy from sources that involve only extraction or capture
Wikipedia: Primary energy is an energy form found in nature that has not been subjected to any human engineered conversion or transformation process. It is energy contained in raw fuels, and other forms of energy received as input to a system.
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