Beware: harmonised values for the efficiency of electricity or heat production ignore end-use efficiency https://t.co/F5fTlhBvEN
— Leonardo ENERGY (@LeonardoENERGY) December 22, 2015
Those values are useful to compare the energy efficiency of a cogeneration system with that of separate generation. But seen from a distance, aren’t they relics from another era? If you exchange an electricity grid connection and a natural gas boiler for a solar PV panel generating the electricity for both your house and your heat pump, isn’t that also a cogeneration system? Moreover, one with infinite efficiency? That is, if you are going off-grid, which is unlikely, because you will have difficulty to match supply and demand.
This brings us to another weakness of those efficiency calculations: they don’t take the time of electricity and heat production into account, while in fact both vary considerably in value over time.