If the government has any green credentials left, then there is a reasoned argument about what happens next.
Solar panel (PV or Photo-Voltaic) has been set up and will make an important contribution to the UK’s power needs. Similarly, wind turbines, remembering of course that wind on land is justifiable in terms of sustainability – provided the equipment is well sited, the lifetime energy output is several times the energy input. Except that is for off-shore wind which may never pay for itself. Both of these are dependent on sun and wind which may not yield power some days. Battery storage will change all of that but it is very expensive and likely to remain so for some time to come.
At present, neither contribute to what is called “base load” which is the level of power used day in day out. To contribute to that, we need a source of power which is 24 hour output, every day, rain or shine. So, look at the following figures, accepting that “capacity factor” would be 100 % if the source operated at full capacity for 24/7.
For a 1MW solar PV plant the capacity factor is about 12%. So energy produced per year is 8760 hours * 1MW * 12% = 1051 MWh
For a 1MW AD plant the capacity factor is about 88%. So the energy produced per year is 8760 hours * 1MW * 88% = 7708 MWh.
So AD produces 7 times the energy per MW over solar.
Now, no AD plant should ever be run on a crop grown especially for the purpose using fertilisers (manufactured or organic) that could be used to grow food. However, the muck from dairy and pig farms, and some urban wastes, can be used and the energy would otherwise be lost.
This is a no-brainer and the dairy industry needs help or we will be importing more milk than we already do.
Bill Butterworth 5 May 16