Solar PV versus Other Energy Sources

Solar PV (Solar Photovoltaics) only generates a small fraction of quoted design output in UK conditions over the course of a yearly cycle.

The chart below is a comparison of various energy generation systems over time, comparing actual performance with designed capability.

Solar Efficiency.jpg

The key facts about Solar PV efficiency are:

  • Solar PV will be available whenever it has power to sell. Solar PV output is very low in the winter months, with the average daily output being around 10% of the peak summer output.

  • Off-shore and on-shore wind will be available when the wind blows. It blows more at sea so the available wind to be captured is greater off-shore and the generators are better.

  • Nuclear will provide some of the baseload, but its output cannot be readily raised and lowered to compensate for changes to output from wind and solar.

  • Gas powered power stations therefore have to be used fill in when solar and wind power output is insufficient to meet the demands of the national grid.

  • Over investment in Solar will result in more gas fired power stations having to be run in the winter when Solar output is consistently low.

Data shows this as a consistent factor over 5 years of monitoring. See this link for full details.