Electricity is a power source that runs the modern world. Meeting the instantaneous power demands of the UK is the responsibility of the National Grid (ELEXON).
The balancing of available energy supply with the instantaneous power demand as logged by ELEXON provides a live snapshot of which fuel type provides the power required needed to match demand. Energy security requires that demand must always be met. I have been monitored ELEXON data since December 2016. Peak demand in general always occurs around 6pm each evening so I use this value to compare the relative importance of different energy sources needed to provide energy security. The values provided by ELEXON are for centrally ‘metered’ power supply and do not include smaller ‘feed-in’ sources. In addition unmetered ‘feed in’ wind farms are estimated to add ~46% to the larger metered wind farms. This correction is applied to the overall results below. Elexon changed format during the winter 20/21 so I missed a couple of months logging before I realised the problem. Despite this the results give a very similar picture to previous years.
The 2 year average contribution for each fuel to peak power are given in the table below below
This result is shown graphically below which compares the peak power(6pm) with the low power demand(4am) . Note how at night the weather dependent wind power increases its percentage as gas is turned down. Nuclear is basically always on and still outperforms wind in both scenarios despite the last operational station being completed in 1995 (Sizewell B).
This analysis shows that it is not feasible to run UK on renewable energy alone. The only realistic zero carbon energy future is one that depends on a steady baseload of nuclear energy. Wind Energy needs a storage method that can iron out large fluctuations and avoid discarding excess power during high wind speeds especially at night. Otherwise we will always depend on Natural Gas as back up for wind lulls as shown below.
Alternative storage for wind energy is pumped hydro, green hydrogen or even green methane. However it is not clear the last two processes are economic.