by Thomas Holdaway, Project Engineer, Catch Energy
For the first time in the history of the UK grid network, electricity demand in the afternoon was lower than the nightly load according to DUKES (Digest of UK Energy Statistics) 2018
What caused this?
The cause of this occurrence is directly linked to the growth of solar PV installations in the UK. Leading up to 2017 enormous growth has been scene in the solar industry with a peak year on year increase in capacity of 86% in 2015. With this increase in solar capacity, overall output during the day has increased dramatically, to the extent that on certain sunny days the increased demand during the afternoon (~5-10MW) is offset by this increased solar production.
Why does this show up as demand and not production?
The UK has no central metering for solar. National Grid and industry statistics on solar output are largely based on reduction in demand estimates. Due to the intermittent nature of solar power, it is consumed as it is generated, though with battery storage this is changing.
So why is this moment quite so significant?
It is one of the first instances of conclusive proof that the UK’s energy demands are shifting. The energy load profiles over the course of a day have remained broadly the same for decades in the UK. Two peaks are seen, one in the morning as people wake up, make breakfast and leave for work, and a second longer, higher peak seen in the evening before people typically head to bed around 11pm. The load in-between these two peaks stays fairly constant, as does the nightly load which is typically considerably lower. Now with solar in the mix that afternoon load reduces dramatically, shifting the emphasis on when the grid is in demand from the afternoon to the peaks and the night-time.
For the National Grid, adapting to this change is a difficult process, generation schedules need to be redrawn and generation supply mapped into the future, critically to ensure grid frequency remains constant. Battery storage helps this process considerably. By storing excess solar during the day, a process called ‘peak shaving’ can be carried out to reduce the morning and evening peaks, thus putting less stress on the grid network whilst also saving the customer money.
At Catch Energy we are helping to facilitate this transition by offering a competitively priced home storage solution which can help customers save up to 70% of their energy bills.