Octopus, the UK’s largest onshore renewables investor and owner of more than 1GW of utility-scale solar in the UK, has said that National Grid’s warnings of ‘summer low’ demand challenges are ringing true as the country continues to bask in a heatwave.
Temperatures have soared in recent weeks and most areas of the country have not experienced rain since early June.
Generation from the country’s circa 13GW of operational solar PV capacity has responded in kind. In late June solar provided nearly 28% of the country’s total demand for a period around lunchtime, enough to see solar become the country’s largest power generator.
Data compiled by Sheffield Solar’s PV_Live tool revealed that around 1.77TWh of solar power was produced in May, a new record, with June and July widely expected to have provided generation approaching that limit, albeit slightly reduced as temperatures and humidity will have reduced operational efficiencies.
But Octopus revealed earlier this week that its portfolio of sites generated 155GWh of solar throughout the 30-day period ending 22 July 2018, nearly 20% ahead of forecast.
“You often hear of record national outputs from wind farms based on our much loved British climate, but the same can be said for UK solar power during sunny spells like the one we are currently enjoying. This is a perfect example of how important it is to develop a truly diversified energy mix,” Matt Setchell, head of Octopus’ energy investments team, said.
But while the energy sector has basked in the sunshine, it has provided network operators with their own challenges.
Much of the UK’s solar generation sits on the distribution network rather than the transmission network. As a result, solar generation is seen as a dip in transmission system demand and therefore considered more difficult to accurately meter.
This, Setchell said, required excess amounts of unused baseload power – provided by traditional gensets connected to the transmission system – to be adequately managed.
National Grid warned in April’s Summer Outlook document that inflexible generator were at risk of a summer of curtailments, forced to make way for soaring solar generation that the TSO was expecting.
Setchell considers that those warnings have proven to ring true.
“As part of our holistic view of the energy system, Octopus has been also investing in smart technology to help enable demand side management and build a more resilient network. It’s no longer just about how much energy you produce, it’s about how you use this energy effectively and at the lowest possible cost to the consumer,” he added.