Octopus Energy's "free electricity" eclipse offer explained
When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.
Ahead of today's solar eclipse — which is due to appear in the UK between 6pm and 8pm on Wednesday, August 12 — Octopus Energy is asking us to avoid using unnecessary electricity as much as possible during the natural blackout. In exchange, it’ll give customers who are signed up to its rewards program a free hour of electricity to use next weekend.
Octopus argues that the eclipse will greatly reduce Britain’s solar power generation. At the same time, because of an incoming heatwave, we’ll likely be using a lot more power running refrigerators, air conditioning and fans that put an increased strain on our power grid.
If Britons are more conservative with their power consumption — especially between 6pm and 8pm when the eclipse is scheduled — and better leverage the 13GW of “untapped” flexible capacity brought about by smart appliances, EVs and home batteries, Octopus says we could reduce the need for gas-powered generators.
But do we really need to watch our electricity use this evening — and if so, why? Here's what university professors and other experts say.
Energy experts are a divided on exactly how much the eclipse will hit the UK's solar energy supply — but they all agree that drastically changing your electricity habits this evening isn't necessary.
"The dip in supply from solar during the eclipse could be significant, and the electricity supply companies are right to be cautious," said Chris Sansom (Professor of Concentrating Solar Power at the University of Derby).
"They have a right to be concerned because quite a significant proportion of our energy comes from solar," he added, sharing the screenshot below from yesterday at 6pm showing that 17.4% of our electricity was coming from solar.
Sign up for breaking news, reviews, opinion, top tech deals, and more.
However, in the grand scheme, the amount of solar power lost to the eclipse won't enormous be due to the time of day.
Across Europe, grid operators expect a 9.7GW power generation reduction during the eclipse, while the UK’s National Energy System Operator (NESO), the body in charge of managing our electricity system, predicts we’ll lose around 0.7GW of power output that would have been generated, though it adds the loss could be as much as 1.3GW (via the Financial Times).
By 7pm, the darkest point of the eclipse, solar energy will be supplying less than 3% of our electricity demand, says Peter Connor (Associate Professor of Sustainable Energy Policy at the University of Exeter). "This drop off happens every night in the summer, and largely is met by turning on more gas power plants, which is what will happen on Wednesday night," he said.
So should we cut our electricity use? "There is no real need in terms of grid stability — if there was a possible problem it would be NESO, the system operator that would be trying to take action," added Peter Connor.
The trade association Solar Energy UK, which represents hundreds of solar photovoltaic and battery storage companies, largely agrees. "The impact of the eclipse will be limited and is well planned for — comparable to a gas or nuclear power station being shut down for regular maintenance," a spokesperson said. "As the eclipse will occur in the evening, only a limited amount of power will be lost — in the order of 0.5-0.8GW at peak," it added.
