It can be confusing if your Agile prices spike during a heatwave, or you get called to Power Down in a Saving Sessions. We get it: it can instinctively feel like a scorching, sunny day should mean endless cheap solar energy, but the reality is a bit more complex. The wholesale electricity market is a balancing act of the entire energy system. Smart tech and saving sessions can really help out, so plug in, charge up, and do the housework while it's sunny, and avoid the 4-7pm peak. Read on to find out why.
In yesterday's heat, we generated heaps of wonderful solar power – so much we could export some of it overseas – but by the evening, all the fans and AC meant we were caught short, had to cancel some of that export and also import more power back from Europe (at vast expense).
First, get the word straight from Greg Jackson our Founder on X.
Extreme heatwaves put pressure on the grid in a few different ways:
Higher demand: Millions of people across the UK and Europe crank up air conditioning units and desk fans to stay cool and fridges are working double time. This pushes up power usage.
Low wind: Summer heatwaves often come with very still air. Right now (June 2026), wind generation is hovering at around 15% of our energy mix, compared to a 12-month average of about 30%.
Fewer imports: We often rely on interconnectors to bring in power from Europe. However, countries like France often sweat through the same heatwaves as us, meaning they use their own energy rather than sending it over to us.
Does hot weather actually make the energy grid less efficient?
Yes, it does. Extreme temperatures hamper the hardware that generates and transports our electricity.
Solar panels: As the silicon inside a solar cell heats up, its electrical properties change (specifically, the voltage drops). This means the panel converts slightly less sunlight into usable electricity when it’s hot.
Power stations: Thermal plants (like gas and nuclear) create electricity by boiling water into steam, and then cooling it back down. This relies on a stark temperature difference. During a heatwave, the rivers or seas they use for cooling are much warmer than usual, destroying that temperature gap and making the whole thermodynamic process less efficient.
The power network: The wires and cables that carry electricity across the country suffer in the heat. High temperatures increase the electrical resistance of the metal, meaning more energy is wasted as heat along the journey. Plus overhead cables expand and sag when they get too hot, so grid operators can’t push as much power through them (which would heat them up even more) because they need to keep them safely above trees and roads.
How can smart home tech help?
When the grid is strained, the country typically relies on expensive, carbon-heavy gas plants to meet the spike in demand. This is where smart home tech can help to save the day.
Intelligent Octopus Go (EV charging): By simply leaving your car plugged in, you give our smart tech the flexibility to make adjustments to your charging schedule. We can pause your charge when the grid is struggling and automatically resume it when there is greener power available.
Vehicle-to-Grid (V2G Discharging): If your EV and charger support V2G, it goes a step further. Instead of just pausing your charge, your car can actively pump clean energy back into the grid when the system is under the most pressure, getting you paid for helping out when it's needed most.
Home batteries: The same goes for home batteries. With Intelligent Octopus Flux, you give our smart tech the power to optimise your battery for the whole grid. We can discharge it to the grid during peak heatwave demand and then top your battery back up when the strain eases. Or check out Charge Pack, our new smart add-on to Intelligent Octopus Go and other tariffs. It offers another way to get paid for using your battery to ease the strain on the grid.
I don't have an EV or a battery. Can I still help out?
Yes! You don't need smart tech to make a very real difference. When the grid is really sweating, we will trigger a Saving Session. By making small tweaks, like waiting until later in the evening to run your washing machine or dishwasher, you take immediate pressure off the grid, and we'll pay you in Octopoints for every kWH you save.