Britain's grid operator is about to nudge households to use appliances when wind and solar are booming. If you've got solar panels and know when they're generating, you're already ahead. Here's how to time it perfectly.
The grid has a new problem: too much clean energy
Britain's electricity system is facing a challenge that would have seemed impossible a decade ago: too much renewable energy.
This spring and summer, the National Energy System Operator (NESO) plans to actively call on households to use more electricity during windows when wind and solar generation outpaces demand. Energy suppliers including Octopus Energy and British Gas have confirmed they'll participate — potentially offering free or heavily discounted electricity during surplus renewable periods.
The logic is simple: when the grid can't absorb all the solar and wind being generated, operators have to pay those farms to switch off. Those constraint payments flow through to everyone's bills. It's far better — cheaper for everyone — to shift household demand to match the supply.
What you're being asked to do
The practical guidance couldn't be more straightforward:
- Dishwasher? Run it at noon on a sunny day, not at 7pm after dinner
- Washing machine? Check the forecast first — a high-sun day means free energy to spare
- EV? Charge between 10am and 3pm when solar generation peaks, not overnight on the standard rate
- Home battery? Let it fill from your panels on a good solar day before drawing from the grid
This is exactly how people on smart tariffs like Intelligent Octopus Go or British Gas PeakSave already think. What's new is that the system operator is now actively managing this at a national level — and the incentives are about to get sharper.
Solar owners are already in pole position
If you have solar panels, you have a natural advantage here. You're generating your own electricity at exactly the times when the grid most wants demand to be high — midday, clear skies, high solar irradiance. Your marginal cost for that power is zero.
The households that will save the most this summer aren't necessarily those with the biggest systems. They're the ones who know when their system is working hardest — and plan their energy use around that window.
Timing is the missing piece
Here's where most solar apps fall short. They tell you what your panels generated yesterday. They show you a graph of last month. What they don't tell you is: tomorrow at 11am, is it worth waiting to run the dishwasher?
That's the specific question Sun Hours answers.
Enter your UK postcode, tell the app your system's best-ever single-day output, and you get a 7-day solar generation forecast personalised to your location and your actual panels — not a generic estimate for a theoretical average roof. When a high-generation day is forecast, you know your free energy window is open. When cloud cover is coming, you know not to wait.
The grid is shifting. Your panels are ready.
The transition happening right now — from "use electricity when you need it" to "use electricity when the sun is shining" — is one of the most practical changes a solar household can make. It doesn't require new hardware. It doesn't require a new tariff. It just requires knowing your forecast.
Britain's renewable energy boom is making free electricity windows more frequent, more predictable, and more valuable. Sun Hours is the simplest way to know when yours is open.
Know exactly when your panels peak
The grid wants you to use electricity when solar is booming. Sun Hours tells you when that is for your specific panels, your postcode, your roof — a 7-day forecast in under a minute.
Get it on Google Play →