The weekend the grid paid you to use electricity

Here’s something that still sounds made up: this Saturday, for most of the daylight hours, electricity didn’t just get cheap — it went negative. As in, the wholesale market would have paid you to switch the kettle on.

It’s not a glitch and it’s not a one-off marketing gimmick. It’s where the energy market is heading, and days like this are becoming more common. We pulled the actual published figures so you can see exactly what happened, in every corner of the country — and more importantly, what it means for your bills.

What actually happened on Saturday?

Britain woke up to a bright, breezy June Saturday. Solar panels were pumping out power all over the country, the wind was turning the turbines, and demand was low because it’s the weekend and nobody’s at work. When the grid has far more clean electricity than it can use, the wholesale price falls through the floor — and sometimes straight past zero.

On the Octopus Agile tariff, which re-prices every half hour to follow that wholesale market, the national average rate told three very different stories across the day:

Look at the gap. The cheapest half hour of the day was worth nearly 30p a unit less than the most expensive one. Same electricity, same socket — just a different time of day. The national average worked out at 4.8p across the whole day, but that average hides the real story: a deeply negative middle and a sharp, expensive evening.

A negative unit rate doesn’t usually land as cash in your bank account — it means the energy itself costs nothing and the market is paying suppliers to soak up the excess. On the right tariff and setup, you benefit by running everything you can during that window: the dishwasher, the washing machine, the EV, the hot water, the battery charging up. The trick is having something that can actually absorb all that cheap power.

Was it the same everywhere in the UK?

Not quite — and this is the part most posts skip. The UK is carved into 14 electricity pricing regions, each with its own local network and its own Agile prices. They all followed the same shape on Saturday, but the highs and lows varied by region depending on local grid conditions.

Here’s the genuine half-hourly data for all 14 regions for Saturday 13 June 2026, pulled directly from Octopus Energy’s published Agile pricing — the original source, not a second-hand summary — and averaged across each region. Every figure includes VAT.

Across all regions the national picture was a low of -8.9p, a high of 20.4p, a day average of 4.8p, and a 4–7pm peak averaging 14.5p.

A few things jump out. Northern Scotland had the wildest ride, dropping to -9.5p before climbing all the way to 23.2p later on. London had the gentlest evening peak at around 13.8p. But wherever you are, the headline’s the same: a long, deeply cheap daytime window, then a costly evening.

I’m not on Agile — does any of this matter to me?

It does, because Agile isn’t the only tariff that moves with the market. These are all time-of-use tariffs — if you want the full rundown of how they work, we’ve explained them properly in a separate guide. EDF’s FreePhase tariff does the same thing in a simpler way. Instead of 48 prices a day, it groups the day into three colour-coded bands, and the dynamic version updates those bands daily using the same wholesale data that drives Agile.

On Saturday, EDF’s published FreePhase band prices looked like this nationally:

That amber daytime band averaging just 0.7p tells the same story as the Agile data: the middle of the day was practically free. EDF also flags genuine free-electricity periods when prices go negative, and both versions of FreePhase carry a 75p-per-unit price ceiling for peace of mind. Different tariff, same underlying market, same opportunity.

And this is the bigger point. Whether it’s Octopus Agile, EDF FreePhase, or one of the other smart tariffs, the grid is increasingly rewarding people who can shift their energy use to when clean power is abundant. The question is no longer “is the cheap energy there?” — it clearly is. The question is whether your home can grab it.

So how do you actually cash in on free electricity?

Here’s the catch. On a normal Saturday, could your house genuinely use enough power between 7am and 4pm to make the most of a -8.9p rate? For most homes, no. You’re out, or you’re pottering about using a few hundred watts. The cheap window comes and goes, and then you pay full whack at 8pm when you actually need it.

That’s exactly the gap that solar and battery storage close.

Solar panels

On a day like Saturday, your own solar panels are generating free power exactly when the grid is awash with it. You use your own first, and what you don’t use you can export to the grid for a payment.

Battery storage

This is the hero. A home battery hoovers up that cheap or negative-priced energy through the day, then powers your home through the 20p evening peak. You shift the whole household onto the cheap stuff.

EV charging

A smart EV charger schedules your car to fill up during the cheapest window. Charging an EV on a near-free daytime rate — or straight from your own solar and battery — is about as cheap as motoring gets.

Heat pumps

A heat pump can heat your water and warm the house during cheap hours, storing that warmth for later. Run it on near-free power and your heating bill barely registers.

Put it together and you stop playing the tariff game

Solar makes your own power. A battery banks the cheap and free grid energy. Your EV and heat pump soak up the rest — and if your car supports it, vehicle-to-home charging can even feed that stored energy back into the house at peak time. Instead of bracing for the tea-time peak, you sail straight through it on energy you stored when it cost next to nothing — or nothing at all. That’s how a day like Saturday turns from a headline into money off your bill.

We’re based in the North East and we install across the region, from Berwick down to Middlesbrough. We design solar-and-battery systems specifically around how you use energy and which tariff suits you — so the kit is sized to actually capture days like this, not just to look good on a quote. Try our solar and battery calculator for a quick estimate, or have a chat with us and we’ll show you the numbers for your home.

Saturday won’t be the last day like this. As more solar and wind come onto the grid, these cheap and negative windows are only going to get more frequent. The homes that benefit are the ones set up to grab the energy when it’s practically being given away — and that’s a setup we can build for you.

Book a free survey → and we’ll size a system around your usage and tariff, so you’re ready for the next day the grid gives it away.

Sources & credit. The Octopus Agile figures on this page were pulled directly from Octopus Energy’s published half-hourly Agile pricing and averaged across all 14 UK regions; the EDF FreePhase band prices are EDF’s published national figures for the day. Hat-tip to Mick Wall at Energy Stats UK, who flagged this Saturday’s negative pricing and tracks live Agile and FreePhase rates for every UK region.

Related: Best time-of-use tariff UK 2026 · Time-of-use tariffs explained · Best home battery UK 2026