For most UK households, solar batteries make better financial sense than just selling energy back to the grid. Whilst you can earn money through the Smart Export Guarantee, storing your solar energy and using it when electricity prices are highest typically saves you more money long-term.
If you’ve got solar panels or you’re thinking about getting them, you’ve probably wondered what to do with all that extra electricity you generate during sunny days. Should you get a battery storage system to keep that power for later, or just sell it back to the grid and pocket some cash?
It’s a really good question – and the answer might surprise you. Let’s break it down in simple terms.
What Are Your Options?
When your solar panels make more electricity than you’re using (which happens quite often on sunny days), you’ve got two main choices:
Option 1: Get a Solar Battery – Store that extra energy in a battery system at home. You can then use this stored power later when the sun isn’t shining – like in the evening when you’re cooking dinner and watching TV.
Option 2: Sell It Back to the Grid – Send your extra electricity back to the National Grid through something called the Smart Export Guarantee (SEG). Energy companies will pay you for this power.
The Smart Export Guarantee Explained
The Smart Export Guarantee replaced the old Feed-in Tariff scheme in 2020. Here’s how it works:
Energy suppliers with more than 150,000 customers must offer to buy your excess solar electricity. But here’s the catch – the rates vary massively between different companies.
Current rates range from:
- As low as 4p per kWh with some suppliers
- Up to 29p per kWh with Octopus Energy (but only if you’re already their customer)
- Around 12p per kWh with Scottish Power (available to everyone)
To put this in perspective, you’re currently paying about 26p per kWh to buy electricity from the grid under the July 2025 energy price cap.
Why Solar Batteries Often Win
Here’s where the maths gets interesting. Let’s say you generate 10 kWh of excess solar power on a sunny day:
Selling to the grid (SEG):
- You might earn 12p per kWh = £1.20 for your 10 kWh
- Later that evening, you buy 10 kWh back at 26p per kWh = £2.60
- Net cost: £1.40
Using a battery:
- Store the 10 kWh for free (well, after you’ve paid for the battery)
- Use it in the evening instead of buying from the grid
- You save the full 26p per kWh = £2.60 saved
That’s nearly double the benefit!
Real-World Savings
According to recent industry data, a typical UK household with a 4kW solar system and battery can save between £485 and £1,110 per year, depending on their energy usage and local electricity rates.
Without a battery, about half of your solar electricity typically gets exported to the grid rather than used in your home. This is because solar panels produce most of their power during the day when many people are at work and using less electricity.
The Battery Investment
Solar batteries aren’t cheap – they typically cost between £3,000 and £8,000 depending on size. But with current electricity prices, most systems pay for themselves within 10-15 years.
Plus, there are some great incentives right now:
- 0% VAT on solar batteries (until March 2027) – saving you hundreds or even thousands of pounds
- Various tariffs like Octopus Go let you charge your battery with cheap overnight electricity (as low as 7p per kWh)
What About Feed-in Tariff Customers?
If you’ve got an older solar system on the Feed-in Tariff (installed before 2019), good news! You can usually add a battery without affecting your generation payments. You’ll need to tell your FiT provider and use an MCS-certified installer, but you can have the best of both worlds.
Special Tariffs Make Batteries Even Better
Some energy companies now offer special tariffs for battery owners:
- Time-of-use tariffs charge different rates throughout the day
- EV tariffs offer super-cheap overnight electricity (even if you don’t have an electric car)
- You can charge your battery when electricity is cheapest and use it when it’s most expensive
The Environmental Angle
Beyond the money, there’s the green factor. Using a battery means you’re using more of your clean solar electricity instead of buying power that might come from gas power stations. It’s a win for your wallet and the planet.
Making Your Decision
Solar batteries usually make more financial sense than just selling to the grid, especially if:
- You use a lot of electricity in the evenings
- You’re on a time-of-use tariff
- Electricity prices remain high (which they’re expected to for several years)
- You can take advantage of the current 0% VAT rate
The only time selling to the grid might be better is if you can get one of the very highest SEG rates (25p+ per kWh) and your household uses very little electricity in the evenings.
Getting Started
If you’re thinking about a battery system, make sure you:
- Get quotes from MCS-certified installers
- Check what SEG rates are available in your area for comparison
- Consider your household’s energy usage patterns
- Factor in the 0% VAT saving whilst it’s available
The energy landscape is changing fast, and with battery storage systems becoming more affordable and electricity prices staying high, batteries are increasingly the smart choice for UK households.
Want to find out more about how a solar battery system could work for your home? The experts at Greener Homes can help you work out the numbers and find the best solution for your family’s needs.
