Four ways to make solar panels more cost-effective
If you're thinking of installing solar panels to make the most of the potential to generate free electricity for your home, one of the biggest considerations is the cost.
Though the price of solar panels has come down over time, they're still a significant investment. You'll need to weigh up how much you can expect to save on your energy bills compared to the initial outlay.
There are plenty of ways to make the most of your panels, whether it's by cutting the installation costs, boosting your returns or maximising how much free electricity you use – all of which will speed up the return on your investment.
Here are our tips to make solar panels as cost-effective as possible.
Read more: how much do solar panels cost?
1. Look for solar panel grants, deals and discounts
You might be able to get financial help with solar PV panels through one of the following schemes:
- Energy Company Obligation – energy suppliers must fit energy efficient measures in some homes, but it's up to them whether that includes solar panels, so you'll need to check with your supplier. To qualify for funding, you'll need to own your home with an EPC of E, F or G.
- Home Upgrade Grant 2 – provides energy efficiency upgrades (including solar panels) and low-carbon heating to households in England that have a low income (less that £36,000 per year), are off the gas grid and have an EPC between D and G. You have to apply via your Local Authority.
You can use our home energy planning tool to see whether your home would qualify.
If not, keep an eye out for discounts offered by solar panel companies you trust.
Which? members can get a 7.5% discount on solar panels via Heatable, a Which? Trusted Trader approved service. This also covers installation, storage batteries and EV chargers installed at the same time.
Get started and make your home more energy efficient with Which? and Heatable.
2. Find the best Smart Export Guarantee rates
If you're likely to export excess electricity from your solar panels, make sure you get paid a good rate for it.
All the major energy firms have solar export tariffs, many of which are Smart Export Guarantee (SEG) tariffs.
The best pay as much as 40p per kWh you export, while some trail far behind what you would pay your supplier for electricity – so make sure you find a good deal.
Energy firms usually offer the best rates to their own customers and those who buy solar panels from them.
Best solar panel electricity export rates October 2024
We've listed available tariffs that pay at least 15p/kWh of exported electricity.
| Energy supplier and tariff | Who can access it? | Solar export/ SEG rate (per kWh) |
|---|---|---|
| Good Energy Solar Savings Exclusive (12m fixed) | Good Energy customers who have solar panels and a battery installed by Good Energy. | 40p |
| Octopus Energy Flux (variable) | Octopus Energy customers with solar panels and a battery. | 20-28p peak rate between 4-7pm (depending on where you live)* |
| E.ON Next Export Premium (12m fixed) | E.ON Next customers who have solar panels and/ or a battery installed by E.ON Next since 1 January 2024. | 21p |
| EDF Energy Empower Exclusive (12m fixed) | EDF Energy customers who bought solar and/ or a battery through EDF (Contact Solar). | 20p |
| Ovo Energy Solar with Battery Install SEG | Ovo Energy customers who have solar panels and a battery installed by Ovo Energy. | 20p |
| So Energy So Bright (12m fixed) | So Energy installed your solar and battery since 1 September 2023. | 20p |
| British Gas Export and Earn Plus (variable) | British Gas electricity customers. | 15.1p |
Rates correct in October 2024.
* Octopus Energy Flux pays different rates depending on when you export electricity. The best (peak) rate is between 4-7pm. It pays less (c.14p/kWh) during the rest of the day and a lower 'flux' rate (c. 5p/kWh) between 2-5am. It's an import and export tariff, so what you pay to use electricity also varies with these times. Read more information about Octopus Energy Flux.
Other firms that offer solar export tariffs at lower rates include 100Green, Co-op Energy, E (Gas & Electricity), Utilita and Utility Warehouse.
You'll need to have an electricity meter that provides half-hourly readings to get a Smart Export Tariff. Usually, this means a smart meter.
Find out more: the Smart Export Guarantee explained.
3. Make the most of free electricity with or without a solar battery
Adding a battery to store excess electricity is one way to maximise how much of your solar-generated electricity you're able to use, as you can charge it during daylight hours and use the energy in the evening when the sun has gone down. However, batteries are expensive and add considerably to the price of a solar panel system. If you're not sure how much use you'd get from it, you may choose to forgo one.
With or without a battery, when you're choosing a solar tariff, compare how much it will pay you to export electricity with the rates you pay to buy electricity from your supplier.
If you'll be paying more for electricity you use from the grid than the electricity your solar panels send back, then it makes sense to use as much of the power your panels generate as possible.
Try these tips:
- Adapt your daily routine so power-hungry tasks happen when your solar panels are generating most electricity
- Make the most of smart timer switches or delay-start functions on appliances so that they only run when your panels are generating, even if you're not around
- Divert excess electricity from solar panels to an immersion heater, so you can convert your solar electricity to heat energy you'll use overnight (you'll need a specific PV immersion-heater controller).
Interested in a battery as well? Here's what you need to know about solar panel battery storage.
4. Get the right size of solar panel system
Too few solar panels could mean you don't generate enough power to make big savings, while too many might leave you footing an installation bill that's bigger than any savings you'll make back.
Household solar PV systems are usually up to 4kWp. This figure is the maximum output of the system.
An installer should be able to advise on the best size of system for you, based on:
- how much electricity you need to generate (taking into account your household power use, likely efficiency of the system, when you're at home, and whether you're planning to install a battery as well)
- how much space you have on your roof
- your budget
Take a look at their calculations and ask them about any assumptions they've made.
See more buying advice for solar panels.
