Can I switch my supplier if I have solar panels?

Introduction

Solar panels are a common sight on homes across the UK. The SEG rules explained in this guide apply in Great Britain; Northern Ireland has separate arrangements. They offer a clear way to cut your electricity bills by generating your own power, and they give you the chance to earn money by selling any surplus energy back to the national grid. With manufacturing costs dropping over the last decade, they have become a more viable long-term investment for many households. The number of homes with solar panels is only going to grow. Under the Future Homes Standard, which came into force in England on 24 March 2027, most new homes will include solar panels, subject to limited exceptions and transitional arrangements.^[1]

However, adding solar panels to your home changes your relationship with your energy supplier. You are no longer just a customer buying electricity; you are also a small-scale generator selling it. This dual relationship often leads to confusion when it comes to switching suppliers. Many households put off looking for a cheaper energy deal because they worry it will disrupt their solar payments, or they assume they are locked in with the company that installed their system.

The short answer is that you are completely free to switch your energy supplier. You can change the company you buy your electricity from as often as you like, just as you would without solar panels. You are also free to choose a different company to buy your excess solar energy. However, the energy market has changed significantly in recent years. While you can separate the two services, doing so often comes with a hidden financial cost. To make the most of your solar panels, you need to understand how modern export tariffs work and how they tie you to your main energy supplier.

How solar panels change your energy bills

Before looking at how to switch suppliers, it helps to understand exactly how solar panels interact with your home and the national grid. When you install solar panels, your home effectively has two streams of electricity to manage: import and export. Import is the electricity you buy from your energy supplier to run your home when your panels are not generating enough power, such as at night or during heavy use. Export is the surplus electricity your panels generate that you do not use, which is sent out to the national grid.

Your home will always use the free electricity generated by your solar panels first. If you turn on the washing machine on a sunny afternoon, the power comes directly from your roof. You only start importing paid electricity from your supplier when your household demand exceeds what the panels can produce. This immediate self-consumption is where the bulk of your savings come from, as every unit of energy you generate and use is a unit you do not have to buy at full price.

The second part of the equation is your export. On a bright day, your panels will likely generate more electricity than your home needs at that exact moment. This excess power flows out of your home and into the grid. To get paid for this surplus, you need an export tariff. This is a separate agreement from your standard energy tariff, and it pays you a set rate for every unit (measured in kWh) that you send away.

This setup means you have two different contracts to think about. You have an import contract, where you pay the supplier a unit rate and a standing charge, and an export contract, where the supplier pays you a unit rate for your surplus. Because these are technically two separate agreements, the rules allow you to hold them with two completely different companies. You could buy your electricity from one supplier and sell your surplus to another. However, as the market has developed, suppliers have found ways to link these two contracts to encourage you to keep both services with them.

The Smart Export Guarantee (SEG) explained

If you have solar panels installed from 2020 onwards, you may be eligible to be paid for exported surplus energy through the Smart Export Guarantee (SEG), provided you meet the supplier's requirements and sign up for a tariff. Launched by the government and Ofgem in January 2020, the SEG replaced the older subsidy schemes and introduced a more market-driven approach to solar payments. Under the SEG, all licensed energy suppliers with more than 150,000 customers are legally required to offer an export tariff to small-scale generators.^[1][2]

The most important rule of the SEG is that suppliers are free to set their own export rates. The only legal requirement is that the rate must be greater than zero. This is a major shift from previous schemes where the government set a fixed, guaranteed rate for everyone. Because suppliers decide how much they want to pay, the SEG has created a highly competitive market for export tariffs, with rates varying wildly from one company to the next.

To qualify for an SEG tariff, you need either a smart meter or a compliant export meter capable of half-hourly readings. Depending on the supplier's terms, readings may be collected automatically or submitted manually. You are paid for the electricity you export to the grid. It is also important to clear up a common misconception: under the SEG, you are only paid for the surplus energy you export. You are not paid for the energy you generate and use yourself.

You do not have to sell your energy to the company that installed your solar panels. You can apply for an SEG tariff with an SEG licensee; other licensed suppliers may also choose to offer export payments. However, some energy companies offer much higher export rates if you choose to use their own engineers to install the system. This is one of the many ways suppliers use export rates to build loyalty and bundle their services together.

The hidden cost of switching: Tied vs standalone tariffs

While you are entirely free to have your energy supply handled by one company and your SEG payments handled by another, it is rarely the best financial choice. This is the central trade-off you must consider when looking to switch suppliers. Energy companies want your import business, as that is where they make their reliable revenue. To attract and keep solar panel owners, suppliers divide their export tariffs into two categories: tied (exclusive) tariffs and standalone tariffs.

A tied export tariff is only available to customers who also buy their household electricity from that specific supplier. In 2026, the most lucrative SEG rates on the market are almost all tied tariffs. Suppliers such as Octopus, Good Energy, OVO, and ScottishPower reserve their highest rates for their own import customers. These exclusive rates typically pay between 15p and 25p per kWh for your exported energy. Some of the absolute highest rates may also require you to have bought the solar panels directly from the supplier or hold a specific type of smart tariff.

A standalone export tariff is open to anyone, regardless of who supplies their household electricity. If you choose to buy your energy from Supplier A, but want to sell your solar energy to Supplier B, you will be placed on Supplier B's standalone rate. Because suppliers have no incentive to reward customers who buy their energy elsewhere, standalone rates are much lower. They generally pay a basic rate of around 3p to 5p per kWh.

This creates a clear penalty for splitting your services. If you are currently with a supplier offering a generous 20p tied export rate, and you decide to switch your import supply to a different company to save money on your standard energy bill, your old supplier will drop you from their premium export tier. You will be moved onto their basic standalone rate, or you will have to apply for a standalone rate with your new supplier. Either way, your export earnings will plummet.

How to calculate if a switch is worth it

Because of the huge gap between tied and standalone export rates, you cannot just look at the cost of the electricity you buy when comparing energy deals. You have to look at the entire package. You must calculate whether a cheaper import tariff saves you enough money to offset a massive drop in your export earnings. This requires working out your 'net bill' — the total cost of the energy you buy, minus the total income from the energy you sell.

To see how this works in practice, consider a typical home that exports 1,000 kWh of solar energy a year. On a tied export rate of 20p per kWh, that household earns £200 a year. If they switch their import supplier to get a cheaper standard energy deal, they will lose that tied rate and drop to a standalone rate of perhaps 4p per kWh. At 4p, their 1,000 kWh of export only earns them £40 a year. That is a loss of £160 in export income. For the switch to make financial sense, the new import tariff must save them more than £160 a year compared to their current supplier. If the new deal only saves them £100, the switch will leave them £60 worse off overall.

Working out your net bill takes a little time, but it is the only reliable way to compare the market when you have solar panels. You will need a recent energy bill or access to your smart meter data to find your annual figures. Follow these steps to compare your current setup against a new deal.

What if you are on the old Feed-in Tariff (FIT)?

The rules are entirely different if you installed your solar panels several years ago and receive payments through the Feed-in Tariff (FIT). The FIT was the government's original subsidy scheme for solar panels, and it officially closed to new applicants in March 2019. If you are already on the scheme, your contract is protected. FIT support is typically payable for 20 years from your installation's eligibility date. Because the scheme ended in 2019, the very last FIT payments will end in 2039.^[1][2][3]

The FIT operates differently from the modern SEG. Under the FIT, you are paid for every unit of electricity your panels generate, regardless of whether you use it in your home or export it to the grid. On top of this generation tariff, you also receive a separate export payment for the surplus energy you send away. For most older systems without a smart meter, this export amount is simply estimated at 50% of your total generation.

If you are on the FIT, switching your energy supplier is much simpler and carries no hidden penalties. Because the FIT tariff basis was set by the government, switching FIT licensee does not change the tariff you are eligible for, although rates are adjusted annually for inflation. Your energy provider acts as a FIT licensee, administering the payments on behalf of the scheme. If you switch the supplier you buy your electricity from, you can either leave your FIT account with your old supplier, or transfer it to the new one. Either way, switching FIT licensee does not alter the tariff you are eligible for, although FIT rates are adjusted annually for inflation. You are free to shop around for the cheapest import tariff on the market without worrying about losing your export income.

Solar panel costs and savings in 2026

If you are considering moving to a new house and installing solar panels, or you are looking at upgrading your current setup, it helps to know the current market rates. While the global cost of manufacturing the panels themselves has dropped significantly, the final price you pay for an installation in the UK has plateaued or even risen slightly in recent years. This is largely due to high shipping costs from Asia, alongside increased local expenses for labour and scaffolding.

In 2026, the average cost of a standard 4kW solar panel system, which is typically suited for a standard three-bedroom house, sits between £6,500 and £8,500. If you have a larger property and need a 5kW system, you can expect to pay around £9,000 to £11,000. These figures cover the panels, the inverter, the scaffolding, and the labour required to get the system up and running safely.^[1]

The return on this investment depends heavily on how much of the generated energy you consume yourself, and which export tariff you secure. Annual energy bill savings typically range from £150 for lighter users on poor export rates, right up to £1,200 for heavy users who secure a premium tied tariff and time their usage well. Based on these savings, the break-even point for a standard solar investment is generally estimated at around 8 to 15 years.

Adding battery storage to the mix

Many households are now choosing to install a home battery alongside their solar panels. Adding battery storage typically adds an extra £2,500 to £10,000 to your total installation cost, depending on the capacity of the unit. A battery changes the way you interact with both your supplier and the grid, and it can significantly alter the maths when you are deciding whether to switch tariffs.

Without a battery, any solar energy you do not use instantly is sent to the grid. With a battery, that surplus energy is stored in your home to be used later, such as during the evening peak when electricity is most expensive. This greatly increases your self-consumption, meaning you buy far less energy from your supplier. However, it also means you have far less surplus energy to export.

Because a battery reduces your export volume, the exact rate you get paid for exporting becomes slightly less critical to your overall finances. If you are only exporting a tiny amount of electricity each year, the difference between a 20p tied rate and a 4p standalone rate might only amount to a few pounds a month. In this scenario, you have much more freedom to shop around and switch to a supplier offering a very cheap import tariff, as the savings on the energy you buy will easily outweigh the small loss in export earnings.