Solar panel calculator

This solar energy calculator estimates potential payments from the Smart Export Guarantee (SEG). The SEG requires energy suppliers to offer tariffs for the electricity you export to the grid.

Signing up to the SEG isn’t automatic, so you’d need to sign up to the tariff to get payments.

There are a range of solar export tariffs available. Deals may be time limited or have other conditions that you should consider carefully before agreeing to a specific tariff.

Solar Energy UK regularly publishes a league table for the best export tariffs available. We recommend you shop around for the best rate for you.

Our tool uses property details such as:

• size
• insulation
• energy performance certificate (EPC) rating from your home or similar homes.

These details help us estimate how much electricity your home uses and how much solar could save you. 

If we can’t find your home in our database, we can still provide potential savings. But they won’t be specific to your home.  

There are a few reasons why an EPC might not exist. For example, your home could be a new build or a recent conversion. 

If your home doesn’t use electric heating, you can still use the tool. We’ll ask you a few more questions about your home to give you an estimate. 

Otherwise, you can get some general advice on whether solar could work for you by visiting our solar panel guide. An installer can also give you a tailored assessment. 

Yes, you can still use the calculator and tailor the results to your home on the personalisation page.

However, EPC data for Northern Ireland isn’t included in our database. This means we can’t access details about your home, so you’d need to select ‘my address isn’t listed’ and enter your details.

If you have an electrically heated home, see our solar panel guide where we’ve looked at savings for a Belfast home with solar panels.

If you have electric heating, the savings are typically higher than for a non-electrically heated home. An installer can provide a tailored assessment for you.

In some cases, the Distribution Network Operator (DNO) may limit how much electricity you can export. This is usually to protect the grid from overload in areas with high renewable electricity generation. 

You can still install solar panels even if limits apply, but your installer may need to:

• Fit a smaller inverter (a device that converts the electrical current for use and export)
• Fit an export limiter.

This could reduce how much electricity you export and the payments you get. Our tool assumes no export limits, so your actual earnings may differ. 

What should I do?

Ask your installer for advice on whether export limits apply to your system and what that means for your payments. They can check with the DNO and explain your options.  

Our estimates are based on common household electricity use – the everyday appliances most homes have, like: 

• lighting
• fridges and freezers 
• cooking appliances (oven, hob, microwave) 
• laundry appliances (washing machine, tumble dryer) 
• computers, TVs and other electronics 

If your home uses high-demand electrical appliances, your savings could be higher than what you see in the tool. This is because you’d use more energy from the solar panels and less from the grid.

Examples of high-demand electrical appliances include: 

• Electric vehicle chargers.
• Saunas or hot tubs. 
• Commercial or workshop equipment at home. 

Tell your installer about any high-demand appliances or equipment. They can give you a more accurate estimate based on your home’s actual electricity use.