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Press Release 2 April 2024

New calculator shines a light on solar panels

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Please note that this page contains information and links most relevant for people living in England, Scotland, Wales.

Energy prices have reduced in Great Britain from 1 April in line with the energy price cap. But average energy bills relating to typical annual energy consumption are still 56% above summer 2021 levels.

Against this backdrop and as the climate emergency also escalates, there’s a growing interest in domestic renewable energy systems, primarily solar panels. This is to reduce both costs and carbon emissions.   

There were more than 183,000 certified solar PV installations across the UK in 2023, a third higher than 2022, according to the latest MCS figures2.

We’re also seeing a sustained interest from people searching for information on domestic solar panels options. This includes panels combined with a battery, a heat pump, or an electric vehicle chargepoint.  

To help people who are considering solar panels for their home, we’ve refreshed our popular solar panel calculator. The tool has been updated in line with revised higher Smart Export Guarantee tariffs and reduced electricity prices set by April’s energy price cap.


The tool takes specific information about a home to provide recommendations and outline the benefits. This includes:

  • the home’s roof position and angle
  • the household’s annual electricity usage

The tool provides a bespoke report, including:

  • the recommended size of solar panel system
  • the number of panels required for the home
  • likely installation costs

Using the latest data, the calculator gives an outline of total annual savings and payments the household is likely to get. These are based on assumptions on the amount of solar electricity they use and the amount likely to be exported.  


As an example, let’s look at a small, detached home in north west England, with a south west facing, partially shaded, sloped roof and two occupants who are at home all day.

They may be able to install a 4.5 kWp solar panel system at a cost of around £7,100. Based on a system this size, the solar panels would be expected to generate 2,850 kWh of electricity a year, equivalent to boiling a kettle 26,000 times.

The two the occupants would be expected to use 35% of this electricity and export the remaining 65%. The annual savings therefore possible under the April energy price cap and combined with payments from the Smart Export Guarantee, would total around £495.

The estimated carbon savings would be 630kg, equivalent to 24% of an average UK home’s carbon emissions1.   

You can use the the solar calculator as a starting point to work out if they’re right for your home. As technology has advanced, most homes installing a solar panel system will now be advised to install a battery at the same time.

This stores excess electricity the panels may generate to use when it’s needed and means you can take advantage of time of use tariffs, helping you benefit from cheaper energy prices. The typical cost of installing a 7.5 kWh battery is around £6,500.  

Joanna O’Loan, knowledge manager at Energy Saving Trust said:

“With electricity prices remaining high and more flexible tariffs becoming available that favour renewable energy generation, it could be a good time to consider if solar panels are right for you.

“In the bigger picture, domestic renewable energy will be an increasingly integral part of the UK’s transition to net zero, supporting the shift to a low carbon society, alongside low carbon heating, transport and a flexible, renewable energy grid”. 

Try out the solar panel calculator.

In line with the energy price cap in place from 1 April – 30 June 2024, We’ve updated our savings figures, covering quick, low and no cost energy saving tips, through to energy efficiency home upgrades.  

Annual solar panel savings and payments are calculated based on average UK electricity prices as of 1 April 2024:

  • electricity unit cost: 24.5p per kWh
  • export payment: 12p per kWh 

The cost per kWh of electricity tells us how much money a home would save by installing solar electricity. The export payments rate tells us how much it would get for exporting electricity to the grid. 


1Total carbon emissions are based on gas and electricity use only and use Ofgem’s Typical Domestic Consumption Values of 11,500 kWh gas and 2,700 kWh electricity. Carbon factors from the UK Government’s Department for Energy Security and Net Zero are applied to these consumption values to create the total, which is then divided by the carbon saved from the solar panels.

Last updated: 2 April 2024