Our Solar Panel Calculator helps you estimate the cost of installing solar panels and how much you could save on your energy bills. It also shows how long it might take for your system to pay for itself.
With just a few details, you’ll get a personalised breakdown, including:
- Installation cost – an estimate of how much you’ll pay for panels and fitting
- Annual energy production – the amount of electricity your panels could generate each year
- Bill savings – how much of your electricity costs you could cut by using your own solar energy
- Export earnings – how much you could earn by selling excess energy back to the grid under the Smart Export Guarantee (SEG)
- Payback time – how long it will take for your savings and earnings to cover your initial investment
Solar panels can help you lower your bills, reduce your reliance on the grid, and even earn extra income. Use our calculator now to see what solar could do for you!
How does the Solar Panel Calculator work?
To get an accurate estimate, you’ll need to enter some details about your home and energy use. If you aren’t sure about any answers, then just leave the answer as the default, as this will fit the majority of people.
Here’s why each one matters:
- Region of your property – Some parts of the UK get more sunlight than others. If you live in the south, your panels will produce more energy than if you live in the north.
- Household electricity usage – This is how much electricity your home uses each year. If you use a lot, solar panels can help you save more by generating your own power. A typical three-bedroom home uses about 2,700 kWh per year.
- Electricity price (p/kWh) – The price you pay for electricity affects how much money you can save. If prices go up, having solar panels will save you even more. We have used the current rate of the Octopus Energy variable tariff.
- Number of solar panels – This decides how much electricity your system can generate. Most three-bedroom houses can fit 10–14 panels, depending on roof space. More panels mean more energy.
- Battery storage – A battery stores extra solar energy for later use, so you can use more of your own power instead of buying from the grid. This increases savings but also costs more upfront.
- Roof orientation – The direction your roof faces affects how much sunlight your panels get. South-facing roofs are best in the UK, but east- and west-facing roofs can still work well.
- Roof material – Some roof types make it easier or harder to install solar panels. Most UK homes have tiled roofs, which are simple to fit panels on. If the material makes it harder to install, then this will likely increase your costs.
- Roof angle (degrees) – The angle of your roof affects how well your panels work. In the UK, a 30–40° angle is best for generating energy.
By entering these details, you’ll get a personalised estimate of how much solar panels could save you and whether they’re a good option for your home.
Solar Panel Calculator
Your Details
Different regions receive varying amounts of sunlight, affecting energy production
Higher usage means more potential savings from self-consumed solar energy
Higher electricity prices increase the value of self-consumed solar energy
The average 3 bed house can take 10-14 solar panels (Estimated roof area: 3.4 m²)
Batteries increase self-consumption by storing excess energy for later use
South-facing roofs receive the most sunlight in the UK
Different roof materials affect installation complexity and cost
30-40° angles are optimal for solar panel efficiency in the UK
Your Solar Panel Estimates
System Size
0.9 kWp
Based on 10 panels (440W DeepBlue 4.0 Pro)
Installation Cost
£5,570
Includes panels, installation
Annual Production
990 kWh
Estimated yearly energy generation
Self-Consumption
40%
Default rate with no battery
Annual Savings
£107
15% of your annual electricity bill (£729)
Export Income
£89
From exporting 60% of energy at 15p/kWh
Total Annual Benefits
£196
Combined savings and export income per year
Payback Period
28 years
Time to recover your investment through savings and export income
Calculation Assumptions
- Solar panel efficiency of 440W per DeepBlue 4.0 Pro panel
- Base installation cost of £5,570 for 2 panels
- Each additional panel costs £285
- Installation costs vary based on roof material
- Battery storage options: 5kWh (£2,577), 10kWh (£5,145), 13.5kWh (£6,900)
- Household electricity usage: Low (1,800 kWh), Medium (2,700 kWh), High (4,100 kWh)
- Self-consumption rates: 40% (no battery), 60% (5kWh), 70% (10kWh), 80% (13.5kWh)
- Export tariff of 15p per kWh for excess energy
- System performance degrades at 0.5% per year (not factored in calculations)
- Regional solar irradiance values based on historical UK data