Free UK solar calculator
Solar Savings Calculator UK
Answer a few simple questions to estimate your solar panel system size, installation cost, yearly savings, payback period, and whether a battery or EV charger could make sense.
Quick estimate
These inputs create a rough estimate only. A real quote needs a roof survey and installer assessment.
Takes around 1 minute
How the calculator works
How SolarCal estimates your solar savings
SolarCal uses your monthly electricity bill, home size, region, roof direction, shading, daytime usage, battery interest, and EV plans to create a simple UK solar estimate. The result is not a formal quote, but it helps you understand whether solar panels may be worth exploring before speaking to installers.
1. Electricity usage
Your monthly bill is converted into a rough annual electricity usage estimate. Higher usage normally means a larger solar system may be useful.
2. System size
The calculator estimates a likely solar panel system size based on your usage and home size, then keeps it within a sensible range.
3. Solar generation
Estimated annual generation is adjusted for UK region, roof direction, and shading because these can affect solar output.
4. Self-consumption
Solar savings are higher when you use more of your own solar electricity at home instead of exporting it.
5. Battery and EV impact
Battery storage and daytime EV charging can increase the amount of solar electricity you use yourself.
6. Payback estimate
The payback range compares estimated installation costs against estimated annual benefit from bill savings and export income.
What affects solar panel savings?
Solar savings vary from home to home. A south-facing roof with low shading and good daytime electricity usage will usually perform better than a shaded roof where most electricity is used at night. Your tariff, export rate, battery choice, EV charging habits, and final installer quote also make a big difference.
- • Roof direction and angle
- • Shading from trees, chimneys, buildings, or dormers
- • How much electricity you use during daylight hours
- • Whether you add battery storage
- • Whether you charge an EV at home
- • Export tariff and electricity import tariff
- • Final installer pricing and product choice
Why your payback period may vary
A solar payback period is only an estimate. The same solar system can pay back faster for one home than another because electricity usage, export income, battery use, roof suitability, and upfront installation cost can all be different.
The calculator gives a useful starting range, but you should still compare installer quotes and check the exact products, warranty, roof survey, scaffolding needs, battery compatibility, and aftercare before buying.
Should you add a solar battery or EV charger?
A solar battery may help if you use a lot of electricity in the evening, want to store more of your solar generation, or have a tariff that makes stored electricity useful. An EV charger may work well with solar if you can charge your car during daylight hours or use smart charging features.
Solar calculator FAQs
Is this solar calculator a formal quote?
No. SolarCal gives an estimate only. A formal quote needs a roof survey, product selection, installer pricing, scaffolding details, electrical checks, and property-specific assessment.
How accurate is the estimated solar saving?
It is a useful starting point, not a guarantee. Actual savings depend on electricity usage, roof conditions, shading, tariffs, export rates, system performance, battery use, and final installation cost.
Does a solar battery always improve payback?
Not always. A battery can increase self-consumption, but it also adds upfront cost. It may be more useful for homes with higher evening usage or tariffs that reward storing and shifting energy.
Can solar panels help with EV charging?
Yes, especially if the car can be charged during daylight hours. If most charging happens at night, a battery or smart tariff may matter more.
What should I do after getting my estimate?
Use the estimate as a starting point, download the free SolarCal guide, compare more than one quote, check warranties, ask about roof suitability, and use the Buyer’s Pack if you want a more detailed checklist before choosing an installer.