Solar Panels UK — Costs, Savings & Grants 2026
Solar panel prices have dropped 60% in the last decade, and with electricity prices still elevated, the payback period has shortened to 6-10 years for most UK homes. After that, you generate free electricity for another 15-20 years. This guide covers everything from costs to savings to whether batteries are worth the extra spend.
Solar Panel Costs 2026
| System Size | Panels | Cost (installed) | Best For |
|---|---|---|---|
| 3kW | 7-8 | £4,000-5,500 | 1-2 bed flat/house, low usage |
| 4kW | 10-11 | £5,500-7,000 | 3 bed house, average usage |
| 5kW | 12-13 | £6,500-8,500 | 3-4 bed house, heat pump |
| 6kW+ | 15+ | £8,000-11,000 | Large house, EV, high usage |
Battery Storage Add-On
| Battery | Capacity | Cost |
|---|---|---|
| GivEnergy 5.2kWh | 5.2 kWh | £2,500-3,500 |
| Tesla Powerwall 2 | 13.5 kWh | £8,000-10,000 |
| SolarEdge Home Battery | 9.7 kWh | £5,000-7,000 |
| Sunsynk 5.12kWh | 5.12 kWh | £2,000-3,000 |
How Much Will You Save?
A typical 4kW system in the south of England generates around 3,400-3,800 kWh per year. In Scotland, expect 2,800-3,200 kWh. At current electricity prices (around 24.5p/kWh from April 2026), each kWh you use directly from your panels saves you 24.5p. Each kWh you export earns you 4-15p depending on your SEG tariff.
The key to maximising savings is self-consumption — using the electricity your panels generate rather than exporting it. Without a battery, a typical household self-consumes 30-50% of what they generate. With a battery, this rises to 60-80%. Run your washing machine, dishwasher, and EV charger during the day when the panels are producing.
Typical Annual Savings
| Setup | Annual Saving | Payback Period |
|---|---|---|
| 4kW panels only | £500-700 | 8-12 years |
| 4kW + 5kWh battery | £700-1,000 | 9-13 years |
| 4kW + battery + EV | £1,000-1,400 | 7-10 years |
Smart Export Guarantee (SEG)
The SEG requires energy suppliers to pay you for electricity you export to the grid. Rates vary wildly — from 3p/kWh (Eon) to 15p/kWh (Octopus Agile export). Octopus Energy consistently offers the best rates. You need an MCS-certified installation and a smart meter to qualify.
Planning Permission
Solar panels are usually permitted development — no planning permission needed. Exceptions: listed buildings, conservation areas, and panels that protrude more than 200mm from the roof surface. Ground-mounted arrays must be under 9m² and not face a highway. Always check with your local planning authority if in doubt.
Roof Requirements
- Direction — South-facing is ideal (100% output). East/west-facing produces about 85%. North-facing is not viable.
- Angle — 30-40 degrees is optimal. Flat roofs need mounting frames (adds £500-1,000).
- Shading — Even partial shade from trees or chimneys reduces output significantly. Modern panels with optimisers handle shade better than string inverters.
- Roof condition — Panels last 25-30 years. If your roof needs work in the next 10 years, do it first. Removing and reinstalling panels costs £500-1,000.
VAT
Solar panels and battery storage for residential properties are currently VAT-free (0% until March 2027, expected to be extended). This saves you 20% compared to the standard rate. Make sure your installer applies the 0% rate — some have been caught charging 20% and pocketing the difference.
Is It Worth It?
For most UK homeowners with a suitable roof, solar panels are an excellent investment. The payback period is shorter than it has ever been, panels last 25+ years with minimal maintenance, and they increase property value. The addition of a battery makes sense if you use most of your electricity in the evening, have an EV, or want protection against future energy price rises.
Get at least three quotes from MCS-certified installers. Use comparison sites like Solar Guide, Eco Experts, or Checkatrade. Beware of door-to-door solar salespeople — they often charge 30-50% more than online quotes.