Solar panels have become one of the most popular home improvements in the UK. With electricity prices high and technology costs falling, more homeowners than ever are considering going solar. This guide covers the real costs, realistic savings, available financial support, and whether solar is right for your home.
How Much Do Solar Panels Cost?
Typical System Costs in 2026
| System size | Panels needed | Typical cost (installed) | Best for |
|---|---|---|---|
| 3kW | 8–10 | £4,000 – £6,000 | Small home, 1–2 people |
| 4kW | 10–12 | £5,000 – £8,000 | Average home, 2–3 people |
| 5kW | 13–15 | £7,000 – £9,000 | Larger home, 3–4 people |
| 6kW | 16–18 | £8,000 – £10,000 | Large home, 4+ people |
Prices include panels, inverter, mounting hardware, scaffolding, and installation. VAT on residential solar installations is 0% — a significant saving compared to the standard 20% rate.
What Affects the Cost?
| Factor | Impact on price |
|---|---|
| Roof type and access | Complex roofs or scaffolding needs increase cost |
| Panel quality | Premium panels (e.g., SunPower) cost more but are more efficient |
| Inverter type | Micro-inverters cost more than string inverters |
| Location | Some regional price variation |
| Electrical upgrades | Older fuse boxes may need upgrading |
How Much Will You Save?
Your savings depend on three things: how much electricity you use, how much you use during daylight hours, and your electricity tariff rate.
Estimated Annual Savings
| System size | Self-consumption 30% | Self-consumption 50% | Self-consumption 70% |
|---|---|---|---|
| 3kW | £300 – £450 | £450 – £600 | £550 – £700 |
| 4kW | £400 – £600 | £600 – £800 | £750 – £950 |
| 5kW | £500 – £750 | £750 – £1,000 | £900 – £1,150 |
| 6kW | £600 – £850 | £850 – £1,100 | £1,000 – £1,300 |
Self-consumption is the percentage of solar electricity you use directly rather than exporting to the grid. Higher self-consumption means higher savings. You can increase it by:
- Running the washing machine, dishwasher, and tumble dryer during the day
- Charging an electric vehicle during daylight hours
- Adding battery storage to use solar energy in the evening
- Using a hot water diverter to heat your water tank with surplus solar
Smart Export Guarantee (SEG)
When your panels generate more electricity than you need, the surplus goes back to the grid. Under the Smart Export Guarantee, your energy supplier must offer you a payment for this exported electricity.
| Supplier | Typical SEG rate |
|---|---|
| Octopus Energy | 4–15p per kWh (varies by tariff) |
| British Gas | 3–5p per kWh |
| EDF | 3–5p per kWh |
| E.ON | 3–5p per kWh |
| OVO Energy | 4–5p per kWh |
Rates vary and some suppliers offer better deals than others. Octopus Energy’s Agile export tariff can pay significantly more at peak times. Shop around for the best SEG rate — you do not have to export to your main supplier.
A typical 4kW system exports roughly 1,500–2,000 kWh per year, which at 5p per kWh earns you £75–£100.
Payback Period
| Scenario | Estimated payback |
|---|---|
| 4kW system, average use, no battery | 8–12 years |
| 4kW system, high daytime use, no battery | 6–9 years |
| 4kW system with battery | 10–14 years |
| 4kW system with EV charging at home | 5–8 years |
Solar panels are typically warranted for 25–30 years and continue producing electricity well beyond that. After the payback period, your electricity is essentially free.
Battery Storage
A battery lets you store surplus solar electricity to use in the evening and overnight, rather than exporting it cheaply and buying it back at full price.
Battery Costs in 2026
| Battery capacity | Typical cost (installed) | Household size |
|---|---|---|
| 3–5 kWh | £2,500 – £4,000 | Small, 1–2 people |
| 5–8 kWh | £4,000 – £6,000 | Average, 2–3 people |
| 8–13 kWh | £5,500 – £8,000 | Larger, 3–4 people |
| 13+ kWh | £7,000 – £12,000 | Large home or EV charging |
Is a Battery Worth It?
| Advantages | Disadvantages |
|---|---|
| Use more of your solar electricity | Adds significantly to upfront cost |
| Reduces grid dependence | Extends payback period by 2–4 years |
| Enables cheaper time-of-use tariffs | Battery degrades over time (80% after 10 years) |
| Backup during power cuts (some models) | Needs space for installation |
A battery makes the most financial sense if:
- You are out during the day and use most electricity in the evening
- Your electricity tariff has a big difference between peak and off-peak rates
- You want to maximise self-consumption above 70%
- You have an electric vehicle to charge overnight
Grants and Financial Support
Current Support in 2026
| Support | Details |
|---|---|
| 0% VAT | No VAT on residential solar installations |
| ECO4 scheme | Free or subsidised solar for eligible low-income households |
| Home Energy Scotland Loan | Interest-free loans up to £7,500 for solar in Scotland |
| Nest scheme (Wales) | Free home energy improvements for eligible Welsh households |
| Local authority grants | Some councils offer additional grants — check your local council |
What Is Not Available
There is no Feed-in Tariff for new installations (closed to new applicants in 2019). The Smart Export Guarantee replaced it but pays less. There is no universal government grant for solar panels in England for standard households.
Is Your Home Suitable?
Ideal Conditions
| Factor | Ideal | Still works |
|---|---|---|
| Roof direction | South-facing | East or west (15–20% less output) |
| Roof angle | 30–40 degrees | 15–50 degrees |
| Shading | No shading | Partial shade (micro-inverters help) |
| Roof condition | Good structural condition | May need repair first |
| Roof space | 20m² for 4kW system | Smaller systems for less space |
North-facing roofs produce significantly less electricity and are generally not recommended for solar panels.
Planning Permission
| Situation | Planning needed? |
|---|---|
| Standard house roof | No (permitted development) |
| Flat roof | No (if panels don’t exceed 1m above highest part of roof) |
| Listed building | Yes |
| Conservation area | Possibly — check with council |
| Ground-mounted panels | Yes, if over 9m² |
| Commercial property | Usually yes |
How to Get Solar Panels Installed
Step by Step
| Step | What happens |
|---|---|
| 1. Get quotes | Get at least 3 quotes from MCS-certified installers |
| 2. Site survey | Installer assesses your roof, electrics, and energy use |
| 3. Choose a system | Agree on panel type, size, and any battery |
| 4. Installation | Typically takes 1–2 days |
| 5. Connect to grid | DNO notification (installer handles this) |
| 6. Register for SEG | Sign up for Smart Export Guarantee payments |
| 7. Monitor | Use app or online portal to track generation |
Choosing an Installer
- Use only MCS-certified installers — this is required for SEG eligibility and most finance schemes
- Get at least 3 written quotes to compare
- Check reviews on Trustpilot, Google, and Which? Trusted Traders
- Ask about warranties — panels should have 25-year performance warranties, inverters 10–15 years
- Avoid cold callers and high-pressure sales tactics
Solar Panels and Your EPC Rating
Installing solar panels improves your home’s Energy Performance Certificate (EPC) rating. A better EPC rating:
- Makes your home more attractive to buyers
- Is required for rental properties (minimum E rating, moving to C)
- Can reduce energy costs further when combined with other improvements
Running Costs and Maintenance
| Item | Cost | Frequency |
|---|---|---|
| Panel cleaning | £100 – £200 | Every 1–2 years (optional) |
| Inverter replacement | £800 – £1,500 | Every 10–15 years |
| Annual inspection | £100 – £150 | Recommended annually |
| Insurance | Check home policy | Your home insurance may need updating |
Solar panels are low maintenance. Rain keeps them reasonably clean, and there are no moving parts to wear out. The main ongoing cost is eventually replacing the inverter.
Summary
| Factor | Details |
|---|---|
| Typical cost (4kW) | £5,000 – £8,000 |
| Annual savings | £500 – £900 |
| Payback period | 6–12 years |
| Lifespan | 25–30+ years |
| VAT | 0% for residential |
| Planning permission | Usually not needed |
| Maintenance | Minimal |
Solar panels are a long-term investment that can significantly reduce your electricity bills and your carbon footprint. With 0% VAT and falling prices, the financial case is stronger than it has been in years.
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