Solar Panel Installation UK: The Complete Guide
Everything you need to know before getting solar panels installed on your home
Key Facts
- Installation time: 1-2 days on-site, 4-8 weeks end-to-end
- Average cost: £5,500-£8,000 for a 4 kW system (0% VAT until March 2027)
- Planning permission: Not needed for most roof-mounted installations
- Annual savings: £670-£1,200 depending on system size and battery
- Payback period: 8-12 years, then 15-20+ years of near-free electricity
Getting solar panels installed on your home is one of the best investments you can make in the UK right now. With electricity prices at 24.5p per kWh under the Ofgem price cap and 0% VAT still in place until March 2027, the economics have never been stronger.
But the installation process can feel opaque if you haven't been through it before. This guide covers every step: from working out whether your roof is suitable, through choosing an installer, to what happens after the panels are up and running.
Is Your Home Suitable for Solar Panels?
Not every roof is ideal for solar panels, but most UK homes are suitable enough to make the investment worthwhile. Here's what matters:
Roof orientation
South-facing roofs generate the most electricity — up to 100% of a panel's rated output. East- and west-facing roofs still produce around 80% of that, which is usually enough to make solar pay for itself. North-facing roofs generate significantly less and are rarely recommended.
Roof angle
The optimal angle for UK solar panels is 30-40 degrees from horizontal. Most pitched roofs fall within this range naturally. Flat roofs work too — panels are mounted on angled frames, though this adds some cost.
Shading
Shading from trees, chimneys, or neighbouring buildings reduces output. Modern panels with optimisers or microinverters handle partial shading much better than older string inverter systems, but heavy shading can still make solar uneconomical.
Roof condition
Panels are designed to last 25-30+ years, so your roof should be in good condition before installation. If your roof needs replacing within the next 10 years, it's worth doing that first — removing and reinstalling panels later adds significant cost.
Not sure if solar works for your home? Our calculator uses satellite data to assess your roof.
Types of Solar Panel Systems
| System Type | How It Works | Cost | Best For |
|---|---|---|---|
| Grid-tied (no battery) | Panels feed your home, excess goes to grid | £5,000-£8,000 | Lowest upfront cost |
| Grid-tied + battery | Excess stored in battery for evening use | £8,000-£14,000 | Maximum self-consumption |
| Hybrid | Battery + smart tariff integration (e.g. Flux) | £9,000-£15,000 | Maximising export income |
Most UK installations are grid-tied systems. You stay connected to the grid, use solar when it's available, and draw from the grid when it's not. Adding a battery lets you store daytime generation for evening use, increasing the proportion of solar electricity you actually use from around 40-50% to 70-80%.
How Many Solar Panels Do I Need?
| Home Size | System Size | Panels Needed | Roof Space | Annual Output |
|---|---|---|---|---|
| 1-2 bed flat | 2 kW | 5-6 | ~10 m² | 1,600-1,800 kWh |
| 2-3 bed house | 3 kW | 7-8 | ~15 m² | 2,400-2,700 kWh |
| 3 bed house | 4 kW | 10-12 | ~20 m² | 3,200-3,600 kWh |
| 3-4 bed house | 5 kW | 12-14 | ~25 m² | 4,000-4,500 kWh |
| 4-5 bed house | 6 kW | 15-18 | ~30 m² | 4,800-5,400 kWh |
These are guidelines based on average UK electricity consumption. Your actual needs depend on your energy usage, roof orientation, and whether you plan to add an EV charger or heat pump later.
Get a personalised system size recommendation based on your roof and usage.
The Solar Panel Installation Process
Here's what happens from first contact to generating electricity:
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Get quotes from MCS-certified installers
Get at least three quotes. Use our installer directory to find MCS-certified companies near you. Every quote should include the system size, panel make and model, inverter type, and a breakdown of costs.
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Site survey and system design
Your chosen installer visits to assess your roof structure, orientation, shading, and electrical setup. They'll design a system specific to your property and confirm the final price.
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Scaffolding and preparation
Scaffolding goes up (usually the day before or morning of installation). The installer checks the roof condition and plans the panel layout.
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Mounting rail installation
Aluminium rails are fixed to your roof rafters using brackets. The bracket holes are sealed to prevent leaks. This is the most critical part for roof integrity.
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Panel installation
Panels clip onto the mounting rails and are wired together. A standard 4 kW system takes a team of two around 4-5 hours.
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Inverter and wiring
The inverter (which converts DC from the panels to AC for your home) is installed, usually in the loft, garage, or utility room. Cabling runs from the panels to the inverter and into your consumer unit.
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Battery installation (if applicable)
If you've opted for battery storage, it's typically wall-mounted in the garage or utility room and connected to the inverter.
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DNO notification and meter setup
Your installer notifies your Distribution Network Operator that you've connected a generating system. If you have an old meter, it may need upgrading to a smart meter.
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MCS certification and handover
You receive your MCS certificate, which you need for Smart Export Guarantee registration. The installer walks you through the monitoring system and maintenance requirements.
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Smart Export Guarantee registration
Sign up with an energy supplier offering SEG payments. Compare rates in our SEG tariffs guide.
How Long Does Solar Panel Installation Take?
| Stage | Duration |
|---|---|
| Getting quotes | 1-2 weeks |
| Site survey | 1-2 hours (1-2 weeks to schedule) |
| Design and approval | 1-2 weeks |
| On-site installation | 1-2 days |
| DNO approval | 1-4 weeks |
| Total end-to-end | 4-8 weeks |
The on-site work is quick — most standard installations are done in a single day. The main variable is DNO approval times, which differ across the UK. Some areas process applications in days; others take several weeks.
Solar Panel Installation Costs
For a full cost breakdown, see our dedicated solar panel costs guide. Here's the summary:
| System Size | Cost Range | Annual Savings | Payback |
|---|---|---|---|
| 3 kW | £4,500-£5,500 | £500-£700 | 8-10 years |
| 4 kW | £5,500-£8,000 | £670-£1,000 | 8-12 years |
| 5 kW | £6,500-£8,000 | £800-£1,100 | 7-10 years |
| 6 kW | £7,500-£9,500 | £900-£1,200 | 8-10 years |
All prices include 0% VAT (available until March 2027). Battery storage adds £3,000-£9,000 to the total cost but increases savings by £200-£400 per year.
Do You Need Planning Permission?
When you DON'T need planning permission
Most residential roof-mounted solar panels fall under permitted development rights. You can install without planning permission if:
- Panels don't protrude more than 200mm from the roof surface
- Your home isn't a listed building
- You're not in a conservation area, World Heritage Site, or AONB
- Panels don't face a highway on a principal elevation (front of house rule in some areas)
When you DO need planning permission
- Listed buildings — always need listed building consent
- Conservation areas — may need permission, especially for front-facing panels
- Ground-mounted systems over 9 square metres
- Commercial properties
Your installer should advise on planning requirements during the site survey. If in doubt, contact your local planning authority before committing.
How to Choose a Solar Installer
MCS certification is essential
Only use an MCS-certified installer. MCS (Microgeneration Certification Scheme) certification means the installer meets recognised industry standards. Without it, you can't register for Smart Export Guarantee payments, and your installation may not be covered by consumer protection schemes like HIES or RECC.
Get at least three quotes
Prices vary significantly between installers. Getting three quotes lets you compare not just price, but the proposed system design, panel brands, warranty terms, and aftercare.
What a good quote includes
- System size (kW), number and make of panels
- Inverter make and model
- Estimated annual generation (kWh)
- Total installed price including VAT (currently 0%)
- Warranty terms (panels, inverter, workmanship)
- Scaffolding, DNO notification, and MCS certification
Red flags
- High-pressure sales tactics or "today only" discounts
- Unrealistic savings projections
- No MCS certification
- Unwillingness to provide written warranty details
- Demanding large deposits before the site survey
Find MCS-certified solar installers in your area with verified reviews.
After Installation — What to Expect
Monitoring your system
Most modern inverters come with an app that shows real-time generation, consumption, and export data. Check it regularly for the first few months to understand your system's patterns.
Maintenance
Solar panels need very little maintenance. An annual visual check and occasional cleaning (if panels are accessible and dirty) is usually sufficient. Rain does a reasonable job of keeping panels clean in the UK.
Warranties to keep track of
- Panel warranty: 25-30 years (performance guarantee)
- Inverter warranty: 5-12 years (may need replacing once)
- Workmanship warranty: 5-10 years (covers roof and installation work)
- Battery warranty: 10 years (if applicable)
Smart Export Guarantee earnings
Once registered for SEG, you'll receive quarterly or monthly payments for electricity exported to the grid. Rates vary from 1p to 30p per kWh depending on your chosen tariff. See our SEG tariffs comparison for current rates.
Frequently Asked Questions
How long does it take to install solar panels?
On-site installation takes 1-2 days for a standard system. The full process from first quote to generating electricity is 4-8 weeks, with DNO approval being the main variable.
Do I need planning permission for solar panels?
Most roof-mounted installations don't need planning permission under permitted development rights. Exceptions include listed buildings, conservation areas, and ground-mounted systems over 9 square metres.
How many solar panels do I need for a 3 bedroom house?
A 3-bedroom house typically needs a 4 kW system — around 10-12 panels. This produces 3,200-3,600 kWh per year and requires about 20 square metres of roof space.
Can I install solar panels myself?
Not recommended. DIY installations don't qualify for MCS certification, meaning no SEG payments, potential warranty issues, and safety risks. The electrical work must be done by a qualified electrician regardless. Always use an MCS-certified installer.
Do solar panels work in winter UK?
Yes. Panels work on daylight, not direct sunshine. A UK system produces around 40% of its annual output during October to March. Output is lower but still meaningful, even on overcast days.
Do solar panels damage my roof?
Not when properly installed. Panels mount on rails fixed to rafters, with sealed bracket holes. A reputable installer provides a workmanship warranty covering any roof issues.
What happens to solar panels when you move house?
Panels stay with the property. They can increase property value through lower bills and better EPC ratings. Transfer the MCS warranty and SEG contract to the new owner.
Do solar panels increase house value?
Yes. Properties with solar panels tend to sell faster at higher prices due to lower running costs and improved EPC ratings.