If you own a home in the UK and you're looking at ways to cut your electricity bills, solar panels are probably near the top of your list. This guide covers everything you need before you commit: what a system costs in 2026, how much you can realistically save, what your roof needs to qualify, and how the Smart Export Guarantee affects your numbers.

This is written for UK homeowners considering a domestic rooftop solar installation. Commercial readers will find some sections useful, but the figures and incentives refer to residential systems unless stated otherwise.

Quick Cost Summary for Solar Panels

A typical domestic solar panel system in the UK costs between £5,000 and £10,000 installed, depending on system size, roof complexity, and panel specification. Most 3-4 bedroom homes install a 4kW system, which runs £6,100 to £8,500 with a quality MCS-certified installer.

Add a solar battery and you're looking at another £3,000 to £5,000 on top of that.

Key numbers at a glance:

• Payback period: 10-14 years for most households (can range from 6 to 21 years)
• Annual bill savings: £150 to £700, depending on your usage, generation and energy costs
• VAT: 0% on eligible installations until 31 March 2027
• Smart Export Guarantee: earn for surplus electricity you export, with rates from 1p to around 20p per kWh

Solar Panel Systems: Size, Panels, and Prices

System size is measured in kilowatt-peak (kWp), which describes the maximum output under ideal conditions. The table below shows typical UK installed costs in 2026:

System Size	Approx. Panels	Typical Installed Cost	Suitable For
3kWp	6-8 panels	£5,000 - £6,500	1-2 bed homes, low usage
4kWp	8-10 panels	£6,100 - £8,500	3-4 bed family homes
5kWp	10-13 panels	£7,500 - £9,500	Larger homes, higher usage
6kWp	12-15 panels	£9,000 - £12,000	Large homes or EV charging

Cost per installed watt currently sits at around £1.30 to £2.20, depending on panel quality, inverter choice, and roof access.

Premium options that add cost:

• Monocrystalline panels cost around 20% more than polycrystalline but generate more electricity from the same roof space
• Premium inverters (such as SolarEdge or Enphase microinverters) add £300 to £1,000 over standard string inverters
• Panel optimisers are worth considering if your roof has partial shading

Typical System Examples and Average Solar Panel Costs

Example 1 - Two-bed terrace, low usage household A 3kWp system with 8 monocrystalline panels and a standard string inverter. Installed cost: approximately £5,800. Expected annual generation: 2,550 kWh in southern England.

Example 2 - Three-bed semi, average family use A 4kWp system with 10 panels, a mid-range inverter, and bird-proofing. Installed cost: approximately £7,200. This is the most common install type in the UK. Expected annual generation: 3,400 kWh.

Example 3 - Four-bed detached, EV and high usage A 6kWp system with 15 high-efficiency monocrystalline panels, premium inverter, and a 10kWh battery. Total cost: approximately £14,500. Higher upfront spend, but the battery and EV charging offset a significant portion of the grid electricity this household would otherwise buy.

On a per-panel basis, modern monocrystalline panels cost £100 to £350 each depending on brand and efficiency rating. The installed cost per panel naturally drops as systems get larger because fixed costs (scaffolding, certification, survey time) are spread across more panels.

How Panels Generate Electricity and Value

Solar PV panels convert sunlight into direct current (DC) electricity using photovoltaic cells. An inverter then converts that DC output into AC power your home appliances can use.

Output varies by location. A 4kWp system in the UK generates roughly:

Region	Estimated Annual Output
South England (e.g. Hampshire, Kent)	3,400 - 3,800 kWh
Midlands	3,000 - 3,400 kWh
North England / Scotland	2,600 - 3,100 kWh

Self-consumption is where the real savings come from. Grid electricity in the UK costs around 24p-28p per kWh in 2026. Every unit of solar electricity you use instead of buying from the grid saves you that full rate. Electricity you export earns you far less (1p to around 20p depending on your SEG tariff), so the more solar power you use on-site, the faster your payback.

A typical household self-consumes around 30-40% of its solar output without a battery. Add a battery and that rises to 70-90%.

Solar Battery Costs and Battery Storage Options

A solar battery stores surplus electricity generated during the day so you can use it in the evening rather than exporting it cheaply and buying it back expensively.

Typical UK solar battery costs in 2026:

Battery Capacity	Typical Cost (supply and fit)
5-6 kWh	£3,000 - £4,000
9-10 kWh	£4,000 - £6,000
13-15 kWh	£6,000 - £9,000

Adding a battery at the same time as your panels is cheaper than retrofitting one later. Installation costs overlap, and some hybrid inverter systems (which manage both solar and battery in one unit) reduce equipment costs. Retrofitting a battery to an existing solar installation typically adds 15-25% to the battery cost versus doing it simultaneously.

Battery lifespan is generally 10-15 years before capacity degrades noticeably, though most manufacturers quote warranties of 10 years at 70-80% capacity retention.

When does a battery improve the financial case?

• Your household uses a lot of electricity in the evenings and mornings
• You pay a high peak rate and your supplier offers a cheap overnight tariff
• You have or plan to get an electric vehicle
• Your SEG export rate is low (under 5p per kWh)

If your household is occupied during the day and already self-consumes 60%+ of solar output, the payback on a battery stretches considerably. Run the numbers with your installer before committing. Our guide to choosing the right size solar battery walks through the calculation in detail.

Smart Export Guarantee and Sending Power Back to the Grid

The Smart Export Guarantee (SEG) requires Ofgem-licensed energy suppliers with 150,000+ customers to pay you for surplus electricity you export to the national grid. Smaller suppliers can offer SEG voluntarily.

How SEG works:

• Your system exports surplus solar electricity when generation exceeds your home's demand
• Your energy supplier pays you per kWh exported, at whatever rate their SEG tariff states
• SEG rates vary from 1p to around 20p per kWh depending on the supplier and tariff type, with some variable tariffs paying more at peak times

Fixed vs variable SEG tariffs:

Fixed tariffs pay the same rate per kWh regardless of time of day. Variable (or time-of-export) tariffs pay more when grid demand is high, typically late afternoon and evening. If your battery charges from solar during the day and you can export at peak times, variable tariffs can meaningfully increase your SEG income.

The average household earns around £100 to £360 per year from SEG payments, depending on system size, usage habits, and the tariff rate secured.

Requirements for SEG:

• Your installer must be MCS certified and your system must carry an MCS certificate
• You need a smart meter that can report half-hourly export readings to your supplier
• Your supplier uses smart meter data to calculate and pay you accurately

Compare SEG tariffs before you sign up. Rates change regularly and differ substantially between suppliers.

Is Your Roof Suitable for Solar Panels?

Not every roof is equally well-suited to solar panels, but a wider range of roofs can work than most people expect.

Key checks:

• Orientation: South-facing roofs produce the most electricity. East or west-facing roofs generate roughly 15-20% less annually but are still financially viable. North-facing roofs are generally not suitable as a primary installation area.
• Pitch: 30-40 degrees is optimal. Steeper or shallower pitches reduce output slightly.
• Shading: Trees, chimneys, and neighbouring buildings that cast shade on panels during peak hours reduce output significantly. Even partial shading of one panel in a string system can reduce output across the whole string. Panel optimisers or microinverters mitigate this.
• Structural condition: Your roof structure must be in good condition. Installers assess load-bearing capacity before installation. Replace failing slates or tiles before the install if possible.
• Roof area: A 4kWp system of 10 panels needs roughly 25-30 square metres of usable roof space.

Flat roof installations are possible using angled mounting frames to achieve the optimal pitch. Flat roof installs typically cost £500-£1,500 more than equivalent pitched roof jobs because of the mounting system.

Ground-mounted alternatives suit households with large gardens and shaded or north-facing roofs. Ground mounts are often cheaper to install and easier to clean, but planning permission is more commonly required.

If your roof is complex (multiple hips, dormers, Velux windows, chimneys, or satellite dishes), get an in-person survey. Installers quote more accurately when they've seen the roof, and hidden complications are far easier to price before work starts than mid-job.

Solar Panel Installation: Process and Hidden Costs

A standard domestic solar panel installation takes one to two days for a competent crew. Here is what the process looks like:

• Survey and design - the installer assesses your roof, reviews your energy bills, and designs the system
• Scaffolding erection - typically arrives the day before or the morning of installation
• Roof work - fixing mounting rails, laying cables through the roof into the loft
• Panel fitting - panels are mounted and connected
• Inverter installation - usually sited in the loft or a utility room
• Electrical connection - cabling to your consumer unit and generation meter
• Commissioning and testing - the installer verifies output and signs off the system
• MCS certification - issued after completion; you need this for SEG registration

Labour costs for solar panel installation average around £300 per installer per day. A two-person crew completing a standard install in one day costs approximately £600 in labour. On a typical 4kW quote, labour accounts for roughly 10-15% of the total.

Hidden costs to watch for:

• Scaffolding: £400 to £900 depending on roof height and complexity. Some installers include this, many don't. Ask specifically.
• Roof repairs: If the surveyor identifies broken tiles or failing flashings, these need fixing before or during the install. Budget £200-£800 for typical minor repairs.
• G99 application: Systems over 3.68kW AC output require a Distribution Network Operator (DNO) application under G99 before the installer can connect to the grid. This process typically adds 4-12 weeks to the timeline and may carry a fee. Your installer should handle this, but confirm it's included.
• Generation meter: Some quotes omit this. You need one for accurate SEG records.
• Cable runs: Long or complicated cable routes from roof to inverter can add labour time and cost.

How Solar Panels Affect Home Value and Savings

Research from the Urban Big Data Centre at the University of Glasgow found that homes with solar panels in the UK sell at a premium of 6.1% to 7.1% over equivalent homes without them, though any uplift varies by property and local market. On a £350,000 home, that points to a potential uplift of around £21,000-£25,000.

Savings example:

For a 4kW system costing £7,500 installed:

• Annual bill savings (at 25% self-consumption rate): around £340
• Annual SEG income: around £150
• Total annual benefit: around £490, depending on your usage, generation and energy costs
• On those figures, simple payback works out at roughly 15 years
• With 50% self-consumption (or a battery), annual savings rise to £600-£700, which would shorten payback to 11-12 years

These numbers tend to improve year on year as electricity prices rise, because solar replaces electricity you'd otherwise buy at prevailing grid rates.

The staying-period question matters. If you plan to move in under five years, the financial case is weaker unless you factor in property value uplift. For homeowners planning to stay 10+ years, the long-term economics are stronger. For those somewhere in the middle, the property premium matters more in the calculation.

Solar PV Performance, Warranties, and Maintenance

Panel lifespan and degradation:

Quality monocrystalline panels degrade at around 0.3-0.5% per year in output. After 25 years, a panel rated at 400W at installation typically outputs 370-385W. Most panels carry a 25-year performance warranty and a separate 10-12 year product warranty covering manufacturing defects.

Inverter lifespan:

String inverters typically last 10-15 years. Budget £800-£1,500 for a replacement inverter at the 12-15 year mark. Microinverters, which sit behind each panel, last closer to 25 years but cost more initially. Factor inverter replacement into your long-term cost planning.

Maintenance:

Solar panels are largely maintenance-free. Rain cleans most dirt naturally. In areas with significant pollution or bird activity, panels may need cleaning every 1-2 years. Professional panel cleaning costs £80-£150. Avoid high-pressure water on panels. A soft brush and clean water is sufficient.

Check your inverter's monitoring app periodically. A sudden drop in output that doesn't correspond to cloudy weather often signals an inverter fault or a panel that's come loose from its connector.

Annual system health checks cost £100-£200 and catch problems before they become expensive.

Financing, Grants, and Cost Reduction Strategies

Finance options:

• Cash purchase: Offers the fastest payback because you avoid interest costs.
• Personal loan: Many households finance solar on 5-7 year personal loans at 6-9% APR. The loan repayment often roughly matches the electricity bill savings, making the net cost close to neutral from day one.
• 0% finance: Some solar installers and energy suppliers offer 0% interest finance for periods of 1-3 years. Availability varies and usually requires a good credit score.
• Green mortgages: Some lenders offer better mortgage rates on properties with high energy ratings. Installing solar can help qualify for these.

Grants and incentives in 2026:

• 0% VAT: Solar panel installations on residential properties attract 0% VAT until 31 March 2027, a saving of roughly £1,000-£2,000 compared to the standard 20% rate.
• Warm Homes: Local Grant: Available in England, this scheme funds free energy-saving improvements including solar panels for eligible households, worth up to £15,000 per property. Eligibility is means-tested. Check with your local council or CRG Direct to see if you qualify.
• ECO4: The Energy Company Obligation scheme helps low-income and vulnerable households access energy improvements, including solar in some cases. Contact your energy supplier to check eligibility.

Cost reduction tactics:

• Get three quotes minimum. Prices for identical systems can vary by £1,500-£2,500 between installers.
• Ask for itemised quotes. A quote that breaks out panels, inverter, mounting, scaffolding, and labour lets you compare like with like.
• Autumn and winter timing. Installer demand peaks in spring and summer. Booking in autumn or winter often gets you a better price and faster scheduling.
• Group buys. Some community energy groups run group-purchasing schemes that negotiate volume discounts with installers. Worth checking if one operates in your area.

CRG Direct Services and How to Get a Quote

CRG Direct is an MCS certified solar installer based in Hampshire, serving domestic and commercial customers across the South and South East of England.

Free site survey: CRG Direct offers a free, no-obligation survey and bespoke system design. The survey covers roof assessment, shading analysis, energy usage review, and a written quotation with full system specification.

Domestic services: Full solar panel design and installation, battery storage systems, hybrid systems, and post-install monitoring support. CRG Direct is NICEIC approved and handles all DNO and MCS paperwork as part of the installation service.

Commercial services: CRG Direct designs and installs larger commercial solar PV systems for businesses, including flat-roof installations and ground-mounted systems. Commercial installs are assessed for planning requirements and often qualify for different incentives, including capital allowances.

Finance options: CRG Direct offers 0% finance options for qualifying customers, allowing homeowners to spread the cost of installation without interest.

To get a quote, book a free site survey at crgdirect.co.uk/quote or call +44 330 133 2497.

Case Studies, Sample Quotes, and Localised Estimates

Domestic case study - Portsmouth, three-bed semi:

A family in Portsmouth with a south-facing roof and two adults working from home installed a 4.2kWp system with 10 panels and a 9.5kWh battery in early 2025. Total installed cost: £11,800 (panels, battery, scaffolding, installation). Pre-install electricity bill: £1,400/year. Post-install bill: approximately £420/year, with additional SEG income of around £80/year. Annual saving: around £1,060, depending on usage and energy prices. Estimated payback: 11 years.

Sample quote ranges:

Scenario	Estimated Installed Cost
Simple south-facing pitched roof, 4kW, no battery	£6,500 - £7,500
Complex roof (hip or multiple aspects), 4kW	£7,500 - £9,000
4kW with 10kWh battery, simple roof	£10,500 - £13,000
6kW commercial flat roof, no battery	£11,000 - £15,000

Regional price variances: Installation labour costs are generally 10-15% higher in London and the South East compared to the North of England and Wales, though panel and equipment costs are similar nationally. Southern England benefits from higher solar irradiance, which improves output and shortens payback periods.

Practical Checklist Before You Book Installation

Work through this before you commit to a quote:

• Check your roof condition. Are all tiles/slates sound? Is the flashing around chimneys and skylights intact? Fix structural issues before installation.
• Establish roof orientation and shading. Use a compass to confirm your primary roof faces south, east, or west. Walk around your property at midday in summer to identify shading sources.
• Check if planning permission is needed. Most residential rooftop solar qualifies as permitted development, but listed buildings, conservation areas, and some flat-roof scenarios require planning consent. Check with your local planning authority if uncertain.
• Verify MCS accreditation. Only MCS-certified installations qualify for SEG and government grants. Check installer accreditation at mcscertified.com.
• Get at least three itemised quotes. Itemised means broken out by equipment, labour, scaffolding, and certification. Refuse any quote that bundles everything into a single number.
• Ask about G99. If your system exceeds 3.68kW AC, confirm the installer will handle the DNO G99 application and allow for the additional lead time.
• Confirm what's included. Scaffolding, bird-proofing, generation meter, MCS certificate, monitoring app setup. Get it in writing.
• Check the equipment warranty terms. Confirm panel performance warranty duration, inverter product warranty, and what happens if the inverter fails in year 11.
• Talk to your energy supplier. Notify them before installation and ask about their SEG tariff. Compare rates across suppliers before your install completes.

FAQs: Cost of Solar Panels on Roof

What is the average cost of installing solar panels in the UK? For a typical 4kW domestic system, expect to pay £6,100 to £8,500 installed by an MCS-certified installer. The average cost for a three-bedroom house runs around £7,500. Adding a battery increases this by £3,000 to £5,000.

What is the difference between monocrystalline and polycrystalline panels? Monocrystalline panels are more efficient, generate more electricity per square metre, and last longer. They cost around 20% more than polycrystalline. Polycrystalline panels are around one-third less efficient and better suited to installations where roof space is not a limiting factor. For most UK roofs, monocrystalline is the sensible choice.

How much can solar panels save on electricity bills? A 4kWp system saves a typical household £190 to £340 per year purely on reduced electricity purchases, depending on your usage, generation and energy costs. With a battery increasing self-consumption, annual savings can reach £500-£735. Solar can cut your electricity bill by up to 70% if sized and used correctly.

How long is the payback period for solar panels? Most UK households see payback in 10-14 years, though this ranges from 6 years (high-usage household, generous SEG tariff, low installation cost) to 21 years (small system, low usage, complex install, no battery efficiency gain).

Is solar battery storage worth the extra cost? It depends on your electricity usage pattern. If you use most power in the evenings and your SEG export rate is under 5p per kWh, a battery typically pays for itself in 8-12 years and shortens the overall payback on your solar system. If you work from home and already use a lot of electricity during the day, a battery adds less value.

What is the Smart Export Guarantee? The SEG requires eligible energy suppliers to pay you for every kWh of surplus solar electricity you export to the grid. Rates run from 1p to around 20p per kWh depending on your supplier and tariff. You need an MCS-certified system and a smart meter to qualify. A typical household earns £100-£360 per year from SEG payments.

Do solar panels work on flat roofs? Yes. Flat roof installations use angled mounting frames to achieve the optimal tilt angle. They typically cost £500-£1,500 more than a pitched roof install due to the additional mounting equipment.

Do I need planning permission for solar panels? Most residential rooftop installs in England and Wales fall under permitted development and don't require planning permission. Exceptions include listed buildings, some conservation areas, and systems that protrude significantly above the roofline. Always check with your local planning authority if you're uncertain.

What is G99 and do I need it? G99 is a technical standard your Distribution Network Operator uses to assess larger grid-connected systems. Any system with an inverter output exceeding 3.68kW AC must go through a G99 application before connection. Your installer should handle this, but it can add 4-12 weeks to your installation timeline.

Can I export solar electricity to the grid without a smart meter? No. Smart Export Guarantee payments require a smart meter capable of reporting half-hourly export data to your supplier. If you don't yet have a smart meter, request one from your energy supplier before or during your solar installation.

Do solar panels increase home value? Research from the University of Glasgow found UK homes with solar panels sell at a 6.1-7.1% premium on average, though this varies by property and local market. On a £300,000 home that points to roughly £18,000-£21,000. The premium tends to be strongest in areas with higher electricity prices and among buyers who understand the savings involved.

Are there grants available for solar panels in the UK? In 2026, eligible households can access the Warm Homes: Local Grant (free energy improvements worth up to £15,000 for lower-income households in England) and ECO4 (energy company-funded improvements for qualifying households). All residential solar installations also benefit from 0% VAT until March 2027.

Sources

• Urban Big Data Centre, University of Glasgow - Solar panel property price premium (6.1-7.1%): How do solar panels affect property prices in the UK?
• Ofgem - Smart Export Guarantee (SEG): official scheme page
• Ofgem - Energy Company Obligation (ECO4): official scheme page
• HMRC - 0% VAT on energy-saving materials (zero rate to 31 March 2027): official guidance
• MCS Certified Installer Register: mcscertified.com