Solar panel compare?

How to compare solar panel quotes in the UK

To compare solar panel quotes properly in the UK, look at the full system and installation scope, not just the panel wattage or the lowest headline price. The best quote should explain roof suitability, system size, inverter design, expected generation, export assumptions, DNO handling, credentials, paperwork, warranties and aftercare.

Two quotes can look similar on the first page but differ once you check scaffolding, roof mounting, cable routes, inverter type, battery readiness, monitoring, commissioning documents and who deals with the Distribution Network Operator. A useful comparison shows what is included, what is excluded and why the design fits your property and electricity use.

For most homes, the right system is not simply the one with the most panels. It is the one that can be installed safely, generates well on the available roof, matches your usage pattern as far as practical and leaves you with clear documentation for maintenance, export tariff applications and future changes.

Compare the whole solar system, not just the panels

Solar panels are only one part of a working PV installation. The inverter, mounting system, roof layout, shading, electrical connection, monitoring and commissioning all affect performance and reliability. If you want the basics before reviewing quotes, start with how solar works. A high-output panel on a poor layout can be a weaker choice than a sensible panel installed on a well-surveyed roof with an appropriate inverter.

In a real quote review, the strongest proposals usually make the practical design visible. They show which roof faces are being used, how shading has been considered, where the inverter will go, how cables will be routed, what access is needed and whether the consumer unit or earthing arrangements need attention.

Panel wattage is also easy to overvalue. A panel’s rated output is measured under test conditions, not as a promise of everyday generation on a UK roof. Annual output depends on roof orientation, pitch, shading, local conditions, inverter design and whether you can use electricity when the system produces it.

What changes the cost of a solar panel quote

Solar panel quote prices vary because properties vary. Roof access, scaffold requirements, roof covering, number of roof faces, cable runs, inverter type, battery inclusion, consumer unit work and DNO requirements can all affect the final specification. A low headline price may leave out work that another installer has included properly.

A straightforward pitched roof with good access is usually simpler to price than a property with fragile tiles, several roof planes, awkward access, dormers, chimneys or heavy shading. If the electrical installation needs remedial work, if the cable route is difficult or if export limiting is needed, the final design may change after survey.

When comparing quotes, separate equipment cost from installation quality. Mounting hardware, waterproofing method, scaffold safety, electrical workmanship and documentation are not always obvious in a sales proposal, but they are central to long-term value. If price is your starting point, use it alongside a wider view of solar installation costs rather than treating the cheapest quote as the automatic winner. Check whether scaffolding, roof work, consumer unit changes, isolators, cable routes, labelling, monitoring and handover guidance are included or listed separately.

• Roof work

  Ask how the mounting system suits your roof covering and whether any tile replacement or roof repairs are excluded.

• Monitoring

  Confirm whether monitoring hardware, app access and handover guidance are included.

• Scaffolding

  Check whether all access equipment is included and whether any extra scaffold may be charged after survey.

• Administration

  Ask who handles DNO notification or application, certification, warranty registration and handover documents.

• Electrical work

  Check whether consumer unit changes, isolators, cable routes and labelling are included or listed separately.

A cheaper quote is not automatically poor, and a more expensive quote is not automatically better. The key question is whether both proposals are pricing the same job to the same standard.

Solar panel comparison checklist for UK quotes

A good comparison table helps you move beyond sales language. The aim is not to choose from one line of information, but to see whether each installer has answered the same practical questions clearly. If a quote is vague, ask for clarification before comparing it with a more detailed proposal. Use the checklist below when reviewing proposals. It is especially helpful for spotting quotes that are not genuinely like-for-like.

Overview

If one quote includes scaffolding, DNO handling, monitoring and a full handover while another treats them as extras, they are not directly comparable. Ask each installer to confirm inclusions in writing before deciding.

How to compare expected generation and savings

Estimated savings are often the weakest part of a solar quote because they depend on assumptions that may not match your home. A credible proposal should show expected annual generation and explain the basis for the estimate, including roof orientation, pitch, shading and system size. For a sense check, compare the proposal against what affects solar electricity generation in UK conditions. It should not rely only on a broad postcode figure or a generic sales calculator.

The saving calculation should separate electricity you use directly, electricity you export and any battery behaviour assumed. Self-consumption matters because electricity used in the home avoids buying from the grid, while exported electricity depends on the export tariff available to you. These are different values, so they should not be blurred into one optimistic figure.

Payback should be treated as an estimate rather than a guarantee. Electricity prices, export tariff rates, household behaviour, battery use and equipment performance can all change over time. Ask how annual generation was calculated, what proportion of solar electricity the quote assumes you will use on site, and which export tariff assumption has been used.

• Behaviour

  Consider whether your actual daytime use, working pattern, EV charging and seasonal demand match the model.

• Degradation

  Check whether long-term panel performance assumptions are explained rather than hidden.

• Export income

  Ask which export tariff assumption has been used and whether it is available from your chosen supplier.

• Self-consumption

  Check what proportion of solar electricity the quote assumes you will use on site.

• Annual generation

  Ask how the figure was calculated and whether shading, orientation and roof pitch were included.

• Battery modelling

  If a battery is included, ask what usage pattern, tariff and usable capacity have been assumed.

A practical sanity check is to compare the quote’s generation estimate with the proposed layout. If two installers quote a similar system size on the same roof but one predicts much higher savings, ask what assumption is different. The answer may be legitimate, but it should be clear.

How to judge panel and inverter specifications

Panel specifications matter, but they should be read in context. Look for a clear datasheet, product warranty information, performance warranty wording, panel dimensions, panel weight, efficiency and whether the chosen module physically suits your roof layout. Larger or higher-output panels can help where roof space is tight, but they do not remove the need for sound design.

Inverter choice is often more important than homeowners expect. A string inverter can be efficient and cost-effective on a simple, mostly unshaded roof. Optimisers or microinverters may be considered where shading, multiple orientations or complex roof faces make the design harder. Hybrid inverters are relevant when a battery is part of the plan, but they should be sized around the actual system and use case.

Do not assume every extra device improves the installation. Optimisers, microinverters, batteries and backup components can be useful, but they add cost, equipment and future maintenance considerations. A good installer should explain what each component solves on your property, including the real factors behind panel efficiency.

• Inverter sizing

  Ask why the inverter size and type have been chosen for the panel layout.

• Panel datasheet

  Check the exact make and model rather than accepting a generic panel description.

• Shading response

  Check whether shading has been designed around or simply mentioned.

• Warranty wording

  Read who provides the product warranty and what is required to make a claim.

• Monitoring detail

  Confirm what you will be able to see after installation and who can diagnose faults.

• Future compatibility

  Ask whether a later battery, EV charger or heat pump has influenced the design.

The best specification is usually the one that fits the site conditions cleanly. A more complex system can be justified, but complexity should have a clear purpose.

Credentials, standards and paperwork to check

A strong solar quote should make credentials and paperwork easy to verify. In the UK, MCS certification is commonly important for consumer confidence and may be needed for some export tariff routes, depending on the supplier’s requirements. If you are unsure what it means in practice, review MCS for solar before accepting a proposal. Consumer code membership, such as RECC or an equivalent scheme, can also matter because it sets expectations for sales conduct, contracts and dispute handling.

Grid connection handling is another key trust signal. The installer should explain whether the project is being handled through the relevant G98 or G99 process and who is responsible for submitting information to the DNO. Do not assume this is included unless the quote says so.

At handover, you should expect clear records for the installed system. These documents help with monitoring, maintenance, warranty claims, export tariff applications and future property sale enquiries. Ask for panel datasheets, inverter details, system layout, serial numbers and user guidance, and confirm who registers warranties.

• DNO process

  Ask whether the installer will notify or apply to the DNO and what export assumption is being made.

• MCS details

  Ask for the installer’s MCS certification status and ensure the named business matches the quote.

• Consumer code

  Check whether the installer belongs to RECC or another relevant consumer protection scheme.

• Commissioning pack

  Ask for panel datasheets, inverter details, system layout, serial numbers and user guidance.

• Warranty registration

  Check who registers warranties and what evidence you receive after installation.

• Electrical certification

  Confirm what electrical certification and test documentation will be provided.

This is not paperwork for its own sake. If a fault appears later, if you want to claim an export tariff or if you sell the property, vague documentation can become a real problem.

Worked example of two similar-looking solar quotes

Two solar quotes may both describe a similar system size and use reputable equipment, yet one may be much stronger when the detail is reviewed. The difference is often not the panel brand. It is the survey quality, installation scope, assumptions and aftercare. Imagine two proposals for the same pitched-roof home. Quote A has a lower headline price and lists panels, inverter and installation in broad terms. Quote B costs more but includes a roof layout drawing, scaffold allowance, cable route notes, DNO responsibility, monitoring setup, warranty registration and a handover pack. Without checking the detail, Quote A may look better. After review, Quote B may be the safer comparison point because fewer assumptions are hidden. The right answer still depends on the property and the final survey. The point is to identify missing information before you sign, not to reward the longest document.

Overview

A good quote does not need to be overcomplicated, but it should answer the practical questions that affect performance, safety and long-term support.

Choosing a solar installation company

The solar installation company matters because design judgement and workmanship turn equipment into a working system. A good installer will not push a final design before checking the roof, electrics, access and your electricity usage pattern. They should also explain what happens if the survey changes the design.

Ask who carries out the survey, who installs the system, who signs off the electrical work and who you contact if monitoring shows a fault later. Subcontracting is not automatically a problem, but responsibility should be clear. You should not be left guessing who owns the handover, warranty claim or DNO paperwork.

Installer comparison should also include communication quality. A credible quote explains assumptions, exclusions and practical constraints. If a proposal promises unusually high savings without showing generation, self-consumption and export assumptions, treat it cautiously.

• Responsibility

  You should know who handles installation, certification, DNO paperwork, monitoring and aftercare.

• Support process

  The quote should explain who to contact for faults, warranty issues and monitoring problems.

• Survey approach

  A proper survey should check roof condition, access, shading, cable routes and electrical constraints.

• Contract clarity

  The proposal should state what is included, what is excluded and what may change after survey.

• Design explanation

  The installer should be able to explain why the selected panels, inverter and layout suit your home.

The best installers tend to be comfortable discussing limitations. If a roof is marginal, a battery is questionable or export assumptions are uncertain, you should hear that before you commit.

When solar panels may not be suitable

Solar is not right for every property. A heavily shaded roof, poor roof condition, limited suitable space, planned roof replacement, awkward access or very low daytime electricity use can weaken the case. Solar can still work in some of these situations, but the design needs more care and the payback depends heavily on actual use and export arrangements.

For flats, rented properties, listed buildings, conservation areas and shared roofs, permissions and ownership arrangements can become more complex. Do not assume an installer can solve these issues after the sale. Check property restrictions, roof rights and planning considerations before committing.

It is also worth being honest about disruption. Most domestic solar installations are relatively contained, but there may still be scaffolding, internal cable routes, inverter placement decisions, consumer unit work and short power interruptions. These details should be discussed before installation day, not discovered during it.

• Heavy shading

  Persistent shade from trees, chimneys or nearby buildings can reduce generation and complicate inverter design.

• Poor usage match

  Very low daytime demand can make savings more dependent on export income or battery assumptions.

• Unclear permissions

  Shared roofs, leasehold arrangements and protected properties need checks before signing a contract.

• Weak roof condition

  If the roof may need replacement soon, installing solar first can create avoidable removal and reinstatement costs.

• Limited usable roof area

  Small or awkward roof sections may not support a system large enough to justify the work.

A trustworthy quote should say when the case is marginal. Solar can be a strong investment for many homes, but it is not a universal answer.

How batteries, EV chargers and heat pumps change the comparison

A battery can change both the economics and the design of solar because it stores surplus generation for later use. It may suit homes with evening demand, time-of-use tariffs or future electrification plans, but it is not automatically the right choice for every household. Before accepting a bundle, compare the system quote with typical solar battery costs and the assumptions used for payback. Usable capacity, charge and discharge power, round-trip efficiency, location, warranty terms and backup expectations all need checking.

EV chargers and heat pumps can increase electricity demand, but timing matters. If a car is usually away during sunny hours, solar may not directly charge it without a battery or smart scheduling. A heat pump uses more energy in colder months when solar output is lower, so the design should be based on realistic seasonal behaviour rather than a simple annual total.

If you may add a battery, EV charger or heat pump later, tell the installer early. It can affect inverter selection, consumer unit planning, cable routes and where equipment is mounted. Designing for future changes is often easier before the first installation than retrofitting around a finished system.

• Battery location

  Check ventilation, access, manufacturer requirements and whether the proposed position is practical.

• Tariff interaction

  Time-of-use tariffs can change how a battery is used, but assumptions should be shown clearly.

• Backup expectations

  Ask whether the battery provides backup power, and if so, what circuits are covered.

• EV charging pattern

  Consider whether the car is at home during solar generation hours.

• Future cable routes

  Ask whether the installation leaves sensible routes for later equipment.

• Heat pump seasonality

  Check that the quote does not assume summer solar generation will fully offset winter heating demand.

A combined solar, battery, EV and heat pump plan can work well, but the design needs to be joined up. Treat each technology as part of the same electrical system, not as separate add-ons.

What to ask before accepting a solar quote

Before accepting a quote, ask for a written design summary rather than relying on a sales conversation. It should show the proposed system size, panel layout, inverter type, expected generation method, battery details if included, shading assumptions and what is included in the installation price.

You should also ask how export is handled. The installer should explain whether the system is expected to follow the relevant G98 or G99 process, who submits DNO paperwork and whether any export limit has been assumed. This is not just administration. It can affect design, timescale and how the system operates.

Finally, compare aftercare as carefully as the upfront proposal. Monitoring access, fault response, warranty handling and documentation all matter after the scaffolding comes down. If two quotes are close, the clearer handover and support process may be the better long-term choice.

A good solar comparison is not about finding the most impressive headline claim. It is about choosing a system that is suitable for the property, properly documented, realistically modelled and supported by an installer who can explain the design clearly.