| DESNZ median price, installs up to 4 kW (2025/26) | £1,595 per kW of installed capacity |
|---|---|
| MCS performance estimate | Required in writing before the contract is awarded |
| Deposit ceiling under the Renewable Energy Consumer Code | 25 per cent of the estimated cost |
Why quotes are hard to compare
Installers present quotes in their own layout. One may list every component, while another gives a single total. So the cheapest figure on the table may hide the smallest scope.
The fix is to put every quote into the same frame before you judge it. This guide uses five steps: the system, the scope, the forecast, the price position and the sales process. Work through them in order, because each one depends on the last.
You can do step four in minutes with our free quote checker. The other steps need the paperwork in front of you.
Step 1: Match the system
Start with a simple table. Give each quote one row, and record the same details every time, because gaps then stand out.
- Array size in kWp, panel count and panel model
- Inverter model, and any optimisers or microinverters
- Battery make and usable capacity in kWh, if one is included
- Mounting system and monitoring
Usable capacity matters more than the headline battery size. Two batteries sold as the same size can store different amounts. Equally, the inverter type changes cost and behaviour, so read our guide to string inverters, microinverters and optimisers before you rank the options.
Under the MCS standard, the installer must send the manufacturer datasheets for the panels and inverter in writing. They must also send a drawing of the proposed panel layout. If a quote lacks these, ask for them now, since they are hard to chase later.
Step 2: Match the scope
Next, compare the work, not just the kit. Many price gaps come from items that one quote includes and another ignores.
Look for scaffolding, roof work, cabling, consumer unit changes, grid applications, commissioning, bird protection, making good and handover papers. Our guide to what a solar quote should include gives the full list. For example, a quote with no mention of bird protection may leave you paying later, so read about solar panel bird proofing before you sign.
Timing belongs here too, although it is easy to overlook. Check that the dates in the quote are realistic. See how long installation takes for realistic expectations.
The Renewable Energy Consumer Code asks its member installers to list what the quote does not cover. That includes site conditions that could add chargeable work, plus the rates that would apply. Hold every installer to that standard, because a good firm will not mind.
Step 3: Match the forecast
A bigger savings figure is not a better system. It may simply use friendlier inputs.
The MCS standard sets the base. The installer must calculate annual generation with a set method and an estimate of self-consumption. MCS also requires a warning that the figures are guidance for the first year and not a guarantee.
Installers may add their own estimates from other software. However, those cannot be given more prominence than the MCS estimate. If a figure is significantly better than the standard result, the installer must add a warning to treat it with caution.
Check these inputs on every quote:
- Orientation, tilt and shading
- Assumed home occupancy and yearly electricity use
- Electricity price and export rate used for savings
- Any ageing of the panels over the years
The Consumer Code adds a rule on savings. Estimates must use your actual energy use, and the assumptions about future prices must be set out and attributed to a reputable source. If finance is part of the offer, payback must count the repayments and the full amount payable.
Step 4: Check where the price sits
Now divide each system price by its kWp, with any battery taken out. This gives a price per kWp that you can set against official data.
The Department for Energy Security and Net Zero (DESNZ) reports a median of £1,595 per kW of installed capacity for installs up to 4 kW in 2025/26. For installs from 4 to 10 kW the median was £1,546. These figures cover April 2025 to March 2026 in Great Britain and exclude batteries. Prices vary, so treat them as a reference point and get written quotes.
A price far below the median deserves a question, not applause, because the gap has a cause. Ask what has been left out. A price far above it deserves the same question. Neither is automatically wrong.
Location can matter as well, since labour and access differ by area. Compare with local guidance such as our pages on quotes in London and what Scottish households should expect. Our page on typical solar panel costs puts the national picture in one place.
Certification affects value too. Ofgem says solar PV up to 50 kW needs an MCS certificate, or an equivalent, to receive Smart Export Guarantee payments in Great Britain. A cheaper non-certified job could therefore cost you export income.
Step 5: Review the sales process
Equipment is only half the decision, however. The way you are sold to matters as well.
MCS certification covers the installation standard. The Renewable Energy Consumer Code covers selling, contracts and aftercare. Ask each firm to confirm both in writing, with numbers you can check on the scheme registers.
Watch for pressure, because it is a warning sign of a poor sale. The Code requires a written quotation signed by an authorised signatory, a “no surprises” pricing policy and a cancellation period of at least 14 days. A deposit should not exceed 25 per cent under any circumstances. For the details, read our deposit and payment checks.
Pushy tactics are a warning in their own right, so read the list. Our list of solar quote red flags shows the most common ones.
Put it together
When the table is complete, the best quote is usually clear. It is the one that names its equipment, defines its work, uses a sensible forecast and sits in a believable price range. It also comes from an installer who answers questions in writing.
If you hold only one or two quotes, you can request more MCS-certified quotes to complete the comparison. Solar Panel Price Check is independent and is not an installer, lender or broker. Your request goes to the operator, who matches you with installers.