A UK solar proposal is not a US solar proposal with the currency symbol changed. The performance estimate has to be produced the MCS way or the installation is not certifiable. The export revenue depends on which Smart Export Guarantee tariff the customer signs, and those range from about 4p to over 15p per kWh depending on the supplier. Battery attachment rates in the UK are far higher than in most markets, which means the proposal has to model self-consumption properly rather than treating export as the default. And almost every proposal platform on the market was designed for a different country.
This ranking is about which tools survive those constraints.
Direct answer. The best solar proposal software in the UK for most MCS-certified installers is Open Solar or SurgePV, depending on whether you need the design and single-line output in the same license. Neither generates an MCS-compliant performance estimate for you, which remains a separate calculation under MCS 003 and MIS 3002. Budget for the proposal tool and the MCS calculation as two different things.
TL;DR
- MCS is the gate. If the installation is going to be MCS-certified, the performance estimate given to the customer has to follow the MCS standard method, and no mainstream proposal tool does that natively.
- The Smart Export Guarantee is supplier-set, not fixed. A proposal with a single assumed export rate is guessing at the biggest variable in the payback.
- UK battery attachment is high, so self-consumption modelling matters more here than in most markets. Half-hourly modelling beats annual averages.
- Grid connection runs through G98 and G99. Under 3.68 kW per phase is notify-after. Above it needs prior DNO approval, and that timeline belongs in the proposal.
- Vendors quote in USD. Budget the exchange rate, and ask whether they will invoice in GBP.
What the UK Actually Changes About Proposal Software
MCS governs the performance estimate. For an installation to be MCS-certified, and therefore for the customer to access the Smart Export Guarantee, the performance estimate must be produced using the MCS standard method under MCS 003 and the relevant installer standard. That method has defined inputs for orientation, inclination, and shading. A generic simulation output from a US-built proposal tool is not a substitute. Practically, most UK installers run the MCS calculation separately and use the proposal tool for the customer-facing document and the financial model.
Export revenue is supplier-dependent. The Smart Export Guarantee replaced the Feed-in Tariff and obliges larger suppliers to offer an export tariff, but the rate is set by each supplier. The spread across the market is wide, and some of the highest rates are tied to the customer also taking an import tariff from the same supplier. A proposal that assumes one export rate for everyone is modelling the wrong thing.
Time-of-use import tariffs change the battery case. UK import tariffs with cheap overnight windows make battery arbitrage a real part of the economics, separate from solar self-consumption. Proposal tools that model solar and battery as one blended saving miss this.
Connection is G98 and G99. Under Engineering Recommendation G98 a single-phase installation up to 16 A per phase, roughly 3.68 kW, can be connected and notified afterwards. Above that, G99 applies and prior approval from the distribution network operator is required, which adds weeks. That timeline is a customer expectation issue and it belongs on the proposal.
VAT. The zero rate on qualifying domestic energy-saving materials materially changes the customer-facing number, and a proposal tool built for another market will not apply it correctly by default.
The UK passed 18 GW of installed solar capacity in 2025, according to the UK Department for Energy Security and Net Zero, with domestic rooftop the fastest-growing segment by installation count.
The 7 Platforms Ranked for the UK Market
| Platform | Best for | SEG and TOU tariff modelling | Battery self-consumption | MCS estimate | Price per seat per year |
|---|---|---|---|---|---|
| OpenSolar | Most UK domestic installers | Good, configurable | Yes | No | $0 plus transaction fees |
| SurgePV | Design plus proposal in one license | Yes | Yes | No | $1,299 to $1,899 |
| Easy PV | UK-built, MCS-aware workflow | Yes | Yes | Closest to native | Subscription, GBP |
| Aurora Solar | Larger commercial-facing teams | Configurable | Yes | No | $1,908 to $3,108 |
| PVsyst | Technical yield for C&I and funders | Not a proposal tool | Yes | No | ~$500 |
| Pylon | Value-tier domestic | Yes | Yes | No | ~$1,000 |
| Spreadsheet plus PDF | Very low volume | Manual | Manual | Manual | Time |
OpenSolar
The most widely used option in UK domestic solar, and the reason is straightforward: it is free at the seat, it handles UK tariffs and battery modelling credibly, and the customer-facing proposal is good. It is monetised through hardware and financing, so the cost is variable rather than absent. For a small installer that trade is usually favourable. We ran the crossover math in OpenSolar pricing.
SurgePV
The pick when the same license also has to produce the technical output. It generates the 3D roof model, 8,760-hour shading, the string design, the single-line diagram, and a white-label interactive proposal. For a UK installer doing commercial rooftop alongside domestic, that removes a second tool and a second modelling pass. It does not produce the MCS performance estimate, which stays a separate step.
Easy PV
Built in the UK for the UK, and it shows in the workflow, which is organised around the way a UK installer actually assembles a domestic job. It is the closest thing to an MCS-aware commercial product in general use. If your business is purely UK domestic, evaluate it seriously.
Aurora Solar
Strong product, priced for the US market, and its greatest strengths, LIDAR roof capture and deep US lender integration, are worth less in the UK than they are in California. Worth considering for larger commercial-facing teams. See Aurora Solar pricing and our Aurora Solar alternatives comparison.
PVsyst
Not a proposal tool at all, included because UK commercial and funded projects still ask for a PVsyst yield report. PVsyst price is roughly $500 per seat.
Pylon
Lower-priced domestic proposal tooling with a growing UK presence. Thinner than OpenSolar or Easy PV on UK-specific tariff handling, but the price is real.
Spreadsheet plus PDF
Still how a meaningful number of small UK installers work. It is not wrong at low volume. It stops working the moment you need to model half-hourly self-consumption with a battery, because that is not a spreadsheet job.
Try the software behind this guide
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What a UK Proposal Has to Contain
- System specification with module and inverter make, model, count, and total capacity.
- MCS performance estimate, produced by the MCS standard method, presented as the annual generation figure. This is the number the customer is entitled to rely on.
- Shading assessment consistent with the MCS method inputs.
- Self-consumption estimate, ideally half-hourly, showing how much generation the household actually uses versus exports.
- SEG export assumption with the supplier and tariff named, not a generic rate.
- Battery modelling separated into solar self-consumption benefit and tariff arbitrage benefit, if a battery is included.
- VAT treatment stated, given the zero rate on qualifying installations.
- Connection route, G98 or G99, with the DNO approval timeline if G99 applies.
- Assumptions for energy price inflation and system degradation.
Items 5 and 9 are where UK proposals diverge most from each other on the same roof. Two installers quoting the same house can show payback periods years apart purely on export rate and inflation assumptions. Put both on the page.
Pricing in Pounds
Every vendor except Easy PV quotes in US dollars.
| Stack | USD per year | Approx. GBP at 0.79 | Covers |
|---|---|---|---|
| OpenSolar | $0 plus fees | Transaction-linked | Proposal and basic design |
| Pylon | ~$1,000 | ~£790 | Proposal |
| SurgePV | $1,299 to $1,899 | ~£1,026 to £1,500 | Proposal plus full design and SLD |
| Aurora | $1,908 to $3,108 | ~£1,507 to £2,455 | Proposal plus design |
| Add PVsyst for C&I | +$500 | +~£395 | Yield report only |
Exchange rate is illustrative. Ask each vendor whether they invoice in GBP, because the ones with a UK presence often will.
What Most UK Installers Get Wrong
They quote a single Smart Export Guarantee rate across every customer.
The SEG rate is set by the supplier and the spread is wide. Quoting the market-leading rate to a customer who will end up on their existing supplier’s basic tariff overstates the payback substantially. Quoting a low rate to a customer who would switch understates it and loses the deal. The right handling is to model two scenarios and show both, and to name the tariff assumed.
The second mistake is modelling battery benefit as if it were purely solar self-consumption. In a UK household on a time-of-use import tariff, a meaningful share of the battery’s value comes from charging cheaply overnight and discharging at peak, entirely independent of the solar array. Proposals that blend those two effects into one number cannot explain to the customer why the battery pays, and cannot defend the figure when challenged.
When Proposal Software Is Not the Constraint
If your bottleneck is that commercial enquiries stall because nobody has time to produce a proper roof layout, a shading study, and a single-line diagram, a better proposal tool does not fix it.
That is an engineering capacity problem, and it is what our solar rooftop detailed engineering design service exists for, alongside solar 3D pre-design for sales-stage 3D and shading models in 48 hours. UK installers commonly keep a light proposal tool for domestic work and route commercial engineering out, which keeps overhead down while letting them bid work they would otherwise pass on. The sample deliverable pack shows the output format, or talk to our team about a live enquiry.
Conclusion
- Treat the MCS estimate as a separate deliverable. No mainstream proposal platform produces it. Assume you need the calculation alongside the tool, not inside it.
- Model two SEG scenarios and name the tariff. It is the single biggest variable in a UK payback figure and the easiest one to quietly overstate.
- Split battery value into self-consumption and arbitrage. A blended number cannot be defended when the customer asks how the battery pays for itself.
In this country series: solar software in the UK, best solar design software in the UK, shading analysis software in the UK, Helioscope review. Tool deep dives: Aurora Solar review, Opensolar review.
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Disclosure and accuracy note
Commercial relationship. Heaven Designs and SurgePV are part of the same group. Treat our recommendation of SurgePV as a vendor making its own case, not an independent verdict. We have tried to describe every other product fairly, and to say plainly where a competitor is the better choice.
Pricing. All prices are indicative, compiled from public sources when this page was written. They vary by tier, region, contract term and exchange rate, and change without notice. Several vendors quote rather than publish, and some price in currencies other than the US dollar, so a converted figure moves with the exchange rate. Confirm current pricing with the vendor before you decide anything.
Trademarks and corrections. All product names and trademarks belong to their respective owners, and are used here for identification and comparison only. Their use does not imply affiliation with or endorsement by those companies. If anything here is out of date or wrong, tell us and we will correct it.
FAQ
What is the best solar proposal software in the UK? OpenSolar for most domestic installers on cost and UK tariff handling, Easy PV if you want a UK-built MCS-aware workflow, and SurgePV when the same license also has to produce the design and single-line diagram.
Does any solar proposal software produce an MCS performance estimate? Not natively in the mainstream international platforms. The MCS standard method under MCS 003 is a defined calculation and most UK installers run it separately, using the proposal tool for the customer-facing document and financial model.
How do proposal tools handle the Smart Export Guarantee? As a configurable export rate. Because SEG rates are supplier-set and vary widely, the quality of the output depends entirely on whether you enter a realistic tariff. Model two scenarios rather than one.
Do I need G99 approval and should it be in the proposal? G99 applies above roughly 3.68 kW per phase and requires distribution network operator approval before connection. Below that, G98 allows connect-and-notify. The G99 timeline affects the customer’s install date, so yes, put it in the proposal.
How much does solar proposal software cost in the UK? From £0 with OpenSolar’s transaction model to roughly £2,455 per user per year at Aurora’s higher tiers. Most UK installers land under £1,500. Cross-platform math is in our solar design software pricing breakdown.
Does the zero-rate VAT get handled automatically? Not in tools built for other markets. Check it explicitly during evaluation, because it changes the headline customer number.
What about the design software decision separately? Covered in our companion ranking, best solar design software in the UK.
