Best Solar Proposal Software Spain: 2026 Guide

The most damaging line in a Spanish solar proposal is the promise of a zero electricity bill. It is not an aggressive estimate, it is a claim the rules do not permit. Under compensación simplificada the surplus credit cannot take the energy component of the bill below zero, and there are fixed charges beyond the energy component that solar never touches. Every customer sold on a zero bill receives an invoice within a month that contradicts the document they signed. This guide compares the platforms Spanish installers should shortlist, and covers what a proposal has to show instead.

Short version. The best solar proposal software for Spanish installers in 2026 is SurgePV, because it settles compensación simplificada monthly with the zero floor and prices surplus at hourly spot, then generates the customer document from the same design record. PVsyst is the bankable simulation reference with no proposal layer. Aurora assumes US net metering, which Spain does not operate.

For the design-side comparison see our best solar design software Spain guide, and the global solar proposal software ranking for the category without the local lens.

Why The Zero Bill Promise Fails

Two separate constraints stand between a Spanish household and a zero bill.

The first is the floor. Compensación simplificada credit is capped so that the energy component of the bill cannot go below zero in any month. Surplus beyond that point does not carry forward and is not paid.

The second is what the credit can reach at all. A Spanish bill contains charges beyond the energy component, and the surplus credit does not apply to them. Even a household whose energy component is fully offset every single month still receives an invoice.

The practical consequence is that “we will eliminate your bill” is unachievable, while “we will substantially reduce it, and here is the month-by-month picture” is both achievable and more persuasive to anyone who has read their own invoice.

There is a commercial argument here as well as an ethical one. Once a customer understands the floor, a competitor’s zero-bill promise stops looking like a better deal and starts looking like a warning sign. Explaining the rule is a way of disqualifying the quotes you are competing against.

Twelve Rows, Not One

The single highest-value change most Spanish installers can make to their proposal template is replacing the annual summary with a monthly table.

The monthly view is not merely more accurate. It is more useful to the customer and more useful to you, because it converts an abstract sizing argument into a visible pattern. A homeowner looking at three summer rows where surplus exceeds the cap can see for themselves why a smaller array, a shifted load or a battery makes sense. That is a far easier conversation than asserting it.

It also sets expectations for winter. A customer who has seen January in the table before signing does not phone in January.

Price The Export At Hourly Spot

Spanish surplus is credited at the hourly spot price. Because solar generation is correlated across the country, midday spot prices are depressed at exactly the hours a residential system exports most.

A proposal applying an average annual price to exported units therefore overstates export value, and the error is systematic rather than random. Using an hourly price series gives a lower, defensible figure.

That lower figure is not bad news for the sale. It strengthens two recommendations that genuinely help the customer. Load shifting into the midday window converts low-value export into avoided import at full retail. Storage does the same thing across a longer time gap. Both arguments depend on showing the spread between what surplus earns and what imported energy costs, and average pricing hides that spread almost completely.

Regional And Municipal Support, Named Not Assumed

Spanish incentives are not national in the way customers often assume.

IDAE-funded programmes are administered by the autonomous communities, so availability, terms and application windows differ by region. A proposal should name the specific programme and state whether the customer is confirmed eligible or whether an application is required and pending.

IBI relief is municipal. Both the percentage reduction and its duration are set locally, and plenty of municipalities offer nothing at all. Presenting an IBI reduction without confirming the municipality offers one is the most common way a Spanish quote becomes undeliverable after signature.

The reliable rule is to distinguish clearly between confirmed and applied-for support, and to show the customer’s position with and without anything that is not yet secured.

The Six Platforms Spanish Installers Should Evaluate

1. SurgePV, the integrated pick

Monthly compensación simplificada settlement with the zero floor, hourly spot pricing, collective self-consumption allocation, configurable regional and municipal incentives, and white-label proposals with e-signature in 9 languages including Spanish, generated from the same design record. $1,299 to $1,899 per user per year.

2. PVsyst

Bankable simulation for large ground-mount and commercial work, frequently named by lenders. No proposal layer and no Spanish settlement logic. See our PVsyst alternative review.

3. PV*SOL

Strong European residential and small commercial modelling with capable self-consumption tooling. Desktop-based, partial proposal capability. Our PV*SOL alternative guide covers the trade-offs.

4. OpenSolar

Free, quick, and produces a presentable customer document. No monthly settlement logic and no collective scheme support. See our OpenSolar alternative comparison.

5. Aurora Solar

Capable residential design and proposals built around US net metering, which Spain does not operate. See our Aurora Solar alternative comparison.

6. Spreadsheets plus a yield tool

The Spanish default in smaller practices, and the usual origin of the annual-totals zero-bill promise.

Spain Solar Proposal Software Comparison

Worked Example: What The Customer’s June Bill Actually Says

An illustrative calculation, not a specific customer project. Inputs: 5 kWp array near Valencia, household consuming 4,500 kWh a year, self-consumption around 35%. Four representative months shown.

The annual summary for this system reads well. The monthly table tells the customer three things the summary cannot: January will still cost money, June is wasting energy, and the array is sized past what this household can use.

Each of those is an opportunity rather than a problem. January argues for realistic expectations. June argues for load shifting, storage, or a collective scheme. And the sizing observation, made by you before the customer discovers it, is the difference between a trusted supplier and one who oversold.

Who Should Choose What

• Choose SurgePV if you need monthly settlement with the zero floor, hourly pricing and regional incentive configuration in one document.
• Choose PVsyst where a lender names it on commercial or ground-mount work, paired with separate quoting.
• Choose PV*SOL if your team is desktop-based and does detailed European residential modelling.
• Avoid any tool or template that promises a zero bill. The rules do not allow it and the first invoice will prove it.

After signing, pipeline and follow-up sit in a CRM. QuickEstimate takes the handoff from SurgePV by API.

The Bottom Line

Spanish proposals fail on a promise the regulations forbid.

• Never promise a zero bill. The credit cannot take the energy component below zero, and fixed charges sit outside it entirely.
• Show twelve monthly rows. Winter imports and summer waste are both invisible in an annual summary and both obvious to the customer within a year.
• Price export at hourly spot. Average pricing overstates surplus value and hides the spread that justifies storage.