Solar panels: claiming when the installation does not deliver
Installations that do not produce what was promised, surplus energy that is never credited to the bill, legalisation files left half-done, roofs that leak, and loans that go on being collected even after the company has vanished. We explain what the self-consumption rules require, what rights you have as a consumer, and how a claim is also brought against whoever financed the deal.
What the installer has to deliver
A self-consumption installation does not end when the panels are bolted to the roof. For the client to have what they bought, several further things are needed, and they are forgotten with striking regularity:
- A technical report or full design, and execution by an authorised installation company, with a calculation of the expected output for that roof, that orientation and that consumption.
- A certificate of the electrical installation and legalisation with the competent body of the Comunidad de Madrid (the Madrid regional government).
- Notification to the distribution network operator and registration under whichever self-consumption arrangement applies, with or without surplus.
- A surplus compensation agreement with the electricity supplier, where that arrangement has been contracted for.
- The paperwork for applying for grants and reductions in the IBI (local property tax) and ICIO (tax on construction works), if that was sold as part of the package.
The most common failure is not technical but administrative. There are installations that have been producing for two years whose surplus has never reached the bill, because nobody completed the registration. The client discovers it when they add up what they have saved and find the figures do not work. That omission is a breach of contract that can perfectly well be claimed on, and it is usually easier to prove than inadequate output.
Compensation for surplus energy, explained
Real Decreto 244/2019 governs the administrative, technical and economic conditions of self-consumption. Its simplified compensation mechanism works as a financial balance within each billing period: the energy taken from the grid is valued at its price and the surplus energy exported is valued at whatever price applies, and is deducted from the bill (art. 14 of RD 244/2019).
There are two limits worth knowing before signing anything, because they dismantle a good part of the sales pitch:
- The value of the surplus can never exceed the value of the energy consumed from the grid in that billing period, which cannot be longer than a month. Put plainly: the bill can bring the energy charge down to zero, but not into negative figures, and what is left over does not roll forward.
- Anyone who opts for simplified compensation cannot take part in any other energy sale arrangement for that same installation.
Where the savings study you were given ignored these limits — and many do — the figure promised was unattainable from day one. That is not a risk the client takes on: it is incorrect information given by someone who knew the rules.
The most common problems
It produces less than designed
Shading that was never assessed, orientation or pitch badly resolved, inverter output badly matched to the panel array, modules of lower performance than those offered. This is established by comparing the actual output recorded by the inverter with the figure in the preliminary study, by means of an engineer’s report.
The promised savings do not arrive
Two things have to be separated. Output is a technical figure; savings depend in addition on the household’s consumption profile and on the price of energy. If the offer contains a specific annual savings figure, calculated by the company from the consumption data the client gave it, that figure forms part of what was contracted for and failure to meet it can be claimed on. If there was only a conversation, the case is much harder.
Damage to the roof
Badly sealed fixings, broken tiles, leaks that appear with the first heavy rain. This is liability for the execution of the works and for the damage caused (arts. 1544 and 1101 of the Civil Code, Código Civil), and it is worth documenting with photographs and an expert before anyone repairs anything.
An unfinished or abandoned installation
Panels put up and never connected, batteries that never arrive, monitoring that is never installed. Where the breach is fundamental and defeats the purpose of the contract, the course is to terminate it and recover what has been paid, together with damages (art. 1124 CC).
The grant that was never applied for
If the company undertook to handle the grant application and did not do so, or did it late or with incomplete paperwork, the loss is the grant that was missed, and whoever took on that task is liable for it.
Doorstep selling: the right of withdrawal
A good proportion of these installations are contracted for in the client’s sitting room, with a salesman who has rung the doorbell or telephoned to arrange the visit. That makes the contract one concluded away from business premises, with a right of withdrawal of fourteen calendar days, extended to thirty where the visit was not requested by the client (art. 102.1 of the consolidated text of the General Act for the Protection of Consumers and Users). And if the company did not give written notice of that right, the period ends twelve months after the date on which the original period would have expired (art. 105.1).
An argument installers use and the courts reject. Companies frequently contend that these contracts fall outside the rules on distance and off-premises contracts because they are contracts relating to immovable property (art. 93 e) TRLGDCU). The Audiencia Provincial de Castellón (the provincial appeal court of Castellón) rejected this clearly in its judgment of 21 February 2025 (ECLI:ES:APCS:2025:185): supplying and installing photovoltaic panels at a home amounts, at most, to attaching movable goods to immovable property, and does not fall within the concept of the creation, acquisition or transfer of immovable property or of rights in it. In that same case the client was held to be a consumer and the extended withdrawal period was applied, because the contract had not given notice of it.
The linked loan
Where the credit serves exclusively to finance that installation and the two contracts form a commercial unit, we are dealing with a linked credit agreement (art. 29.1 of Ley 16/2011, on consumer credit agreements). The consequences are decisive:
- If you withdraw from the installation contract, you cease to be bound by the loan, with no penalty whatsoever (art. 29.2).
- If the installation was not delivered, was only half delivered, or does not conform to what was agreed, and you have complained to the supplier without obtaining satisfaction, you may exercise those same rights against the finance company (art. 29.3).
- The ineffectiveness of the installation contract carries with it that of the credit agreement (art. 26.2 of the same Act).
This is the element that decides whether the case is actually worth money. Installers appear and disappear; the finance company is still there. Which is why the complaint to the supplier has to be made in writing and kept: it is the legal requirement for proceeding against the lender afterwards.
Communities of owners and collective self-consumption
The installation of common or private systems for harnessing renewable energy may be approved, at the request of any owner, by the vote of one third of the members of the community representing one third of the participation quotas; and the community may not pass on the cost of the installation or of its upkeep to those who did not vote in favour, although anyone who later wishes to join must pay the share that would have fallen to them, updated (art. 17.1 of the Ley de Propiedad Horizontal, the Commonhold Act). It is a very attainable majority, and it is worth bringing the item to the meeting properly prepared — a quotation, how the output is to be shared, the allocation criteria for collective self-consumption — rather than improvising on the day.
What can be claimed, and within what period
- Bringing the installation into conformity: completing, repairing or replacing it, free of charge and without significant inconvenience, including removing and reinstalling what is already in place (art. 118 TRLGDCU).
- A reduction in price or termination with repayment of what has been paid, where repair is impossible, disproportionate or has failed.
- Completion of the legalisation and of the compensation registration, or the cost of having someone else do it.
- Damages: the energy you went on paying for, the damage to the roof, the grant that was lost (art. 1101 CC).
- Time limits: three years of guarantee from delivery (art. 120.1 TRLGDCU) and five years in which to claim from the moment the lack of conformity becomes apparent (art. 124); five years for personal claims for breach of contract (art. 1964.2 CC); and the withdrawal periods already set out.
How we handle it, step by step
Gathering what you signed and what you were shown
Contract, output and savings study, brochures, loan, invoices, certificate of the installation, registration with the network operator and the electricity bills since. The preliminary study is the key document.
Checking the legalisation
We verify whether the installation is registered, whether the self-consumption registration was processed and whether there is a surplus compensation agreement. It is quick, and often resolves the matter on its own.
Technical report on output
An engineer compares the inverter’s actual output with the output designed for, and examines shading, orientation, inverter and workmanship. Without that comparison, an argument about performance is not won.
Withdrawal or claim, whichever suits
If the withdrawal period is still open because notice of it was never given, that is the cleanest route and it takes the loan with it. If not, a formal demand to the installer and to the finance company.
Proceedings against installer and lender
With both defendants in the same proceedings, which is what makes a favourable judgment worth something. We explain the cost and the scenarios beforehand.
Frequently asked questions
Eight months have passed since I signed. Am I still in time to withdraw?
Quite possibly. If the contract was signed away from the company’s business premises and you were not given written notice of the right of withdrawal, the period does not expire after fourteen or thirty days: it ends twelve months after the date on which the original period would have expired (art. 105.1 TRLGDCU). The first thing we look at is whether the contract contains that information and the withdrawal form.
The installer says there is no right of withdrawal because it involves a building.
That is the exception in art. 93 e) TRLGDCU, designed for the creation, acquisition or transfer of immovable property or of rights in it. The judgment of the Audiencia Provincial de Castellón of 21 February 2025 (ECLI:ES:APCS:2025:185) rules it out for the supply and installation of solar panels at a home: installing panels and equipment is, at most, attaching movable goods to immovable property.
My surplus never shows up on the bill.
This is usually because registration for the surplus arrangement under simplified compensation was never processed, or because there is no compensation agreement with the electricity supplier. It is worth checking that before arguing about output: if the registration is missing, the breach is clear and the solution can be a quick one.
Can I stop paying the loan while I claim?
Not on your own initiative and without more. Stopping payment without first having exercised whichever right applies can end in a debt claim and an entry on a credit blacklist. What you can do is withdraw where the period is still open — in which case the loan falls away — or assert against the finance company the rights you have against the installer, having first complained to the installer without result (art. 29.3 of Ley 16/2011). The order matters.
It produces, but less than the study said. Is that enough to claim?
It depends how much less, and how the study was worded. A small variation against an estimate falls within what is reasonable; a significant and sustained shortfall against an output guaranteed in writing is a lack of conformity. The engineer’s report, using the inverter’s own data, is what marks the difference between an impression and a claim.
Where we work
Our office is in Villanueva de la Cañada, and we act regularly in Brunete, Villanueva del Pardillo, Valdemorillo, Quijorna, Majadahonda, Las Rozas, Boadilla del Monte and Pozuelo de Alarcón, where self-consumption on detached houses has become widespread in recent years. This page forms part of our civil law practice; see also heat pump installations, building and renovation contracts and consumer rights.
Tell us about your case
If your photovoltaic installation is not producing what was promised, is not legalised, or you are still being charged a loan for something that does not work, tell us what you signed and what you were shown before signing. We study every case before taking it on, and we tell you frankly whether it has any prospect of success and against whom.
First consultation: quoted before we start.
28691 Villanueva de la Cañada (Madrid)