Physical battery
A unit in your home that stores real kWh. It is yours, it works with any supplier and, with the backup option, it can keep the lights on during a power cut.
Solar panels in Xàtiva, with a proper study
A residential solar installation sized with data: your roof's real radiation and your hour-by-hour consumption. No closed packs and no guesswork sizing. Engineering from Xàtiva for La Costera and the surrounding areas.
The study: PVGIS and your hour-by-hour consumption
Before proposing anything, we cross two things: the radiation your roof receives according to PVGIS, the European Commission's database, and your real hourly consumption curve, the one your meter records. That tells us how much energy you will produce each hour of the year and how much you will actually use.
A bill is not enough. The bill says how much you use per month, but not when. And the when is everything: a house that uses power at midday is nothing like one that switches everything on at dusk. Sizing from a bill is sizing blind.
You receive the study signed, with estimated month-by-month production and savings calculated on your hours, not an average customer's. And when you decide, the paperwork with the council and the regional government (GVA) is handled by us from start to finish.
The battery is no longer the extra: it comes first
According to UNEF, 61% of households that installed solar in 2025 did so with a battery. It makes sense: you store the midday energy you do not use and spend it at night, when the house uses most and electricity costs most. In the study we size it with your curve, and if it does not pay off for you, we tell you just as plainly.
“Virtual battery”
Not a battery: a wallet held by your supplier. It records the value of your surplus so it can be offset against other bills. It usually comes with a lock-in period and with terms the company itself sets and changes. It can be worthwhile, but call it what it is before you sign.
Simplified compensation
What RD 244/2019 provides: your surplus is discounted from that month's bill, up to a cap. You are never paid cash: at most, the energy part of your bill drops to zero. What you are paid per kWh depends on your tariff.
The three options compared with data, lock-ins included: physical battery, virtual battery or surplus.
What each supplier pays for your surplus, with numbers: surplus tariffs compared.
What does the price depend on?
The installation carries no catalogue price because we do not sell packs: every quote comes from a study, and two houses that look identical from the street can need different installations. Our paperwork and certificate services do carry a published price, VAT included, because their scope can be defined. For the installation, what you can have is a market reference: according to APPA, the average residential price in Spain in 2025 was around 1,215 €/kW installed. These are the variables that move your figure:
The system size you need
Not whatever the special-offer pack happens to include. It comes from the study: how much you use, at what hours, and how much fits on your roof.
Your roof
Working on curved Arabic tiles is not the same as working on a flat roof. Nor is a roof at street level the same as one that needs scaffolding.
The electronics chosen
String, optimisers or microinverters. The right choice depends on your shading and your roof, and each one has its own cost.
The battery
It is the part that moves the total most. That is why it is sized with your consumption curve, not by eye.
The electrical run
The distance between panels, inverter and your consumer unit. And the state of the house's own wiring.
The paperwork and your tax return
Both are included in our work. And there are tax deductions in force that change the final sums considerably.
Every variable in detail, with the market benchmark and its source: how much solar panels cost in 2026.
The state and regional deductions currently in force are explained in grants and deductions 2026.
Get a feel for the savings in one minute
Three questions and we give you an honest range, with every assumption in plain sight. No phone number or email needed to see the result.
If it is not on the list, type it anyway. Across this area, sunshine per kWp barely changes from one town to the next.
You can try more roof and usage combinations in the solar savings calculator for La Costera.
How much do shading and orientation matter on your roof?
Three things decide how much a roof produces: which way it faces, how steep it is and what casts shade on it. All three are measured in the study, not assumed.
An east-west roof works. It produces somewhat less overall than a south-facing one, but it spreads production across morning and evening, which is exactly when most households use power. For self-consumption, that spread often makes better use of each kWh than one huge midday peak that ends up exported to the grid.
A small shadow can do serious damage. In a string installation, panels are wired in series: a chimney shading one panel mid-afternoon slows the whole row, not just that panel. That is why shading is studied hour by hour across the whole year. And why the electronics are chosen after seeing your shading, not before.
Tilt is worked with, not fought. On most pitched roofs in this area, panels go flush with the roof, following its pitch. The difference against the theoretical ideal tilt is small and rarely justifies raised structures, which cost more, load the roof more and suffer more wind.
The detail of each case, including what a partial shadow really costs: solar panel shading and orientation.
Microinverters, optimisers or string? Which one and why
There is no best option in the abstract: there is a right one for your roof. Anyone who always offers you the same thing is not choosing for you, they are selling what they have in the warehouse.
String inverter
A clean roof, no shade, a single orientation.
Panels are wired in series to a single inverter. It is the simplest and cheapest option. Its limit: the series performs at the pace of the worst panel. With no shade, that limit does not get in the way.
Optimisers
Partial shade or a roof with two faces.
Each panel carries an optimiser that lets it work at its best even if the one next to it is shaded. It keeps a central inverter and adds panel-by-panel monitoring.
Microinverters
Complicated roofs, several orientations, difficult shade.
Each panel has its own small inverter. None depends on another and there is no single point of failure. It is the most expensive option. We propose it when the roof justifies it, not as a routine.
When each option genuinely pays off and what maintenance it brings later: microinverters, optimisers or string.
What happens to brands and warranties in 20 years?
Your quote will show the make and model of every piece of equipment, with its warranties in writing. No generic “top-brand panel”. And with the panel's two warranties listed separately, because they are not the same thing.
Product warranty: covers defects in the panel as a device, normally between 12 and 15 years depending on the manufacturer. Performance warranty: promises the panel will still produce a minimum percentage after 25 or 30 years. That is the small print worth reading: a panel loses around 0.4% of its production per year, so at 25 years it still delivers the vast majority of what it did when new.
The inverter is another story: its usual warranty is around 10 years and it is the piece of equipment most likely to need replacing during the installation's life. Worth knowing from day one and including in the long-term sums, which is what we do in the study.
What if the manufacturer disappears? It happens, and a 25-year warranty is worth only as much as whoever signs it. That is why we choose manufacturers with years of history and a structure in Europe, not the cheapest unknown brand of the month. And that is why it matters that your installer is still around: we watch over your installation every day and, if something fails, we take on the claim with the manufacturer for you.
At the end of their life, panels are recycled. Most of a panel is glass and aluminium, materials recovered through recycling channels already running in Spain. You will not be leaving an orphan waste problem on the roof.
What each warranty covers and who answers if the manufacturer closes: solar panel brands and warranties.
How do you pay for a solar installation?
By milestones, and never 100% up front. Each payment is tied to something that has already happened: the equipment ordered, the installation finished and working, the paperwork filed. The exact schedule is set out in your quote, before you sign anything.
If someone asks for all the money before setting foot on your roof, ask yourself what binds them to come back. Our model is the opposite: we charge as we deliver, and afterwards we stay on watch to see that your installation produces what the study promised.
Questions we hear before people decide
Could the panels give me roof leaks?
Done properly, no. On Arabic tile we use mounts that respect the tile, and every anchor is sealed onto the batten, not onto a loose tile. On flat roofs, where the structure allows it, we mount on ballast without drilling. And one red line: if your roof is asbestos cement (uralita), it is not touched. First removal by a licensed company, then panels. Anyone offering to bolt on top of it is creating a legal and health problem for you.
If there is a power cut, do I still have power?
No, unless you have a battery with a backup function. Every grid-connected installation carries anti-islanding protection: if the grid goes down, the inverter shuts off for the safety of the crews repairing it. The blackout of 28 April 2025 made it plain: panels on their own went dark too. If you want power during an outage, say so in the study and we choose a battery with backup and the circuits you want to keep alive.
Do I have to change electricity supplier?
No. Solar panels work with any supplier. What is worth doing is checking what yours pays for your surplus, because offers differ widely. We explain it on the surplus tariffs page.
Should I tell my home insurer?
Yes. Notify your insurer so the installation is recorded in your home policy. It is a short formality and saves arguments if you ever make a claim. With the CIE certificate and the documentation we hand over, it takes one phone call.
Start with the study
Tell us where your house is and we will tell you what we need to study your roof and your consumption. No obligation and no salesman knocking on your door. We work across La Costera and the surrounding villages, town by town.
A Captia Technology company. Chartered, qualified engineers.
Before you decide, have a look at these
- Batteries for solar panelsWhat installing a battery covers, what it does not, and what drives the quote.
- Energy certificateIf you are selling or letting the home, an engineer signs it after the visit.
- EV home chargerThe same roof can charge the car. It is studied together with the panels.
- Shared solar for buildingsIf the roof belongs to an owners association, the split and the paperwork change.
- Systems above 10 kWAs the power rises, the file needs a signed project and site supervision.