A battery stores the energy your panels produce during the day and gives it back at night. The unit carries no catalogue price: it depends on usable kWh, on DC or AC coupling and on the electrical work. The upfront paperwork check does: €49, VAT included, and credited back if you go ahead.
If you are still weighing a real battery against a virtual one or plain surplus compensation, that comparison lives in battery or surplus. This page is the other half: what we install, what we do not, how it is done and what paperwork it drags along.
What does carry a published price today
The documentary check on your existing panels. It is the first step whenever a battery is added to a system that is already in place.
Upfront assessment
€49
VAT included
€49 credited back if you book a €199-or-more service within 30 days
Resolution work, from €199
Last legal review: .
It solves a timing mismatch: panels produce at midday and most houses use their power early in the morning and at night. Without a battery that surplus goes to the grid and is offset on the bill at whatever your tariff pays. With a battery it is stored and used when buying that same energy would cost more.
It is not compulsory and it does not always pay off. What decides is your consumption curve, not a catalogue. What suppliers pay today for each exported kWh is in surplus tariffs compared, and the order of magnitude of a full installation is in how much solar panels cost.
What falls outside is covered by: legalising an added battery, checking the state of your paperwork.
Six steps, each with someone responsible for it. Installation dates sit in your quote, on equipment already ordered: we do not publish a generic works deadline because it would depend on the unit chosen and on your house.
Step 1 · You
You send us your latest bill, the hourly consumption recorded by your meter and, if you already have panels, the installation paperwork.
Step 2 · Captia
We cross your consumption curve with your roof's output according to PVGIS and work out how many kWh you would really store. If a battery does not pay off for you, we say so in writing.
Step 3 · Captia
You get the quote with make, model, usable capacity, warranties, a milestone payment schedule and an installation date. That date sits in your quote, with the equipment already ordered.
Step 4 · Licensed installation company
Fits the battery, connects it and issues the installation certificate for the work carried out.
Step 5 · Captia
Commissioning, configuration of charge and discharge modes and handover of the folder with the equipment documentation.
Step 6 · Captia and the authorities
If the battery is added to an installation that already existed, the official file has to reflect it. That is a separate service and its decision time belongs to the authorities, not to us.
Six things, none of which require you to know about electrics. The first three are enough to start sizing.
The battery and its installation carry no catalogue price, for the same reason a full installation does not: the scope cannot be defined without seeing your consumption, your inverter and where the unit goes. What does carry a published price, VAT included, is the documentary work, and here it is with the figure in front of you.
| Item | Amount |
|---|---|
| Battery, installation and commissioning | Quoted after the study, with make, model and usable capacity. No catalogue price. |
| Documentary check on your panels, if you already have them | €49, VAT included |
| Credit from that check | €49 credited back if you book a €199-or-more service within 30 days |
| Legalising a battery added to an existing installation | A separate service, with its price published on its own page. |
| Third-party fees on that check | No third-party fees |
According to the annual self-consumption and storage report by APPA Renovables, the average residential price in Spain in 2025 was around 1,215 €/kW installed. That average covers the photovoltaic installation and does not include the battery, which is the line item that moves a quote the most and can approach the cost of everything else. According to UNEF, 61% of homes that installed panels in 2025 fitted a battery from the start.
There are three different clocks and they should not be added up. The installation one sits in your quote, with a date, because it depends on the unit chosen and on the manufacturer's supply. The one belonging to the authorities we never commit to. And ours, the documentary work that comes first, is the only one we do commit to, with its figure and with what it does not promise.
2 working days
Counted from: Que el formulario esté completo y los documentos subidos.
What this turnaround does not cover
Your grid operator
Confirmación del CAU o de la modalidad de autoconsumo registrada.
No date commitment on our side.
Your electricity retailer
Aclaración de por qué la factura no refleja compensación de excedentes.
No date commitment on our side.
We commit to filing a complete application and following it through. The decision date is set by the authority, not by us, so we do not promise it.
A battery can be added, and it is the most common case. Before touching anything it pays to know what your file says, because the modification is made on what is already on record. If it does not turn up, we find out what is there first.
Two ways out: AC couple the battery onto your current inverter, or replace it with a hybrid one. The second is more expensive and is quoted separately, with the figure in front of you before you decide.
Only a battery with a backup function gives you that, installed with the function enabled and with the circuits chosen in advance. Without it, a grid outage shuts the panels down too, because of the inverter's anti-islanding protection.
Then a battery may not pay off yet, and you will see that in writing in the study. Storing energy makes sense when you use at night what you produce during the day.
Adding storage to a file that does not exist is not a modification, it is a regularisation. It gets sorted first and quoted for what it is.
The file of a self-consumption installation describes one specific installation. If you add storage, the installation changes and the file has to change with it. Which modification applies depends on the architecture of the unit, and that is the first thing we classify. When the battery is part of an installation we carry out, the paperwork is inside the same job; when it is added to an existing installation, it is a service with its own page and price.
Only if it is a battery with a backup function and the installation has been prepared for it. Every grid-connected installation has anti-islanding protection: if the grid drops, the inverter disconnects for the safety of whoever is repairing the line. Without backup everything shuts down, battery included.
Yes. We start by looking at what paperwork the installation has and which inverter it uses, because that is what decides whether the battery is DC or AC coupled. That check has a fixed price and is credited back if you then book the service that resolves whatever comes up.
Not always. If your inverter is a hybrid or accepts a battery module, the battery is DC coupled. If it does not, the battery can be AC coupled with its own charging inverter. Replacing the inverter is the third option and we propose it when the numbers justify it, not as a default.
A home battery warranty is expressed as two conditions at once: years and cycles or total energy processed, and it ends with whichever comes first. The quote shows make, model, usable capacity and both conditions in writing, not the generic phrase leading brands.
No. A virtual battery is not equipment: it is an accounting credit with your supplier, on terms that supplier sets. It stores no kWh and gives no power during an outage. The full comparison of the three options is on our battery or surplus page.
The requirement that the file of a self-consumption installation describe the real installation comes from Royal Decree 244/2019, on electricity self-consumption, verified on .
Send us the bill and the hourly consumption and we will tell you how many kWh you would really use, which unit fits your inverter and what paperwork it brings with it. If the numbers do not favour you, you will see that in writing too.
A Captia Technology company. Chartered, qualified engineers.
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