An off-grid house in Mallorca is technically feasible and makes most sense where there is no grid connection. In 2025 the Balearic Islands covered about 24% of their demand through the subsea cable from mainland Spain, and 62% of local generation came from combined-cycle plants (Red Eléctrica). For most homes, solar panels with a battery and a grid connection are the better route. Our solar PV in Mallorca page shows how we design them.
By the technical team of Greentech Balear · Published 2 September 2025 · Updated 14 October 2026
How does Mallorca get its electricity?
Mallorca gets its electricity from power plants on the island and through a subsea cable from mainland Spain. In 2025 this cable covered 24.3% of Balearic demand. Demand reached 6,313 GWh, 4.1% more than the year before (Red Eléctrica, March 2026).
Generation on the islands in 2025 broke down as follows:
| Technology | Share of generation in 2025 |
|---|---|
| Combined-cycle plants | 62.3% |
| Solar PV | 14.5% |
| Gas turbines | 8.3% |
| Diesel engines | 6.3% |
| Waste, renewable and non-renewable | 2.7% each |
| Coal | 1.9% |
| Cogeneration | 0.8% |
Source: Red Eléctrica, Balearic electricity system 2025. Including self-consumption, the renewable share was 17.6%. The islands have 205 MW of self-consumption systems, 95.2% of them solar PV.
Grid-tied, with a battery or fully off-grid?
For a house with a grid connection, solar panels with a battery are usually the best solution. A fully off-grid system, or stand-alone installation, makes most sense for fincas without a connection.
| Option | Grid connection | Surplus | During a power cut | Best for |
|---|---|---|---|---|
| Solar without battery | yes | credited under RD 244/2019 | switches off | homes with daytime use |
| Solar with battery | yes | credited or stored | keeps running if inverter and battery offer backup | main homes and holiday homes |
| Stand-alone system | no | stored, otherwise unused | no grid dependence | fincas without a connection |
Choose a stand-alone system only if there is no grid connection or connecting would be disproportionately costly. In every other case the grid gives security in winter and credit for your surplus. Our article on the solar backup system for a second home explains how a battery helps during outages.
What does a house without a grid connection need?
A house without a grid connection needs four building blocks: solar panels, a battery, an off-grid inverter and a reserve for long spells of bad weather. Everything must be sized for winter consumption, when the days are short.
This is how we plan an off-grid house with Greentech Balear:
- Consumption analysis across the whole year, split by day and night.
- Solar capacity sized for the winter month with the lowest yield.
- Battery sized for night-time use and the reserve days you want.
- Choice of off-grid inverter and reserve, for example a generator.
- Installation, testing and documentation as a generating installation under the low-voltage regulation (ITC-BT-40).
- Remote monitoring and annual maintenance.
On rural land, self-consumption on legally built properties is permitted under article 48 of the Balearic climate law, Ley 10/2019. For the rooftop system itself, a prior notice to the town hall is usually enough. We explain each step in our article on solar panel installers in Mallorca.
What we see on off-grid projects in Mallorca
Many owners first want to understand how the island is supplied. According to Greentech Balear’s Search Console data (July to October 2026), the German version of this article appeared 1,546 times in Google Search, 323 of them for “Stromversorgung Mallorca” (Mallorca electricity supply) and its variant.
In our consultations, the wish for autonomy usually turns out to be a wish for reliable supply. Solar panels with a backup-capable battery usually meet that wish at lower cost than a stand-alone system. We design fully off-grid systems where the grid is far away. For more on using your own power, read our article on photovoltaic self-consumption.
Frequently asked questions
Is a fully off-grid house allowed in Mallorca?
Yes. A stand-alone system is a generating installation under the low-voltage regulation (ITC-BT-40) and must be carried out and documented by a registered electrical contractor. On rural land, article 48 of the Balearic climate law allows self-consumption on legally built properties. For the installation, a prior notice to the town hall is usually enough.
Will my solar system keep running during a power cut?
A solar system without a battery switches off during a grid failure for safety reasons. It keeps running only with a battery and an inverter that offers a backup or emergency power function. When you request a quote, ask specifically about this function and which circuits are supplied in an outage.
How big does the battery need to be?
That depends on your night-time consumption and how many sunless days you want to bridge. For a grid-tied house, a battery for one night is often enough. A stand-alone system needs more reserve or a generator. A consumption analysis across the whole year shows the right size.
Where does Mallorca’s electricity come from?
In 2025, 62.3% of Balearic generation came from combined-cycle plants and 14.5% from solar PV, with smaller shares from gas turbines, diesel engines, waste and coal. On top of that, the subsea cable from the mainland covered 24.3% of demand. These figures come from Red Eléctrica, published in March 2026.
Is an off-grid holiday home worth it?
For a holiday home with a grid connection, a stand-alone system rarely pays off. Solar panels with a battery cover use during the season and bridge power cuts. The grid operator credits your surplus. A stand-alone system mainly makes sense when there is no connection or connecting is very costly.
Sources
- Red Eléctrica — Balearic electricity system 2025 (press release, Palma, 11 March 2026): demand 6,313 GWh (+4.1%), subsea cable 24.3% of demand, generation mix, 205 MW of self-consumption.
- Govern de les Illes Balears — Step 4: prior notice and/or planning licence: prior notice for rooftop systems; art. 48 Ley 10/2019 for rural land.
- BOE — Royal Decree 842/2002, Low Voltage Electrotechnical Regulation (ITC-BT-40): low-voltage generating installations, including stand-alone systems.
- BOE — Royal Decree 244/2019 on self-consumption: self-consumption modes and surplus compensation.
Would you like your Mallorca home to depend less on the grid? Call us on +34 644 450 672, write to info@greentechbalear.com or visit our solar PV in Mallorca page.
By the technical team of Greentech Balear – energy solutions and building services in Mallorca: solar PV, air conditioning, heat pumps, heating and maintenance.