Tens of thousands of homes and businesses in Spain have relied on solar self-consumption to gain energy independence and reduce their electricity bills. However, power outages have revealed that most installations are not prepared to operate autonomously in the event of an interruption, unless they have certain advanced components.
Over the past few years, solar self-consumption has grown steadily , driven by the removal of regulatory hurdles and European subsidies. Today, there are almost half a million homes and more than 75.000 businesses in Spain with photovoltaic systems for self-consumption, primarily located on rooftops. However, in 2024, the rate of new installations has fallen significantly compared to previous years, reflecting the new reality of the sector.
One of the recurring concerns for self-consumers is why, despite having solar panels and even batteries, they lose power during a blackout. The answer lies in the technical and regulatory configuration of most systems: only installations with hybrid inverters suitable for "island mode" and specific backup systems can continue operating on solar power and batteries if the main grid fails.
The Spanish market is thus facing a changing landscape : while more than 240.000 self-consumption units were installed in 2022, the figure fell to 127.000 in 2023, and dropped even further in 2024, to less than 80.000. The reasons are varied, ranging from the disappearance of the "pull factor" due to high electricity prices and subsidies, to uncertainty surrounding regulations and negative prices in the electricity market.
Why does my self-consumption system shut down if there is a power outage?
One of the main misunderstandings among self-consumption users is assuming that simply having solar panels is enough to guarantee supply in case of a blackout.
Most grid-connected self-consumption systems automatically disconnect their production when they detect a voltage drop in the public grid. This action is mandatory by regulation (anti-islanding protection) to protect grid technicians during potential maintenance work.
For a home or business to be able to take advantage of solar energy during a blackout, it needs:
- Hybrid inverter or inverter with backup function capable of operating in island mode
- A battery bank adequately sized
- Switching system (bypass) that isolates the installation from the network
- Management system that prioritizes critical consumption (lighting, refrigerator, Wi-Fi, essential appliances, etc.)
Currently, the vast majority of the approximately 500.000 self-consumption installations in Spain do not meet these requirements , hence the loss of grid connection means being left without supply even if solar panels and batteries are installed.
Types of self-consumption installations and their behavior during blackouts
There are three main photovoltaic self-consumption configurations from the point of view of backup capacity:
- Grid-connected installations without batteries: These are the most common (around 85% domestic). They provide instant solar energy in parallel to the grid, but In case of a power outage they automatically disconnectNighttime or bad weather power is always covered by the grid.
- Grid-connected installations with batteries (without island mode): They allow solar energy to be stored for use when there is no production, but They also require the presence of a network to functionThey also disconnect during blackouts unless they incorporate special backup systems.
- Hybrid installations with backup (island mode or backup): These facilities can continue supplying solar and battery power to the home or business during a power outage, provided they have the appropriate inverters and automation systems. They are a minority in Spain but predominate in countries like Germany.
Spanish regulations (RD 244/2019, UNE-EN 50438:2014, REBT…) regulate the technical and safety requirements that these systems must meet, differentiating between conventional installations and those enabled to operate autonomously.
The importance of batteries and the advancement of storage
Solar batteries have become a strategic component for maximizing self-consumption and moving closer to energy self-sufficiency. In Spain, 26% of new residential installations already incorporate them, although most still do not allow for off-grid operation.
According to data from the Spanish Photovoltaic Union (UNEF), 327 MWh of battery storage were installed in 2024 , 34% less than the previous year, reflecting the sector's slowdown. However, the use of batteries is growing in the industrial and commercial sectors, where continuity of supply is more critical.
Storage allows:
- Extend the use of solar energy for more hours a day
- Reduce grid dependence during times of high prices or polluting generation
- Improve facility planning and efficiency
- Ensure emergency supply if the facility is prepared for it
While in countries like Germany and Italy, more than 70% of residential installations include batteries, in Spain this percentage ranges from 10% to 26% depending on the source, with an upward trend as prices fall and awareness increases.
Regulations, administrative challenges and the future of self-consumption
Self -consumption of photovoltaic energy in Spain is regulated by a legal framework that has evolved significantly since 2019, favoring the expansion of residential and industrial installations. The main regulations involved include Royal Decree 244/2019 , the technical directive UNE-EN 50438:2014, and the Low Voltage Electrotechnical Regulations, among others.
In recent months, the sector has been calling for new measures to continue growing , especially after the slowdown of the last two years:
- Simplification of administrative procedures and digitalization of processes
- Review of the fixed term of the electricity rate to encourage savings
- Legal recognition of self-consumption without license plates (only storage and smart management)
- Extension of the power range with simplified processing up to 500 kW
- Creation of the figure of the collective self-consumption manager to streamline shared projects
There are also calls for greater standardization of procedures between Autonomous Communities and distributors, and for tax policies that include reductions in taxes on materials and components to facilitate access to technology.
Industrial and collective self-consumption: advantages and obstacles
Industrial self -consumption leads the way in installed capacity in Spain , representing nearly 74% of the total compared to 26% for residential use. Companies are finding in solar energy a way to increase their competitiveness, protect themselves from the volatility of electricity prices, and take firm steps toward sustainability.
However, collective self-consumption (communities of neighbors, industrial parks, etc.) is progressing slowly due to the complexity of procedures, the lack of concrete incentives and the poor administrative coordination.
Among the most notable obstacles are:
- Difficulty coordinating distribution agreements and additional counters
- Inequality in the application of regulations according to the Autonomous Community
- Poor preparation of urban networks to manage collective energy flows
- General lack of awareness about the advantages and options of shared self-consumption
Future prospects involve accelerating the digitization and standardization of procedures , promoting access to financing, and continuing to reduce the costs of key equipment such as hybrid inverters and batteries.
Despite the contraction experienced in the last two years, photovoltaic self-consumption remains one of the most accessible and competitive technologies for advancing towards decarbonization and energy self-sufficiency. Energy storage and smart management will play a key role in the path towards a more sustainable and decentralized energy model in Spain.
