El 27% of Spanish homes with solar panels house batteries to store energy and maximize savings, according to a report by the solar installations firm Sotysolar, shared at the second storage and hydrogen summit organized by UNEF, the Spanish Photovoltaic Union. Unlike panel installations, where two thirds of projects serve industrial or corporate clients, storage deployments are led by the residential sector, which accounts for about three quarters of all installations.
Batteries enable electricity to be produced during the cheapest hours of the day and stored for use during peak-priced periods, boosting the efficiency of solar panels. Yet cost remains the main hurdle. When considering price as a barrier to solar panel installation, 36% say batteries add up to 2,500 euros to the total, while 28% estimate an increase between 2,500 and 5,000 euros. The average cost of a solar installation without batteries for the residential sector sits around 4,500 euros, including equipment and labor.
But there is more. In the past year, the end of European recovery funds for self-consumption, the falling price of electricity, and the rise of a new concept called the ‘virtual battery’—offered by major energy suppliers to autoconsumers and representing a discount on the final bill based on surplus energy—have slowed the growth of this technology. In 2023, the photovoltaic federation reports only 495 MWh of storable solar energy were installed for homes and businesses, a 64% drop from the previous year (1,328.84 MWh).
“Thinking about autoconsumption should include batteries. Yet there is a lack of clear education. It cannot be that last year 1.7 gigawatts of autoconsumption were installed while storage behind the meter barely reached 1.8 GWh in total,” argues Xavier Cugat, product director at battery maker Pylontech. The gap persists when looking at accumulated figures: by the end of 2023, autoconsumption capacity hovered near 7 GW, while storable energy behind the counter stood at only 1.8 GWh in total.
To reignite expansion, industry leaders advocate for new funding schemes to accelerate installation. “Financing schemes that make these installations more competitive are needed, such as VAT exemptions or tax breaks,” proposes Jose Donoso, general manager of UNEF. Sector representatives also call for greater participation in the electricity market as a formal player, a point echoed by Franc Comino, chief executive of Sonnen Spain, a view acknowledged by the energy ministry as well.
Storage will become increasingly important in the energy system as a key tool for integrating renewables into the grid. This matters not only for large-scale facilities but also for smaller installations during peak hours when the system requires more power to prevent outages or price spikes. The natural flexibility of the electricity system—its ability to adapt to demand—begins to wane as renewable sources, unlike gas-fired plants, are not easily managed.
Earlier in 2021, Spain released the Energy Storage Strategy, a non-binding framework outlining steps to promote this technology, including projected installed megawatts by 2030 (around 20,000). However, there has not been a bespoke regulation for storage, either for large facilities or for small ones. “Storage systems allow us to use excess energy—energy not consumed at the moment of generation—in the future, and in the coming years, batteries will hold the same importance as solar panels,” Donoso predicts.
Citations: Sotysolar report; UNEF statements; industry executives; UNEF and Sonnen Spain leadership remarks; general government energy strategy notes.