A recent study showed that a partially charged electric vehicle could keep a typical Spanish home running for five days during a blackout, highlighting the growing interest in using mobile storage as a household backup.

Rapid growth of residential storage

European households are installing battery systems at a faster pace. Since 2020, 5.4 million homes have added combined solar‑plus‑storage setups, and more than 1.5 million of those were installed in 2025 alone. Germany leads the market with over 2 million residential batteries, while roughly 12 million European homes have solar panels but no storage capacity, creating a large retrofit market.

The European Commission reports that current electricity storage capacity stands at about 55 gigawatts. The Commission’s 2030 target of 200 gigawatts is intended to cover demand during low‑consumption periods and to smooth the grid when renewable output falls.

Cost and economics

An 8‑kilowatt‑hour home battery typically costs between €5,000 and €8,000, a price that is about 45 percent lower than a year ago. Despite the falling price, Belgian NGO Bebat estimates payback periods of eight to twenty years, depending on the level of electrification and the tariff structure. An 8 kWh battery can supply roughly one day of average household electricity consumption, making it a useful tool for rooftop‑solar owners to capture economic value from their generation.

Storing excess solar generation helps households avoid buying expensive peak‑hour electricity, reducing exposure to price spikes that have risen since Russia’s invasion of Ukraine in 2022 and the recent US‑Israel conflict. France and the Netherlands have introduced grant schemes that subsidise part of home‑battery installation costs, and some countries are considering tax credits linked to the amount of renewable energy stored.

Technology and market composition

Lithium‑iron‑phosphate batteries dominate the market, accounting for roughly 90 percent of deployed storage capacity. Most modern electric cars carry 60–80 kWh of usable battery energy, but only a subset can export power to a house or the grid. During last year’s severe heatwave in Spain and Portugal, owners of compatible electric cars used their batteries to power essential appliances, although using an electric car as a daily backup accelerates battery degradation and is generally not cost‑effective under normal conditions.

Policy and future framework

The EU is drafting a vehicle‑to‑grid framework that would allow owners to sell surplus power back to the network. The framework includes a requirement that new electric vehicles be V2G‑capable by the end of 2027, offering a larger energy reservoir than dedicated residential batteries.

Consumer organisations are calling for EU‑wide certification rules to ensure battery safety and interoperability in apartments and multi‑unit dwellings. The European Trade Union Confederation has urged the inclusion of training programmes alongside storage targets to support the emerging job market in manufacturing, installation and recycling.

Expanding storage capacity is seen as one of the most effective ways for rooftop‑solar owners to capture economic value from their generation while contributing to grid stability and job creation across Europe.