On 17th April 2025, plug-in photovoltaic kits and batteries were authorized in Belgium. Based on figures provided by Belgian distribution system operators, just over 8000 declarations of these systems have been submitted in Belgium over one year. More than 75% of these declarations concern residential batteries located in Flanders. However, according to several market signals, the actual number of systems in operation in Belgium is significantly higher than these declarations. The first year of plug-in systems in Belgium shows very different adoption dynamics across the Regions.

The sector celebrates its first anniversary

Authorized on the Belgian market since April 17, 2025, plug-in systems have quickly gained visibility and adoption, while also triggering the usual debates associated with any new energy technology becoming accessible to the general public (safety, grid impact, profitability, societal relevance, etc.). The sector has undergone several regulatory adjustments, such as the removal of the EnFluRi sensor requirement for batteries in October 2025. Tensions regarding the application of the Bebat circularity contribution to residential batteries have also intensified over the past 12 months with the arrival of plug-in batteries. In any case, these new systems have established themselves in the public debate, even being voted “Product of the Year 2025” by readers of the Flemish daily De Standaard [1].

Contrasting regional dynamics

In Flanders, declarations to Fluvius are largely dominated by batteries: around 6200 units compared to nearly 1200 plug-in PV kits recorded at the end of March 2026. The end of the compensation mechanism in Flanders (reverse-running meter) encourages households to maximize self-consumption, making plug-in batteries particularly attractive. Flanders is also where the highest number of group purchasing initiatives can be observed, particularly for residential batteries. In Brussels, only around sixty systems have been declared over one year, evenly split between panels and batteries.

In Wallonia, the two main grid operators Ores and Resa together report around 550 declared plug-in PV kits, but do not (yet) monitor plug-in battery declarations separately. Through its interactions with users, Pluginfo observes that the Walloon market is more oriented toward photovoltaic kits than the Flemish market [2]. This is likely due to the fact that many Walloon prosumers still benefit from the reverse-running meter until 2030, which reduces the economic interest of residential batteries.

By extrapolating these figures to other distribution system operators, we estimate just over 8000 plug-in declarations in Belgium since April 2025. Compared to its European neighbors, Belgium remains an emerging market. In Germany, 435 000 plug-in PV kits were registered in 2024, with a total installed base estimated between 1.5 and 4 million units [3]. In France, more than 66 000 very small-scale PV installations (≤1 kW) were connected by the end of 2025 [4]. However, both in Belgium and abroad, official figures are likely well below the actual number of operational systems.

Why is the actual volume so hard to estimate?

Unlike traditional photovoltaic installations and residential batteries, plug-in systems are very small and inject little, if any, electricity into the grid. Their purpose is primarily based on directly covering part of a household’s electricity consumption. This makes them highly cost-effective, but also largely invisible to grid operators, even when smart meters are in place. In addition, declaration obligations to distribution system operators remain poorly known by the general public and vary across Regions, while some sales channels are difficult to track.

As a result, official data only reflects part of the market. Based on several economic signals, such as sales volumes, stakeholder declarations and cross-observations, the actual number of operational systems could be five to twenty times higher than the number of declared units.

A market study is currently being conducted within Pluginfo to estimate the actual installed base in Belgium. In the course of 2026, we will publish a report providing the first independent estimate of the number of operational plug-in solar and storage systems in Belgium. Follow updates on our professional page.

Sector challenges

From a societal perspective, plug-in systems help broaden access to energy transition tools for population groups that are currently less equipped, such as apartment dwellers, tenants, or vulnerable households. Given their relevance, Pluginfo considers it important to support their deployment in a realistic and pragmatic way: improving market monitoring, adapting regulations to non-specialist users, better informing users, and framing commercial practices. Experience in neighboring countries shows that a controlled and safe rollout is possible, provided these systems are treated as standard household appliances, with simple usage rules and reliable information.

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[1] De Standaard : https://www.standaard.be/economie/het-product-van-2025-batterij-en-zonnepaneel-met-stekker/121340696.html

[2] Cfr article https://pluginfo.be/blog/les-wallons-veulent-du-pv-les-flamands-veulent-des

[3] Source : BSW-Solar, lthe German Solar Association

[4] Source : Enedis https://data.enedis.fr/pages/parc-raccorde/