VREY, a Berlin-based energy software company making it easier for landlords to install and resell rooftop solar in multi-family buildings, has raised €3.3 million in seed funding. The round, announced on 23 April 2026, is led by Dutch impact investor Rubio Impact Ventures, with participation from Germany’s High-Tech Gründerfonds (HTGF) and Kopa Ventures.
Founded in Berlin by chief executive Julius Pahmeier and Cedric Jaeger, VREY has built an integrated software platform that allows property owners to generate solar power on apartment building roofs and supply it directly to tenants, while handling the metering, billing and regulatory compliance work that has historically made such projects commercially unattractive. The company operates as a certified smart-metering and billing partner, measuring each tenant’s share of on-site solar consumption and invoicing accordingly.
Inside the round
The seed follows the September 2024 passage of Germany’s Solarpaket 1 legislative package, and in particular §42b of the Energiewirtschaftsgesetz (EnWG), which created a streamlined model known as gemeinschaftliche Gebäudeversorgung — effectively allowing landlords to share rooftop solar with tenants without being regulated as full-scale energy utilities. VREY has been among the most active software vendors built explicitly around this new regulatory regime.
Rubio Impact Ventures, which recently closed a €70 million fund focused on climate and social impact across Europe, leads the round. HTGF — one of the most prolific early-stage investors in German deep-tech and cleantech — joins alongside Kopa Ventures. The investor group reflects the dual nature of the bet: a policy-enabled climate opportunity in a market structure that favours well-capitalised software-first operators.
The new capital will fund team expansion — VREY currently employs around 20 people — and further development of the platform, including deeper integration of adjacent building-energy assets such as batteries, heat pumps and EV charging.
The majority of property owners want to future-proof their buildings, but until now, practical solutions were missing. With VREY, we make solar in multi-family buildings simple and economically viable for the first time.
Julius Pahmeier, co-founder and CEO, VREY
Why the multi-family gap matters
Germany has roughly 1.9 million multi-family residential buildings, and they represent the largest underserved segment of the country’s otherwise mature rooftop-solar market. Single-family homes have adopted solar aggressively over the last decade, and utility-scale projects have scaled on rural sites. Multi-tenant blocks, by contrast, have been held back by a complicated mix of Mieterstrom regulation, split-incentive problems between landlords and tenants, and the operational overhead of billing individual residents for shared rooftop output.
Solarpaket 1 was designed to remove the worst of those frictions. Building owners can now install photovoltaic capacity, allocate generated electricity to tenants via agreed keys, and bill them without triggering the full set of utility obligations that previously applied. VREY’s pitch is that turning that simplified legal model into a working operation still requires metering infrastructure, allocation logic, invoicing, and grid and tax compliance — and that those are software problems.
The competitive landscape
VREY enters a space that includes established Mieterstrom aggregators such as Solarize, Metergrid and SOLARIMO, as well as larger energy groups and housing-sector integrators. Pahmeier’s argument — reflected in Rubio’s and HTGF’s willingness to back the round — is that the new §42b regime resets the game, rewarding platforms designed natively around it rather than retrofitting older Mieterstrom architectures.
The company’s broader ambition is to become the default software layer for residential building energy: starting with solar and metering, then extending into batteries, heat pumps and EV charging as German policy continues to tilt toward electrified, decentralised building energy.
What to watch
Three questions will determine how far €3.3 million takes VREY. First, sales cycle length: housing-sector customers in Germany are notoriously slow to procure, and the startup will need repeatable channels into large Wohnungsgesellschaften as well as private landlords. Second, hardware and installer economics: software-first plays must avoid being dragged into low-margin installation work to grow. Third, regulatory drift: further German or EU-level updates to Mieterstrom rules could either expand or erode the §42b advantage.
For Sesamers readers tracking European climate-tech rounds, VREY is a clear example of a policy-enabled venture thesis: a specific law creates a white-space market, and capital flows to the operators best positioned to exploit it. Whether that thesis scales into a category-defining platform will depend on execution over the next 18 months, but the investor syndicate assembled around this seed round gives VREY an unusually strong starting position for a €3.3 million raise. See our fundraising hub for ongoing coverage of European climate-tech rounds.
Source: Tech.eu — Berlin-based VREY raises €3.3M to unlock shared-roof solar (23 April 2026)