Sesame Summit 2026 – application open

Berlin’s VREY Raises €3.3M Seed to Unlock Rooftop Solar for Multi-Family Buildings

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)

you might also like

Founder in Biarritz
Events 2 weeks ago

The event calendar goes quiet in July and August. Deadlines don’t. This article assumes you’re an early stage founder, pre-seed or seed at most, without a marketing team. You are the events team. The next eight weeks are the only window of the year where you can work on your startup event strategy instead of running it. Here’s how to use them, roughly in order of urgency. 1. Search for calls for speakers Most Q1 and Q2 2027 conferences select their speakers in autumn, which means applications open now. SXSW PanelPicker is the obvious one and since it closes on July 26th they always lack submissions from Europe. But every major event runs some version of it, usually buried three clicks deep on their website. Before you apply anywhere, build a speaker one-pager: your topic, three talking points, a short bio, one decent photo, and links to any previous talk. Program teams review hundreds of proposals. Make theirs easy. 2. Apply to startup competitions Autumn competitions open their calls in summer: One warning from someone who reads hundreds of these applications every year: judges can tell when ChatGPT wrote your answers. Roughly 80% of the applications I review show obvious AI usage, and the low-effort ones go straight to the no pile. Use AI to structure your thinking if you want. Write the answers yourself. Sophie wrote a full breakdown of how startup competitions work from the organizer’s side. Read it before you apply. Knowing what organizers optimize for changes how you write. 3. Apply to your country’s delegation for major events CES, MWC, Web Summit: most countries send an official startup delegation, and the selection happens months ahead. For CES only: Netherlands, France, Hong Kong, etc. A quick LinkedIn search gives you tons of results.  Delegations get you a subsidized booth, press attention you’d hardly get alone, and a cohort of founders going through the same thing. The application effort is low compared to what you get. The catch is timing: CES delegations typically close applications in September. 4. Get feedback from founders who exhibited in your industry Summer is the one season when people answer cold messages. Search LinkedIn for founders who exhibited at the last edition of the trade show you’re considering using its hashtag. Ask for 15 minutes. Ask three questions: what did it cost in total, how many qualified conversations did they have, and would they do it again. Three of these calls will teach you more than most post-event reports the organizer publishes.  That’s what we learned interviewing ReSnack founders. 5. Run a pitch practice session with your peers, and moderate it Get five founder friends on a call or around a table. Everyone pitches, everyone gives feedback. You moderate. The pitching part is obvious. The moderating part is the underrated one: keeping time, asking follow-ups, managing the room. That’s a skill you’ll need on every panel you ever join, and nobody teaches it. As Lubomila Jordanova told us on the Selected podcast, small formats with harsh feedback are where you learn to hold an audience. 6. Volunteer at a startup event Unglamorous advice, and one of the best access you’ll ever get. Volunteers see how the machine works from the inside: how speakers get booked, how the VIP room operates, who actually makes decisions. You’ll meet the organizing team, and organizing teams remember people who showed up to work. An obvious one is Slush where 1,800 volunteers come together to produce one of the best startup events on earth: https://slush.org/audience/volunteers  7. Plan a side event for the back-to-office season Every ecosystem has a September event where everyone reappears. For example FDDay in Paris. Don’t compete with the main program. Host a breakfast before it opens or drinks after it closes, 20 to 30 people, one clear theme. Side events cost a fraction of a booth and put you in the host position instead of the badge-wearing position. Start planning now: venues and calendars fill up faster than you’d expect for the first week of September. 8. Budget your 2027 event strategy Nobody wants to open a spreadsheet in July. Do it anyway, because budget season at your company happens whether you participate or not. The mistake founders make is counting the ticket and the flight and stopping there. Every event day requires two preparation days: outreach before, follow-up after. That’s the 2:1 rule, and it changes the math on which events deserve a slot at all.  Pick a maximum of 5 events for 2027. Assign each one a job: sales, hiring, fundraising, or press. If an event has no job, it has no budget line. 9. Check if your summer festival has a business track A growing number of music festivals run pitching sessions or networking programs alongside the main stage. Tomorrowland even hosts a dedicated event around impact & social innovation: Love Tomorrow Summit.  Is the deal flow serious? Sometimes. Is it the most pleasant place you’ll pitch all year? Definitely. If you’re on holiday near one anyway, the marginal cost is a badge upgrade. 10. Rest The circuit restarts in September and doesn’t stop until Christmas. Slush alone will take a week out of your life, and that’s before the follow-up emails. Founders treat rest as a productivity hack, which slightly misses the point. Take actual time off. Turn off the notifications. The events will still be there in September, and so will everyone else, looking exhausted already. Don’t be them. Photo credit: Anik Labreigne on Unsplash + Gemini

la fabrique a nuage la barbe a papa sans sucre qui revolutionne le snacking 1726502154
Startups 3 weeks ago

The founders behind NUAGE, the sugar-free cotton candy rated Nutri-Score A, share their playbook for event strategy, budget, and pipeline ROI. If you’ve walked the aisles of a French food trade show recently, chances are you’ve seen — or tasted — a small cloud of the impossible: cotton candy with zero sugar and a Nutri-Score A. Behind it is Re.Snack, a startup founded in 2023 near Dijon by Vanessa and Florian, on a mission to reinvent confectionery. Their first product, NUAGE, is built on Sucr’A, a proprietary sugar substitute developed with AgroSup Dijon that uses plant fibres (isomalt and inulin) to recreate cotton candy’s signature melt-in-the-mouth texture — without sugar, allergens, colourants, or preservatives. The traction speaks for itself: revenue up from €200K to €7M in two years, distribution from 100 to 5,000 points of sale, more than 15,000 online orders, national TV exposure on M6 — and a reported acquisition offer from Lindt that the founders turned down. They’d rather build a brand than become a subcontractor. A sugar-free, fat-free popcorn is next. But what caught our attention is how they grew. For Re.Snack, trade shows aren’t a marketing expense — they’re the core of the sales machine, with a dedicated budget, pipeline targets, and hard ROI thresholds. So we sat down with the team and asked the five questions every founder should be able to answer about their event strategy. Sesamers: Let’s start with the basics. What role do events play in your sales motion — sourcing net-new pipeline, accelerating open deals, or closing? Re.Snack: Events are our number one growth channel. They generate new business, strengthen relationships with existing customers, and accelerate ongoing opportunities. In the food industry, people buy products, but they also buy the team behind them. Face-to-face interactions build trust much faster than emails or calls. That’s a big claim — number one channel. Does the budget reflect it? What share of your sales & marketing spend goes to events, and what target does it carry? Around 25% of our sales and marketing budget is dedicated to events. We consider them a strategic investment rather than a communication expense. Our objective is that every euro invested generates multiple times its value in qualified commercial opportunities over the following 12 months. Twelve months is a patient window. When you look across the whole portfolio of events, what does the blended pipeline ROI actually come out to? On average, we generate between 8x and 12x pipeline ROI across our major trade shows. Some flagship events, such as SIAL or ISM, can significantly outperform that because they concentrate the world’s key retail buyers in one place. Meetings are easy to count, revenue less so. Which events actually convert — not just into conversations, but into business? The events that convert best are those attended by decision-makers with active buying projects. For us, SIAL Paris, ISM, Snack Show, and major retail buying conventions consistently generate tangible business. Success isn’t measured by the number of meetings, but by the quality of follow-up and execution afterwards. Last one on the numbers: at what point do you decide an event has earned a bigger budget? What’s your threshold for scaling up? We increase investment once an event consistently delivers at least a 5x pipeline ROI and proves it can generate repeatable business over multiple editions. We look at long-term customer value rather than immediate sales, because retail cycles can take several months. Before we let you go — for the food founders reading this, what would be your top 5 events? My top five would be: What founders should take from this Beneath the answers sits a playbook any startup can copy, whatever the industry. Events have a job description. Re.Snack doesn’t attend trade shows to “be visible” — events source new business, deepen existing relationships, and accelerate open deals. If you can’t name the job an event does in your sales motion, you have travel expenses, not a strategy. The budget is an envelope with a target attached. A quarter of sales & marketing spend, set deliberately and measured against a pipeline expectation over 12 months. No target, no budget. ROI is measured blended, on a realistic clock. Individual events fluctuate; the portfolio number — 8–12x pipeline-to-cost in Re.Snack’s case — is what tells you whether the channel works. And the attribution window matches the sales cycle: judging a trade show by orders signed on the show floor would kill investments that pay off two quarters later. Conversion beats meetings, and follow-up is where ROI is made. The filter is decision-makers with active buying projects — not badge scans. The event budget implicitly includes the week after the show, not just the days of it. Budget growth follows proven return. A 5x floor, plus repeatability across multiple editions, before a single extra euro flows. One great year doesn’t unlock more spend; a pattern does. Run this way, events stop being a cost centre with nice catering — and become a growth channel with receipts. Company background via nuage.resnack.fr, France 3 Bourgogne-Franche-Comté, and Traces Écrites News.

Sesame Summit 2026 Workshop
Events 1 month ago

This week I read about a hackathon claiming 6,000 attendees over a single weekend. The venues hosting it can’t accommodate more than 1,000 people. Nobody in the comments asked how the math worked. That gap between the claim and the room is what this article is about. For most event organizers, event metrics are marketing, not measurement. Once you understand how attendance numbers are built, why ROI stays a black box, and why matchmaking is often bad on purpose, you’ll read every post-event press release differently. Here’s a decoder. The vocabulary nobody explains to you The event industry has precise definitions. It just doesn’t advertise them. UFI, the global association of the exhibition industry, publishes calculation standards and auditing rules for all of them. Independent bodies like ABC audit against them. Here’s the short version. Visitor. One human being who came to the event. If I attend all three days, I’m one visitor. Visit. One entry through the doors. My three days now count as three visits. UFI accepts both figures in its audits, defines visits as visitors plus repeat visits, and requires the term used to be clearly indicated on the audit certificate. Guess which number ends up on the homepage. Attendee / participant. No standard definition. These are the marketing words. They can mean visitors, visits, registrants, exhibitor staff, speakers, press, students or the organizer’s own team, in any combination. When you read “50,000 participants,” you’re reading a number with no agreed method behind it. Registrant. Someone who signed up. Free registration events love this one, because no-show rates of 30 to 50 percent are common and registrations cost nothing to inflate. Exhibitor. Elastic too. UFI distinguishes direct exhibitors, who contract with the organizer, from co-exhibitors, who are part of a shared stand (think country pavilions). Both count. Daily exhibitor. A company present for a single day, typical in startup zones and rotating programs. A startup using a shared booth on day 2 only counts as one exhibitor, exactly like the anchor brand that paid for 400 sqm across the full show. Pavilion / delegation. A block of space booked by one entity, usually a national export agency, a region or a corporate, then filled with smaller companies. One contract, one invoice, 25 logos. Pavilions are how organizers cluster small booths into themed areas, and how “1,200 exhibitors” can describe wildly different realities. Net vs. gross exhibition space. Net is the square meters actually rented. Gross includes aisles, catering areas and that giant entrance arch. As a rule of thumb: net space is 50% of gross space at an average show.  The prosumer padding One more layer on the attendance side. Many events count audiences that are professional on paper only. Student groups bused in for the afternoon. Employees of a corporate partner who run one workshop on day 3. Startup founders’ plus-ones. Locals with a discounted badge. I’m not saying these people have no place at events. Some of the best energy on a show floor comes from them. But if you’re an exhibitor paying for access to buyers, a headline number that mixes procurement directors with second-year students is not relevant. Ask for the audience breakdown by profile. If the organizer can’t produce one, that tells you something too. The ROI black box Here’s the uncomfortable part: almost nobody wants to know if an event actually performs. CEIR, the research arm of the U.S. industry association IAEE, paused its exhibitor spend research for years and only resumed it in late 2025. Its 2026 Marketing Spend Decision Report finds that management evaluates exhibition ROI mainly on lead volume and post-show closed deals, and documents a gap between what practitioners track and what leadership actually cares about. The industry’s reference dataset on exhibitor spending had not been refreshed since 2017. Read that again: the largest B2B marketing channel went eight years without updated benchmarks. The exhibitor side confirms the fog. Vendelux’s 2026 B2B Events Survey of 120+ marketing and events leaders found that 86 percent can’t accurately attribute ROI to events, and 98 percent struggle to justify event spend to leadership. Yet 80 percent are maintaining or growing their sponsorships anyway.  Organizers benefit from this fog. Some only release their data points after the event is over, when your booking decision for next year is already locked in early-bird pricing. Others share nothing beyond the headline number. Try asking for the seniority breakdown of last edition’s visitors, or the ratio of buyers to service providers walking the aisles. I wrote before that founders systematically underestimate what events cost them, hence my 2:1 preparation rule. The other side of that equation is just as broken: they can’t estimate what events return, because the data to do so is withheld. The GDPR excuse When pushed, some organizers invoke GDPR as the reason they can’t share more. Let’s be precise. GDPR restricts sharing personal data: names, emails, badge scans tied to individuals. It says nothing about aggregated, anonymized statistics. “42 percent of our visitors have purchasing authority” contains zero personal data. An organizer who can’t tell you that either doesn’t know it or doesn’t want you to know it. Neither answer is reassuring. If startups are solving it, ask why organizers aren’t A whole category of companies now exists to answer a question organizers could answer themselves: was this event worth it? Full disclosure: at Sesamers we’re building mytradeshow.ai on this exact gap, so I have a horse in this race. Here are five others working the same seam: Sit with the logic for a second. Organizers gather and process the registration data, the badge scans, the floor plans, the exhibitor contracts. They are the best-placed actors in the world to measure event performance. If third parties have to reconstruct that picture from the outside, it’s because the people holding the data have decided that transparency isn’t always in their interest. Bad matchmaking is a feature One last thing, and it’s my favorite. Whenever an event’s matchmaking is mediocre, don’t

Subscribe to
our Newsletter!

Stay at the forefront with our curated guide to the best upcoming Tech events.