Delta Green raises €2M to turn European homes into virtual power batteries

Prague-based energy scaleup Delta Green has secured €2 million in fresh funding from Credo Ventures, Tilia Impact Ventures, and Purple Ventures to accelerate its pan-European expansion. 

Delta Green aims to turn ordinary European homes into a powerful force on the energy market. The company's platform connects ordinary homes into a virtual power battery, enabling households to shift consumption, discharge batteries, and export rooftop solar at times of peak demand. Every kilowatt activated at the right moment lowers bills, supports renewables, and reduces fossil fuel reliance.

Delta Green is co-owned by four engineers and developers, David Brozik, Prokop Cech, Lukas Benes and Jan Hicl. I spoke to Delta Green co-founder Jan Hicl to learn more.

Delta Green was originally called Nano Green and has been around for about 13 years. 

Why the energy industry's conservatism is creating opportunity

According to Hicl, "We acquired and rebranded it three years ago to focus on what we do now."

"Our background is in building software startups, so we've turned Delta Green into a software-first company for the energy sector — which is traditionally quite conservative and slow to change."

According to Hicl, a good example of that conservatism is the growing number of negative price hours on the spot market.  "Everyone knows how to fix it — by shifting when electricity is produced and consumed — but very few are acting fast enough.  The fact that those hours are still increasing shows just how rigid the industry remains."

Hicl shared that this is why "flexibility' has become such an energy buzzword: everyone recognises it's critical for the transition, but real-world implementation is still limited."

We've already seen small blackouts in the Czech Republic, Spain, and Portugal. However, without flexibility to stabilise the network, especially at the low-voltage level — the local networks closest to households. 

Hicl contends that most investment goes into high-voltage transmission networks and utility-scale batteries, "but the real fragility is in local distribution systems."

"These networks were built decades ago for completely different consumption patterns.

If five EVs on one street start charging simultaneously, you can overload the grid.  That's where residential flexibility — our speciality — becomes essential.

Our platform can coordinate devices, telling some to wait and others to charge, so the network doesn't collapse."

How ending subsidies is actually helping Delta Green grow

Greentech is a tough sector for many startups at the whim of European policy priorities, especially in areas like EV-subsidies and ESG. But interestingly, Hicl asserts that the fact that many countries are ending net-metering schemes—where households could feed excess solar power into the grid in summer and draw it back in winter, is helping the company. 

He admits, "That was effectively a form of subsidy, and now it's disappearing."

However, the end of subsidies is actually prompting both consumers and retailers to consider energy management more seriously. 

"As a result, consumers are starting to ask new questions: When should I consume energy? How can I use what I produce more intelligently? 

Retailers, too, have lost many of their government incentives, so they're looking for new ways to stay competitive. Our technology gives them that edge.

While first movers benefit most from the shift, it's more difficult in markets where there aren't enough EVs, heat pumps, or residential batteries—" assets we can control.

But overall, the shift away from subsidies is creating stronger demand for what we do."

Further, household flexibility is no longer in a pilot phase — "our business growth proves it works across thousands of households," says Hicl.

"We're now accelerating our plans as market demand is clear, with major retailers across Europe approaching us to deploy our solution."

From test lab to pan-European platform

In the Czech Republic, Delta Green is a small energy supplier, serving about 7,000 customers. 

"That's our test lab, where we can develop and refine our technology before scaling it," shared Hicl.

"Then we license our platform to large utilities. They use it to manage flexibility across their customer base."

Delta Green runs a lean ship, which Hicl admits is partly out of necessity.:

"Margins in the energy sector are extremely thin — around 1 per cent. When we entered the industry, we were shocked to find that no one accepted credit card payments.

Then we discovered that card processing fees are about 1.5 per cent, which would instantly wipe out profits! We've managed to stay profitable because we utilise our proprietary technology to operate efficiently.  We make money from our customer portfolio and from selling the platform to other suppliers.

We're sustainable, even if we're not the fastest-growing company out there — and that's okay. A lot of hyper-growth players in our space have already burned out."

Hicl asserts that for decades, we've been accustomed to having electricity available whenever we want it, at a constant price. That era is ending.

"In the future, prices will vary hour by hour depending on supply and demand. Sometimes electricity will even be free, or have negative prices.

For households, that means comfort will come at a cost. If you insist on consuming energy during peak times, you'll pay more. But if you're flexible — if you shift your consumption, like charging your EV or heating water when solar or wind generation is high — you'll save money and help stabilise the grid."

E.ON partnership sparks snowball effect across Europe

By the end of this year, Delta Green platform will manage tens of thousands of households, putting it on track to become Europe's largest household-based virtual power plant. 

"We just closed first deals in Romania, Italy, Hungary and Slovakia, and we are in advanced discussions with several major international energy suppliers about adopting our technology," shared Hicl. 

Since its last funding update in 2024, Delta Green has made significant strides. It has become the first company in CEE to successfully involve households directly in grid balancing. 

In the Czech Republic, one of country's top three energy providers E.ON has integrated Delta Green's flexibility service into its operations and plans to scale it to thousands of customers within the next 18 months. Thanks to this collaboration, E.ON customers can earn up to €200 per year by monetising their household energy flexibility. 

Hicl admits that the momentum has created a snowball effect — "everyone realised they needed something similar to stay competitive. That's when we knew we were ready to expand internationally."

"Now we're active in Austria, Romania, and Hungary, and preparing to launch in other European countries."

From here on, Delta Green is expanding the types of assets it can control.

"Right now, we mainly manage home batteries, but we're adding heat pumps and EVs to the platform."

"We are really happy to see that Delta Green's timing for their flexibility aggregation solution was perfect. Just as the market realised the importance of this kind of solution for energy transformation towards greater sustainability, the company already had a real solution in place that the energy companies can instantly use, because it's been tested on Delta Green's own retail customers," says Tilia Impact Ventures partner, Pavel Petřek. 

Delta Green's mission is clear — to place households at the very centre of Europe's energy transition and build the continent's largest network of flexible homes.