NOX Energy Raises $3.4M to Build Europe’s Energy Flexibility Network

NOX Energy raised $3.4 million in seed funding to connect household heat pumps and solar systems with European electricity markets.

The startup says it has connected more than 10,000 devices, as European grids seek flexible capacity to manage growing renewable generation.

Rise PropTech and Volve Capital co-led the round, following NOX’s $1 million raise in December 2024.

NOX Energy has raised $3.4 million in seed funding to expand software that turns household energy equipment into flexible grid assets.

The Belgian startup connects heat pumps and solar panels with electricity markets. Its technology allows devices to adjust consumption based on electricity prices and grid conditions.

Rise PropTech and Volve Capital co-led the round. Seeder Fund, Uneti Ventures, Fair Capital Impact Fund and 100in also participated.

NOX says it has connected more than 10,000 devices and works with energy suppliers including Eneco and Frank Energie. Its team has grown to 13 people.

“Every time money moves between two banks, it runs over SWIFT. We want to be that for energy flexibility. Millions of homes already have a heat pump, battery or solar panels connected to their manufacturer’s app. Energy suppliers and grid operators need the flexibility these devices can offer, but every manufacturer and every market works differently. NOX sits in between as the infrastructure of flex, connecting both sides. Our goal is for every kilowatt-hour of flexibility in Europe to run through NOX,” said CEO Axelle Moortgat.

Turning homes into flexible grid assets

Europe’s electricity system is becoming increasingly dependent on variable renewable generation.

Wind and solar supplied 30% of EU electricity in 2025, according to Ember. That exceeded fossil fuels, at 29%, for the first time.

Higher renewable penetration increases the value of flexibility. Electricity demand must increasingly respond to periods of abundant or constrained generation.

Homes can provide part of that flexibility without major changes for residents. A heat pump, for example, can pre-heat a property when electricity is cheap. It can then reduce consumption during periods of tighter supply.

NOX connects its software to devices through manufacturers’ or energy suppliers’ existing applications. The platform forecasts a heat pump’s consumption for the following 24 hours and adjusts its operation accordingly.

Grid operators can pay for this flexible capacity. NOX then shares part of that revenue with manufacturers and households.

The company says households can achieve savings of up to 28% and earn up to $225 annually, without installing additional hardware.

Its live integrations cover heat pumps and solar panels. Partners include DeWarmte, NextEnergy, Frank Energie and NIBE Group brands through myUplink.

Competition grows around household flexibility

The market is becoming crowded as investors target software capable of coordinating distributed energy resources.

London-based Axle Energy says it manages more than 300,000 devices representing over two gigawatts of flexible capacity. It raised a $25 million Series A led by Energize Capital after earlier seed and pre-seed rounds.

Germany’s 1KOMMA5° raised about $169 million in an extended pre-IPO round in 2025. The company planned to invest more than $112 million in software between 2025 and 2027. Its Heartbeat AI virtual power plant reportedly controls more than 500 megawatts.

Berlin-based Nomos raised about $22.5 million from Index Ventures in September 2026. Its model connects home batteries, electric vehicles and heat pumps to Germany’s electricity market.

Belgian competitor LIFEPOWR raised about $6.4 million in 2025 and manages more than 22,000 connected assets. Companion.energy raised approximately $8.8 million this year, although it focuses on industrial customers.

NOX is positioning itself as a neutral infrastructure layer rather than building a consumer-facing energy supplier. Its current focus remains heat pumps and supplier applications in Belgium and the Netherlands.

Expansion targets Europe’s fragmented flexibility market

The new capital will fund expansion beyond those two markets. NOX also plans deeper integrations with manufacturers and energy suppliers.

The company previously raised about $1 million in December 2024. Its latest round brings disclosed funding to roughly $4.5 million.

For energy companies and investors, the opportunity sits at the intersection of electrification, grid constraints and digital infrastructure. Europe is adding renewable generation while simultaneously electrifying heating and transport.

That creates both pressure and opportunity. Millions of distributed devices could help stabilise electricity systems, but manufacturers, suppliers and grid markets still operate across fragmented technical environments.

NOX is betting that a common software layer can bridge those systems. Its challenge will be achieving scale while larger competitors pursue the same flexible capacity.

If household electrification continues to accelerate, the companies controlling those connections could become an increasingly important part of Europe’s power market infrastructure.