On a mission to change the Belgian energy market

Context

Belgium is at the forefront of the energy transition, with energy retailers facing the shared challenge of integrating rapidly growing distributed renewables while maintaining grid balance.

Problem

As SmartKit, Luminus’s in-house energy management system, scaled to tens and eventually hundreds of business installations, the trading desk needed an efficient way to manage these growing assets. At the same time, Luminus wanted to ensure openness to all customers and all EMS providers.

Approach

The collaboration took an agile, hands-on approach that tested value with residential customers first, then proceeded to build out the B2B platform through close collaboration with home energy systems, connecting everything to Luminus’s trading operations.

The challenge

The energy world has flipped from a one-way street, supplier to consumer, into a two-way system. Electricity now flows both ways, and flexibility is the new currency.

“We don’t just sell electricity anymore. We buy it back, and increasingly, we also need to buy flexibility from our customers.”
Edouard De Bruyne, Head of Flex at Luminus

1. Aggregation at scale

Luminus’s trading department was used to managing large, centralised assets like gas turbines. Suddenly, they faced a swarm of smaller assets, all behaving differently.

“Our trading team was used to steering big assets like gas turbines, not hundreds of small devices. They can’t operate a hundred little buttons for every solar panel.”
Edouard De Bruyne, Head of Flex at Luminus

2. Available for all customers

For a market leader like Luminus, flexibility could not just be a niche service. It had to work for every customer, no matter what energy management system they use.

3. Trading and balancing

Managing solar panels and batteries at scale is a technical exercise that changes the business model too. The solution also had to connect to Luminus’s trading desk, so traders could stay sharp on the flexibility market while keeping the grid balanced.

The solution

Aggregation made simple

The workspace acts as a middleware layer, transforming hundreds of small devices into one manageable entity. Instead of traders wrestling with a hundred little buttons, it does the heavy lifting: connecting, aggregating, disaggregating and pooling all assets, from EVs to solar installations and batteries.

Open to everyone

Openness was non-negotiable for Luminus. The platform integrates with Luminus’s own SmartKit, third-party energy management systems, direct equipment manufacturer APIs, and cloud-to-cloud control of household systems.

“If tomorrow a client comes with a different system, we are now able to integrate it into the same VPP. That openness makes Powernaut’s platform stand out.”
Edouard De Bruyne, Head of Flex at Luminus

Smart forecasting and optimisation

The forecasting and optimisation engine predicts flexibility every minute, figures out the most efficient way to dispatch it, and verifies delivery at site and asset level, which billing depends on and reporting back to grid operators.

Implementation

Luminus went from pilot to full scale in six steps.

1. Prove the concept. We pooled flexibility from more than ten different EMS across 25 Luminus households. The result: clear proof the approach works in the real world.
2. Map the business needs. Powernaut and Luminus ran workshops, documented requirements in detail, and set up a solid project management framework.
3. Go live in six weeks. With connectors already in place, the workspace linked straight to Luminus’s SmartKit and existing home systems. The platform was live with customers in just six weeks.
4. Build flexible asset pools. Different assets come with different contract terms and optimisation rules, so we created dedicated asset pools, making it easier to manage residential and business installations side by side.
5. Integrate billing and verification. Flexibility verification and settlement were built right into Luminus’s existing billing system. Even meter correction was added, ensuring customers are not penalised for supporting the grid.
6. Keep innovating. On top of the core platform, Powernaut is expanding with cloud-based solar curtailment, white-label onboarding flows, and new APIs tested with inverter manufacturers.

The impact

Proven business cases

The results of the pilot project with 25 households were promising, and they scaled. This proved the same approach works for both residential customers and business clients.

End-to-end validation

We proved the full chain works: forecasting flexibility, dispatching assets, and verifying delivery down to each site. We set up asset pools with ambitious capacity targets and showed the models hold in real market conditions.

Real market integration

Luminus’s trading teams are already using solar flexibility in daily operations through the platform. And when Belgian grid operator Elia required overrides for solar curtailment, the system adapted instantly.

Future-ready infrastructure

Luminus now has the technical foundation to keep scaling flexibility services as the market evolves.

Collaboration

This was not our first mission together. We had already joined forces with Luminus on earlier pilot projects, and the results spoke volumes.

“We’d already worked with Powernaut on pilot projects before sending out RFPs. They consistently proved flexible, reliable in execution, and simply pleasant to collaborate with. That gave us confidence early on. Most importantly, their deliverables were high-quality, on time, and within scope and budget.”
Edouard De Bruyne, Head of Flex at Luminus

“What stood out in that process was Powernaut’s open-mindedness. There were no egos, just logic and facts guiding the discussion. We all focused on what made sense for developing decentralised flexibility at scale.”
Edouard De Bruyne, Head of Flex at Luminus

The future

Luminus can now work with flexibility from all business customers, no matter what EMS they use. This openness means Luminus can serve the whole market, keep options open, and give customers real choice. Looking ahead, Powernaut and Luminus will focus on scaling: both in volume and in the variety of assets, going beyond solar panels and batteries to include more B2B assets such as e-boilers, fridges, and EVs.

“It’s all about scaling: more assets, more variety. That’s where the market is heading too.”
Edouard De Bruyne, Head of Flex at Luminus