On a mission to change the Belgian energy market

Belgium is racing ahead in Europe’s energy transition. Solar panels, batteries, and EV chargers are connecting to the grid at record speed. For energy retailers like Luminus, that’s exciting … but also tricky. How do you integrate thousands of distributed renewables while keeping the grid in balance? That’s where Powernaut comes in. 

With our Open VPP, Luminus was able to scale its flexibility services fast. Edouard De Bruyne, Head of Flex at Luminus, explains how.

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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

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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

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SOLUTION

Powernaut’s Open Virtual Power Plant (VPP) platform gave Luminus a solution that could aggregate their SmartKit systems, work with third-party EMS providers, and connect directly to equipment manufacturers through APIs

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APPROACH

The collaboration took and 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 and connecting everything to Luminus's trading operations

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IMPACT

Luminus now has a scalable, future-ready system managing distributed energy assets that can grow with the market. The business case has been proven across different asset types like solar and home batteries, and strengthened Luminus's position as a flexibility leader

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Luminus x Powernaut
Facts & figures

• Type: Energy retailer
• Location: Belgium
• Scope: Residential sites 
• Assets Managed: Solar installations, home batteries, EV chargers, heat pumps
• Business Target: Significant capacity onboarding by Summer 2025
• Key Result: Proven business cases across all asset types, for example solar installations (PV) generated significant value through imbalance steering.

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The challenge: upscaling flexibility

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

Before teaming up with Powernaut, Luminus was already ahead in the flexibility game with their own in-house Energy Management System: SmartKit. But as they scaled up from dozens to hundreds of business installations, new challenges appeared. 

1. Aggregation at scale 

First off: Luminus’ 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. 

The first challenge for Powernaut was to connect and aggregate those devices so they could act as one virtual asset.

CTA: More on connection & aggregation

2. Available for all customers 

For a market leader like Luminus, flexibility couldn’t just be a niche service. It had to work for every customer, no matter what Energy Management System (EMS) they use. 

“As Belgium’s second-largest energy supplier, we need to offer flexibility to everyone. If tomorrow we have a client with a different system, we want to be able to integrate it into the same platform.” - Edouard de Bruyne

3. Trading & balancing 

Managing solar panels and batteries at scale isn’t just a technical exercise, it changes the business model. That’s why 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.

CTA: More on trading & settlement

The solution: our Virtual Power Plant

With our Virtual Power Plant (VPP), we delivered exactly what Luminus needed: a platform that turns scattered flexibility into a manageable entity at scale. More than a tool, it was a strategic fit for Luminus.

1. Aggregation made simple

The Open VPP acts as a middleware layer, transforming hundreds of small devices into one manageable entity. So now, instead of traders wrestling with “a hundred little buttons,” the VPP does the heavy lifting: connecting, aggregating, disaggregating and pooling all assets. From EV’s to solar installations and batteries.

2. Open to everyone

Openness was non-negotiable for Luminus. Unlike closed systems, Powernaut’s platform integrates with anything: 

• Luminus’s own SmartKit
• Third-party Energy Management Systems
• Direct equipment manufacturer APIs
• 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

3. Smart forecasting & optimisation

The VPP doesn’t just connect devices, it makes them smarter. A powerful forecasting and optimisation engine:

• predicts flexibility every minute
• figures out the most efficient way to dispatch it
• verifies delivery at site and asset level, crucial for billing and reporting back to grid operators.

CTA: More on forecasting & optimisation

Implementation: from pilot to full scale

In short, Powernaut gave Luminus exactly what it needed: a single, reliable workspace to manage flexibility for every customer and asset at scale. Here’s how we got there:

Step 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.

Step 2: Map the business needs

Together, Powernaut and Luminus ran workshops, documented requirements in detail, and set up a solid project management framework.

“Things went smoothly thanks to thorough preparation: workshops, clear documentation of requirements, and a proper project management framework.” — Edouard, Luminus

Step 3: Go live in six weeks
With connectors already in place, our Open VPP linked seamlessly to Luminus’s SmartKit and existing home systems. The platform was live with customers in just six weeks.

Step 4: Build flexible asset pools

Different assets come with different contract terms and optimisation rules. We created dedicated asset pools, making it easier for Luminus to manage residential and business installations side by side.

Step 5: Integrate billing & verification

Flexibility verification and settlement were built right into Luminus’s existing billing system. Even meter correction was added, ensuring customers aren’t penalised for supporting the grid.

Step 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. Future-proof by design.

The impact: turning flexibility into value

With our Open VPP, Luminus now runs a scalable, future-ready system to manage distributed energy assets. One that grows with the market and strengthens their position as a flexibility leader. While the solution runs in the background and isn’t directly client-facing,Edouard highlights that its biggest win is for Luminus’s trading department:

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“The real beneficiary is our trading department, which gains efficient, real-time access to available flexibility. That’s where the real impact lies, even if it’s invisible to end users.” - Edouard De Bruyne

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✔️Proven business cases

The results of the pilot project with 25 households weren’t just promising, they were scalable. 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 our platform. And when Belgian grid operator Elia required overrides for solar curtailment, the system adapted instantly.

✔️Future-ready infrastructure

With our Open VPP, Luminus now has the technical foundation to keep scaling flexibility services as the market evolves.

The collaboration: open minds, shared vision

This wasn’t our first mission together. We’d 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.

For Luminus, the choice wasn’t just about today’s requirements, but about finding a partner that could grow and adapt as the market evolves.

“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

The future: more assets, more variety

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Thanks to the Open VPP, 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. That means going beyond solar panels and batteries to include more B2B assets such as e-boilers, fridges, and EVs. 

"Tomorrow, in a B2B context, flex should be a key enabler to lower operational expenses, or at least the energy costs of a company. Be it with their solar panels, batteries, e-boiler, fridges or EVs. All of those assets should be within the comfort zone of the client, should be able to be flexed, so that, in the end, the operational costs of the client get reduced and they can be more competitive."

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

And while Powernaut may be a young company, the collaboration has already proven its strength.

“Many colleagues are surprised at how advanced Powernaut is for such a young company. They’re small, but their capabilities are impressive. At first glance, working with a small startup like Powernaut can feel risky. But once you collaborate, you see their delivery is top-class.” - Edouard De Bruyne

Together, Luminus and Powernaut are ready to grow, innovate, and capture new opportunities in the flexibility markets. And this mission has only just begun. 🚀

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