Green energy supplier in Belgium: how to spot a genuinely renewable offer in 2026

In Belgium, almost every supplier now sells electricity labelled '100% green'. That does not mean each of them produces or finances renewable energy. The 'green' label rests on a system of certificates — guarantees of origin — that a supplier can buy separately from the electricity it actually delivers. In other words, one label covers very different realities. Here is how to tell them apart, and which concrete benchmarks to rely on.

What does 'green energy' mean on a Belgian offer?

It means the supplier holds, for each megawatt-hour sold, a guarantee of origin corresponding to renewable production. That is a legal definition, not a promise about its own generation fleet.

A guarantee of origin is an electronic certificate issued for each MWh of electricity produced from a renewable source — wind, solar, hydro, biomass. The supplier must hold as many as it sells in 'green kWh'. The sensitive point is that this certificate trades independently of the physical electron. A producer can sell its electricity on one side and its guarantees of origin on the other, to a supplier that meanwhile buys fossil or nuclear electricity on the market. The result: the offer is 'green' in the regulatory sense, without the supplier producing or investing a single euro in renewables.

Why isn't '100% green' enough to judge a supplier?

Because the label does not distinguish the supplier that produces its renewable electricity from the one that buys certificates on the European market. Both display the same '100% green'.

This is precisely the criticism that environmental organisations such as Greenpeace have levelled at the system for more than ten years: it lets a supplier sell electricity from fossil sources under a green label by buying sometimes very cheap guarantees of origin. The certificate and the electron then follow two separate paths, and the consumer has no way of knowing it from the invoice alone. Traceability exists, but it concerns the certificate, not the electron actually delivered.

How do you recognise a genuinely green supplier in Belgium?

The most reliable benchmark is the Greenpeace ranking, published on monelectriciteverte.be, which scores every Belgian supplier on its production, its mix, its purchasing policy and above all its real investment in renewables.

That ranking has a decisive merit: it is not fooled by certificates. Under its methodology, guarantees of origin count for only a minority share of the overall score — around 15% — with the rest depending on what the supplier concretely does to develop renewable production. A supplier that merely buys certificates without ever investing in a turbine or a solar farm therefore scores poorly, whatever label appears on its offers.

Three simple questions help narrow things down even before consulting the ranking: does the supplier itself produce renewable electricity? Does it reinvest in new projects? Does it buy the rest of its electricity from green producers, or on the undifferentiated wholesale market? A genuinely green supplier answers 'yes' to the first two.

Which suppliers come out on top of the ranking?

In recent editions of the Greenpeace ranking, citizen cooperatives dominate: Ecopower and Cociter score the maximum of 20/20, covering the bulk of their deliveries with sustainable production and reinvesting in new renewable projects.

Behind them, players such as EnergyVision and Aspiravi score well (around 18/20 and 17/20 in recent editions), thanks to local, renewable production. Conversely, several large commercial suppliers stall around 4/20 — not because they sell 'fake' electricity, but because they invest too little in renewable production and buy a large share of their electricity on the European market, with high carbon content.

These scores change from one edition to the next: always check the most recent version of the ranking before deciding. And to place each supplier on price as well as the rest, our ranking of energy suppliers compares offers against a reference household.

Does a green energy offer cost more?

Not necessarily. Greenness and price are two independent criteria: some genuinely green offers are very competitive, others less so, exactly as with conventional offers.

The mistake would be to give up a green offer assuming it must cost more. The only way to decide is to compare the total cost in euros per year — the per-kWh price times your real consumption, plus the annual standing charge — rather than the headline per-kWh price alone. This comparison logic is the same as for any supplier switch: if you want to review it in detail, our guide to switching energy supplier in Belgium describes each step, and our analysis of the electricity price per kWh in Belgium gives up-to-date orders of magnitude.

How can you check the green percentage of your electricity yourself?

In Brussels, the regulator Brugel provides the Greencheck tool, which lets every consumer verify the percentage of green energy actually linked to their supply. It is the most direct way to check what a supplier's label is really worth.

In Flanders and Wallonia, the guarantee-of-origin system is overseen by the VREG and the CWaPE respectively, under the broader supervision of the CREG at federal level. These regulators ensure the traceability of certificates but do not publish a qualitative judgement on how 'sustainable' a supplier is: that is precisely the role the NGO ranking plays alongside them. For a complete picture, cross-reference the two: the regulatory check for the official green percentage, the Greenpeace ranking for the sincerity of the commitment.

And what about green gas?

Gas too can be offered as 'green' or 'offset', but the nuance matters. Some offers rest on biomethane genuinely injected into the grid; others rely on carbon offsetting through projects, with no renewable molecule delivered.

The volumes of biomethane available remain low in Belgium, which mechanically limits the reach of truly renewable gas offers. As with electricity, read the offer in detail: does it rest on injected renewable gas, or on simple offsetting? The two are not environmentally equivalent.

Key takeaways

The '100% green' label has become the norm on the Belgian market, to the point of no longer distinguishing anything on its own. What separates a genuinely green supplier from a mere certificate buyer is production and investment: does it produce renewable energy, does it reinvest in new projects? The Greenpeace ranking and, in Brussels, Brugel's Greencheck tool let you check beyond the marketing. And because green is not incompatible with a good price, take ten minutes to compare offers on the ranking of energy suppliers before you sign.