Solar panels: an income, or rather a saving?

For years, solar panels were sold as an investment: the meter ran backwards and the electricity fed into the grid was worth as much as the electricity used. That era is ending. Today, solar panels mainly pay off through the electricity you consume yourself. It is not an income, it is a saving, and that is already a lot.

What has changed

With a meter running backwards, the grid acted as a free battery: electricity produced in summer offset what was used in winter. This system is gradually disappearing in all three Belgian regions, and similar net metering schemes are being phased out across Europe.

• In Wallonia, only installations commissioned before 1 January 2024 keep the offset, until 31 December 2030, according to information published in 2026. More recent installations count what they feed in and what they draw separately.
• Electricity fed into the grid is bought back at a few cents per kWh, while electricity you draw costs around €0.30/kWh.
• In Flanders and Brussels, digital meters and regional rules lead to the same logic: what matters is self-consumption.

The new calculation: self-consumption

Every kWh produced and used directly saves you the full price of electricity, about €0.30. Every kWh fed in earns only a few cents. Profitability therefore depends on the share of your production you use at the moment it is produced.

To increase it:

• run the washing machine, dishwasher and water heater during the day;
• charge an electric car at midday;
• install a heat pump or a heat-pump water heater;
• add a home battery, provided its price is justified by the real saving.

According to estimates published in 2026, a well-sized installation typically pays for itself in 6 to 10 years, with a lifespan of 25 years or more.

Energy sharing and communities

All three regions are developing energy sharing: selling or giving your surplus to a neighbour, a family member or within a local energy community. It is a way to get more value from the electricity you feed in, provided your region's framework and your grid operator allow it.

Uses for the surplus

• Heating water with a solar diverter.
• Charging a vehicle.
• Running a machine: some people use a summer surplus for mining or a ThreeFold node. The calculation only makes sense with electricity that would otherwise be sold back very cheaply.

For landlords

Solar panels improve the energy performance certificate (EPC), reduce the tenant's bills and can justify a higher rent within the indexation rules linked to energy performance. In a building with several units, sharing the electricity produced requires technical and contractual organisation.

Before signing a quote

1. Analyse your hourly consumption with your digital meter.
2. Size the installation to your consumption, not to the roof area.
3. Compare at least three quotes from certified installers.
4. Check the subsidies and rules in your region at the time of purchase: they change often.
5. Beware of door-to-door sellers promising a ‘free’ installation or a guaranteed return.

Where to find these services

• Énergie WallonieSubsidies and rules in Wallonia (French)
• Brussels EnvironmentSubsidies and green certificates in Brussels
• Flemish Energy and Climate AgencyRules and subsidies in Flanders (Dutch)
• CWaPEThe Walloon energy regulator: prosumer tariffs and feed-in

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This article is educational and is not personal investment, tax or legal advice. Figures change: check them with the sources cited or a licensed professional before deciding. Read the full disclaimer.