2026: New electricity rates in Belgium: why
is optimizing your photovoltaic surplus becoming essential?
The Belgian energy landscape is undergoing significant changes. With the gradual implementation of new tariff mechanisms and the end of old compensation systems, the profitability of photovoltaic installations now relies on a key factor: self-consumption.
For households equipped with solar panels, one question becomes central: how
to consume as much of the electricity produced on-site as possible, rather than injecting it into the
grid at low value?
In this context, solutions for optimizing photovoltaic surplus — particularly
for the production of domestic hot water — emerge as a simple, effective, and immediately profitable response.
At Soliseco, the results observed across all our clients are clear:
➡ +32% self-consumption, on average
➡ -46% fossil fuel consumption (gas or oil)
Understanding the new tariff challenges in Belgium
The tariff changes implemented in Belgium aim to better reflect the actual costs of the grid and to encourage smarter electricity consumption.
Three major changes directly impact owners of photovoltaic panels.
1. The end of full compensation
For recent installations, electricity injected into the grid is now compensated at
For recent installations, the electricity injected into the grid is now compensated at
a rate significantly lower than that of purchased electricity. Specifically, a household can
sell its surplus for a few cents per kWh, while buying electricity at a much
higher price.
The consequence is immediate: each kWh self-consumed is worth much more than a kWh injected.
2. Rates increasingly sensitive to consumption peaks
The new pricing structures incorporate more the notion of power and peaks of
withdrawal from the grid. Households that consume a lot in the evening — when the
panels no longer produce — are directly penalized.
Without a solution for valorizing the surplus, the majority of solar electricity produced during the
day remains underutilized.
3. Increased pressure on energy costs
In addition, there is a general context of rising and volatile electricity prices, as well as
gas and oil. Reducing dependence on fossil fuels becomes both an economic and environmental issue. In this context, the question is no longer just about producing solar electricity but especially about what to do with it.
Valorizing your photovoltaic surplus: an effective alternative to electrical storage
When talking about optimizing self-consumption, the electric battery is often
mentioned. However, another path exists: directly using the photovoltaic surplus to
produce heat, particularly domestic hot water. This is precisely the core
of the Soliseco solution.
Significantly increase self-consumption
Without a specific solution, a residential photovoltaic installation generally shows
a self-consumption rate of 35 to 45%. The rest of the electricity is fed into the grid.
Thanks to the utilization of the surplus for the water heater, Soliseco customers achieve an
average self-consumption of 72%, which is a gain of +32%.
The electricity produced during the day is thus used locally, at the very moment it is
available, to cover an essential household need: hot water and heating.
Significantly reduce gas or oil consumption
Domestic hot water represents a significant portion of a household's energy consumption.
By producing it mainly through photovoltaic surplus, the results are
immediate:
➡ –46% fossil fuel consumption on average among Soliseco customers
This reduction translates to:
• a direct decrease in the gas or oil bill,
• less exposure to price fluctuations,
• a significant reduction in CO₂ emissions.
Each kWh of solar energy converted to heat is one less kWh of fossil fuel consumed.
Economic analysis: concrete and sustainable gains
Unlike some heavy or complex solutions, the utilization of surplus
photovoltaic energy for hot water is based on a simple and robust principle.
Main sources of savings
The savings generated by a Soliseco solution come from two combined levers:
• Increase in electrical self-consumption
→ less electricity purchased from the grid
• Direct substitution of gas or oil
→ decrease in fuel consumption
Specifically, the Soliseco solution allows for the valorization of approximately 3,350 kWh per
year of photovoltaic surplus.
With a feed-in tariff for injected electricity estimated at ±€0.07/kWh in 2025, this represents a direct gain of about €235 per year, simply by consuming this energy
on-site rather than injecting it into the grid at low value.
In addition, savings on gas or oil bills contribute to a
total gain of several hundred euros per year, without changing the household's
consumption habits.
A quick return on investment
By relying on the electricity already produced by the panels, the Soliseco solution:
• does not require expensive electrical storage,
• does not rely on charge/discharge cycles,
• maintains a logic of simplicity and sustainability.
The return on investment is generally short and stable, while extending the value
of the existing photovoltaic installation.
Client case: a better-utilized photovoltaic installation
At Soliseco, the results are consistent from one client to another:
• Self-consumption: from ±40% before installation to ±72% after
• Gas or oil consumption: –46% on average
• Unchanged or even improved comfort, thanks to optimized hot water production
These gains are achieved without modifying the existing photovoltaic installation, and without any negative impact
on household comfort.
A complementary, simple, and sustainable solution
The valorization of photovoltaic surplus into heat has several key advantages:
• proven and robust technology,
• simple integration into existing installations,
• no dependence on complex electrochemical components,
• direct reduction of fossil fuel consumption.
It is particularly relevant for households heated by gas
or oil, looking to quickly improve the profitability of their solar panels.
Conclusion: turning surplus into a real resource
With the new tariff mechanisms, photovoltaic surplus is no longer a detail,
but a central issue. Letting it go to the grid at low value amounts to underutilizing your installation.
The results observed among Soliseco customers show that it is possible to:
• significantly increase self-consumption (+32%),
• reduce fossil fuel consumption by almost half (–46%),
• sustainably improve the profitability of photovoltaics, without unnecessary complexity.
The future of residential solar lies in the intelligent and local use of the energy
produced
Do you want to valorize your solar surplus?
Contact us today for a free analysis of your situation.