Guide to the counter that turns upside down

Everything you need to know about the meter that turns upside down in Wallonia

Understanding the backwards-turning meter system is important for owners of photovoltaic panels in Wallonia. This mechanism, which underwent major changes in 2024, is explained to you by your Vectura experts.

How does the “meter that turns upside down” work in Wallonia?

The upside-down meter works like an energy balance between your production and your consumption. Let’s take the example of a house equipped with photovoltaic panels. On a sunny day, when the panels produce more electricity than the house consumes, the surplus is fed into the grid, literally turning the meter in the opposite direction. At night, when the house consumes electricity from the grid, the meter turns back in the normal direction.Example to illustrate the principle

To illustrate how this works, let’s consider a family consuming 4,000 kWh per year.

With a 4 kWp photovoltaic system producing around 3,600 kWh annually, here’s how compensation works:

• Daytime: production of 10 kWh, consumption of 4 kWh = 6 kWh injected
• At night: consumption of 6 kWh, no production since your panels don’t collect solar energy.

Over a year, this family will only pay the difference between its total consumption (4,000 kWh) and its production (+/- 3,600 kWh), i.e. 400 kWh, to which must be added the annual prosumer tax.

Since January 2024, the prosumer tariff has been replaced by the injection tariff in Wallonia.

The feed-in tariff is the price at which your supplier buys back the electricity you inject into the grid. Since January 2024, this system has replaced the reverse meter for new installations in Wallonia. The tariff varies from supplier to supplier, generally fluctuating between €0.05 and €0.06/kWh.

To qualify, your installation must :

• Be equipped with a dual-flow meter, known as intelligent.
• Have a maximum power rating of 10 kVA(kVA = maximum electrical power your meter can handle).
• Be declared to the grid operator (which you can find according to your postal code via the CWAPE website).

Changes in 2024: the end of the reverse meter system in Wallonia

On December 31, 2023, the backwards-turning meter came to an end in Wallonia. and has been replaced by the obligation to install a bi-directional/communicating meter when installing photovoltaic panels.

What should you do if you have installed photovoltaic panels in Wallonia before 12/31/2023?

For installations still benefiting from the counter that runs in reverse, a few practices can help optimize the advantages of the system:

• Keep panels in good condition to maximize production
• Increase the output of your photovoltaic system by a maximum of one kW of net developable power (e.g. by replacing the old inverter with a newer one, slightly more powerful by one kW, and adding a few panels) → If the increase is at least 1kW, you’ll have to redo your electrical compliance, declare this change to the GRD and therefore make a clean sweep of this meter system that runs backwards.

Is it still worth installing photovoltaic panels in 2025 in Wallonia, even without the “meter that turns upside down”?

For private customers who have not installed their system by December 31, 2023, photovoltaic panels are still profitable, despite the absence of a meter that turns upside down. Find out why!

Costed example for an installation after 12/31/2023

To understand this profitability, let’s take the example of a family consuming 4,000 kWh per year. With a 4 kWp installation producing +/- 3,600 kWh annually, with 40% self-consumption, the investment pays for itself in around 6 years.

Of the 3,600 kWh produced :

• 1,440 kWh are self-consumed, avoiding purchase at €0.30/kWh, i.e. savings of €432
• 2,160 kWh fed into the grid, generating revenue of €108 (at €0.05/kWh)

That’s an annual saving of €540, not counting the likely increase in electricity prices.

Optimizations without the counter running backwards

After 12/31/2023, the key for Walloon owners of photovoltaic panels is to consume as much of the electricity generated by their photovoltaic system as possible. Here are a few tips to help you do just that.

Maximizing self-consumption

Intelligent programming :

1. Start the washing machine between 10 a.m. and 4 p.m.
2. Programming the dishwasher during the day
3. Use the tumble dryer during production peaks

Technology and home automation :

• Install connected sockets that activate automatically according to production levels
• Use a monitoring application to track production in real time
• Programming the water heater during production hours

Electric mobility :

• Charging your electric vehicle during the day
• Use a smart charging station that adapts power according to solar output

Storage and management :

• Consider installing a domestic battery
• Use energy management systems that automatically optimize consumption

These adaptations enable self-consumption of 60-80%, maximizing the profitability of your photovoltaic system even without the meter running backwards.

Can my meter turn backwards?

• If you have installed a photovoltaic system that has been approved before 12/31/2023, yes. Whether you have a conventional meter or a bi-directional meterit will run in reverse until 2030, and you’ll benefit from benefit the prosumer tariff.
• If your installation was accepted after 12/31/2023, your meter is no longer eligible for the compensation system.

Do I need a special meter for photovoltaic panels?

Since January 1, 2024, the transition has intensified with the obligation to install a smart meter for all new installations or modifications to photovoltaic systems (> 1 kW). This change is part of the overall modernization of the Walloon electricity grid. However, the legislator has provided for a degree of flexibility: although installation of the meter is compulsory, each consumer retains the right to deactivate the remote communication function if they so wish. This option addresses consumer data protection concerns while enabling the modernization of the power grid.

What are the advantages of an upside-down meter?

A meter that turns upside down has several important advantages:

• Lower electricity bills: Thanks to this mechanism, you can sell excess electricity produced by injecting it into the electricity grid, significantly reducing your electricity bill.
• Energy autonomy: In the event of a grid failure, you can use the electricity generated by your photovoltaic panels to power your home, increasing your energy independence.
• Additional savings: By using your own electricity to power your electrical appliances, you make additional savings on your energy bill.

How can you save on your bills with a meter that runs backwards?

Photovoltaic panels are still an interesting way of reducing your energy bill, even without the backwards-turning meter system. Discover the article on whether or not solar panels are profitable in Wallonia and contact us for a free free study of your installation! Our experts will be happy to advise you!