Hey everybody,

I am located in eastern Wallonia and would like to install \~12-14kWp solar panels with a 10kwp inverter to not get over the prosumer limit. As ORES states:

[https://www.ores.be/particuliers-et-professionnels/production-energie](https://www.ores.be/particuliers-et-professionnels/production-energie)

… I have to register my setup with them. In the required form they state, that they need the contact data of the installer, photos and some other stuff. Has anyone had experience with this process without having a company installing your panels? Is it enough to have an electrician doing the wiring after the inverter or do I need someone with special certifications/training?

Furthermore I would like to ask for a smart meter, because they are free of charge until end of 2023 – bad idea? I think I will need one, because I still have the old one-way meter (ferraris) in my house.

My plan is to not supply any energy back to the public network – instead I will heat my buffer tank or my beer fridge with the exceeding energy to avoid prosumer fees.

7 comments

  1. Rules in Wallonië are different than in Flanders, so I’m not aware of every rules – like rewinding meter (which is not possible anymore in Flanders).

    But no, wiring doesn’t need to be done by a specialized person. You can do wiring yourself, or an electrician is also possible.

  2. With the actual cost of electricity, I assume it’s more interesting to pay the prosumer fee and just let the meter feed excess energy to the grid.

    You definitely need a certifier to check your installation in order for ORES to validate it.

  3. What you are attempting might be illegal. (Try by to dodge the prosumer by not injecting current).

    I’m also curious how do you plan on having a 10kW inverter working without hooking that thing to the grid. Can you really use all of that energy when it’s at peak production?

    Have you made a profitability calculation accounting for prosumer tax and the old meter wich turn backward?

    Have you not learned that the smart meter is a bad idea VS the old meter + prosumer?

    With the smart meter you won’t have prosumer normally as you will be paid for the injection of the current separately than you’ll pay for what you consume.

    You need to seriously read on what you are attempting to do and calculate how to do it correctly because you seems to be ignorant on the subject (I’m not talking about if you can connect + with + technically here).

  5. Don’t know about Walonie but in Flanders you can do everything yourself. You only have to pass official certification by BTV or some other company before hooking everything up to the grid. When going this route, keep in mind you’ll also need to draw your plans and other documents needed for certification.

    I’d advise you to hook up to the grid because it solves a lot of issues with your overdimensioned installation. If it’s possible to keep the old meterand prosumer tax: do that. But I suspect when they come to hook everything up, they’ll install a digital meter. Which can also benefit you (in contrast to what people tend to say). Say for example you only use 30% of your produced energy on average, then you’ll be payed for the remaining electricity you inject. At a certain point, you’ll earn more than when using the old meter to have 0 usage. Of course I don’t know if your installation IS overdimensioned and by how much.

    Apart from the above, some other people here already stated it seems you don’t have that much experience with electricity. I’d advice you to read/learn much more about it before attempting a solar installation. Maybe start by doing some simple 1x230vac installation.

    There’s a lot of stuff to keep in mind once solar get’s into an installation, a lot of calculations and technical knowledge are needed. Electricity can be dangerous and I’d rather pay a pro than burn my house.

    PS; I don’t know if an electrician wants to do the remainder of your installation after you do the solar part. Seems like a risk to take.

    PSS; I don’t know which connection you have at home but for that kind of power you defo need 3x400vac. If you don’t have an electric installation of that kind, you’ll need to change the current installation by a lot.

  6. Actual expert here regarding legislation, not placement or specifics about the wiring.

    Not supplying anything back to the net is not an option, because you’re connecting it to a network that is on the grid. The only way to avoid that is by decoupling your consumption as well, which requires quite an expensive and intricate setup to work which is not worth it in Wallonia for now.

    Wallonia still has the meter option to inversely count anything which you inject, which is an insane benefit. The “prosumententarief” is very little compared to the net profit you’re gaining, especially with current pricing.

    The most important you need to know is that solar panels are meant to reduce your energy usage. So you gotta get an estimation of what your setup with your buffer tank, fridge and whatever usage you have will use on a yearly base.

    10kw inverter means you’re estimated to generate +- 8.000 kWh. If your usage with your setup is around 5.000-6.000 kWh, then you’re needlessly overplacing. 1kWp is about 800-810 kWh average yearly.

    If your usage is 8.000 kWh or higher, you should just go for the full 10 and put it on the net. Currently in Wallonia you can abuse the net as a live battery, and if you break even the usage yearly, you’re getting a bill which only consists of prosumententarief, which is a fraction of what regular users pay.

    Some side tips, the moment you have the panels and are injecting on the net, be sure to only ever switch suppliers during the month of your meter reading, and when you switch that you give the last meter reading of the previous year rather than the current reading. Anything that deviates from the “0” line is either lost (negative) or has to be paid (positive). I’ve known people with a 10kv that accidentally switched during a winter period when only 3-4 months passed, that had horrible financial consequences.

    Also be prepared that the Wallonia Government will sooner or later follow suit with what Flanders is doing. Wallonia is always 3-4 years behind when it comes to these legislations, but they do follow.

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