Planning a solar setup in Belgium

Hi there,

For the past weeks I have been reading up on this forum and now I decided that it was time to make my own topic seen as there are multiple Belgian powerwall owners here.
As the title says, I'm currently making a "feasibility study" for myself on what is possible and what isn't.


Currently in our house, wejust have a basic grid connection, where we use about 2700Kwh yearly (divided as 1133Kwh Daytime / 1620Kwh Nighttime).
The idea is to put a solar setup in place as our house has a south-facing tilted roof.For this I have already received some price quotes.

The estimations there are based around:
10 x 270w panel
2,5KW inverter (typically an SMA Sunny Boy 2.5 is referred to here)

For this, the best offer so far appears to be around 4.9K EUR (all work included). I have no idea how competitive this price is...
On top of that, I would need to get my day/night meter replaced by a single tariff one.

Now the real questions I'm having are based around the Belgian regulations enforced on grid-connected solar setups.
1.There is a yearly fee to be paid which is based on the inverter size. In my case that would be +/- 260EUR per year. -> I'm not very fond of this as it directly cuts into the profit, without taking actual production into account.
2. Any overproduction (at the end of the year)completely goes to waste without any financial return for it from the electrical company.
3. There is a motion to introduce so-called "Smart energy meters" in every home within some years. These meters will even further split used vs created power which seems like a way to differentiate between daytime production vs nighttime usage.

My conclusion to counter these three "issues" was a battery setup. At this point however, I am running into a more practical set of issues:
- The grid connection and electrical box in our home is next to our front door, in a medium sized cabinet.
- Our basic solar setup would have the panels on the front side of our roof, with the inverter being added inside the cabinet next to the front door.
- For safety reasons I do not wantto have a battery bank inside the house. We do have a decently sized (12sqm) garden shed to which there is already an underground mains connection straight from the electrical cabinet.
- For budgetary reasons, I want to be able to start with solar and build the battery part on top of this system while gradually expanding that part.

Having said all that, my current most burning questions are:
- Is this a good idea at all? I have been said that our power usage isn't that high to start with, so the high startup cost of the infrastructure will cause for a very long payback time.
- I have read that it's possible to have a grid-connected inverter in one place, with a battery-based inverter somewhere else physically. Are there people here running such a setup? I imagine there has to be communication between the solar inverter and the battery inverter in this case?
- Is there a way to get around the Belgian fee for grid-connected inverters, while keeping a proper (legal requirements etc) power infrastructure within the home?
- Generally, how do the Belgian powerwall users deal with this?

I am sure there will be more questions as I go forward in this journey, but for now I would really appreciate any feedback really

Welcome.
The big problem for many people here are the regulations. Second is that hooking a base system up to battery is not realy doable unless you want to tinker around alot and then you most likely break all rules you can.

If you dont go with battery directly and offgrid you need to hook it to the grid = you need to pay your fee. Thats what you wanted to not to do.
If you want an offgrid system that have NO connection to grid in terms of sending electricity there you need the battery. No system works without battery in that case.

The units that claim they operate without battery they also send to grid. And to stay legal you need them to be approved. Most of the chinese units arent approved in many countries im afraid.

My knowledge in SMA and those are very very limited and i kept myself away from them due to the price.

My sugestion is to: Add solar. Have the battery and main electronics for charging in the shed. Dig down a new AC wire to the house. Add a new switchboard and just move over some of the wires from the house to that switchboard. Have a ATS or just manual Switch that you can switch between solar power and AC power. Doing this you really dont cause any issues to the grid power. In sweden thats legal but how it is where you live im not sure.

Hi Nick,

And welcome,

2700 Kwh usage a year, is prettylow, ( i useabout 7000 Kwh/year due to a heatpump heating/ac ).
2.7 Kwp solar with a inverter SMA 2.4Kw sound right and at a price of 4900 Euro, installation included,is a good deal i believe.
Replacing your day/night meter, is a must if you not going to use battery's.

The real questions:

1) The yearly feed you are talking about (100Euro/Kw inverter/year)isonly when your inverter is feeding back into the grid. so if you decide to use a battery storage keep in mind to get a inverter whithout feed-back function (or you stillhave to pay this feed). Minus on this is when the battery's are full, solar power production stops, exept for the load at that time.

2) Overproduction on a grid-tie system is not realy wasted, in case there is some more consumption the next year you are still getting it back, if there is to much production every year... yes, you are wasting solar power, this means your solar installation is to big and you have payed to much on this part, the solar energy on itselve is free (as long there is no tax on daylight )

3) Yes, the smart meters.... we are not there yet,but nobodyknows what the concequences are for solarpanel owners... time will tell.... This is one of the reasons why i would like to go off-grid, to be not longer subjected to the "goodwill" of orgouvernant and electrical compagny's.

For now, in Belgium,i am sure te most easy, andstill cheapest, way to get a lower electricity bill is a simple grid-tie solar system ( besides lowering your consuption ).
For you, it is maybe a good idea to install a battery bank, not to big, for night time use... it is possible to connect a grid-tie system and have a battery based sysem at the same time, no problem, but as ,Daromer mention you need to install ( manual or automatic ) transfer switches to prevent "Island working".
There is no need of communication between inverters, they do their own thing.

It is smart to installyour battery's on a safe place, outside the main house, do not forget a bms system with capabilaty to disconnect the system.
The 220v part need to be approved and certificated, on-grid and off-grid, for insurrance reasons.

So, only way to avoid the feed-back fee... is to not feeding back into the grid... A system withbattery's is a way to do this, but is more expencive as a basic grid-tie system. To make some mony on such a system in the long run, you have to go 100% off-grid and avoid all taxes and fees.
Keep in mind, to go off-grid in Belgium you need at leastoneway to generate power besides solar, for in the winter and darker day's.

I am not sure it is possible to make money on these kind ofsystems at all.... For myself and for sure for a lot of members of this forum "payback" is not the reason to do what we do, is is more a " i can if i want to "or hobby and fascinationthing.

Building my install was the most fun i had in a long time , anyfinancial advantage, isa plus

wim said:

Hi Nick,

And welcome,

2700 Kwh usage a year, is prettylow, ( i useabout 7000 Kwh/year due to a heatpump heating/ac ).
2.7 Kwp solar with a inverter SMA 2.4Kw sound right and at a price of 4900 Euro, installation included,is a good deal i believe.
Replacing your day/night meter, is a must if you not going to use battery's.

The real questions:

1) The yearly feed you are talking about (100Euro/Kw inverter/year)isonly when your inverter is feeding back into the grid. so if you decide to use a battery storage keep in mind to get a inverter whithout feed-back function (or you stillhave to pay this feed). Minus on this is when the battery's are full, solar power production stops, exept for the load at that time.

2) Overproduction on a grid-tie system is not realy wasted, in case there is some more consumption the next year you are still getting it back, if there is to much production every year... yes, you are wasting solar power, this means your solar installation is to big and you have payed to much on this part, the solar energy on itselve is free (as long there is no tax on daylight )

3) Yes, the smart meters.... we are not there yet,but nobodyknows what the concequences are for solarpanel owners... time will tell.... This is one of the reasons why i would like to go off-grid, to be not longer subjected to the "goodwill" of orgouvernant and electrical compagny's.

For now, in Belgium,i am sure te most easy, andstill cheapest, way to get a lower electricity bill is a simple grid-tie solar system ( besides lowering your consuption ).
For you, it is maybe a good idea to install a battery bank, not to big, for night time use... it is possible to connect a grid-tie system and have a battery based sysem at the same time, no problem, but as ,Daromer mention you need to install ( manual or automatic ) transfer switches to prevent "Island working".
There is no need of communication between inverters, they do their own thing.

It is smart to installyour battery's on a safe place, outside the main house, do not forget a bms system with capabilaty to disconnect the system.
The 220v part need to be approved and certificated, on-grid and off-grid, for insurrance reasons.

So, only way to avoid the feed-back fee... is to not feeding back into the grid... A system withbattery's is a way to do this, but is more expencive as a basic grid-tie system. To make some mony on such a system in the long run, you have to go 100% off-grid and avoid all taxes and fees.
Keep in mind, to go off-grid in Belgium you need at leastoneway to generate power besides solar, for in the winter and darker day's.

I am not sure it is possible to make money on these kind ofsystems at all.... For myself and for sure for a lot of members of this forum "payback" is not the reason to do what we do, is is more a " i can if i want to "or hobby and fascinationthing.

Building my install was the most fun i had in a long time , anyfinancial advantage, isa plus

Click to expand...

Hello you all passionate guys,

I am aware that passion and loving to tinker are driving me. I still hope that this work will payback somehow financially because emotionally it the activity of learning pays back a lot...
I
Speaking of "payback" not being the reason to what we do have a few questions.


1. After you know what my usage is, 3500 kWh per year, what do I need to design my system?
2. What makes the decision between having an "off grid" or "grid tied" system?
3. What is the schema that permits adding a wind turbine later in the system?
4. What do we need in a schema to allow increasing the PV power?
5. Can we start with pv power first and then later add the storage battery later?
6. How do we need to create the system to allow increasing the battery storage capacity?
7. What percentage of your capacity are you covering?
8. How do you manage things in the winter?


I appreciate your support and wisdom,

Ioan

Hi Nick,

I'm from Belgium and building a Powerwall.

My current solar system is 21 on-grid 265 panels. Connected to 2 small SMA inverters, due to different sun angles/times.

I have around 4700 KWH per year, for 7 years now, and use about 5500 KWH.
Indeed, the new taxes cut hard in the revenue model of a solar system. However, when I bought the system, I paid 22000 Euro (and that was cheap back then). But I still benefit subsidies for my system.

So making changes in my on-grid system is a NO-GO !!!

I plan to make a second electrical circuit in my house for certain devices in my house which consume a lot of power and are in a centralised place. That way, I can come in my house with 1 wire and distribute over some powersockets.
I think about my Qnap 8xHDD setup, second fridge, waterpump for rainwater, 24/7 pc, and maybe some other appliances.

That way my on-grid has to come to zero (current solar setup - consumption) and off-grid circuit has "nothing" to do with my current electrical system.

Hope this helps.

BTW, 2700 is really low... doing good job for the environment .

Sounds like how I ran my system last year. I had ongrid some parts and then i had a 4th phase going into the house that was from the Offgrid system. This was powering some high powere appliances that we run during night and other and the electrical units like TV+ server and so forth.