”This would never have been possible with a string inverter”

22 apartments in Axel without gas.

Have you heard of the most closely watched installers in the Netherlands? Erik de Zwart is his name, 33 years old, from Zeeuws Vlaanderen. No less than 21,000 people have already looked closely at his latest 88 kWP installation powered by 220 solar panels at home in Axel. Erik is not only an excellent ambassador for his employer Zonnepaneel Zeeland from Terneuzen but he is always looking for the latest innovative solar technology to benefit his customers and guess what! That ‘s how he came across APsystems. This Housing Association project from Woongoed Zeeuws-Vlaanderen is good proof of this.

The client was faced with a dilemma: Demolish or renovate a 40-year-old residential building? He opted for the latter, Erik explains, but then those 22 homes had to be cut off from gas. A contemporary challenge, which obviously preceded by a lot of research and calculations. Energy in the homes had to switch from gas to electricity for both hot water and heating. The power for this had to come from solar panels.


Erik: “Ultimately, it was decided to connect every home to 10 solar panels. Together these would provide 4000 Watt Peak to each residence. However, space was lacking and the roof offered just too little capacity. That’s how I thought about completing the solar powered roof with a cladding project for 20 panels which, according to our calculations, was the optimum size of the installation. But it was not the end yet, a new challenge arose: How do you divide all those panels among the residents in a fair way? We chose the ideal mix. Each house received 10 panels, some on the east, also a few on the west and south. In this way, every home is guaranteed a minimum yield.


ZonnePanelen Zeeland has been installing APsystems microinverters for years, also in Axel, where we have installed 110 DS3 Microinverters. As a matter of fact, connecting all those panels with different orientations together with a string, would have never worked. The flexibility offered by the DS3 dual microinverters from APsystems assured that every home would get an optimal “solar power generation package” to cover its boiler and heating.” “Am I going too fast for you?” Erik asks with a genuine Zeeland accent.  “I’ll explain it all to you in my videos on YouTube, search on ‘Op pad met de zonnestroom installateur’’.  Would you like to know more about the installation of the 220 Trina Solar panels? Then take a look at the other videos and search on YouTube for ‘Flat van het gas af”.

That was quite a unique job, installing solar on the wall. I don’t do that often. The final shot gives a spectacular picture of the entire project.”


Erik has been posting a video of every project on YouTube for 2.5 years. Why? “I just like to talk about my profession. I truly believe solar is a great part of the solution to our energy transition and I want that to be recognized in the field. Those videos attract a lot of attention and I get a lot of thanks too. The questions are usually very practical in nature. The technology behind an APsystems microinverter is explained well on your site, but you won’t find why the DS3 is a great tool for solving the most complicated distribution problems.”

We still have one question. How is the monitoring arranged in Axel? Erik grins: “Not settled yet. We have yet to install it. Do not worry. With the APsystems ECU-C, all current data is collected to get a good picture of the yield of the solar panel system. In this way we keep our finger on the pulse. From a distance.

Do you want to know more. Visit my channel and send me an email. I have to go”.

Full story + images

Installater: Zonnepaneel Zeeland
Where: Axel, Zeeuws-Vlaanderen
System capacity: 80 kW
Microinverter: DS3
Panel: 220 x Trina Solar 400W