PV panels, they rock

[Joost Schuttelaar]

My most recent home improvement project was to upgrade the garage roof with 6 panels, for a 2000 WP system. Together with the main roof, now 21 panels in total (4KWP + 2KWP), which should be sufficient for all use (the 4000 WP system gives about 4500KWh per year).

The main roof was an expensive (±7000 euros) system consisting of LG panels and a SMA inverter. Everything carefully tuned and modelled by professionals, installed a bit more than 2 years ago.  

The garage roof is a dinky system, with the cheapest panels available (Jinko 340WP) and a cheap Goodwe inverter (GW2000-XS). Around 1000 euros. The mounting gear to put it on the roof brings it to 1500. Basically an experiment to find out, how well does a super simple and cheap system perform?

The answer to this is: remarkably well. The panels are facing south, so it’s expected that they’re now at peak performance, but they’re bringing in around 13KWh on a good day. If my simple back of the napkin envelope calculation follows, the system should pay itself back in 4 years (including installation).

Hooking up was simple too: in my case I put an extra circuit box in the garage (to prepare for three-phase electric car charging in the future), which I simply connected for now on the single phase power conductor coming from the main house. So: electric grid → main circuit box → mains switch → dedicated breaker with RCD for the garage → underground cable → garage circuit box → garage mains switch → dedicated breaker with RCD for the power inverter. The panels themselves come with pre-attached cables, it’s one loop with all panels connected in series, and towards the inverter you also buy solar cables with the plugs already attached.

So in summary, solar rocks :)

Cheers,

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Joost Schuttelaar
The Hague, NL