vk_1

Hi guys, let me share the recent update of my solar lab!
Originally I had 20kWp of PV on the roof, which was great, but the available space was not utilized optimally. Namely because there was the chimney blocking part of the west roof. Not to mention long shadows it casted each winter. After a couple of years I demolished that chimney (with the big help of my friend Kobra) and built a new fireplace, plus new chimney that freed the space on the roof.
For a shame, width and height of the panels that I had was not ideal, so even with the chimney removed I was still unable to utilize space optimally:

Therefore, I was continuously looking at the PV modules market each year, in order to find new panels that would fit better. As you might know, the manufacturers of PV modules are introducing new models each year, with their dimensions derived from the physical size of the actual solar cells used. And as solar cell makers are gradually able to produce bigger silicone crystals (that the cells are cut from), the PV modules are getting bigger and bigger, even when the number of cells per module stays within the standard amounts (like 72, 144 etc.).
Finally, in 2025 I found PV modules with the size of 1961 x 1134 mm, which was perfect for me as it would fill the roof from side to side almost completely, while still allowing me to put 4 rows of panels on it. So I went for 500Wp double-glass/bifacial, all-black panels and bought 3 palettes of them. Although these panels are bifacial, they are NOT transparent as the space between the cells is of opaque black color. On the other hand, putting bifacial panels on the dark roof makes no sense anyway. The price was excellent (for me) 77USD + VAT per panel. Let's see how these double-glass panels will hold up in the long run.



Firstly, I had and idea to remove all the old panels by myself, but found it being too labor-intensive. Looks like I am getting old, to be honest. So, after removing 18 panels out of 72 (with the help of my friend Vitek) I gave-up and called a third friend of mine, David, who is running a business of building large PV power plants for factories and other commercial customers. David's guys were amazing and after a couple of days, all the old panels were down, aluminium rails repositioned and leveled. Also, the new rails for fourth row of panels were added and finaly there was 86 panels installed.
West roof:
East roof:
Now it's 43 kWp of solar, composed of 6 strings:
East: 14s + 14s +14s
West: 14x +14s +16s
To be continued...