Hello All!
I am in the process of installing PV on the ground (south facing). I want to align the PV well with the sun to make the best use of the spring / summer / autumn time.
I am looking for a reasonable calculator (preferably open source) that will help me calculate the optimal panel tilt for ~ (52N, 21E).
Can anyone recommend something worth attention?
Thanks in advance for any constructive feedback.
That appears to be for the US only. So US (as in UnServiceable) for the rest of the world.
Where’d you see that?
Unless they’re lying to us, their landing page says:
and the “about” section says:
I did not know this abbreviation explanation before.
Nevertheless the site seems to calculate some results for other countries as well.
When I tried to tell it where I lived. I gave it the first 3 characters of my postcode, it showed the map putting me the opposite side of the city to where I live, when I clicked on my true location as instructed, it told me my address wasn’t in the US. Which is true, it isn’t.
The other website mentioned earlier worked fine for me, and appeared to be credible.
If you give it Birmingham UK vice your post code, you get this:
The blue rectangle on the map indicates the NREL National Solar Radiation Database (NSRDB) grid cell for your location. If you want to use data for a different NSRDB grid cell, double-click the map to move the rectangle. Dragging the rectangle will not move it.
If your location is outside the NSRDB area, the map shows pins for the nearest alternate data sites instead of a rectangle: Click a pin to choose the site you want to use.
Using the “defaults” for each calculator, I got:
PVWatts:
PVGIS:
A difference of 139 kWh over the span of one year.
This is not a definitive answer.
I’d say don’t bother and design for convenience and aesthetics after taking care that all solar panels are above fence/obstructions and tilted by more than 30 degrees to tip off the snow. Rule of thumb is that at 52.4 degrees North, set panels at 4/5 of that; about 42 degrees, facing due South.
I had an extra solar panel leaned on a heap of bricks to try out different angles and orientations. Chasing the sun direction was gainful, but not gainful enough by comparison to just buying more solar panels and setting up 1/4 of them all facing SW at 40 to 60 degrees slope and 1/4 of them SE at 40 to 60 degrees slope, with the rest south facing at 30 to 50 degrees. Alignment to look neat on the house is perhaps more important than chasing the last cosine(10 degrees) of theoretical solar output power.
In Birmingham, I bet that it is bright cloudy weather often enough to throw the theoretical calculations in the bin and just build it as big as you have space for.
