posted 3 hours ago
Hi;
The standard recommendation for solar panel angle is your latitude;
ex. 45 latitude; 45 angle from horizontal
Panels work best when perpendicular to the suns rays, so 45 from horizontal is a
a compromise between summer (45 + 23 = 68) high angle sun with optimal panel angle of 22 from horizontal, vs.
winter (45-23 = 22) low angle sun with optimal panel angle of 68 from horizontal.
But I do not think the latitude angle works best for typical situations.
i) Grid tie: This depends upon the utility deal.
My jurisdiction pays 1:1 for energy exchange, cand cancels any excess export above consumption to 0 at the end of the year.
I should maximize annual production up to consumption, at minimum capital cost.
In my climate that means a lower panel angle, towards summer optimum, because that maximizes annual production per panel & racking.
Coincidentally, bungalow roofs are less than 45, and so approximate a good summer angle for 1:1 grid tie.
From the utility point of view, they would prefer me to maximize winter production when demand is higher here; eventually regulations will likely push that way.
ii) Summer use off grid: similar to grid tie; optimize near the summer angle to minimize investment in panels & racking required.
iii) Year round off grid: panels near winter angle will maximize scarce winter production, and shed snow better.
The cost of panels is now low, so 'wasting' panels in summer is not a big detriment.
But panels need racks, and rack costs have not decreased, even if home built.
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