I am not a solar researcher. I'm just an average-joe solar user. I've been doing my own research into "what do I want" for a year now.
One thing I've found frustrating is that solar installers don't seem to understand, or want to share, the fundamentals. They do it one way, the cookie cutter way.
For example, most sites are space-constrained and that leads to concern about efficiency. I'm less space constrained, but that doesn't seem to change their ideas.
Most people have fixed-pitch roofs, so angles are what they are. Being flat, I choose the angle, and direction. There's very little data though on the best angles or the best direction. Are adjustable angles useful? Should I bias the direction to the west to compensate for morning/afternoon consumption patterns? All i get are blank stares.
On the up side, being forced to figure it out is interesting. And over the next few years I can generate actual data, testing various approaches, to see what actually is the most useful approach.
Sure, panel efficiency gets all the glory, but there's a lot more involved once you start building a system, and I think more practical research could be done there.
[1] one interesting point is the cost of the frame versus the cost of the panel. If I just "lie the panels flat" the frame price is negligible. Sure the panels are less productive, but Does spending the frame money on more panels offset that? Is overall production (not effeciency) better or worse? Factoring in summer as well as winter production.
[2] my city allows me to feed power into the grid, giving me about 40% credit. They are effectively a very large, 40% efficient battery, with no capital cost or maintainence cost. Plus they are long term, I can "charge" the battery in summer, use it in winter. I've yet to find an installer though that understands why this is good - they all balk when I say 40%.
FWIW I did my own solar installation, 50 panels in four different orientations (set of 18, two sets of 8 and two more sets of 8). This takes care of spreading the peak around solar noon at the expense of some of that peak. My panels are at 'inefficient angles', but they start generating very early in the morning and they finish really late.
When you look at it from a financial perspective in a net metering setup it is a bit less efficient, but when you look at it as if netmetering no longer exists (which I expect will happen here soon) then it suddenly comes out way ahead. It also has the added advantage that it avoids generating a lot of power when the power price is potentially negative.
My daily surplus in summer months is 80 KWh give or take, but during the winter, even with all this generating capacity I'm still running short. But proper insulation helped to cut down the gas consumption considerably and now energy costs for the whole house (about 2000 sq ft, freestanding) is < 300 euros / month including last winter's gas prices. Next winter should be better still (because I now have 18 more panels).
Total installed capacity is 16 x 265 (older panels) and 34 x 370 (newer, glass-glass panels). Inverter capacity is 4 KW on the high roof and 17 KW on the low one, with about 12 KW of output during the peaks in the summer.
Best day of the year so far made 99.8 KWh, worst days can be a few KWh so then you really need the grid. Average power draw of this house when we're careful is ~300 Watt, but cooking is a pretty big (and usually short) exception to that as is running the water cooker (but that's only a minute or two and during the day doesn't begin to approach the amount of power generated).
One downside of having panels flatter is that they foul up, some 3d printed clips helped with that but it isn't perfect.
Great info thanks. I'm starting with 20 panels, 480w, and a 16kw inverter, so room to add more panels next year if it makes sense. I figure after 2 years of actual data I'd be able to design the perfect setup for this building :)
I've heard of the flat-flat problem of pooling water, so I'd likely be at least 10 degress of angle.
Those little clips make a big difference. They use capillary action to help remove the standing water from the edges and work like a charm.
20x480 is a pretty good system to start with! And yes, insight comes with time, I'm lucky in that I already did a ton of this stuff while in Canada 20 years ago so now I can re-use that knowledge. One of the better things I did here is to create a covered space next to my garage that uses the panels as roofing. Two birds with one stone: very nice covered space and glass-glass panels allow some light to shine through and it helps keep the panels cool because there is plenty of airflow underneath them. Mounting them flush with some polymax in between to make it all watertight was a bit of a job though.
One thing I've found frustrating is that solar installers don't seem to understand, or want to share, the fundamentals. They do it one way, the cookie cutter way.
For example, most sites are space-constrained and that leads to concern about efficiency. I'm less space constrained, but that doesn't seem to change their ideas.
Most people have fixed-pitch roofs, so angles are what they are. Being flat, I choose the angle, and direction. There's very little data though on the best angles or the best direction. Are adjustable angles useful? Should I bias the direction to the west to compensate for morning/afternoon consumption patterns? All i get are blank stares.
On the up side, being forced to figure it out is interesting. And over the next few years I can generate actual data, testing various approaches, to see what actually is the most useful approach.
Sure, panel efficiency gets all the glory, but there's a lot more involved once you start building a system, and I think more practical research could be done there.
[1] one interesting point is the cost of the frame versus the cost of the panel. If I just "lie the panels flat" the frame price is negligible. Sure the panels are less productive, but Does spending the frame money on more panels offset that? Is overall production (not effeciency) better or worse? Factoring in summer as well as winter production.
[2] my city allows me to feed power into the grid, giving me about 40% credit. They are effectively a very large, 40% efficient battery, with no capital cost or maintainence cost. Plus they are long term, I can "charge" the battery in summer, use it in winter. I've yet to find an installer though that understands why this is good - they all balk when I say 40%.