Gww, thanks for the kind words..... now...
If we are going to use cheap solar effectively for life style,and not figures, we need to shift the way we think.
With limited solar we need to get the azimith and angels correct, use mppt, and generally wring the max kwh out of the panels we can...... but...
If we have lots of solar, (and it is dirt cheap now), we do things different..... first throw the books away.
I have so much solar I do NOT want it all performing as well as it can.... I can't use 10kw..... so I want to spread the kw over the day IF it is sunny.
I don't want or use mppt ( except it is in the grid tie ).. so simple pwm odes fine. $20 dollar controller will control 100 amps@ 60v or more... so cheap.
I don't want the panels set for 45-50 degrees as I should for this latitude, I want them to be predominately 15 degrees or so for the main banks... why??? because i don't particularly care where they are when the suns out, they will over power the system anyway, and need tempering from the pwm
It is when the sun is not out that we need to give some thought. Trackers are useless for this. Ambient light will come from near everywhere, and a panel pointing straight up will do best in a lot of cases, but we still need some angle to keep it clean... no other reason.
Local factors then need to be counted in. We need to set the system for what happens in the lousy insolation days.
Here the sun if there is going to be any in the winter seems to be in the first few hours of the day, and then it clouds over for the rest of it.... so a few kw pointing east at 25 degrees will get the best of morning sun, rather than using 45-50 degrees facing north ( southern hemisphere ) If I can get a few kwh early in the morning, I will have gone a long way to replacing the o/night stuff.
If it is a cloudy start, we get all the panels working, as there is no light point in the sky to face anyway.
A kw facing west for late afternoon topping up as long as we can before the sun sets is next. Probably 25 deg or so will do, the rest can point north at 15 degrees.
Moral of story, plan the system for WORST light days, and not give a toss about sunny days.
Today the place was fogged in , but the capture was such that 25 amps was coming in from fairly early on, as the whole sky was white, and radiation was coming from N S E and West.... so planer panels were best..... but at 9.30am. the sun came through , and we shot up to over 90 amps@55v or more, and it has been adding amp hours at a 45 second rate... it does not take much sun to fill the thing and begin pwm control.
10am came, the 2.5kw hot water started up to replenish the o/night temp loss ( about 10- 15C for 120liters) from showers dishes etc etc. It finished the night at 53C.. so it will use a few kwh to get back to 65c, and turn off.
The rest of the day will be spent in absorb..... very boring which is what we want. A sunny morning will see it full at 9am in the summer... the rest is waste unless you want to irrigate with a big motor, or use air conditioning all day, and that would not be seen anyway.
...............oztules