alt Hacker NewsHorses for courses. My system is off grid, so any extra power is just not used, and its designed in a way that a 2-5% change doesn't do anything. That might be a more meaningful change if I were selling power to other folks.
Kind of off topic, but I see a lot of folks proximate to me have built systems to turn panels so they face the sun more closely. I can see the use in that if you don't have much space or if you have a large commercial operation, but this area is very rural.
My array (4kw) which I built myself has 10 400W panels. The panels cost me $1200 because the minimum order is 12 and the supplier suggested buying extras; shipping large panels one at a time isn't cheap. In fact, the shipping for the entire system (about $5000 worth of equipment) was almost $1000.
But my feeling is that for the cost of a moving array that tracks the sun / time of year would have cost quite a lot more and have involved construction that I personally wasn't comfortable with. The conclusion I came to is that it would cost about the same to build a second array, angle it for "summer" (mine is angled to be most efficient in winter), and hook it to the other MPPT on my controller.
That would take up a lot of space, but a) I am 40 acres and b) then I could run a mig welder with impunity during the day...
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It does no longer pay to be clever with solar panels; they're too cheap. Angle not quite right? Add a couple extra. Summer vs. Winter? Add a couple extra.
A lot of these designs are an artifact of a time when the panels themselves would have been far and away the most expensive component in the system. The place I'm in originally had 10 125W panels that probably cost north of $8k when installed, and they were mounted on a rotating, tilt-adjustable post. Also the entire house was wired to run off DC as much as possible, with three different wiring schemes throughout and rare & expensive appliances. It reminded me strongly of RV power schemes, and maintenance was probably a huge headache.
I replaced it all with 9kW worth of panels (about $3k, shipped) on 4 simple 60° ground mounts, normal wiring and appliances. Angle is optimized for early spring / late fall - there's effectively no sun in winter, and the rest of the year I have excess power even with fixed, sub-optimal angles.
The diminished cost of panels alone over the past 20 years has transformed "off-grid" from a pastime for wealthy hippies into a reasonable solution for remote living.