Solar Tracking Systems. Are they worth it for home owners? (Pros and Cons)

[curtis63]

I am looking at putting in a solar system. I use an average of 1300 kWh per month and have a really big south facing roof. I have looked around a bit online for Solar Tracking systems. The only ones I can find have arrays of 12 or more panels mounted on them and have a big post. Does anybody make a Solar Tracking system that will move individual panels based on the sun's location?

How much do they cost? What are the different options? Is it worth it to buy them, or would I be better off just purchasing more solar panels?

When I was looking around, they say a 2 axis solar tracking system will improve energy output by up to 40%. So that would mean if I was going to need 40 panels, I would only need about 29 to get the same power output, if I used a solar tracking system.

However, I'm guessing these tracking systems vary QUITE a bit based on how much they can move. So I'm trying to picture a solar panel mounted to my roof. If it is stationary and mounted optimally, it would have about 5 hours per day of useful sunlight, on a sunny summer day. If I were able to have it tilt 15% left to right, how much power improvement would I see?

How much difference does the angle of the panel make in power output? What sources would be good to investigate this? For example, how much is the power reduced as my panel angle is further away from an optimal angle?

Anyway, thanks for answering these questions. Hope this sparks some good discussion about Solar Tracking Systems.

Thanks a bunch,
Curtis

[Sunking]

No they are not worth it. Only to be used if space is very limited. Trackers at best only harvest 25% more power, 12 to 18% is more realistic. That being said it is less expensive to just add more panel wattage. The other other ugly thing with trackers is they are very high maintenance items requiring periodic adjustments and motor replacements.

So unless you have very limited space, trackers are useless. Even if you have limited space a Tracker may or may not solve the problem. If you need say 1000 watts of panels but only room for 600 watts, a Tracker is not going to work. Basically you would be SOL.

[J.P.M.]

I am looking at putting in a solar system. I use an average of 1300 kWh per month and have a really big south facing roof. I have looked around a bit online for Solar Tracking systems. The only ones I can find have arrays of 12 or more panels mounted on them and have a big post. Does anybody make a Solar Tracking system that will move individual panels based on the sun's location?

How much do they cost? What are the different options? Is it worth it to buy them, or would I be better off just purchasing more solar panels?

When I was looking around, they say a 2 axis solar tracking system will improve energy output by up to 40%. So that would mean if I was going to need 40 panels, I would only need about 29 to get the same power output, if I used a solar tracking system.

However, I'm guessing these tracking systems vary QUITE a bit based on how much they can move. So I'm trying to picture a solar panel mounted to my roof. If it is stationary and mounted optimally, it would have about 5 hours per day of useful sunlight, on a sunny summer day. If I were able to have it tilt 15% left to right, how much power improvement would I see?

How much difference does the angle of the panel make in power output? What sources would be good to investigate this? For example, how much is the power reduced as my panel angle is further away from an optimal angle?

Anyway, thanks for answering these questions. Hope this sparks some good discussion about Solar Tracking Systems.

Thanks a bunch,
Curtis

1.) About the best increase you'll get in available irradiance for a dual axis tracking scheme over an ideally orientated fixed array is about 38% over an optimally orientated fixed array - facing south, tilted at local latitude. (Solar Radiation Data Manual for Flat Plate and Concentrating Collectors, NREL). That's in Albuquerque, NM. Phoenix is about the same. In most other places, that # is lower, commonly <~ 25-28%, or about what Sunking suggests.

That's only the increase in resource availability, not performance or output enhancement, which may be a bit more or less than those percentages depending on how the tracking design changes the panel temp. relative to a fixed array design - A little higher if the tracking system increases air flow around the panels and helps the panels run cooler, a little lower if the direct irradiance advantage of the tracking array makes the panels run hotter, or a combination of those and other factors.

That "up to 40%" sounds like peddler's B.S.

2.) You may save a few $$'s on panels, but the maint. time/cost and PITA factor may not be worth it. Also, tracking systems are usually more visible, affecting aesthetic considerations some.

3.) Try PVWatts and compare outputs for fixed, single and dual axis tracking mechanisms for a SWAG estimate of long term performance.

4.) Tracking systems have been discussed on this forum for some time. I'd guess there is some consensus that while tracking systems have some application, the cost, the complexity and attendant increased maint. make them less viable than a fixed array system.

[Sunny Solar]

there are almost no real gains using trackers now.. Panel costs are low and a far better alternatiive is extra panels..
remember a tracker will gain you very little between 10 am and 2 pm. And that is when the panels are receiving most sun power.. They only work before and after those times. but the sun power is lower also so gains are lower.
As everyone will tell you all trackers need maintenance..