Which give most. Fixed south or single axix tracker east west

[svetz]

It was how you wrote that confused me.

I think you've confused me with someone else, not that I'm not confusing too.

I can't see why the extra cost is not worth it..

It's because the cost of the tracker is typically higher than adding more fixed panels to get the same amount of power with the tracker.
That doesn't mean it can't be done though. I thought about DIYing one, but gave up on it due to our high-winds here...wanted them rock solid.

 

[chrisski]

You can look up on a solar calculator to get exact numbers. IME, moving panels makes a lot more than 25% extra panels. Each situation is unique. Lack of real estate for installation can make a tracker worth it.

I have ground panels I move three times by hand, and I have noticed significantly more output at 32 degrees north in the winter months than in the summer months.

In the winter months on the shortest days of the year when the sun is low to the horizon, I would get more charge out of 400 watts of ground panels moved by hand three times a day than I would 1050 watts of flat panels on my RV.

This became less extreme when the days grew longer and the sun was higher.

You can take the guess work out of output by going to the solar calculator in my signature block. It has tracking options.

 

[timselectric]

I guess that we all got sidetracked to whether it was cost effective.
But the question is actually if tracking gives more output.
So, the short answer is yes.

But, it's not cost effective. Unless, you are limited by space.

 

[nc73]

Some like to make things more complicated than it has to be

 

[SeaGal]

I guess that we all got sidetracked to whether it was cost effective...

No we didn't - I answered the question in post #6

 

[timselectric]

No we didn't - I answered the question in post #6

Ok, so count yourself out of the "we". lol

 

[MichaelK]

Don't know where people are coming up with their numbers. I myself have made manual dual-axis trackers, which I can move for both azimuth and declination. What I've MEASURED myself is ~80-90% extra production.

I made relatively cheap trackers that I have to go out and move myself. This is not a big detriment to me because I mostly need the extra power on irrigation days, and I need watts early in the morning. On days I'm not pumping water, I can get by with far less power.

What I'm finding is that I can start my well-pump at 8AM if I rotate my panels facing Eastward, and keep it running till 4PM after rotating Westward. I calculated that I would need 4X the number of panels if I wanted to power my pump at 8AM with a fixed array.

Changing the azimuth makes a big difference. I've found though that changing the declination gives me lower gains, and I have just stopped bothering to change it. So, now I just change declination seasonally, and largely forget it.

To tell the truth, I have fun making the azimuth adjustments. I walk out and tweek the arrays a little to the right, or a little to the left to get that extra 100-200W in the early morning. Better than watching television.

 

[timselectric]

Don't know where people are coming up with their numbers. I myself have made manual dual-axis trackers, which I can move for both azimuth and declination. What I've MEASURED myself is ~80-90% extra production.

I made relatively cheap trackers that I have to go out and move myself. This is not a big detriment to me because I mostly need the extra power on irrigation days, and I need watts early in the morning. On days I'm not pumping water, I can get by with far less power.

What I'm finding is that I can start my well-pump at 8AM if I rotate my panels facing Eastward, and keep it running till 4PM after rotating Westward. I calculated that I would need 4X the number of panels if I wanted to power my pump at 8AM with a fixed array.

Changing the azimuth makes a big difference. I've found though that changing the declination gives me lower gains, and I have just stopped bothering to change it. So, now I just change declination seasonally, and largely forget it.

To tell the truth, I have fun making the azimuth adjustments. I walk out and tweek the arrays a little to the right, or a little to the left to get that extra 100-200W in the early morning. Better than watching television.

It depends on how much value you put on your time.
If you're home all day and have the free time, it's not a big deal.

 

[MichaelK]

It depends on how much value you put on your time.
If you're home all day and have the free time, it's not a big deal.

I'm not out there rotating the panels every 15 minutes. I've found that I can make just maybe three adjustments per day to get the power I need. It meets my needs, and works for me. If it doesn't work for you, then who cares.

 

[jvin248]

.

Also depends on the sizing of your inverter ... If you 'over panel' your inverter to grab more power at the tails of the day then the inverter may clip all the peak mid-day off your output. I'm going for a low angle 'V' (viewed from above) so I get more AM and PM power, giving up top output at mid-day but seeing less clipping. I added more panels to get more output rather than worry about tracking.

Tracking mounts are going to require a lot more maintenance and their complexity can cause severe reliability problems. Plus how are the storms and winds in your area? Will a tracking mount remain in place during severe weather and functional after?

I'm also thinking panels are only going to improve efficiency in the future. So replacing or adding upgraded panels will be sufficient for most systems.

.

 

[rcrracer]

For what it's worth, Jacksonville FL has a solar farm at 30.52 lat. about 1/2 mile north of the airport. The panels track the sun during the day. Looks like it is to maximize land area usage. Or maybe it was just laid out like that to sell the maximum number of solar panels for larger kickbacks to the politicians and JEA bosses.

 

[MichaelK]

Tracking mounts are going to require a lot more maintenance and their complexity can cause severe reliability problems. Plus how are the storms and winds in your area? Will a tracking mount remain in place during severe weather and functional after?

My mounts are 5 years old now, and I've had to apply zero maintenance. Not even touch-up paint. Simplicity is my key I guess. With no motor (other than myself) there is little to go wrong. I worry most about my welds cracking. I started out as a pretty crappy welder, learning as I went.

Also depends on the sizing of your inverter ... If you 'over panel' your inverter to grab more power at the tails of the day then the inverter may clip all the peak mid-day off your output. I'm going for a low angle 'V' (viewed from above) so I get more AM and PM power, giving up top output at mid-day but seeing less clipping.

That works very well for me. Now I'm positioning additional arrays facing due West, to get more power in the late afternoon. By about 5pm, my primary arrays are in deep shade, so even rotation doesn't make a difference. The extra arrays allow me to run the air-conditioner later in the day without any battery depletion.

 

[timselectric]

I'm also over paneling, east and west.
It makes a difference for battery usage.

 

[Doggydogworld]

Most new large US solar farms use trackers. Usually single axis. They generate more, but it's when they generate that really matters. A horizontal axis array will generate less power at noon when the panels point straight up vs a fixed array tilted south. But the single axis array generates a lot more power in the morning and evening. Evening generation is especially valuable in areas with high solar penetration. Just look at recent TOU pricing trends in CA and HI.

A flatter power curve also saves these big farms money on inverters and interconnect. They may only get a little more output per MW of panel, but they get a lot more per MW of inverter.

It's different for individuals. You won't have hundreds of identical tracking systems with a trained tech on hand and a shed full of spares for maintenance and repair. On the other hand, you may like to tinker. And you might set up a tilted axis system that doesn't lose much noon-time output, so the extra morning/evening power is all gravy (farms usually can't do this due to shading issues and tracker economics).

Most individuals can get panels a lot cheaper than tracking systems. So it's often less expensive, not to mention simpler, to just buy extra panels and point some east and west instead of south.

You can use a calculator like PVWatts to crunch the output numbers for your particular location. Then you can do the cost math.

 

[Zwy]

I really don't understand what you mean. What is a tilting array fixed south?

A tilting array fixed south would be an array fixed on an azimuth that allows for adjustment of solar declination as the seasons change. It is a single axis tracker. It can be manual or auto, manual is usually adjusted at least 4 times a year for solstices or equinox.

 

[wheelman55]

We’ve had a Wattsun HZLA up and running for 5 years. Zero maintenance.

FYI. We are at 29 degrees latitude in a sunny area.

Pros:

1. Produces 80% of nameplate watts about 30 minutes after sunrise until 30 minutes before sunset.
2. Batteries are fully charged within 1-1/2 hours of sunrise and stay at 100% until sunset.
3. Needs fewer solar modules and fewer batteries.
4. Allows use of mini split AC for most of the day without dipping into the batteries.
5. Zero maintenance, no need for lubrication.

Cons:

1. More expensive
2. Longer install time
3. Your friends and neighbors might laugh at you?

We like ours. It really is no maintenance.