Dual axis solar tracker Design

[ajit.nayak87]

Dear all,

I am trying to construct dual axis tracker .I need below help from this forum

1. control flowchart algorithm for dual axis tracker
2. We know that dual axis can move either horizontal or vertical axis. When it will be moving horizontal/vertical axis??
3. Nrel code gives azimuth & zenith angle . Which angle i need use to calculate sun path.

List of supportive links:

1. inclinometer for feedback:http://www.leveldevelopments.com/pro...-out-7-35v-in/
2. 2) spa c code: http://www.nrel.gov/midc/spa/

[inetdog]

Dear all,

I am trying to construct dual axis tracker .I need below help from this forum

1. control flowchart algorithm for dual axis tracker
2. We know that dual axis can move either horizontal or vertical axis. When it will be moving horizontal/vertical axis??
3. Nrel code gives azimuth & zenith angle . Which angle i need use to calculate sun path.

List of supportive links:

1. inclinometer for feedback:http://www.leveldevelopments.com/pro...-out-7-35v-in/
2. 2) spa c code: http://www.nrel.gov/midc/spa/

Hello Ajit,

May I ask why you are planning on a dual-axis tracker? With the current low cost per watt of panels a fixed array or at most single axis tracker will be more economical unless you have severely limited space for panels.

The single axis tracker with a manual seasonal adjustment for elevation (horizontal axis) is a good fit for higher latitudes (outside the tropics.)
For near tropical areas a single axis tracker with horizontal axis only is a very good fit and allows putting a long line of panels on one controller.

The azimuth is the compass direction facing toward the sun. The azimuth the angle above the horizon.

Which axis motion is most important at which time of day will depend greatly on your geographic location.

Examples:
1. At the equator at the equinox, the azimuth will be +90 in the morning and -90 after noon, while the elevation will go smoothly from zero to 90 and back down over the course of the day. The actual tracking can be done by varying elevation from zero to 180 while not changing azimuth at all. (Single axis horizontal)
2. At a high latitude in the winter, the elevation will vary from zero to a small angle (low in the sky) and back down to zero while the azimuth goes smoothly from +90 to -90 (single axis vertical will do quite well.)

I would not expect a dual axis tracker to be more than an interesting project with little practical use given the construction and maintenance costs.
If you do go with a dual axis tracker for some reason, decide which axis will be changing most rapidly during the sun's travel and use two different time constants for the two control loops to minimize interactions and instability.

[inetdog]

I see you posted almost the same questions on "the other forum".
We shall see which gives you better answers. I will not bother answering you there.

[ajit.nayak87]

Which axis motion is most important at which time of day will depend greatly on your geographic location.

Examples:
1. At the equator at the equinox, the azimuth will be +90 in the morning and -90 after noon, while the elevation will go smoothly from zero to 90 and back down over the course of the day. The actual tracking can be done by varying elevation from zero to 180 while not changing azimuth at all. (Single axis horizontal)
2. At a high latitude in the winter, the elevation will vary from zero to a small angle (low in the sky) and back down to zero while the azimuth goes smoothly from +90 to -90 (single axis vertical will do quite well.)

Thanks for the suggestions. It just customer requirement , So that reason we are going with dual axis tracker.
That means in day of time for dual axis tracker both axis will move along its direction or slowly in according season.
what are above two points meaning. Which locations you are pointing at,

[Sunking]

Well if this is for a customer you might be doing them a disservice installing a tracker. Unless space is an issue, a tracker does not add any value, just makes things more expensive than need be, and not as reliable. A tracker only harvest and extra 25%. Unless this is a very large system it is less expensive to just add more panels.

[ajit.nayak87]

Well if this is for a customer you might be doing them a disservice installing a tracker. Unless space is an issue, a tracker does not add any value, just makes things more expensive than need be, and not as reliable. A tracker only harvest and extra 25%. Unless this is a very large system it is less expensive to just add more panels.

I know that one,since worm gear boxes itself added more cost. They are ready for it.they are going with parabolic tracker with dual axis systems

[Sunny Solar]

If they going for a dual axis tracker for no really technical proved reason . go for it, let them waste their money .. business is business.
After using and collecting data from single and dual axis trackers there is just about nothing to be gained by using a dual axis tracker. Far more reliable and cheaper to buy more panels..

Trackers give almost nothing extra between about 10 am and 2pm if the angle they are installed at is ok for midday. its only before and after these times you gain anything useful.

Just buying extra panels to the same value as a dual tracker will give greater gains between 10am and 2pm than the tracker will gain you before and after those times..

The times 10 am to 2pm are right for most areas in tropics they can be later above and below. But you install to suit your location.

We have dual and single trackers at work in Brisbane Australia. and over the year the averages are 22% dual and 16% single..

Also trackers need maintenance usually 2 times a year..

[ajit.nayak87]

If they going for a dual axis tracker for no really technical proved reason . go for it, let them waste their money .. business is business.
After using and collecting data from single and dual axis trackers there is just about nothing to be gained by using a dual axis tracker. Far more reliable and cheaper to buy more panels..

Trackers give almost nothing extra between about 10 am and 2pm if the angle they are installed at is ok for midday. its only before and after these times you gain anything useful.

Just buying extra panels to the same value as a dual tracker will give greater gains between 10am and 2pm than the tracker will gain you before and after those times..

The times 10 am to 2pm are right for most areas in tropics they can be later above and below. But you install to suit your location.

We have dual and single trackers at work in Brisbane Australia. and over the year the averages are 22% dual and 16% single..

Also trackers need maintenance usually 2 times a year..

I need some guideline here for selection of motor Drive and motor selection.
1) how to choose proper motor drive gear box.
2) how torque is been decided for worm gear box. my horizontal load is 700 kg and altitude load is 300kg
3)which motor will work good for dual axis tracker i.e dc motor, servo motor, steeper motor.

http://www.heliotrack.com/Parabolic.html

[phillipallison]

Dual-axis tracking systems generate more power than fixed arrays by continuously positioning the PV array so that the incident angle of solar energy is 0°

[ajit.nayak87]

I need guideline for selection of motor relevant motor driver.

1)Selection of worm gear boxes. what are points it included for selection.
2) selection of motor like linear actuator, stepper motor, dc motor, servo motor etc
3)motor Driver and current carrying selection.
4)current carrying capacity of motor with/without load
5) gear ratio selection.
6)torque calculation steps for worm gear boxes.

[Sunking]

I need guideline for selection of motor relevant motor driver.

1)Selection of worm gear boxes. what are points it included for selection.
2) selection of motor like linear actuator, stepper motor, dc motor, servo motor etc
3)motor Driver and current carrying selection.
4)current carrying capacity of motor with/without load
5) gear ratio selection.
6)torque calculation steps for worm gear boxes.

Good luck getting the answer. Most of the pros here like myself have ethics and will not help you take advantage of a customer unless you can convince us there is a justification to use trackers. It appears at this time you are not ethical and screwing your client out of money.

[J.P.M.]

Good luck getting the answer. Most of the pros here like myself have ethics and will not help you take advantage of a customer unless you can convince us there is a justification to use trackers. It appears at this time you are not ethical and screwing your client out of money.

FWIW, Big, BIG second on that.

J.P.M.

[J.P.M.]

Dual-axis tracking systems generate more power than fixed arrays by continuously positioning the PV array so that the incident angle of solar energy is 0°

Respectfully, They may do that, but the added complexity, attendant additional maintenance, likely decreased reliability and increased downtime probably (that is almost always) make them less cost effective than other configurations.

[Sunny Solar]

The only time you REALLY do need dual axis trackers is"if you are using concentrated sun solar panels" ie like used in outer space.. ie Emcore.

If you don't use trackers the output drops to less than half for just a few deg out..

I really don't believe this is whats been proposed to be used.. If it is and you really can prove it let me know and can give you the manufacturers of the items you need. But be warned they are expensive.
Example a slew drive of the capacity you need will cost upwards of $9000 for the basic drive plus aprox $3000 for the control gear.

[Naptown]

I think this is for a parabolic collector for water heating or steam production.