# Ways to boost solar panel input/output?



## Orange_Monkey (May 24, 2008)

I just purchased the (90599) 45 Watt 3 panel kit from Harbor Freight to experiment with. Can anyone tell me ways to boost the light input to increase the power output of their pv panels? For instance, if I have half the normal sunshine due to clouds can I use mirrors to direct more light to the panel? Living in Pennsylvania, even on a bright sunny day I obviously don't have the same sunlight as I would in the Nevada dessert, is there a way to know when I've done all I can do? I also plan to play with directional controls to follow the sun. Is there much interest in this method of optimization? These panels are the amorphous type, seem very sturdy and can probably dissipate alot of heat but should I be concerned about overheating the panels with additional sun energy? Any comments about optimizing the light input/power output of these panels would be appreciated.


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## dunewalker (Mar 4, 2007)

Orange, you've mentioned techniques I've played with. I put a reflecting field on the ground in front of my panels, which boosted their production slightly. Mirrors might be too intense, but worth trying, especially on cool days. I put my rack of panels on a single metal pole, atop an inner pole, much like a satellite dish. Then it can be turned manually to track the sun. I usually adjust it 4 or 5 times a day when home, or else leave it locked into the noon position. This technique can add 30 to 40% to production.


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## wy_white_wolf (Oct 14, 2004)

1. Tracking

2. MPPT or PWM controllers

3. Lower temperature of panels. 

Forget the mirrors or trying to reflect additional light into the panels. That's a real good way to ruin a panel. They are not designed to handle the higher amperages or heat that can be achieved by doing that.


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## Orange_Monkey (May 24, 2008)

Thanks for your responses. So are you aware of any purely mechanical trackers that would use something that didn't use electric power to move the panels. I'm thinking someone has figured out how to use heat or hydraulics to track the sun. Also if the panels only use part of the spectrum, is there an efficient way of filtering out the part they don't use and possibly also some of the heat so more of just the useful spectrum could be concentrated. I guess for $200 its just more efficient to buy another set of panels...right?


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## wy_white_wolf (Oct 14, 2004)

Freon can be used to move panels on a tracker. Zomeworks builds one. They are prone to wind blowing them off kilter.

An article in MEN on building one.
http://www.motherearthnews.com/Mode...11-01/Mothers-Super-Simple-Solar-Tracker.aspx


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## Orange_Monkey (May 24, 2008)

I've been thinking about the tracking and I realized that the majority of the time the object of it would be to point directly at the sun at all times. I know the course of the sun each day varies slightly but that could be adjusted manually. If the panel was on a rail so it would ride in perfect relationship to the arc of the sun, it could be controlled by a clock mechanism. I mean, how many times would you get more light to make it worth while to be able to point anywhere in the sky? What do you think?


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## dunewalker (Mar 4, 2007)

Orange_Monkey, early on, I experimented with a few manual tracker ideas. One I called the "trickle tracker"--water trickling from a jug on one side of the panels to a jug on the other side caused them to turn, much as a clock-type arrangement would. Then I built a solar tracker, using 2 miniature solar panels placed at right angles to each other and wired to a small electric motor that drove the panel rack. When the sun favored one of the panels it drove the motor that way-when the sun favored the other panel it drove the panels the other way. This system actually worked very well. The chief problem with both was the force of the wind. Over a few months the wind destroyed the gearing system. The lesson here is that whatever you devise to track your panels has to be strong enough to withstand the wind. In the end I found it easiest and most efficient just to manually turn the panels during the day and lock them into place. Both of my next-door neighbors do it this way also. I believe the closer neighbor got this idea from his original installer, Larry Elliot, one of the founders of Home Power Magazine.


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## Orange_Monkey (May 24, 2008)

Thanks, Dunewalker, so you do agree that the panels are more efficient when they are adjusted toward the sun as opposed to being in a fixed position. The trick is to devise an accurate method which keeps the panel pointed directly toward the sun. I noticed that my panels get hot as the sun beats down on them so I plan to place a coil of copper pipe on the underside of the panels using a heat transfer paste similar to the kind used for power transisters. This would keep the panels cooler prolonging their life and also collect heat for hot water.


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## PD-Riverman (May 24, 2007)

I built a Home-Made tracker using a motor/gearbox off a kids battery operated car to turn the panel/rack(4, 80 watt), It works great. The timer circuit was a little complicated to build. What I want to do as soon as I get some free time is build another "deal" using a small panel at a angle to the rack to activate a relay to turn on the motor and do away with the timing circuit. I will have to work it all out but I feel it will work.


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## SolarGary (Sep 8, 2005)

Orange_Monkey said:


> Thanks for your responses. So are you aware of any purely mechanical trackers that would use something that didn't use electric power to move the panels. I'm thinking someone has figured out how to use heat or hydraulics to track the sun. Also if the panels only use part of the spectrum, is there an efficient way of filtering out the part they don't use and possibly also some of the heat so more of just the useful spectrum could be concentrated. I guess for $200 its just more efficient to buy another set of panels...right?


Hi,
There are some simple trackers here:
http://www.builditsolar.com/Projects/PV/pv.htm#Tracking

The "$35 DIY PV Tracker" uses the tracker kit that Duane at RedRok.com sells -- its cheap and has a good reputation. It works with commonly available satellite dish actuators. 

----

At the same link, there are also some ridge "soft concentrators" that provide a low concentration for PV panels -- probably safe to use on conventional PV panels -- its probably no more than you would get from the reflection off a freshly fallen snow field.

---
The NREL Redbook will give you the actual gain you would get from both 1 axis and 2 axis trackers in your part of the country.
Its a free download here:
http://rredc.nrel.gov/solar/pubs/redbook/

The Redbook will also tell you how much extra you can get by just adjusting the tilt manually about 4 times a year -- e.g. tilt at latitude near the spring and fall equinox, at latitude +15 deg winter, and latitude -15 degs in summer. 
For one location I checked this was worth an about 8% yearly increase.

Gary


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## dunewalker (Mar 4, 2007)

Orange_Monkey said:


> Thanks, Dunewalker, so you do agree that the panels are more efficient when they are adjusted toward the sun as opposed to being in a fixed position. The trick is to devise an accurate method which keeps the panel pointed directly toward the sun. I noticed that my panels get hot as the sun beats down on them so I plan to place a coil of copper pipe on the underside of the panels using a heat transfer paste similar to the kind used for power transisters. This would keep the panels cooler prolonging their life and also collect heat for hot water.


Yes, the panels produce more when aimed toward the sun as opposed to being stuck at noon all day. But you don't have to be precise--within 30 degrees or so will take care of it. That means a morning position, noon position, afternoon position will get most of the available sun. An additional 2or 3 positions doesn't hurt, but it's not necessary to get overly concerned about aiming exactly at the sun all day. As for your cooling idea, it sounds like a fun hobby but probably won't make much difference. I know it's fun to tinker though. Solar panels DO produce more when cool. Air flow under the panels might be more effective than the copper tubing heat sink you're describing. It's important to maintain a good air flow.


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## Calvin Wiles (May 14, 2008)

Don't know if this would help or not? I have a 30' travel trailer that I permanently anchored on my Ranch and Painted the top with a thick coating of reflective white roof coating. I put two 130TM Kyocera Solar Modules on it mounted flat with the top. An hour after the sun hits it in the morning it is 1/2 production and 2 hours after it is at full amp. Same before sunset. The Trailer has the ends east and west and the panels are long ways with the trailer. Don't know what will happen in the winter when the sun goes south or later in the summer when it goes farther north, but now it is almost directly straight overhead and it runs about 14 amps through my 15 amp charger over 8 hr. a day now with long days.


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