I've been giving some thought to building a cheep home built solar tracking system based on the Direct Power & Water "PowerFab" racks that I am using. I have 3 arrays that we currently rotate by hand, this works great for now. I was thinking I could develope some kind of sensor system that could have 2 light sensors mounted on an array facing 45 degrees off center of the array line of sight. This would put the two sensors facing 90 degrees from each other. In this setup, when the array is no longer facing directly toward the sun, one of the sensors would recieve a higher concentration of light than the other. Some simple circuit would cause the array to rotate toward the greater light concentration. Only stopping when both sensors read the same level of light concentration. That way as the sun moves the light concentrations will change and once the difference in light level is great enough to reach the max tolerance of the sensor the array will rotate slowly until both sensors are in equilibrium. My problem here is that I dont have much experience with breadboards and electrical circuits. This should not be an issue as I have friends that do have that experience. Another problem is that there are 3 arrays and I dont want to build 3 systems so one sensor would need to control all 3 arrays. This makes me wonder if it would be better set up some kind of small motor with a small gear box on each array linked to the same sensor or if I should use Satallite Dish Actuator Arms. If I used an actuator arm.... maybe I could weld an extension arm on all 3 racks, link them together with another long connecting rod and use a single actuator apparatus to rotate all 3.... Or if the sensor didn't work I could always figure out a way to wire small motors or an actuator to a rotor box in the house to be controlled by hand or by the PC that monitors the Solar Inverter, Wind Turbine, & Weather Station. Also I realise that this would not track vertically only horizontally and thats all I want it to do. Any thoughts or advice?

I don't know if this would work, but it would be much simpler than the light sensors, which could possibly work erratically, and then having a computer (although a simple one) to monitor things

Since you know fairly closely where the sun will be throughout the day, why couldn't you set up a small motor to turn on every hour or two, move the array slightly, and then turn off? At the end of the day, the motor would reverse and move the array back to the original position for the next day. I don't know if it couldn't work on somewhat the same principle as a VHS tape player, which rewinds at the end of a tape.

I thought about that, problem is there is a huge difference between the summer sun position and the winter sun position. In winter the sun rises in South-South East and sets in South-South West. In the summer it's different, the sun rises in East-North East and sets in the West-North West. I would need to adjust the array rotation timing at least once a month to keep pace with the shifting position of the sun throughout the year.

I started thinking about that too, and there are two separate ways to overcome it.

First, you could have the motor turn on more ofen in the summer for a shorter time period, to allow it to track east to west over several more hours than in the winter. During the spring and fall the time the motor runs could be adjusted somewhere in between.

Or, you could have a "3-speed" gearbox. One for summer, one for winter, and one for spring and fall. That way, even though the motor runs the same amount of time, the movement would be greater or less depending on the gear.

It just seems, hopefully without offending, that depending on light sensors would be extremely challenging, especially when it is possible to calculate the position of the sun on any given minute of any day you choose.

I just joined the fourm, thanks to Lewis at Sun Electronics for recommending this site.

I built my first solar tracker for a solar concentrator steam generator. In that application, I used a "C" band satellite mount with dual axis. The DC powered linear actuators provided a rigid driving force and withstood wind loading forces.

I used 2 home built electronic sensors (bridge curcuits) to follow the sun, one on a north south axis and the other east west. They are capable of providing either 12VDC or 24VDC with plenty of amperage to drive the linear actuators. It is pretty much hands off, just keep the actuators lubricated and the sensors clean. The sensors duty cycle is adjustable so if clouds interfere, the system will not quickly send a position adjustment to the actuators. I have since applied this to my solar array on a single E-W axis with excellent results.

It is a pleasure to find this site and read all the posts.

Congratulations on building a successful tracker... On the surface, building anything like that is not trivial once you get into the details.

However, what really caught my eye was the Steam Generator--What is up with that? What do you use the steam for? How have you made a reliable solar steam boiler and what is the working fluid?

-Bill

the steam generator (solar boiler is more accurate) consists of aluminum melted with copper tubing inside of the AL block, I use an eythel Glycol mixture which is fed into a 15 gallon blue color Dr. Pepper syrup drum. I use a submerrsible 12VDC high pressure fuel pump for engines with fuel injectors to provide sufficent flow and pressure to go up to roof. the back and side of the collector is covered with fiberglass house insulation. the tank temprature reaches about 120F and radiates heat into living room, and it is shut off when sun goes down by a timer activated thermostat. to coil the copper tubing without collapsing/or kinking it, I filled it with packed sand which i left in the tubing when melting the AL to emcompass the tubing. and of course i used black high temp BBQ grill paint on the face of the block. the Tubing line is encased in A/C system foam insulation to minimize thermal loss. there are many other designs out there, but this design was something that was more practicle for me to accomplish. I used a 3ft parabolic dish with 100 something 2in square mirrors glued onto it (silicone glue) with 2 adjustment screws per mirror, to align the mirrors i used a 400 watt work light aimed straight toward the dish. each mirror had a peice of tape on it which i removed while adjusting that mirror, then put the tape on and went to next mirror. very time consuming and tedious. Since i am retired, I apply my talents to mentally challenging projects have several homebuilt wind generators, about 4 KW of solar panels, an XSW-4024 Xantrex inverter, 3 charge controllers, 2 of which are mppt flex max. the battery bank, purchased at a junk/recycling yare are brand new Concord 2000 AH cells (12) which are wired for 24 volts. I live in an urban neighborhood in city limits and dare not make the 10,000 watt wind turbine with the generator head i bought at harbor freight. it would be too tall and noisy.

I'll save you a lot of time. Pick up an LED3X from RedRok, about $20 for a kit, $35 assembled. Get the reverse inhibit option, it's way cool and worth it. Tell him Jim Parish in Florida sent you

http://www.redrok.com/led3xassm.htm#led3xc3

I have four trackers built from old recycled C-Band dishes holding 12 KC120/KC130's.

http://wizbandit.wordpress.com/2008/03/ ... r-tracker/

Feel free to browse my whole SOLAR SECTION.

Wow, that redrok thing is exactly what I had in mind. Guess I wasn't the first to think of it and Im glad I didn't go throught the effort to try to build one. Thanks for the link WizBandit!