Simple solar panel tracking system

[MikeD74T]

40% is a huge increase. At latitude 44.5 degrees I also have a large summer arc to deal with/take advantage of. MikeD74T

 

[marksmu]

Kays, yes that freon system is still around and works just as you described. Expensive though, and I'm cheap and like to build things, hence my water powered system.

What system is in place to prevent it from just getting rocked around during a storm?

The system is quite clever, and I am impressed, but I would be worried that heavy winds would have this thing beating itself until it broke.

 

[texasjohn]

I love it when technology meets simplicity. Great job, wonderful photos.:thumbsup:

 

[spurlocktool]

What system is in place to prevent it from just getting rocked around during a storm?

The system is quite clever, and I am impressed, but I would be worried that heavy winds would have this thing beating itself until it broke.

At first I was concerned that might be a problem, but wind has no effect and being in the hills we get plenty of strong gusty wind. The panel pivots on it's center, so wind pressure is equal on right and left sides of the panel. Plus there is a certain amount of friction in the pivot bolts and washers due to the weight of the panels. There is also a bit of friction in the pulleys that guide the ropes, so any tendency to move from swirling winds is dampened. My first tracking system has been in use for twelve years, and the second for 6 years with no problems on either.

 

[johnrex62]

I haven't tried it on solar panels but on a solar heater a sheet of white styrofoam (or any white material) placed horizontally at the bottom of the panel increases the temperature within the panel 25ｰF in short order.

You don't want to do this with Photvoltaic systems. Heat is an enemy to electric production as it reduces the efficiency of the panels. Heat is the goal for a solar heater, but not for a pv panel.

I saw a show on Discovery a while back where someone was producing a combination panel that used a solar heating panel to capture the heat and cool the PV panel. Think of it as a radiator attached to the photovoltaic panel using the pv panel as it's engine.

 

[Kays Supply]

I didn't read the whole article. What is the expensive part of the freon system?

 

[spurlocktool]

I didn't read the whole article. What is the expensive part of the freon system?

Commercial trackers are sold as a complete mechanism to install on either a mast or ground mounted. Prices depend upon how big a solar array they can hold. For instance, Zomeworks makes freon passive trackers in six sizes to fit 20 sq. ft. of panels @$700 on up to their largest (168 sq/. ft.) at $4,200.00

My water-weight tracker only has to handle 9 sq. ft. of panel.

 

[Kays Supply]

I finished the article. $39 total cost. Seems cheap enough to me.

 

[GeraldStecker]

I'm not sure if this is the right place to post this project - maybe it should be over at the Rural Living Forum since it doesn't involve tractors? My apologies if that's the case, but it is definitely in the build-it-yourself project category.

I have two water wells on my property with 24 volt DC submersible pumps powered by photovoltaic (solar) panels. The pumps are hooked up PV direct; in other words there are no batteries in the circuit, the panels power the pumps directly. Since the pumps only run when there is sun on the panels, to maximize well output I need to maximize the hours of sun exposure. Having the panels rotate throughout the day to track the sun's movement does that. Since my wells are low gallons per hour, being able to pump for more hours per day can increase production by 40% in the summer. Commercial PV panel tracking systems are available but quite expensive, so I came up with a simple low tech method that has worked perfectly over the years. PV direct water pumping really benefits from tracking, especially in the summer when you typically need more water and the sun moves across the sky in a bigger arc. But any small solar panel installation would benefit from the same system. I also use pump controllers with linear current boosters, which dramatically increase pump speed during low light conditions.

My system uses the weight of water in a 5 gal. bucket to rotate the PV panel four times a day. The PV panel mounts with two pivot bolts to a triangular frame so it can rotate through 90 degrees. Springs pull the panel toward the east, while the bucket pulls a rope to rotate the panel toward the west. A battery powered irrigation timer is set to add water to the bucket four times per day. Each time it does, the bucket pulls harder against the panel, rotating it to a new position. At the end of the day a separate timer drains the bucket, and the springs rotate the panel back facing east again for the next morning. The PV frame mounts to a tower with adjustable struts so I can manually adjust the north/south tilt flatter in summer and angled more southerly in winter.

Calibrating the timer and springs was simple. I just went out at around 10:30 a.m., manually turned on the fill timer, and noted how long it needed to run to rotate the panel the right amount. I repeated this at 12:30 p.m., 1:30, and 3:30 and programed the timer accordingly. I used three springs that engage successively to apply more resistance as the panel rotates. The springs and bucket connect to the panel with ropes, guided by small pulleys. Half of an old bicycle rim attached to the panel works like a big pulley so the ropes pull on the panel at a constant radius. The panels track consistently, even on windy days. I imagine another method would be to use a linear actuator or gate opener powered by a sprinkler timer (the type that turns sprinkler valves on and off). In my case since I am pumping water I had water supplies near each well. Since solar systems are so expensive, it really makes sense to maximize system performance with tracking.

Awesome man thanks for sharing out the details of the system..With plenty of sunshine I can surely use the system to increase the output..

 

[rd_macgregor]

Spurlocktool...I wonder if you could convert your bucket to an autosiphoning system (ie, when it reaches a certain level it automatically siphons itself dry and resets to the east via the springs)? Then, you could eliminate one set of timers; you'd only need to get the fill rate right to have the bucket fill and empty on schedule. I love seeing these home-made engineering solutions!
Bob