solar turn table

[MattInTheHat]

Brand new subscriber here so this idea is likely to have been posted - if so, apologies in advance - BUT:

Has anyone put their solar array on a frame or platform that swivels using hardware for a lazy susan? Just a brief search at Lowe's and Amazon turned up some cheap hardware that will support weights beyond what I need.  Below is the one I'm likely to buy ($7).



Attaching even a small,  tilt-able wooden (or aluminum) stand on top of the hardware would increase the efficiency of any panel or panels... and just set it on the ground.  I'm probably gonna build a small lower stand out of 1" sq aluminum tubing (about $20 for an 8' piece) to keep mine off of wet ground.  The higher in latitude you are, the more you'd want to do something like this.

I'm planning a 100W single solar panel build to power some LED light strips, USB phone chargers and a bilge vent blower to run an ice chest a/c in the event of a power outage from a hurricane.  I've seen some great ideas like the guy with the 435W panel on his Expedition tow vehicle that he moves throughout the day to keep the panel under direct sun - this is what I'm after b/c I need to get as much as I can out of my little one-panel system.  Depending on how well my homemade a/c works, I could use it to augment my home's HVAC during peak summer temps, too.

 

[Trebor English]

Ice chest air conditioning depends on having a supply of ice.  

A 100 watt panel mounted flat with good exposure unshaded by trees can harvest all you need for your LED lights, cell phone, and bilge fan.  No amount of tilting and tracking will generate enough to make ice to keep a van or a room cool.  

With an EER (Energy Efficiency Rating) of 10 a 5000 BTU per hour air conditioner will need 500 watts.  Melting ice absorbs 144 BTUs per pound.  Making ice to cool air will use more electricity than just cooling air.

 

[RVTravel]

Good idea.

 

[Weight]

I fail to see the need for a complicated stand to position a 100 watt panel. Lean it against a stick or the side of your car. There is not enough energy with 100 watts to really mater.

 

[DLTooley]

If you could find a swiveling easy chair you good scavenge the frame and have a single device that would also tilt. Personally, I like leaning mine on my windshield - that helps to keep the rig cool as well.

 

[ISAWHIM]

Tilting offers more gains than rotation, unless you would just like it to rotate due to an inability to face an ideal location.

I think they said that the gains were marginal, for rotation, when simply angled correctly in a fixed location. It was cheaper to just add another solar panel, in most cases. (The additional hardware required to rotate and angle the cells, while holding them securely, and power-losses of the "positional system"... Were not justifiable.)

When you angle solar cells, they create shadows and block light on other cells. You would need a massive "wall of cells", or you have to space them further apart. The final calculations state that it is better to place more flat-cells that use all the light, than to remove rows, to space them for the inclination and rotation changes.

However, if you only have a limited space, and you can't get more efficient solar-cells, then your only option for more power is to have them rotate and angle to "chase the sun".

There are a lot of claims, of 20%-40% (dual-axis trackers)... But that has no real data to support them, in the real world. The gains are all on "perfect days", or in "lab-tests", or other various rare uses. That is also compared to, of all things, an improperly aligned cell. Which is where they get the "Up to 40% gains"... (Also, in areas where the sun rotates a LOT across the horizon, like Alaska, where the sun is up all day, but it just rotates around the horizon. Yup, 40% more power! )

The other thing to think about, is the fact that the more you create, above the "expected fixed-angle use", the more the cells degrade. You could focus mirrors on a solar cell and double the output, but you will also cut the life short by 50%, which is what some power stations do. They want faster returns, and that is how they get them, along with "chasing the sun". (Never buy used solar cells from a power company! They only get rid of them when they output less than half power or they have broken cells.)

There is a little girl who made a "bamboo and coin", solar tracker... It has virtually no moving parts to replace. (The bamboo needs replacement after a few years. The coins last forever.)

Even if you get 20%, constant increase, that is 120watts from your 100watt cell. Adding a 20watt cell to control the "positioning drive", would net you 0% gains, for a single panel.

 

[lenny flank]

Alas, the problem with movable panels is that setting them up and adjusting them all the time becomes a PITA.

Ice ACs are in general a waste of effort--they don't work. Even if they did work, you won't run one with a 100w panel.

If you REALLY need an effective AC, then you are looking at several hundred watts on the best of days. ACs require a LOT of power.

 

[MattInTheHat]

Thank you for all the replies. Much has changed in 3 years. Apologies for ghosting this post.

 

[Cammalu]

Wow. I thought Lenny was back!

 

[MrNoodly]

...to keep mine off of wet ground...

Solar panels are waterproof, because rain.