Solar Towers

It is critical for us to be able to set up and tear down the solar array quickly and efficiently. We considered several mounting approaches that would be quick to set up and still allow tracking for the sun. Unfortuntely most of these designs ended up being overly complicated and had the issue of partial shading of panels by each other.

We finally focused on an approach incorporating lightweight collapsible towers made out of carbon fiber tubes that look very much like chunky umbrellas.

This folds up like an umbrella into a compact tube section:

The solar panels attach to the rectangular subframe structures via magnets and thumbscrews so they can be quickly attached/detached. The entire tower can be unfolded and assembled in less than a minute. To provide additional stiffness we’re planning on augering a screw into the ground when we set it up and attaching it to a metal loop built into the base of the tower. That way it can’t blow away.

To validate the design we’ve built an initial 600W tower that stands 6ft tall. This is fully functional and includes motors inside the tubes for both the Elevation and Azimuth motions as well as a motor control circuit in the base. There are power and data connections in the base and all wiring runs up the inside of the tube.

At the moment the prototype have polycarbonate panels that don’t have real cells on them. However they are constructed using the same basic construction process as the final panels. We’re in the process of constructing panels with real cells to replace these.

The combined weight of the tower and panels (including all of the motors and electronics inside) is currently 22lbs. The real cells should add only another 2-3lbs of weight. So it should end up at roughly 25lbs. The 1.2kW towers will be about 50% bigger than the current prototype (surface area vs volume). But even if they weight twice as much as the current tower (50lbs) then eight of them would weight a combined total of 400lbs. That is well within our weight budget.