Solar "Gen-1"

Solar Panel (1st Generation)...

a "proof-of-concept" project...

I had no choice but pursue this project, just to have the piece of mind that I can recharge a battery in the absence of the grid.

Although I'd tinkered with Photo-Voltaic cells in the past, I can't say that I'd every really taken them seriously or had any stellar successes to report.

The 2 (two) cells mounted on the push cart were wired in parallel to a 3rd 12" by 12" panel.

The third panel is leaning up against a deep cycle marine battery. Over the course of a few days I carefully maintained the battery at 12.75VDC with a 4 to 6 hr charge duration in strong sunlight (cloudless day).

The battery would be used for approx 1 1/2 to 2 hrs before reading 11.5VDC, and was returned to the charger. Perhaps not earth shattering, but a start.

At present, I have the mixer/sifter that requires 12VDC, a secondary sand fluffer for the foundry and the electric motor for the fishing boat. I hope to learn more about battery maintenance and basic renewable energy to keep some batteries available to relieve a portion of our dependence on the grid.

Personally I don't see the grid as a bad thing, rather a great thing, but growing dependence on it's availability may be an ill placed trust.

The initial success of my first trials inspired me to make the 3rd panel a more permanent fixture.

Of the issues I noted while shuffling the cart to manually follow the sun, there was a noticeable voltage drop at mid day when the sun's energy was at it's peak. Picture to the upper right is a clever slotted arm that I installed to maintain peak efficiency through the day.

Admittedly this system requires a measure of baby sitting, but the work that 1 charged battery can do is worth the effort (for now). As I'm working in the general area that the panel is located it takes only seconds to adjust a few directional and angular parameters per hour. The auto-tracking system will eventually come about.

These reflectors are made of 1/4" hard board that was painted silver. The boards are mounted with hinges that allow them to be tilted in or out to gather more light.

I measured the output voltage (open Circuit) with the boards flat (no reflective increase) and measured 19.2V, with the reflectors tilted as shown, I could raise the voltage to 19.7V a net gain of 0.5VDC.

At the time I was more interested in simple voltage measurements, and hadn't had the foresight to measure short circuit current.

This is a stack of hard disk platters.

The platters have a highly reflective surface polish, on a metallic disk. The hard disks were cannibalized for aluminum to be used for castings.

I had considered mirrored glass, but the ready availability of the platters and their more durable nature made me dismiss that idea.

One of the twins, was kind enough to drill a mounting hole on each of the platters.

A simple jig was installed such that all holes were drilled identically on the circular reflectors.

A simple grid is drawn onto the board and the reflectors are screwed down.

The hard board seemed some what flimsy, so each row of reflectors is backed with a short length of strapping to provide better support and something for the screws to bite into.

The reflectors have shaved approx 1 hour off the charge time of 11.5VDC to 12.75VDC, about 5 (five) hours.

I certainly appreciate that there is variability between how clear the day is, making the directional and angular adjustments at the same times etc.

The best indicator that the reflectors actually do something beyond looking cool is in the current that the panels can source.

Using a generic Digital multi-meter, the panels read 540ma current without the reflectors and 890ma with the reflectors as shown above. I repeated the measurements a few times to be sure. The voltage increase was still negligible approx 0.75VDC gain. The meter measured a current draw by the battery at 350ma without the reflectors, and approx 600ma with the reflectors in place. This is a substantial boost in power.

The weight of the metal reflectors and the extended reflector boards does make the movable platform somewhat unstable. As well I have concerns about the excess heat generated by focusing the additional light onto the panels.

The follow up to this project will be to assemble a second array of 3 more panels, but split the reflectors to half their current width. Both arrays would be mounted on a more robust structure in a semi-permanent location (with future provisions for auto-tracking).

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