Fortunately for me, my PV Powered 4800 inverter had the ability to handle the 5 extra panels, bringing my cost per watt down to a very reasonable $2.50, installed. The result was a substantial 31% increase to 5.58kw and a summer monthly output averaging 812kwh. While still far short of July's 1800kwh, it will produce a surplus in the spring and fall, when demand drops into the 600's.
However, only the top row mounts function as
hinges. The bottom row mounts are separated at the hinge pin and a 24" piece of square tubing is
placed between the hinge halves. Bolts are then inserted through the hinge pin holes to lock the tubing in place.
These hinges allow for 22° of movement, a few degrees less than ideal. However, achieving more movement would have required taller hinges, which would have put more stress on this design than I desired.
Panels in the winter position. I designed the
coal bin roof with a 45° angle. Not the optimum
winter angle for our latitude, but a good compromise between the requirements for the coal
Panels raised 22° for the summer months. Not the optimum setting, but close enough. Overall, I'm pleased with the design. The tilt can be changed in a matter of minutes, and even 22 degrees gives me a significant advantage over fixed systems.
After panels are raised, a link with tapped holes
ties adjacent panels together. The bolts now serve
2 purposes, attaching the legs and linking the
panels. The result is an extremely rigid structure
that does not move even in the strongest winds.
The system has been in operation nearly one year, and has performed very well, even through our cloudy winter. The winter output is surprisingly good, given that the system had to cope with snowstorms and fewer daylight hours. Below are charts of the electric production, my consumption, and the amount the system is saving me at our current rates of $0.15/Kwh.