I have written a new spread sheet using the Visual basic language to estimate the power from a user specified solar panel rig. This spread sheet will estimate the power at all latitudes, at any time of the day, for any cloud cover and for either the PWM or MPPT charge controller. To my knowledge this is the first sophisticated program of its kind to do this. This model computes the sun azimuth and elevation at a given time of the day, computes the insolation(power) of the sun, attenuates the insolation through the user specified cloud cover, projects the insolation onto the user specified solar panel and estimates the current from either the PWM or MPPT charge controller. It uses scientific models from Global Warming studies for accurate results. Specifically the program provides : AmpHrs vs time of day, Daily amphrs vs latitude, daily amphrs vs month of the year, the amphrs for both the PWM and MPPT controller, the total amphrs and kilowatthrs for the entire year. A special feature of the spreadsheet allows the user to enter his own measurements and compare them to the simulation values. We used this feature onboard the s/v Star and were able to double our power output by making small installation changes verified by the simulation.
A very neat solar panel installation is also described that mounts the panels on top of a bimini. This design requires no drilling through the stainless tubing and includes leveling screws for alignment.
We would be very interested in getting comments on the simulation which is available for free from our web site at http://YachtSoftware.org
. If after you have tried the software, and found it useful, we ask for donations of $50 or so. The money goes into our beer and wine fund to keep the crew happy on the s/v Star