Use the worksheet below to determine your solar requirements. We have included an example column and a column for your system.
Locate your site on the average yearly insolation map in the FAQ section and list the nearest figures.
Take the daily corrected total loads in watt hours from your load evaluation sheet.
Divide line 2 by line 1. This is the number of watts we need to generate per hour of full sun.
Find actual power produced by your selected module and enter. (rated amperage x battery voltage during charging). Example: Using KC120's, one module produces 7.1 amps. 13 volts is a common charging voltage for 12 volt systems. Actual power = amperage x charging voltage.
Divide line 3 by line 4. The result is the number of modules required for your system. When rounding this number, remember that sets of 2 modules are needed for a 24 volt system, sets of 4 for 48 etc.
Example
Actual Figures
Step
yearly average
yearly average
1
5.0 sun hours per day
2
1000 watt-hours per day
3
200 watts
4
(7.1x13) =92.3
5
2.17
Insolation Map shows southern Ontario with an average of 4 hours of sunlight daily.
7 6 5 4 3
U.L. Lovett Incorporated RR #41, London, ON N6H 5L2
