Boston
Average Solar Insolation figures
Measured in kWh/m2/day onto a horizontal surface:Jan | Feb | Mar | Apr | May | Jun |
1.80 | 2.62 | 3.61 | 4.46 | 5.13 | 5.50 |
Jul | Aug | Sep | Oct | Nov | Dec |
5.60 | 4.99 | 4.04 | 2.93 | 1.89 | 1.54 |
200 Watt array * 1.80 hours of sun (January) * 0.52 off grid AC system eff = 187 WH per day
200 Watt array * 1.80 hours of sun (January) * 0.61 off grid DC system eff * 1/12 volt DC battery = 18 AH @ 12 volts per day (if you were running DC loads)