MAAPS - Solar Power

~ Calculate Your Costs ~

Use this easy worksheet to figure out what a professionally installed solar-electric system might cost.
If you have last year’s electricity bills handy, grab them and your calculator, and get started!

1. First, figure the daily output needed from your PV system:
Average Monthly Electricity Use ____________ KWH
x 1,000 [converts KWH to Watt-Hours] = _____________ WH
x Percent ( _____ %)* of Monthly Electrical Use from PVs = _____________ WH
÷ 30 days = Daily PV Output Needed _____________ WH
(*Example: for 25%, multiply by 0.25)

2. Then, calculate the minimum system size [in watts]:
Daily PV Output Needed [from Step 1] _____________ WH
÷ Average Peak Sun Hours ( ______ hrs.) Per Day = _____________ W
÷ 0.7 [for 70 % System Efficiency Factor]
= Minimum System Size _____________ W

3. Next, determine the number of PV modules you’ll need:
Minimum System Size [from Step 2] _____________ WH
÷ Wattage Rating ( ________ W) of Chosen Module
= Number of Modules Required _____ Modules

4. Now you can figure the size of the system:
Number of Modules Required [from Step 3; round up] _____Modules
x Wattage Rating ( ________ W) of Chosen Module [also from Step 3]
= System Size [in Watts] _____________ W

5. Last, find the approximate system cost:
System Size [from Step 4] ____________ W
x System Cost Per Watt [from sidebar opposite] $______________
– Rebates & financial incentives $___________
= Approximate System Cost $___________

Print this page out and write on it!!.

Once completed, don't forget to contact MAAPS for a quote!
Phone: 618.416.0346
E-mail: info @ maaps.us