Sizing Your System

Now that you have gathered all the necessary information, we can begin to size your solar energy system.

Our calculation formula will show you how to find approximately the size of system you will need to cover 100% of your energy demands.

Simply enter in the information gathered from the first step, and reference our solar zone insolation map below.

Is Solar Right for You?

Determining Your System Type

Sizing Your System

Design Your System

Since you have your annual KWh average usage, and your solar hours per day (see map below to reference), you can now formulate the total system size. The formula is as follows:

Array Size (kW) = (Annual kWh usage) / (365 days/year) / (Solar Hours/day) / (0.82 derate factor)

For Example: My annual KWh usage is 12000 KWh (1000 per month) ÷ 365 Days in a year ÷ The property located in Zone 3 (receive 5 sunlight hours each day) ÷ Standard derate factor of 0.82 (real world losses) = Total Array Size of 8.2 kW.

(12,000 kWh/year) / (365 days/year) / (5.00 kWh/day) / (0.82) = 8.02 kW Array

*This calculation is based from average annual sunlight hours. During winter months, the system will likely yield less energy. To be sure that the system will be sized for 100% power during these months, subtract 1 – 1.5 sunlight hours from the zone you used in your calculation (annual average), to account for decreased sunlight during those months. This ensures your system will be properly sized to provide the minimum year-round power for all your energy demand.

*Sun Hours/Day Zone Map

Zone 1      6 hours
Zone 2      5.5 hours
Zone 3      5 hours
Zone 4      4.5 hours
Zone 5      4.2 hours
Zone 6      3.5 hours

These hours will affect how much energy your system will be able to generate daily. The hourly figure is based on the average annual insolation. The system sized will provide more power during summer, and less during winter when based from this chart.

1,050

<< What Type of System?

Pick Your Components >>