The size of the solar system should be specific to your own usage needs. You will want to take many things into consideration when choosing the size of your solar system. Contractors can help with the process, but it’s good to know how to size a system yourself.
Step 1: Contact the Cooperative and ask for a 12-month usage history. You can use this to gauge your consumption trends. Look at the usage (kWh) and the demand (kW) values for each month.
Step 2: You can use sites like PVWatts Calculator to model a system. It will give you a monthly estimate on how much a DRG system of any given size will produce based on your geo location and other variables.
Step 3: Compare the monthly kWh data from Steps 1 and 2 and customize your system to your needs.
Step 4: If the system is larger than 15 kWdc, verify that the size of the DRG system does not exceed 110% of your maximum historic demand.