Energy Buys LLC (406)690-1572

Need help sizing a solar system? You've come to the right place. 

To estimate what size solar system you will need, a useful resource is the FindSolar "My solar estimater". This estimater includes electricity costs based on your zip code.

Solar System Size Calculations:

Before you buy solar equipment we suggest that you spend some time to determine what your electrical requirements are so you can most accurately decide which solar panels, charge controllers, batteries and inverters you may need.

For your convenience, we've included basic system sizing information for Off-Grid and On-Grid solar systems. Some additional resources that you may find useful are shown below:

PV worksheet - An Excel spreadsheet to size your solar system. Be sure to read the PV instructions worksheet. The worksheet also contains information on selection of a backup generator and charge controllers.

NREL Redbook - Expected average sun hour data.

PVwatts - Iincludes the data from NREL and automatically calculates system solar production.

If you have any questions regarding designing your solar system design, please give us a call at (406)690-1572 or send us your questions via email tim@energybuys.com.