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Real Goods Off-Grid PV System Sizing Worksheet


Appropriately sizing your off-grid PV system takes time, but it’s time well spent. While you don’t want to fall short on power, you do want to buy just the right amount of equipment to get the job done, and not much more. As a rule of thumb, system equipment will cost about $1,000 - $3,000 for every kilowatt-hour (kWh) you use each day. Start with conservation and trim your usage to the bone:

  • Don't use incandescent light bulbs or older standard refrigerators
  • Make sure all your appliances are energy efficient - use ENERGY STAR appliances
  • Dry your clothes the old-fashioned way, on a line or rack


Click here to view and download the Real Goods Off-Grid PV System Sizing Worksheet (.pdf)
(You will need to have the free Adobe Reader software installed on your computer to open the file)



After downloading the worksheet above (also available on page 127 of our 14th edition Solar Living Sourcebook), follow the steps to get a realistic usage estimate. The average daily kWh you come up with will be the basis for all future design considerations, so you want this number to be as accurate as possible. Once the worksheet is completed, start browsing off-grid solar equipment or call our technicians at 800-919-2400 for help sizing the PV array, the battery bank, and everything else you’ll need in order to power up.