The Ultimate Off Grid Solar Power Calculator - Figure out how much solar you need.
The first step in figuring out how many solar panels you need and what size of off-grid solar power system will work for you, is to know how much energy you use on a daily basis. No matter how big or how small, the first step is always calculating how many watts per day you will need.
We created this off-grid solar load calculator in order to help you quickly and easily add up all of your daily energy consumption and get this total in watts.
A couple points before we get started. We generally advise against adding any appliances that can be propane-fuelled, such as cooktops, hot water heaters and electric heat as these won't require any of the solar power we're harnessing.
If you'd like to know the EXACT watts of the specific appliance you're going to be using, you can usually find this on the back of most appliances, under their "energy use information" and you can enter these manually.
Solar Load Calculator
Grab a pen and paper. Use the image below and make 4 columns (shown below):
Appliance | Running Wattage | Run Time/Day (Hours) | Total
Now that we have our columns, write down all of the appliances you plan on using + their average running wattage (from the chart) + for roughly how many minutes and/or hours per day you'll be using that appliance.
Average Wattage of Household Appliances:
(Right click to open full-size image in new tab)
Add up the totals for the two numbered columns (wattage & time) by multiplying the running watts by run time/day. If it's minutes, do it as a percentage of 1 hour (ie. 30 mins = .5 hrs)
It should look something like this:
Now that we know your average daily usage, we can start looking to calculate the right size battery bank and the number of solar panels you'll need to charge that battery bank. For step by step instructions on these calculations, read this guide here.