Sorry guys, my down time has been less internet centric recently... I've been in and out of the country and have been using my down time for house remodeling and other projects...

So, to start off... I fubar'd my math earlier. These are nominally 3x the cost of Lead Acid, but the value proposition is still there as they will easily outlast a L/A bank, probably by more than 3x the life.

How many of these for your house depends on your average electricity usage. The average household in CO is usually around 600-800KWH per 30 day usage period. So, if we take the 800 number, that gives some houses a cushion.

So 800/30 is 26.66KWH per day.

The batteries I linked are rated at 3KWH@80% depth of discharge. This means you actually get the 3KWH while maintaining the batteries health and the 10yr/10,000 cycle warranty. So, to go completely offgrid without much of a buffer you would need 9 of them. In the interest of cloudy days, or snow on the panels, I would probably aim for ~12 to provide a longer buffer.

Understand, that is a 100% off grip usage scenario, which many are unlikely to move to in their current homes. To use these in a more likely scenario for lots of folks, you would only need a few to maintain the items you want to move off the grid and onto either a grid tie system (grid charges the batteries and then batteries discharge during power outage) or a separate set of circuits that are fed by a smaller solar array and battery system. For instance, your deep freeze, your furnace, and maybe just a few lights in key areas. Depending on what you have interest in supporting, you can get away with 1-3 batteries and still make it through power outages without loosing any frozen food, heating in your house, etc...

I have only toyed around with small solar systems on my current house, and I will likely be moving in the coming year, but with a more permanent house, I intend to be mostly off grid, with grid power for the welders, lathe, mill, etc.


If you want me to run through more complete/accurate numbers just find out what your average usage is across a 6-12 month period, and I can run through the numbers and also include panel calculations.