I'm wondering how to properly size an off-grid system where the primary use will be to power a small 5.3 cu. ft. chest freezer when I don't really know how much it will run in the summer time at my new location.
Location Info: Remote woods in southern Missouri about 80 miles due east of Springfield. My land is on a south facing slope at 1400'. Using TMY2 data for Springfield, MO, annual solar radiation should be around 4.9 with December being the lowest month at 2.8 and July the highest at 6.9. March through October, average solar radiation comes out to 5.68 so I figure 4.0 to 4.5 should be a good number to plan on since I doubt the freezer will run much in the winter time.
Freezer Info: The freezer sips power when the compressor is running. Using a Fluke 334 clamp meter, I am showing 69W when running. The Fluke is supposedly accurate to within 1% but it is several years old so I am sure it is no longer this tight. However, the in-rush current is 1300W when the compressor has been off for 24 hours, so I am going to need a fairly high-quality sine wave inverter to run this. The energy star label, for whatever it is worth, says 215 kWh estimated annual usage but I have no clue what ambient temperature they are basing this on.
I figure a 24V bank would be best but what size of a bank and PV array would be best to start with if I want to dedicate an array just to this freezer. The freezer will be stored in a small tool shed tucked into the woods next to the clearing for the array. I simply do not know how much it will run in the summer time and I suspect it will not run much at all in the winter time. I will have a generator for backup.
Any thoughts? Thanks.
Location Info: Remote woods in southern Missouri about 80 miles due east of Springfield. My land is on a south facing slope at 1400'. Using TMY2 data for Springfield, MO, annual solar radiation should be around 4.9 with December being the lowest month at 2.8 and July the highest at 6.9. March through October, average solar radiation comes out to 5.68 so I figure 4.0 to 4.5 should be a good number to plan on since I doubt the freezer will run much in the winter time.
Freezer Info: The freezer sips power when the compressor is running. Using a Fluke 334 clamp meter, I am showing 69W when running. The Fluke is supposedly accurate to within 1% but it is several years old so I am sure it is no longer this tight. However, the in-rush current is 1300W when the compressor has been off for 24 hours, so I am going to need a fairly high-quality sine wave inverter to run this. The energy star label, for whatever it is worth, says 215 kWh estimated annual usage but I have no clue what ambient temperature they are basing this on.
I figure a 24V bank would be best but what size of a bank and PV array would be best to start with if I want to dedicate an array just to this freezer. The freezer will be stored in a small tool shed tucked into the woods next to the clearing for the array. I simply do not know how much it will run in the summer time and I suspect it will not run much at all in the winter time. I will have a generator for backup.
Any thoughts? Thanks.
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