Anyone have a solar powered refrigerator?

[angel]

I live in Florida and am looking for practical information on powering a refrigerator or freezer using solar power. Does anyone have one set up? Ideally it would be stand alone so that the solar panels, batteries etc are only for the frig or freezer. But regardless how is it working for you?

Thanks
Angel

[Just a Jarhead]

I live in Florida and am looking for practical information on powering a refrigerator or freezer using solar power. Does anyone have one set up? Ideally it would be stand alone so that the solar panels, batteries etc are only for the frig or freezer. But regardless how is it working for you?

Thanks
Angel

Hi Angel,

I'm in Florida also and I have acquired extensive knowledge from personal research in this area. No time to expand on this now but will hopefully sometime by the end of the day with calculations and suggestions and links on equipment etc. I know this realm fairly well.

[Just a Jarhead]

Let me preface this with, that while I have done extensive research, I have not yet purchased any components to build my system. So everything below is based on research.

The best two companies I would limit my purchase to are:
Sundanzer http://sundanzer.com/
Sunfrost http://www.sunfrost.com

Both are well built and designed. Both are well insulated and use the highly efficient Dan Foss brushless compressors. Distinctions between the two are that Sundanzer makes 2 smaller top-loading chest style units; 1.8 cubic foot & 5.8, and 1 smaller upright combination refrigerator with a small freezer up top at 4.7 cubic feet. Sunfrost makes uprights like your standard refrigerator from 4 cubic feet to 19 cubic feet. So if you absolutely need a larger unit, Sunfrost is the most logical choice.

It's just my wife and I so we're focused on a smaller Sundanzer 5.8 c.f. refrigerator first, adding a separate freezer later. 5.8 c.f. is a little larger than a large portable marine cooler. I'm thinking survival & portable...period. From my research, the Sunfrost uprights tend to be slightly more efficient (Amp hours/day) but they don't seem to hold up as well as the chest style in regards to needing repairs in a few short years such as door seals, handles etc from what I've read in reviews. The chest style just seem to be sturdier and more durable.

It's efficiency is determined by its daily energy consumption in Amp hours/day rating.

Determining a solar array needed, if a refrigerator requires 40 amp/hours a day to operate (it will be listed), and you have 4 hours of peak sun per day, you need a solar array that can produce 10 amps output.
(4 hours sun x 10 amps = 40 amp hours) (or better perhaps is 40 amp-hrs/4 hours of sun day = 10 amps)

Solar panels are listed as 45 watts, 100 watts, 235 watts etc. This is how many watts per hour produced in peak sunlight. If it doesn't list in the spec sheet of the solar panel the amp output, then use 16 volts as an avg and you can determine the amps. Example: 100 watt panel/ 16volts = 6.25 amps. (you'll find this is pretty accurate and a 100 watt panel will produce approx +- 6 amps.

So now you know you need 40 amp hours per day to run the refrigerator as listed on the manufacturers spec sheet, you have a panel that produces 6 amps/hour, you get 4 hours of sunlight a day, you can produce 24 amps of power a day. You will need (2) 100 watt panels as each panel will produce 24 amps per day (6 amps per panel an hour x 4 hours of sunlight). (or (1) 200 watt panel)

The Sundanzer 5.8 cubic foot refrigerator I'm leaning toward requires only 14 amp/hours per day.(1) 100 watt panel will suffice for my needs.

Batteries: You want to have sufficient batteries as to never drain any of them less than 50%. Doing this will significantly preserve a batteries life. The most efficient batteries for this use seems to be 6 volt golf cart (electric vehicle) batteries (225 amp hour) wired in series to produce 12 volts. 12 volt deep cycle Marine batteries will work but they have a smaller amp/hour rating (around 180) and you'll need more of them to do the same job. The Trojan T-105 battery seems to be well liked from research and can be had for about $105 each. http://www.google.com/search?q=troja...ient=firefox-a

I want to have sufficient battery power for 5 days stored incase of sunless days or inclement weather. Using the 40 amp hours per day requirement example, and only using 50% of a batteries capacity as to not drain to deeply to preserve battery life (puts less stress on the plates), you would need a sufficient amount of batteries to produce 400 amp-hours. (40 amp hours per day x 5 days /50%). You will need (2) 6 volt 225 Ah batteries.

The Sundanzer 5.8 c.f. Refrigerator I'm leaning towards requires only 14 Ah/day. (2) 6 Volt 225 Ah batteries will give me enough power for 16 days. (450 Ah {(2) 225 Ah batteries)}/14 Ah day x 50%). That's pretty damned efficient!

Lastly, I need a solar charge controller to prevent from over charging the batteries and destroying them. You also want one with a low voltage “cut-off” so it shuts off if the batteries get too low to protect their life.

No inverter needed or used. Much more efficient running straight DC & not using any type of inverter converting from 120 A/C to 12/24 v DC. Also worth noting at this point is that a freezer of equal size will require nearly triple the Amp hours to operate.

Cost:
Sundanzer 5.8 c.f. Refrigerator = $1,189
(1) 100 watt solar panel = $150
(2) Trojan T-105 6 volt 225 Ah batteries = $250
(1) 20 amp charge controller = $100
--------------------
$1,689

Hope this helps some. Below is a simple wiring diagram attached as a .jpg.

[mallowpufft]

This is a subject I'm interested in but won't be doing anything about until next year at the earliest.
However, upon googling "solar powered chest fridge", one of the first results was a pdf about converting a chest freezer to a fridge due to the efficiency of a chest freezer's design.

[angel]

Thank you Jarhead! That was the best summary I have read and exactly what I needed. I was thinking about buying an enclosed trailer like 6X10 or so and fitting the roof with the solar panels and the freezer/batteries inside. Build in some shelves and maybe a gun rack. It would be my bugout trailer. Total cost is looking like $3000. On a moments notice I can pack the food, fill the freezer, load the guns and ammo, important papers etc.. and head for Georgia. I live in a very metropolitan place and have decided I will leave when necessary. I thought about finding a mountain lodge or resort that I can have on speed dial to make reservations in case of civil unrest or a hurricane and drive up. Once there I can re-evaluate. Those are my plans I hope to have completed by summer. Meanwhile I am stocking food, guns ammo.
Angel

[montanadave]

Great post, Jarhead.

I had toyed with the idea of going "off the grid" at the property we recently purchased and when the utility company told me they would need $30K to run power to my building site, that sealed the deal.

The Sundanzer chest fridge was the one I've been looking at and your post was very informative. I'm planning a small solar setup to run a fridge, a few lights, and a charge pump for the pressure tank. I've been doing some reading on solar systems but I'm still on the steep side of the learning curve. Working through the calculations really helps.

[Abraxas]

Interesting thread