BajaNomad

solar deep freeze

bledito - 7-23-2013 at 07:11 PM

we like to freeze fruits, veggies, breads and especially annes' homemade italian gravy (sauce). we are not always around the homestead to insure the electricity is on. What would it take to isolate the freezer from the main panel . then have it run off a solar panel and battery system independantly ? I would be concerned about the power lapsing and the food spoil and refreeze without knowing, and worst of all losing all those nice fresh frozen veggies and especially the sauce. I know it can be done but at what cost $$$ ?

willardguy - 7-23-2013 at 07:16 PM

you didnt say where you are, how hot is it and how much sunshine do you see?

bledito - 7-23-2013 at 07:18 PM

lower baja , hot , lotsa sun.

bledito - 7-23-2013 at 07:20 PM

freeze size like 3x3x4 tall

Oggie - 7-23-2013 at 09:58 PM

When we leave our baja house we place a few ice cubes in a zip lock bag. If they are still frozen cubes ok, if not then we clean out the freezer. It is not worth eating spoiled food.

Pacifico - 7-23-2013 at 10:45 PM

Look up Sundanzer Freezers...

All you need is a couple panels, batteries, and a charge controller. Freezer is about a grand. You can do it all for 2-3 grand.

durrelllrobert - 7-24-2013 at 09:30 AM

Quote:
Originally posted by Pacifico
Look up Sundanzer Freezers...

All you need is a couple panels, batteries, and a charge controller. Freezer is about a grand. You can do it all for 2-3 grand.


Cheaper to just throw out thawed food unless you have a sentimental attachment to all those YT :lol:

willardguy - 7-24-2013 at 10:48 AM

assuming you need 4 days of reserve power (50% DOD) in 100 degree heat, I think a realistic system would be in the neighborhood of a 200w panel/ 400 amp hour battery and a small mppt controller. lots of variables here though! and......jmho

edm1 - 7-24-2013 at 02:20 PM

Quote:
Originally posted by bledito
we like to freeze fruits, veggies, breads and especially annes' homemade italian gravy (sauce). we are not always around the homestead to insure the electricity is on. What would it take to isolate the freezer from the main panel . then have it run off a solar panel and battery system independantly ? I would be concerned about the power lapsing and the food spoil and refreeze without knowing, and worst of all losing all those nice fresh frozen veggies and especially the sauce. I know it can be done but at what cost $$$ ?


It will likely cost you around $2000 in freezer, panels, battery and controller costs.

monoloco - 7-24-2013 at 02:42 PM

My neighbor has a couple of these:
http://www.steca.com/index.php?Gefriertruhe_en
Very efficient, runs on 2- 100w panels and an AGM battery

bajagrouper - 7-24-2013 at 03:05 PM

I would build a dual system, solar panels and a small wind generator...the wind gen. could supply energy to batteries 24 hours a day...........

vandy - 7-25-2013 at 05:33 AM

As a camper, I try to KISS (Keep It Simple, Stupid!)
I have wanted a solar fridge/freezer on the beach for years, and keep pricing systems. I want to keep it inexpensive too.
There are all kinds of things to consider:

cheap chest freezers use the outside wall of the unit as a heat-sink, as opposed to those with a fan and cooling fins. This means you can't insulate them well on the outside.

cheap solar panels will put out 30 volts, making a cheap charge controller very inefficient.

cheap modified sine-wave power inverters are reputed to have issues with running AC motors. True sine-wave inverters are expensive.

When you look into this "solution", it is no longer simple and cheap.
I can put a solar system together for about $500, including used chest freezer, used solar panels, new charge controller, new power inverter and 2 new marine 12v batteries, but I wouldn't trust it if I left for a week.

A solution for you would be to get a couple of good batteries and a power inverter and have them cut-in when the power goes out. They could run your chest freezer for a couple of days to maybe a week.
You'd need an automatic battery charger too.

monoloco - 7-25-2013 at 10:06 AM

There is also the Engel option, I ran one for 9 months on 2-75w panels and a Costco marine battery. They are great for traveling too.
http://www.engel-usa.com/why-choose-engel/why-choose-engel-f...

willardguy - 7-25-2013 at 11:50 AM

consider this. assuming you already have a freezer you're happy with, buying NEW top of the line gear ( panel,controller,inverter,and batteries), you're lookin at 16-17 hundred bucks. with the exception of the batteries all this stuff can be found on craigslist. keep in mind a new sundanzer will save you the cost of the inverter, around five hundred bucks.

bajagrouper - 7-25-2013 at 11:53 AM

If you live near a golf course you may be able to buy used golf cart batteries...

willardguy - 7-25-2013 at 12:19 PM

Quote:
Originally posted by bajagrouper
If you live near a golf course you may be able to buy used golf cart batteries...
you don't want to skimp on the heart of the system! ;D

MitchMan - 9-26-2013 at 10:03 AM

I have a 7 cu ft Frigidaire freezer chest in La Paz (cost $4,500 pesos two years ago). It uses about 40 to 45 watts AC 110 volt Mexican grid power per hour. Not sure, but wouldn't two 100-watt solar panels, a basic inverter and controller and a used golf cart battery do the trick? If so, the whole solar system would cost about $800 - $1,000 USD.

I'm new at this...I could be way off.

willardguy - 9-26-2013 at 12:26 PM

Quote:
Originally posted by MitchMan
I have a 7 cu ft Frigidaire freezer chest in La Paz (cost $4,500 pesos two years ago). It uses about 40 to 45 watts AC 110 volt Mexican grid power per hour. Not sure, but wouldn't two 100-watt solar panels, a basic inverter and controller and a used golf cart battery do the trick? If so, the whole solar system would cost about $800 - $1,000 USD.

I'm new at this...I could be way off.
mitch the problem is will that used golf cart battery run that freezer for a minimum of four days without sunshine? :no:

larryC - 9-26-2013 at 12:51 PM

There is another way to attack this problem. Just get a 1000 watt (large enough to run whatever freezer you have) or so true sine wave inverter/charger. A battery bank capable of running the freezer for the duration of the average power outage. Then hook the battery bank to the inverter and the grid power you have available to the AC in on the inverter. Now you have AC grid power passing through the inverter and running your freezer and charging your battery bank at the same time. When the grid power fails the inverter will switch to inverter mode and run the freezer as long as your battery bank lasts. Hopefully you sized it correctly. No solar panels or charge controllers are necessary with this system since you have grid power to charge the batteries. Very simple. I advise a true sine wave inverter because most motors do not like modified sine wave power, they run hotter and use more amperage and their lives are shortened.
Larry

MitchMan - 9-27-2013 at 09:08 AM

Quote:
Originally posted by willardguy
Quote:
Originally posted by MitchMan
I have a 7 cu ft Frigidaire freezer chest in La Paz (cost $4,500 pesos two years ago). It uses about 40 to 45 watts AC 110 volt Mexican grid power per hour. Not sure, but wouldn't two 100-watt solar panels, a basic inverter and controller and a used golf cart battery do the trick? If so, the whole solar system would cost about $800 - $1,000 USD.

I'm new at this...I could be way off.
mitch the problem is will that used golf cart battery run that freezer for a minimum of four days without sunshine? :no:


MitchMan's Answer: No, not even close.

For the last two years in La Paz, as far as I can tell, power outages haven't lasted very long and are much less frequent than before 3 years ago. I use the 'put some ice cubes in a cup' for the duration of an absence from Baja and see if the ice melted upon return to Baja. So far, no meltage over the last 3 years. Doesn't mean it couldn't happen.

A freezer could go out for 4 to 6 hours (maybe even 8 hours), and, unopened during that outage, the contents of the freezer will be safe. But, if there is no sunshine for a couple of days, well, that's a problem. I put a few small plastic trash buckets of water to freeze in the freezer chest in order to keep the volume in the freezer occupied as much as possible. I think that helps keep things cold longer in a power outage.

The only think I keep in the freezer is fish, beef, chicken, mango meat, bread, cheese. It's OK if those things actually thaw to some extent, so long as it stays below 38 Fahrenheit in there.

I think that I might use the above-described solar system I suggested and just risk having to throw everything out that spoiled if there was a prolonged outage. As a little insurance, maybe add a solar panel to help get some more current during no so sunny days.

rhintransit - 9-27-2013 at 09:52 AM

solar power is great, except when there is no sun for days on end. if you are going to be gone during any of the 'norther' months, you need to up the battery storage capacity to compensate or have electric backup. I kinda like the electric, then solar back up suggestion.


[Edited on 9-27-2013 by rhintransit]

monoloco - 9-27-2013 at 01:19 PM

With the low price of solar panels these days, it's pretty easy to have enough capacity to charge the batteries even when it's cloudy. I have a back-up generator, but in the last year, I've only started it to exercise it, I would get along just fine without it.