The key point to remember when choosing a solar system is not to look at what another person has but what would suit you and your needs the most.
We have eight 150 watt panels and a 1030 amp/hr battery bank and all of the associated gear to make it work but only because we live entirely off the grid.
For someone that only wants to run a fridge or charge a phone ours would be far too big a system for them.
There has been discussion in this thread about running refrigerators in a SHTF scenario. Remember that our grandparents never had refrigeration and they still managed to live healthy and productive lives. Refrigeration is our largest consumer of the electricity that we produce and in a post SHTF situation we are geared up to live without it as no matter what system you put in it is eventually going to break down or the appliances you use are.
By practicing sustainable gardening that allows you to eat all year around from your garden and preserving your produce, especially excess fruit, will help eliminate the need for a lot of fridge/freezer space.
We are in the midst of the worst drought that locals in the area have ever seen and we are at the present time putting in more water storage and thinking of setting up a hydroponic system to save water and yet still enable us to grow our food.
To us, the ability to save, retain water, would be far more important in a post SHTF situation than having electricity as we can live without it but we cannot survive without water.
Spanner away, that's what it's all about, preparing, sharing ideas and I'm 100% behind better ideas! Great page you've got there on alternatives to fridges and sure, there's tons of alternatives to refrigeration. I'm glad you've had some real world perspective about running a fridge on solar and what size you actually need, it's really helpful.
I have some questions as I did some calculations. 160W of cells with an AGM battery in 'Melb' will make 660W/h [on average] during summer and June 230W/h [on average] accounting for losses. Sydney's annual average is 8% more and Brisbane 16% more.
I grabbed some figures and obviously the outside temp is not constantly 21°C and in winter they will use less power but they're the best figures. 43°C uses about 37Ah for NLR-40.
My question is what size/model you were using for the family and also have you run it continuously in winter because the figures suggest you're not making enough juice though real world is the better test.
Sorry to take so long to get back to ya Mate...Missed the Post. My National Luna is a 74lt, and DC runs at 2.5 Ah @18deg C. Having the danfoss compressor make it very efficient!. being a top loading allows the cold to stay in when opened like a freeze! Yes it ran 24/7-365 on the boat for 4 years and I never had a problem. I have it at home now and we use it as a drink fridge at times. But it will be or it's replacement (getting a second one 105lt) will be our main fridge WTSHTF!
But speaking of Freezes, I have bought the conversion from the US to convert one of ours to a fridge!
Post by doomsdayprepper4570 on Mar 25, 2017 7:34:22 GMT 10
To run 2 fridges and 2 freezers we use 12 x rolls surrette 1350 amp hour batteries, 2 midnite classic regs, 20 x 200 watt hyundai panels and a 3kw latronics inverter. This will also run a toaster, sandwich toaster and rice cooker during the day. The system produces 13-18 kws of usable power daily. It is expensive to set up and I had to piece the system together over 3 years. You can buy 2nd hand grid tie solar panels for $50 each so do not got spending $100's on new panels off evil bay! Through a good reg 45 volt panels will charge any system voltage from 12 - 120 volts. Latronics inverters are made on the sunshine coast in qld and can be bought cheap at times off evil bay and gumtree. Unless you are an electronics geek go with flooded lead acid batteries as they are easier to maintain and a bit more forgiving to solar newbies. Trojans make a new carbon series battery for solar system and I will be getting some of them for my sons setup as they have an expected service life of 15 years if cycled properly (20% discharge per cycle and not 50-60% as some people think you can do). If you are travelling then a larger system is not practical as this system weighs 4,500 kgs plus including panels You can of course get by with a lot less power production. But come overcast weather you have big problems and fuel costs.
One thing I have been thinking about as a back up and winter power to supplement solar, is a steam engine. The difficulty will be finding one now. There was a company making them in South Australia up until 2 years ago when the owner retired and nobody took over the business. An added bonus is it will also heat your water. The one I was looking at was quite efficient using only about 2/3 of a wheel barrow of wood a day. It even came with a train whistle as an option!!
There's also gasifiers as a potential, just add wood. Can turn the creosote waste into a limited amount of fuel for the chain saw whilst you're at it. If you're further north, you could use a methane digester directly using the gas as your 'propane' source on a 3 way fridge with the right sized jets [would be close already] and probably need a few people/cows poop to do so. In Melbourne you'd probably have to heat it, could be done with solar and I did contemplate it.
Personally none of my preps need refrigeration and you can preserve what you grow if you have the resources put aside to do so. Recently my experiments with standard jars for pressure canning turned out great, if anything they're superior to Bell type jars. From there you can preserve anything. There's no reason we don't collect those for such purposes and do away with a fridge entirely and use the power elsewhere.
Having said that, my sums should be accurate, even in Melbourne, even in winter. Just use a chest freezer converted to a fridge and you'll use only a trickle of power. Reduce the need for a fridge and freezer, have a small one and you can downsize the power and cost needed for it.
Another crazy idea is the idea might be to use the sun of the day to make ice for the night so you're not running on batteries, rather using the thermal [cold] battery of the ice to keep things cool. Panels are very cheap second hand, about 30c/W. You'd have to work out the power needs and block sizes necessary to do that, perhaps having some reserve ice, though it would work.
Last Edit: Mar 26, 2017 16:14:19 GMT 10 by shinester