Energy efficient refrigerators on solar power?

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Comments

  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    > Problem with "coasting" is that you get freezer burn and wilted vegetables, etc...

    There is no doubt that a thermal storage refrigerator/freezer needs to over-cool something (not necessarily any food) to work well. Water phase changing to ice an a good choice for refrigeration. And ice below 0F is still better than most materials for keeping a freezer at or below 0F.

    I am available for custom hardware/firmware development

  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    Looking at an economically designed GE at Costco for about $450. 15 cu ft and ~350 Kwh/year. Pretty good for solar applications.

    Just bought a nicely designed and unused Samsung for $320. It is 19 cu ft and ~550 Kwh/year. Uses about 35% more energy and offers about 20% more storage. Also offers two compressors with digital readouts and the freezer section in the bottom...a nicer design in my opinion.

    Guess I'll keep the Samsung and chalk it up to inexperience. I failed to account for rising energy prices when I was comparing yearly operating costs. A hazard of working on 20 projects at the same time?

    My overnight SOC falls to 91%, largely due to the refrigerator. Using 8Ds batteries which are automotive in design. Figuring I need to keep my SOC above ~70% to prevent undue harm.

    Buying automotive type batteries for solar was an ill fated beginners mistake. Though they were ~30% cheaper pound for pound. A lure that seemed quite attractive at the moment. It is quite easy for a beginner to believe that lead is lead and a pound is a pound.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • kaipo_boy
    kaipo_boy Solar Expert Posts: 143 ✭✭
    Lead is lead and a pound is a pound! hahahaha, well said, Softdown. Its the same problem facing all of us. Cycle life vs cost vs size/weight vs battery type. Does anyone here devote any serious time to the study of replicating a Ni-Fe type battery in a home shop environment? I think there was a yahoo group dedicated to trying to replicate one and I was hoping to just snipe their source list and try to make one for myself for evaluation purposes, but I haven't seen anything posted recently which indicates any real progress was being made by anyone. Does anyone here know of a site that shows any real progress or is this a pipedream? I did get a couple quotes from the IronEdison people, and while they are nice folks with, I think, a great product, when I compare the costs of their batteries vs simple replacement of golf cart batteries every few years, there is just no comparison. Doesn't even come close to breaking even, the lead-acid is far far cheaper. I have yet to investigate used traction batteries (i.e., forklift type batteries) although I do have a used Prius battery lying around that I was supposed to fool around with to see how good it would work in a home or workshop use... so many projects, so little time!
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    I think one could expect five years from golf cart batteries once they learned the ropes. GC battereries aren't bad at all. Traction batteries are the best....until a cell goes bad. Pretty tough to replace a bad cell on a fork lift battery.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • softdown
    softdown Solar Expert Posts: 3,812 ✭✭✭✭
    Thanks Photowit. Are they all that easy?
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries