Suggestions on how to power a refrigerator/shower with no AC!?

Discussion in 'The Projects Forum' started by Kim_Kusanagi, Jan 1, 2011.

  1. Kim_Kusanagi

    Thread Starter New Member

    Jun 3, 2010
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    Hello, fellows. 2010 was a <snip> of a tough year professionally (personally, it was weird).

    I hope your year was good enough for you, and I hope 2011 turns out to be better. To me, it looks like this huge desert/beach I have to go through, I must be strong!

    On topic, a while ago, an uncle-in-law asked me on how to power his shower and refrigerator without having to plug them to the AC grid. He basically thinks the electric company is somehow scamming him, and he wants to take as much load as possible and power it with alternative sources. At that time, the first thing I thought was to power them with a solar cell, but they're expensive, just like a wind generator.

    On New Year's, early today, he basically lashed out at me because I haven't done the prototype yet (seems to forget that I have a daily job the rest of the year and I only rest on Sundays, but whatever) and he wants me to come up with an alternative, basic device, as cheap as possible so he can pay for it and later put it in a box and sell it (yes, he wants to sell MY project).

    Since this lash-out has finally triggered the creative side of my obsessive side (I have some of this not-so-much-of-a-disorder), I want to use a regular acid battery, an elevator transformer, powerful enough to power the 5kW showerfor at least 30 minutes, and perhaps LEDs to indicate when is the battery recharging and when is it powering the loads. The idea is, via some relay or something, when the shower is out of service, the battery is plugged to the AC, reloading. When the shower needs to get powered by the device, the battery unplugs itself from the AC and starts powering the shower. The LEDs are supposed to let him know this.

    Now I realize I should have a low-battery warning.

    To feed the fridge it would be different. The battery should have to feed it at the same time it is reloading...

    Also, I have to obviously convert the battery's (6V or 12V) DC to 110/120VAC.

    I'm ready to hear any and all suggestions you could give for a running start doing this thing and clear my head.

    Thank you, my professional brothers.
     
    Last edited by a moderator: Jan 1, 2011
  2. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Tell your uncle-in-law to move to Lesotho. My son lived there for 2 years without electricity or running water. Thankfully, he returned safely this Thanksgiving.

    Other suggestions, move to Minnesota and store ice in caves for use during July.

    Never heard needing electricity for a shower. Isn't he on municipal water? What's wrong with a hand pump.

    Next question, how much over weight is the guy?

    John
     
  3. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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    Ice truck for the fridge, hand pump for the shower. Location would be helpful.

    What's a 5kW shower anyway? Electrical shower?
     
  4. #12

    Expert

    Nov 30, 2010
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    I think he wants WARM WATER for his shower.
     
  5. #12

    Expert

    Nov 30, 2010
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    There are refrigerators that are powered by burning a gas fuel.
     
  6. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    I guess "uncle" just means male, not man. Sorry.

    Heat the water on a wood burning stove.

    John
     
  7. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    I don't think the way you are working at solving the "over-billing" is going to work, if it is possible at all for under low-to-mid 5 digit price tag worth of equipment.

    The 2.5kW-H just for the shower is above what most people "off the grid" use in a full day.

    Heat water for the shower in a black bag hanging outside, or on a gas stove.

    To get to the root of the problem, have him get a few Kill-A-Watt plugin meters that go between devices and the outlet to inform him how much current they are drawing. He may find that he isn't using quite a few devices that can be drawing a dozen (or more) watts while idle.

    Older "Wall Warts" that are transformer based (easy to find, they weigh a ton compared to new SMPS designs) will draw around 1-2W while idle. If they only power a battery charger once a week, it would be better to leave them unplugged. Those are the biggest "hidden users" of electricity, simply due to the sheer number that come with every product these days. For transformers that power equipment continually, make sure you switch to an SMPS "wall wart" to save a bit.

    Anything plugged in that gets above room temperature is drawing at least 5W typically, so you can usually feel the power drains without the meter, but the meter is quick and easy.

    Turn off everything you don't use, and by "turn off", I mean "Unplug". Get a "smart" power strip that powers up all outlets when one main device is turned on. Such as turning on the TV will give power to the DVD player, Receiver, etc. Turning off the TV will disconnect all devices from power.

    Living off the grid is NOT "Convenient" by any stretch. It is well enough livable, society got along fine until about 100 years ago without electricity. They also went weeks without bathing, rode horses, and didn't have TV or computers or light at night.
     
  8. kenster2001

    New Member

    Sep 29, 2010
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    What? Why?

    It sounds like you want to build an online UPS system to power an electric shower and refrigerator.

    Commercial offerings are in the 5-10k USD range for such a device.

    If I am not misunderstanding, you want to convert utility power into direct current so you can charge a bank of batteries which you can then power an inverter with to convert said direct current back into alternating current to power a water heater.

    I fail to understand how this will save any money whatsoever.

    Let's make some assumptions:

    The battery charger is 90 percent efficient.

    The inverter is 90 percent efficient.

    The short of this is that your system will use 23 percent more electricity after installation than before, not to mention it's initial cost.

    Obviously one of us is misunderstanding something.
     
  9. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    I think the OP have realized that the next morning, January 2, 2011.

    John
     
  10. BillB3857

    Senior Member

    Feb 28, 2009
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    Just get a gasoline or propane powered generator set. After fuel bills and cost of maintenance on the unit, you will think the electricity from the grid is cheap!
     
  11. edgetrigger

    Member

    Dec 19, 2010
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    "plug on to the sun". Use solar panels and inverters and also use a peltier based cooler so green house emission will also come down.
     
  12. wayneh

    Expert

    Sep 9, 2010
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    Do you have ANY idea how impractical that is? A peltier cooler needs about 10kWhr for every 1kWhr it moves from cool to warm side. That's about 100X more power - most as waste heat - for cooling than needed by a conventional compressor-based system, which moves about 10 for every 1 consumed. The ONLY reason peltiers are used is when space or other restrictions prevent using more efficient alternatives.
     
  13. Papabravo

    Expert

    Feb 24, 2006
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    Sorry to say, but I don't think your uncle has his feet on the ground. He certainly believes in some exotic mythologies.
     
    Last edited: Jan 5, 2011
  14. nomurphy

    AAC Fanatic!

    Aug 8, 2005
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    For the shower, you need a perpetual pump to continuously recycle and filter the water. For the refrigerator, a Zero Point Module should work just fine.

    Tell your uncle that it costs money to make energy, think of all the food you have to eat just to enjoy laying on the couch.
     
  15. Kim_Kusanagi

    Thread Starter New Member

    Jun 3, 2010
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    I meant an electrical shower. And I don't know how much overweigth can he be. I only know I am fine.
    Yes.
    LOL. There is no space and getting wood over here is rather expensive.

    That's what I would do, but he seems to think we are some Star Trek-like techno providers.

    I already told him more than 1 YEAR ago to do that. Needless to say, it seems he forgot about it. It seems I am going to have to buy me my own or one of these:

    http://www.mtpinc.com/Products.htm?CD=38

    Oh yeah, and he's also quite fond of letting the TV stay on the WHOLE night, even when they're sleeping. At least my cousin uses the auto sleep feature with his own TV, or else that bill would be insane.

    Not exactly at this point. I want a non-utility power source (it could be a rechargeable DC battery, for example) to be inverted into an approximately 5kW 110VAC source. Almost like an UPS, but not exactly one.

    Maybe in the long, LONG, run.
    Any economical suggestions? He wants ME to design my own homemade DIY solar panel and inverter. He's kinda old, so I can't tell him he's crazy and that I have more pressing issues, but with economic parts for the panel and a diagram of an inverter that turns out to be easy to build, I could finish with this.

    I truly thank all of you who have posted in this topic. I'll try to check more often, if I manage to control the ADHD :)

    Thank you.
     
  16. Kim_Kusanagi

    Thread Starter New Member

    Jun 3, 2010
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    You don't need to be sorry. In fact, as life has gone by, I've seen he comes from a family that believes that we do sci fi things real in a matter of days. My cousin, even though he believes in similar things, at least is more grounded in reality. For now.
     
  17. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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    Gas power generator.
    [​IMG]
    http://www.chinagasolinegenerator.com/ks-5kw-generator/
     
  18. wayneh

    Expert

    Sep 9, 2010
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    A battery is NOT a power source - it's a storage device. They're very inefficient because, for every bit of power you store and reclaim, much more energy is lost. So any battery use INCREASES your total power consumption. This necessary evil is tolerated for solar and wind systems because there's just not much choice. But it's not something you would design for if there were other choices.

    I still don't think it's clear (to me, anyway) what you're trying to accomplish. Everybody wants to save money, but most of what you're talking about would cost much more than just buying off the grid, so there must be ulterior motives. How much do you want to spend for those motives? I mean, if you have something against the utility company and are willing to spend X to avoid giving money to "those thieving bastards", then that's fine but these goals need to be more clear to get good help here. I don't think I'm the only one confused. if so, it wouldn't be the first time!
     
  19. wayneh

    Expert

    Sep 9, 2010
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    Full end-to-end wind solutions - small ones - are starting to show up in hardware stores. Maybe that would make him happy? (They still require "design" in the sense of placement, installation and wiring.)
     
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