Solar Setup - Specific questions

Discussion in 'Designing, building, making and powering your life' started by Shack Living, Apr 6, 2008.

  1. Shack Living

    Shack Living Junior Member

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    I have done a lot of research via the web and books on setting up my shack on solar electricity, but have a few few questions: :D

    1. If I install a regulator that has a readout display, is there any benefit putting in a battery monitor?

    * battery monitor shows State of Charge, Volts, Amp Hours, Amps, Time Remaining (basically current in & out, and voltage)

    * battery regulator shows the volts, amps, and resettable cumulative amp hours for a solar array, DC loads, or diversion loads (basically voltage and current)

    they seem to do the same thing or am I missing something? Is it just that the monitor is more accurate as it uses a "shunt" to give a better idea of batteries condition? If I get a battery monitor, then should I buy a regulator without display?

    2. Should I buy the biggest regulator possible, assuming it simply means charging the batteries quicker? I am told the rule of thumb is 10% of the battery capacity for max charging rate. So if 1125ah battery setup, this means it will take a max of about 112amps charging. So should I buy a 60amp regulator rather than a smaller 20-35amp one? thinking it will charge them a lot faster for short sunlight days (have plan about 500Watts of panels)

    3. If I have 12volt solar panel setup, and want to add a 12volt wind generator, I assume I just wire it in parallel to my 12 volt solar panels if they are nearby to each other. Does this mean I need to add diodes to the capacity of the panels, so that power wont flow into the panels on windy nights or shady windy days?
     
  2. Ojo

    Ojo Junior Member

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    Re: Solar Setup - Specific questions

    hard to answer specific questions without knowing specific equipment you're using and their capacities. Will the wind generator have a built in charge controller?

    Some wind turbines have charge control features built-in, diverting their own excess current and allowing it to dissipate as heat through the wind turbine housing. In most turbine systems however, the charge controller is an external unit, and while DC rectifiers are always included as part of a basic wind turbine package, the load diverting controller may not be.
    https://www.absak.com/library/wind-turbine-home-power

    "why can I NOT use a Solar or PV charge controller with my wind generator?"
    https://www.tlgwindpower.com/ccontrollerinfo.htm

    https://www.air403windgenerators.com/403Wire.html
     
  3. Shack Living

    Shack Living Junior Member

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    Re: Solar Setup - Specific questions

    thanks for your reply Ojo, and the useful links. I purchased a cheap wind generator, thinking it would be a good way to see if our location is suitable for wind harvesting. Here is what I purchased (cheap china import):

    https://www.jaycar.com.au/productView.as ... BCATID=855

    https://www.jaycar.com.au/products_uploa ... Manual.pdf

    In reading I now realise it produces AC power, so will simply run its own wires to the batteries, and it has a box the that regulates it to DC.
     
  4. Ojo

    Ojo Junior Member

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  5. dgriffith

    dgriffith Junior Member

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    Re: Solar Setup - Specific questions

    It seems from your description that the battery monitor and regulator will show you the same thing.

    As for the size of the regulator, 500W of panels is 35 to 40-ish amps..... which will either (a) be throttled back to match the lower capacity of your regulator or (b) trip your regulator's current protection, which might need manual intervention/button pressing to reset. So, I'd go for the larger one if it's affordable now, as opposed to later when you decide to squeeeeze another panel or two onto the roof and run across this problem every day :lol:

    Also, be careful with the voltages for the two regulators (solar/wind). You want the wind one to cut out at a slightly higher voltage than the solar one, not the other way around. Otherwise it's possible that on a sunny,windy day, a badly designed load dump/shunt regulator on the wind side of things will cop both wind + solar output in its effort to keep the battery voltage at a set level.... and burn out. Seeing as it's made in China, it's probably poorly designed (or, to be generous, designed without consideration for other factors). The solar regulator should be able to handle this setup as long as it's PWM (pulse width modulated) type one , not a shunt regulator. Seeing as it sounds relatively modern (with display) and is relatively large (25+ amps) it's very likely that the solar regulator is a PWM design.

    It all sounds easy if you say it quick enough :D
     
  6. hardworkinghippy

    hardworkinghippy Junior Member

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    Re: Solar Setup - Specific questions

    Hi Shack living,

    I've two systems, the older one is wired up for 300watts of solar and has two Rutland 910 windchargers (75 watts nominal each) I wanted to overcome the problem of overload into the solar controller so I rang a friend and he suggested feeding the windgenerators into their own controller first to control the load, then feed them into the solar controller.

    Here's a photo of the wiring. The small cheapo controller on the right with the red light on is the wind turbines (the red light means it's dumping power), the solar controller is on the bottom - showing it cleaning up the batteries automatically at over 14v.

    [​IMG]

    This has worked fine for about 9 years and the system has never been short of energy for loads of lights, music and TV in our 168m² house, I also use it for my laptop, sewing machine, charging tools etc. when it's windy and there's no sun.

    I hope that helps. :)
     
  7. gardenlen

    gardenlen Group for banned users

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    Re: Solar Setup - Specific questions

    g'day hwh,

    your wind generators seem to be some distance from the house/storage facility? that could be just how the pic' looks?

    if so do you lose any proportion of the power as it is transported over that distance? might be dumb question but i am not technical at all, just have heard that in solar particularly to have power collection and distribution as close over a shorter distance as possible, hope that makes sense?

    is it ok if i put your energy page BLOG link on my site for others to be informed?

    and to 'sl',

    i didn't realise that there where a/c generqators for home use, which would be an advantage as i see it if there was some way of capturing that energy for use by the appliances, the thinking to cut out some equipment in the middle so to speak ie.,. inverters. so to use an unit then requires the addition of another piece of equipment to converts to d/c which then gets converted back to a/c before the appliances, does how i say it make sense?

    the less equipment needed would mena less cost and more efficiency in not relying on that equipment.

    len
     
  8. hardworkinghippy

    hardworkinghippy Junior Member

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    Re: Solar Setup - Specific questions

    Len,

    You're right that DC (Direct current) power is lost in the form of heat (which is really dangerous inside your house/cabin/yurt) along the length of the cable. If the cable's thick enough for the length, you won't lose a lot of power. We bought a very thick cable for the wind generators, because as you say they're a fair way from the house, but we had to site them where they are because it was the best place without protection from the house and trees to make the most of the wind.

    Here's a link to a site which helps you determine the size of cable you need for the length and the watts:

    https://www.unlimited-power.co.uk/cable_sizing.html

    I agree, I think it's daft to reconvert to DC, but if you want to store the power then you need to use batteries which are DC. I wonder if we'll ever come up with a better way to store electricity ?

    I'd be honoured if you put a link in your blog to mine Len.

    Irene
     
  9. gardenlen

    gardenlen Group for banned users

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    Re: Solar Setup - Specific questions

    thanks hwh,

    this thread is about the best thread to date for giving a real insight into stand alone, for us the only way because that way you are not reliant on the normal grid even if only in times of some emergency?

    now all we need do is take the gold diggers out of it and make it more affordable, so homeowners can have a real and positive impact.

    not sure about propellor driven turbines in the suburbs? (not an issue with us) but i bet there is some hidden bi-law that prevents their use, in built up areas. would be great to see some evelopment of a turbine more in the style of those roof ventilaters which may then be more acceptable in the suburbs, if that is an issue of course?

    for those over here there is access to second hand forklift batteries, which going by reports of those using them is far more affordable and very workable. and i suppose in true p/c recycle/reuse form it is making use of an already manufactured item.

    do you have a stand by gen' set for times of no wind or whatever?

    len
     
  10. hardworkinghippy

    hardworkinghippy Junior Member

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    Re: Solar Setup - Specific questions

    No we don't have a generator, but we can borrow one if we really need to for big power tools for building.

    We started off in a cabin with no electricity, so what we have now is real comfort. :D

    Our new house is almost "normal" with lights everywhere, TV, computer, and music. We've no washing machine, but we've recently bought a 2kw wind generator which we'll put up when we've finished building an extension to the house with an area where we can store the (second hand fork-lift !!) batteries, inverter and controller. Then we should be able to run a washing machine when it's windy - I can hardly wait !

    We heat the house and the water with wood and solar. We built the house to take advantage of winter sun and to keep cool in summer so we don't use a lot of electricity. Around the winter solstice we have to be a bit careful but I usually have enough electricity to do what I need to do on the computer and even on grey windless days there's always plenty of energy for LED and compact fluo lights.
     

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