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I am broke - How do I make Solar work for me?


KLEVA

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Hi

Solar is awesome, but it comes at a cost... Solar Electricity, and it's costs, are still way off the mark to warrant a "saving" of your Metro cost or Eskom cost, Solar Water heating is still best value for money so far.

So how can you implement Solar power and get both the known "green" benefits and the cost benefits? (ie: We want to get the best of both worlds)

If you have a small or no budget:

  • Start with Water (it is much cheaper) - Solar Geysers, Solar Water Panls and/or Evacuated Tubes...
    • Nobody on this forum (and many others) would discount the fact that Solar Water heating is far more effective and cost effective than Solar Electricity. You biggest electricity saving (for most) is by not using your geyser element to heat up water.
    • Put in a Solar Geyser (yes, this can be pricey, but still saves you more than Electricity in the long run), install evacuated tube system to provide your heat. You can do this with any basic geyser that has solar input (eg: Kwikhot). The supplier of the geyser isn't relevant, but make sure it will accept solar.
    • When you set up you Solar Tubes or flat-panel (Please avoid flat panel unless cost is really beating you), then make sure you install some kind of controller and pump to put the heat in the right place. Many suppliers will tell you that the temp diff will move the water/heat... It's most often BS, use a small pump, it will do as well on a basic system as well as a high-end system.
    • Invest in a GeyserWise... I personally think they are horrible, but until something else comes along they are currently the best equipment available that any starter will be happy with. GeyserWise TSE is a basic unit, but if going Solar, then don't stuff around, just do the GeyserWise Max, it will control your pump and temps for you properly.
  •  Play small - Start with anything that needs a 12V supply. Gate Motors, Alarm Systems, CCTV systems, DSTV,, and many more... How can you feed that with free 12V?
    •  You have to use a battery, a controller to charge the battery, and a solar panel. The best part about a small system is that the cost is small, and you can learn. Think about the fact that almost every Gate Motor that opens 10 time a day, can be happily controlled by a 10Ah battery, a 50W panel, and a basic cheap charge controller, and almost never run out of power... A Gate is almost the perfect condition for you to learn about the fact that sometimes there isn't enough power (batteries aren't charged enough, charge power isn't working, and many other issues)., The next best part about a small 12V system, is that you can buy a cheap charge controller. Almost every supplier in SA has cheap controllers (eg: Ellies) and you can get some decent chinese variants... They usually are under R700 for a 12V PWM charge controller. When you are working with 12V, it is not critical to use a high end MPPT controller and a PWM controller is perfectly adequate. (MPPT control is great, but you are not going to be able to buy that off the shelf, it might work better but for small needs, a PWM controller is Ok). Next you can think about the battery... A spare car battery will work, but you will learn in time that it stops working or goes faulty... So you need to get a decent Deep Cycle battery to keep your system working properly. I personally still use old car batteries where I can get away with it (money/cost), and you can also use the basics. When you on this voltage and small level you can make mistakes and learn from them.

 

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Morning Kleva,

What about also just running the pool pump, say 750 Watts motor. Can this not also save a few pennies in the medium term?

What would the basic kit consist of?

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The tough part about a motor or a element is that they "kick" (my term, not a technical one) when they switch on. Motors are quite intensive for a few split seconds when they switch on, and use well above their rated power/Amps. This means that you have to be careful with motors as they might use nearly 10x more for split seconds on startup.

The next trick is trying to find a DC pool pump... If you are going to stick with an AC pump, then you will have to have an invertor (at least 3kW). If you can find a DC pump then the kick, isn't as bad, but you have to look at providing it with at least 2x the power on startup (like when the timer kicks in), so that it doesn't trip or blow fuses.

If you want to do things cheap (as per the Blog), then you have to ignore motors and elements, and even sometimes compressors (fridges/freezers/AC units).

If you want to only power your pool pump, then look at about a 2kW to 3kW Invertor. But in my humble opinion you are going to spend a lot more money getting that pool pump off the grid than you will ever save/warrant.

To give you an example: I run a single 12V Freezer (about 40l size wise) off of 300W of panels and 2 x 12V batteries (24/7 in my camper - the freezer is always at 0 degrees). That is a expense of nearly R6000 just to run a freezer 24/7 off-grid. It works fantasically, but definately a huge expense, and there are some periods it just cant work (average of 5 days in a month that the freezer can't run due to low battery or something due to previous weather or parking place). I just was determined to have cold beer when I travelled:D

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Speaking about cheap or broke - The moment you have to invest in an Invertor to change your solar power into AC power for a device, then you are already out of the cheap/broke category... Now you have to investigate the rest of this forum and/or Blogs to understand a lot more.

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Save money but not time , you should build a DIY powerwall. If you worked off bottom balancing or you were very diligent in how you monitored the batteries you could get away without a BMS, but....

If you changed your lights to LED and had a gas stove and solar hot water is there much in the way that would inspire you cost wise to invest in PV pannels?

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