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.