After extensive investigation for a large house I'm restoring I've decided against solar and will be using a heat pump for hot water production. It works brilliantly and costs about half the price of solar. Another advantage is it works day or night, so you don't need solar radiation to produce hot water. Heat pumps are used in most large installations such as hotels, resorts, prisons, hostels, etc. The technology is well-proven, mature, and reliable. Just unknown in the SA domestic market. Check out www.flyinghippo.co.za or www.tekniheat.co.za (this website does not list their domestic model).