ABSTRACT
Solar energy has finally come of age! Of all the applications of solar energy, thermal technologies are the oldest and most mature. Solar water heating is the longest-standing and most well-established kind of renewable energy system for heating water, pre-dating the widespread use of electricity or gas for heating. Archaeological evidence from Greek and Roman sites indicates that heating water with sunlight was an established practice thousands of years ago, as was the use of passive solar design concepts, with the use of southern facades for maximising solar gains for northerly locations.
