Solar power a hot topic: Harnessing the sun's power helps everyone

Border Mail
Wednesday 28/3/2007 Page: 31

Conergy is one of the largest renewable energy companies in the world, manufacturing components and systems for generating electricity, heat and cooling from renewable energy sources.

In addition to solar thermal, which uses the sun's warmth, and solar electric, which harnesses the sun's light, it is expanding into wind power and bioenergy and to that end it acquired an Australian wind farm developer Taurus last year but it is still probably best known in Australia for its solar hot water systems - the most widely and solidly established area of the renewable energy industry in this country.

Solarco co-owner Craig Martin said the community had embraced solar hot water and it also was being driven by tougher building guidelines in almost every state. "With the BASIX building system in place in NSW, it's unlikely you would achieve enough points to build a house without solar powered hot water these days," he said.

"And for many people it's a good alternative when their existing gas or electricity hot water unit dies. You can save up to 3.4 tonnes of CO2 emissions a year and there are very good rebates available but the best thing is that 90 per cent of your hot water is free." Conergy boasts two versions of its hot water solution, the thermosiphon system and the split system.

With the split system the storage tank is located on the ground and the collectors are located on the roof. Cold water is pumped from the tank to the solar collector. As the sun heats the water in the collector it is then pumped back into the storage tank. Hot water is then taken from the top of the tank for use in the household. With the thermosiphon system, both the collectors and the tank are on the roof. The tank is located above the collectors and cold water runs naturally from the tank to the bottom of the collector.

Through the law of density, water rises naturally from the bottom to the top of the collector as it heats up. Once it reaches the top of the collector it then continues into the tank for consumption in the household. The cycle continues as the water moves from tank to collector while the sun is shining. Both systems can be installed with an existing electric system or with an instantaneous gas boost system. This means that even on cold days you will still be able to produce hot water.