green your solar water heating

Submitted by sproutingforth on Fri, 2008-05-16 12:11

Everyone’s talking solar, which is no real surprise given the power crisis. It isn’t just a national crisis however but part of a far wider reaching global energy ‘over indulgence’ in dirty, non-renewable energy.

Whatever the reason for reading this – whether it’s that you want to take advantage of Eskom’s solar water heating incentive programme, or that you want to live a greener life - there is an urgent need to shift to renewable, non-polluting energy sources, like the sun, to provide our energy needs.

The difference between solar water heating and solar photovoltaics
Some people are confused when it comes to solar energy. They tend to lump solar in a hand basket and refer to it collectively as ‘solar power’. But there is a difference. Solar energy can be sourced as a form of heat, which is used to heat hot water or as electricity, where one uses solar photovoltaic panels to convert the sun’s energy into electricity – often referred to as part of ‘getting off the grid’ – a far more costly (at the moment, but watch this space…) affair.

For more information about solar photovoltaics

Solar water heating
Heating your water using solar energy is one of the most cost-effective uses of solar energy. By harnessing the sun’s rays you can get hot water for showers, dishwashers and washing machines and cut your electricity consumption between 30% and 50% (according to Eskom).

Solar water heaters are not just a sound idea economically; they’re also really environmentally friendly and provide heating even in cloudy weather.

In a basic direct (open circuit) solar water heating system flat panels with internal water pipes and a transparent cover are attached to your roof, onto which the sun shines. This heats the water in the pipes, which then rises to the hot water cylinder – usually just above your panel or inside your roof – which then gives you hot water from your taps.

Things get a bit tricky if you live in an area prone to frost and you may need an indirect (closed circuit) system to prevent water from freezing in the pipes. Closed circuit systems rely on a freeze resistant fluid to transfer the heat from the panels containing the pipes to the hot water cyclinder.

Further information on how solar water heating works

You’re looking at spending between R10 000 and R30 000, depending on the size of your solar panel and the type, and if you live in an area where frost is a factor a freeze-tolerant system will usually cost more. However, one not only recovers the investment within 2 to 5 years, but you have hot running water despite blackouts, never mind the green kudos of a solar panel on your roof!

Where can I find suppliers of solar water heating?

Eskom’s accredited suppliers of solar water heaters

The country’s push to use solar water heaters
You don’t have to be a genius to realise that the push to switch from conventional geysers to solar water heaters will help reduce the load on the electricity grid.

The South African Government has set a target for renewable energy to contribute 10 000 gigawatt hours (GWh) of final energy consumption by 2013. Research completed by the Department of Minerals and Energy estimates that solar water heating could contribute up to 23% of this target.

Eskom’s incentivised roll out
Eskom is subsidising the installation of solar water heaters. The incentive amount is calculated based on the efficiency of the solar water heating system and you receive the discount directly from the supplier of your system, provided it is one of Eskom’s ‘recognised’ or approved suppliers. Find out more about the programme

What do I need to look out for when buying a solar water heater?
Eskom outlines a number of questions you need to ask yourself when selecting a solar water heater so that you can quickly gauge the right size for your family.

Your system has to be registered with Eskom and the minimum guarantee for suppliers on this programme is 5 years. You should end up with a guarantee certificate in your hands, and a CoC (electrical certificate of compliance) for installing your solar water heater.

The list of accredited participating suppliers of solar water heaters

Homemade solar water heating systems
Not everyone can take advantage of the Eskom incentive because of the large capital outlay. You can choose to buy and install the systems yourself or conversely, even make your own solar water heating system as outlined on mother earth news.

If R20 000 is too much for you to spend right now, get creative like this man in China, who recently made a solar water heater using beer bottles and hoses. His ingenious contraption involves beer bottles lined up on a board in rows, all connected by hoses, which allows cold water to flow through them and be heated by the sun. [dailytimes]

Read our other green guides, including green your electricity and green your heating and cooling.