Tube me up, Scotty In the solar water heating industry the benefits of evacuated tube systems are often weighed up against solar geysers that use solar panels. We investigate. Click here to find out more.  Ever since load shedding hit in January 2008, topics that were far removed from the public's mind suddenly became important. For convenience's sake, many households started to appreciate the sustainable solutions alternative energy sources provide. With an energy crisis that has the potential to cripple the economy, the media quickly took up its role as educator in alternative energy. However, because alternative energy is not a topic that has always received media attention, many journalists were, and still are, in the dark when it comes to alternative energy solutions. In the solar water heating industry the benefits of evacuated tube systems are often weighed up against solar geysers that use flat plate collectors. The media in general seems to think that evacuated tube systems are a better choice because the solar hot water from evacuated tube systems is generally hotter than the water in other systems. What a lot of people, including the media, don't realise is that the efficiency of a solar system, whether it's an evacuated tube system or flat panels, is relative to various factors. These include the amount of solar radiation, whether it's a direct or indirect system, the insulation of the system as a whole and the orientation of the system. What's more, the performance and durability of the entire system needs to be taken into account, not only the efficacy of the collectors. Consumers need to consider factors such as safety, the quality of the tank, heat retention and continued overall performance. Although evacuated tube systems may be well suited to certain climates, this is not necessarily the case in South African conditions. The South African annual solar radiation value is somewhere between 1 450 and 1 950 kWh/m2 per annum, compared to an annual average of 910kWh/m2 in Europe. In the case of evacuated tube systems, especially in pre-feed systems where the hot water is pumped directly into an electric geyser, water that is too hot has the potential to cause damage due to the excessive pressure.  Although many flat plate collector manufacturers have products that can attain efficiencies higher than evacuated tube systems, those panels aren't installed in South Africa because of the high radiation levels and the subsequent risk of damage to the storage cylinders. The matter of heat loss should also be considered. Heating water to boiling point is one thing. Ensuring that the water stays warm over an extended period without sunlight or electricity is an entirely different matter. The collector panels have nothing to do with heat retention. A properly insulated tank and pipe work is needed to retain heat. Furthermore it is of pivotal importance that you are sure of the after sales service that you will receive when buying a solar water heater, regardless of the system you purchase. Always do extensive research into the companies you're considering. Pay special attention to accreditation, warranties and market experience. Ask for referrals.		Companies that are part of the Eskom DSM programme are reputable companies that have to comply with certain standards, in addition to adhering to the SESSA code of conduct. You will also receive cash back from Eskom if you get your solar geyser form one of these companies. To find out more about Solahart solar geysers and the collector panels we use, click here. To speak to a dealer in your area, click here. Dinner by candlelight Doing your part for the environment can be as simple as flicking a switch. WWF South Africa hopes that is exactly what one million South Africans will be doing on 28 March. Click here to read more. WWF South Africa recently announced their Switch Off to Switch On campaign. The campaign forms part of the global Earth Hour campaign. The aim of the campaign is to get one million South Africans to switch off their lights for an hour on Saturday, 28 March. According to an email distributed by WWF, 60 countries will be taking part in the initiative. Cape Town mayor Hellen Zille pledged her support for the campaign and even Table Mountain will be cloaked in darkness between 20:30 and 21:30 on the day. Sign up for the campaign on www.earthhour.org, and remember to plan a candlelit dinner for 28 March. Image of the Week This week's Image of the Week was taken by Melissa Griffin. To see more of her pictures visit http://missy-g.deviantart.com. Environmental Tip of the Week You might not think leaving your personal computer on overnight has anything to do with the state of the atmosphere, but you're wrong. Leaving a PC on every night consumes around 1000kWh of energy per year. That is the equivalent of 3 fridge/freezers over the same time period. Remember to shut down. To find out how your company can help, click here. To find out how Solahart solar geysers can help you reduce your carbon footprint, click here.