August 10, 2009
Electricity consumers facing supply disruption in the wake of power rationing can turn to solar and permanently bid farewell to Kenya Power and Lighting Company in three days, industry players say. The rationing plan that leaves large sections of the country without power for at least 72 hours a week began last Thursday and is expected to cut productivity in the economy by at least one quarter and increase job losses. Energy sector entrepreneurs are, however, responding to the crisis with solutions that analysts say could get a large number of consumers off the national grid, leaving enough room for a return to normal supply.Erratic weather In Nairobi, the alternative power supply revolution is being driven by solar energy providers who are promising long-term solutions to a crisis Kenya is expected to face in the next decade as it strives to develop new energy sources to meet growing demand. The crisis is rooted in the fact that nearly 70 per cent of electricity consumed in the country comes from hydro sources that are linked to the increasingly erratic weather patterns. Kenya has been an active market for solar systems for almost a decade, during which more than 150,000 units have been installed on a commercial basis.
An estimated 15,000 to 25,000 panels are installed yearly, says a report on renewable energy. Climacento Green Tech, a solar energy systems provider, says its solution can drastically reduce households' spending on energy by up to half and permanently get consumers off KPLC's roll. Globally, solar energy works well for most items except electric appliances that use an electric heat element. Climacento Green Tech says solar energy can and is now widely used to heat water as well as power other appliances that rely on a heat element.
For lighting, solar companies are installing panels, batteries, battery charge controllers and inverters that take a direct current and switch it back and forth to produce alternating current. It takes two days to fit a three bed roomed house that is already wired with a solar system. Although the solar panels would be enough to supply energy for lighting, or watching television, the company boasts of the ability to install other technology that can run appliances with heating elements more effectively than just solar panels.
Solar technology uses Standard Vacuum Tubes for water heating. Each tube consists of two glass tubes made from strong borosilicate glass with high chemical and thermal shock resistance. The outer tube is transparent allowing light rays to pass through with minimal reflection while the inner tube is coated with a special selective coating which features excellent solar radiation absorption and minimal reflection properties. To them the insulation properties are so good that while the tube inside might be 150 degrees hot, the outer tube is cold to touch. The tubes are able to absorb the energy from infrared rays that can pass through clouds.
Wind and low temperatures have less effect on the functioning of the tubes compared to flat solar panel collectors due to the insulating properties of the vacuum. This means that tube water heaters can perform well even in cold weather when flat plate solar panels perform poorly due to more consistent heat loss. Climacento also installs uncovered solar collectors it says are suitable for pool heating and rural areas. The uncovered solar collectors absorb the energy without either the glass of standard vacuum tubes or the thermal insulation of conventional solar panels.
The Italian manufactured panels made of a polypropylene compound conducive for absorbing power, can be rolled out and rewound making them portable and easier to install on any flat surface that catches enough sunlight. An average home (one to three bed-roomed) that does not utilize a fridge requires one panel (1m by ½ m) to supply it with energy for 8 hours daily. Three extra uncovered solar panels each providing 150watts of energy would be needed in a home that uses a fridge that remains on for 24 hours. Depending on the size, these kinds of panels range in cost from Sh44,000 to Sh75,000.
To be completely disconnected from KPLC, it would cost a three bed roomed home Sh250,000, inclusive of the panels, battery, charge controller and inverter required to generate the solar energy. That would be enough to supply energy for a television set, lighting and other appliances that don't use too much energy. An extra Sh50, 000 is charged to cater for appliances that consume a lot of energy such as washing machines and heating appliances. solar panels can last up to 25 years while batteries, charge controllers and inverters need to be serviced from time to time. That may spare homes from power blackouts and the risk of increased utility bills from KPLC. - African Laughter
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