 |
menu powered by Milonic
|
|
|
menu powered by Milonic
|
| log in |
| You are here: | Comments and remarks to Wim Jonker Klunne |
|
Aquaculture Alternative Energies, headed by Peter Grossmann, secured the licence agreement for the technology of hemispheric design that was developed by German engineer Herbert Beuermann in Spain over 20 years. What sets the technology apart from conventional rotor windmills with blades is that it is based on hemispheres — similar to wind-speed measuring systems on boats — turning in ball bearings together with a patented ring generator around a vertical steel tower. Traditional windmills are fast runners, with speeds of up to 15 times the wind speed, prohibiting their use at heights of 100m. Hemispheres, on the other hand, are slow runners, turning at a speed of 0,75 of wind speed, or wind speeds of up to 50m a second, which means they can be used at optimal heights of up to 500m, Grossmann explains. For the uninitiated, this may sound like obscure science speak. But the hemispheric ability to take advantage of higher-altitude wind speeds underpins the commercial viability of the technology. Conventional wind power technology’s commercial potential is limited to small-scale use. The conventional rotors do not perform optimally because of their dependence on wind directions, while the technology itself means the equipment takes a tremendous amount of strain, is susceptible to changing wind speeds and presents huge maintenance costs. And they are noisy. But the hemisphere technology can withstand hurricanes, and maintenance costs are relatively low. The hemispheres of the new technology can be perched on tall towers, taking advantage of truly powerful wind speeds found at higher altitudes. Wind speeds at 300m or higher have the potential to supply the energy needs of the entire world population fifteenfold, and this can be achieved without burning finite fossil fuels, or poisonous emissions being pumped into the atmosphere. Applications of the new technology can vary in scale. Rooftop-bound energy islands producing between 12kWh and 625kWh a day are the smallest, and can meet the energy needs of individual households, hospitals or small housing estates. But Alternative Energies SA is also looking at building land-based hemisphere towers with power-generating capacity of up to 15MW. These wind-power plants, which could have solar modules attached to optimise energy output with 45% solar energy, could be built on land or offshore on floating platforms to optimise wind utilisation. The technology does not come cheap. The rooftop unit for household use will set you back R150000. But compared with conventional power-generating methods currently used on a large scale, Beuermann’s technology presents a compelling alternative from a costs perspective. The development cost of a new coal-fired station with generating capacity of 1600MW, such as the Alpha station mooted for development at Lephalale in Limpopo, will set the government back R27bn. To develop a nuclear plant with the same generating capacity, those capital costs rise to a stunning R37bn. By comparison, the development of a 1600MW wind farm, consisting of 120 wind towers with 12,5MW output each, would cost a relatively modest R24bn. The comparative production costs of these technologies also tip the scale in favour of hemispheric wind technology. Grossmann calculates it costs 38c/kWh to generate nuclear power, and coal-fired power comes in at between 30c and 40c/kWh. But with hemispheric wind technology generated by a 260m wind tower, the cost will average 18c/kWh generated. And, says Grossmann, wind power comes without hidden costs, such as transport and storage of nuclear waste and carbon capture, variable raw material input costs associated with finite resources and costs associated with possible green taxes. If a mooted carbon tax is implemented, the operating costs of coal-fired power stations would rise — with increments of 16% per 1% in carbon tax levied. The technology has been tested. The energy islands will be rolled out commercially within eight months, while the wind towers will be available within 18 months. Grossmann says Johannesburg City Power is interested in the technology. The company, in which the Umkhonto we Sizwe military veterans association has a 40% stake, is also set to meet Eskom, which has indicated it wants to partner private sector companies to commercialise wind power. Additional information: News date: 13/06/2007 |
|
|