i) Solar-thermal power: Parabolic Mirrors focus sunlight on tubes filled with oil. The heated oil boils water in a heat exchanger, and the steam turns a turbine to create electricity. In the Mojave Desert in California, 1.5 million mirrors produced over 95% of the nation's solar electricity in 1995-96.
ii) Photo-voltaic technology is still largely experimental and costly to manufacture. Semiconductor cells convert sunlight directly into electricity. Current uses are generally restricted to irrigation pumps, billboard lights, pocket calculators, remote residential systems and other small-scale applications due to the cost of manufacture. However, Western Power has been building a solar power plant for Kalbarri, approximately 500 kilometres north of Perth, Australia. This system has an expected peak AC output of 20 kW.
It must be noted that regardless of power generation route, passive solar systems could be installed throughout the township and within industries to cut down on overall electricity consumption. In this case, the total electricity generated in the power plant would be an inadequate measure of usefulness unless the reduction in electricity consumption due to passive systems be taken into account. Passive solar methods include water heaters, effective window treatments and coverings, orientation of buildings and windows, and effective insulation.
Solar power plants are technically feasible, but they are still experimental, inefficient, and unable to meet most towns' demands. Photo-voltaic plants economically not feasible with current costs of manufacture. The dependence of solar power on climatic conditions means it must be backed up by a more reliable power generation route
Installation costs after manufacture of PV units relatively low, but very large tracts of land are required, which may raise land ownership issues and land costs, not to mention the very high costs of manufacture of photo-voltaic cells.
However, after installation, the cost of generation and maintenance is very low, and requires a very small workforce to manage the plant. The most attractive fact is that solar power plants harness a renewable, free energy source, and there is absolutely no waste and associated disposal costs. Unfortunately, current technology is still inefficient: today's water pumps and standalone supply systems produce approximately 0.108PJ per year. Studies around the world are working hard on this problem.
A major factor that must be considered with solar plants is geography: it needs reliable, long sunlight hours. Depending on town expansion trends and town climatic conditions, the plant may be far from consumers, which increases transmission costs, although naturally there are no transportation costs for fuel.
Go To Page: 1 2
