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8.3.1 Describe how solar power can be harnessed for use in domestic products.
Consider active solar collection and various arrangements of photovoltaic cells (PVs), for example, small individual cells on portable equipment, use of PVs in sustainable building design for hybrid systems, incorporation of PVs into roof design to enhance the sustainability of buildings and also doubling as shelter over car parking areas.
8.3.2 Identify the advantages and disadvantages of solar power.
Consider set-up costs, running costs and maintenance, and continuity of supply.
8.3.3 Describe the design of a solar cooker.
A solar cooker is a simple machine that focuses the rays of the sun into a small area where they can be used to heat food. The sunlight, both direct and reflected, enters the solar box through the glass or plastic top then converting the sunlight into heat energy. This oven uses no power, making it easier to use in areas where electricity and fuel are scarce. Solar cookers work by using parabolic mirrors to concentrate the light at a focal point and heat up that point. This works because every parabola has a focal point at which all lines bouncing off the parabola will eventually reach. The box uses the greenhouse effect and traps the heat inside making temperatures high and sufficient enough for cooking.
8.3.4 Discuss the importance of solar cooking in sustainable development.
In some rural areas, for example, Nepal, traditional cooking methods involve the burning of biomass fuels and result in indoor air pollution, which is one of the four most critical environmental problems in developing countries. Women and children are more likely to be exposed to indoor air pollution as many women in developing countries spend hours per day cooking near an open fire often with a child strapped to their backs. Indoor air pollution can damage lungs, contributing to acute lower respiratory infections, chronic lung disease, lung cancer, asthma, low birth weight and heart disease. Collection of wood and other biomass fuels contributes to deforestation, with impacts on the water table.
Solar cooking is a different way to cook food by using natural solar energy rather than non-renewable resources. The purpose of this is to be useful to people, while simultaneously preserving the environment. A helpful video on this topic can be found at http://vimeo.com/7386533.
Another helpful link on this topic: http://cat.inist.fr/?aModele=afficheN&cpsidt=2936630
Energy and transport
8.3.5 Compare individual and mass transport systems for sustainable development.
For development in urban areas, mass transport systems are more likely and feasible. A shared vehicle is more efficient than a private vehicle, considering today's oversized cars and light trucks. It is always the green move for an individual to take existing mass transit over their cars, because the transit is running anyway, so there is no incremental cost for carrying one more passenger. USA Transit efficiency, portrayed in the picture below, can be made greener, reversing the trend of poor efficiency, but transit budgets are planned on decade scales. Ironically in Europe, transit is 2.5 times more efficient, and in Asia, 4 times more efficient, due to their more efficient vehicles.
Advantages to mass transit, other than energy efficiency, are:
Further Reading: http://www.templetons.com/brad/transit-myth.html
8.3.6 Discuss the barriers to transition from individual cars to mass public transport systems.
Consider convenience, flexibility, systems integration, for example, park-and-ride systems.
8.3.7 Identify the advantages and disadvantages of small-scale and large-scale wind energy generating plants.
Consider small-scale wind energy generating systems, for example, for isolated houses, and large-scale wind energy generating systems for communities and feeding into the national grid.
When making a large or small scale wind energy farm, certain advantages and disadvantages can be found.
8.3.8 Discuss the issues associated with the siting of large wind farms.
Consider impacts on the environment; noise and visual pollution; community lobbying and “not in my back yard” (NIMBY); who pays for the developments; onshore and offshore developments.
Who pays for the developments
Noise and visual pollution; community lobbying and “not in my back yard” (NIMBY)
Onshore and offshore developments
Numbered list and italicised paragraphs are excerpted from Design Technology: guide. Cardiff Wales, UK: International Baccalaureate Organization, 2007.
Images are clickable links to its location.