2. What is Solar Power Solar power is the technology of obtaining usable energy from the light of the Sun. Where solar radiation is high enough it can be used as a genuine replacement to fossil fuels. It can also be used where other energy supplies are absent such as in space. Its application is spreading as the environmental costs and limited supply of other power sources such as fossil fuels are realized.

3. Uses of Solar Energy Solar energy is currently used in a number of applications: Electricity Generation – Uses photovoltaics to turn energy from sun into electricity. Heat – (hot water, cooking, building heat) (Sea water desalination)

4. Types of Solar Technologies Many technologies have been developed to make use of solar radiation. Some of these technologies make direct use of the solar energy (e.g. to provide light) while others produce electricity. Passive Solar – (sunlight –> useable heat for air ventilation) Water heating – Different systems to heat domestic water or large spaces. A solar box cooker traps the sun's energy in an insulated box; such boxes have been successfully used for cooking, pasteurization and fruit canning

5. Photovoltaics – (solar cells) Generate electrical energy from sunlight. Solar thermal electric power plants - Solar thermal energy can be focused on a heat exchanger, and converted in a heat engine to produce electric power or applied to other industrial processes. Solar Ponds – Pools of water with three layers all with different densities to avoid convection (transfer heat to ground) which collects and stores heat energy. A solar cooker

6. Theoretical annual mean insolation, at the top of Earth's atmosphere (top) and at the surface on a horizontal square meter.

7. Availability of Solar Power The amount of solar energy intercepted by the Earth every minute is greater than the amount of energy the world uses in fossil fuels each year. Tropical oceans absorb 560 trillion gigajoules (GJ) of solar energy each year, equivalent to 1,600 times the world’s annual energy use. Annual photosynthesis by the vegetation in the United States is 50 billion GJ, equivalent to nearly 60% of the nation’s annual fossil fuel use.

8. Advantages of Solar Energy The amount of sunlight reaching the earth is plentiful considering the average needs of humans Pollution free during use Solar electric generation is economically competitive where grid connection or fuel transport is difficult, costly or impossible. Grid connected solar electricity can be used locally thus minimizing transmission/distribution losses Once the initial capital cost of building a solar power plant has been spent, operating costs are low when compared to existing power technologies

9. Disadvantages of Solar Energy Solar cells are costly, requiring a large initial capital investment. Creating barriers for LEDC’s. To get enough energy for larger applications, a large number of photovoltaic cells is needed. This is both capital and land intensive. It can only be used in transport by a complicated electrolysis process. (capital expensive) Solar cells produce DC which must be converted to AC when used in currently existing distribution grids. This incurs an energy loss.

10. What is Next????? It is clear that industrialised nations share a need for electricity and solar can be increasingly used as a clean alternative to fossil fuels. The Solar powered car has been the engineers dream for the last 20 years.