RENEWABLE ENERGY FOCUSING ON SOLAR ENERGY

NON-RENEWABLE ENERGY

NATURAL GAS - usually is methane gas and piped into homes/ buildings fur heating, cooking, washing or drying - cleanest burnt fossil fuel

PETROLEUM OR OIL - black liquid formed below earths surface - in order to be used it is refined to make gasoline and the byproducts are used in rubber, fertilizers textiles, paints, etc.

COAL - more abundant fossil fuel - mined by underground or strip mining

RENEWABLE ENERGY

WOOD Wood - ‘poor person’s oil’ being used by 50-60% of the world for basic energy needs - huge contributor of carbon dioxide

HYDROELECTRIC - collected behind dams and creates electricity by turning turbines - degree of power generated decided by amount of water and distance it falls - ocean tide underwater windmills

GEOTHERMAL - Energy from the heat deep within the Earth - Shows itself through geysers

BIOMASS - this is garbage, manure, septic tank sludge, pond-bottom muck, that produces methane - same as methane of natural gas but this is renewable

NUCLEAR - slitting of uranium atoms which releases tremendous amount of heat energy - produces electricity

WIND - unequal heating of the earths surface creates wind which can be converted into mechanical and electrical energy - Energy can be used to drive pumps or generate electricity

SOLAR ENERGY - sun is 93 million miles away yet is the primary source of all energy on earth - sunlight created fossil fuels long ago, runs the water cycle and unevenly heats earth producing wind energy - Solar energy used to cook food, heat water and generate electricity - Cleanest energy source of all renewables

CONSUMPTION BREAKDOWN World Average of Renewable Use: 8%

HISTORY OF SOLAR ENERGY - Used to by clothing, animal skins - Preserve meat, dry crops - Evaporate sea water to produce salt Around 500BCE Greek cities were planned to position buildings so that sunlight entered them in winter, but not in summer. Heavy building materials were used to retain the heat and buildings built together to shelter from the wind. - Greenhouses were built to grow vegetables

SURFACE RECEIVES 47% OF TOTAL SOLAR ENERGY THAT REACHES EARTH

HEATING LIVING SPACES Passive Solar Trombe Wall Passively heated home in Colorado

HEATING LIVING SPACES A passively heated home uses about 60-75% of the solar energy that hits its walls and windows. The Center for Renewable Resources estimates that in almost any climate, a well-designed passive solar home can reduce energy bills by 75% with an added construction cost of only 5-10%. About 25% of energy is used for water and space heating. Major factor discouraging solar heating is low energy prices.

POWER TOWERS Power tower in Barstow, California.

ADVANTAGES OF SOLAR - running costs are low - no carbon dioxide emissions which contribute to GHG effect - no sulphur dioxide emissions which cause acid rain - Is easy to set up in remote areas - can charge batteries to provide on demand electricity

DISADVANTAGES OF SOLAR - Initial cost to get solar cells is high - Output depends on weather conditions and time of day - large areas of land (or roofs) are required - Many solar panels are needed to produce that of a power station

FINAL THOUGHT Argument that sun provides power only during the day is countered by the fact that 70% of energy demand is during daytime hours. At night, traditional methods can be used to generate the electricity. Goal is to decrease our dependence on fossil fuels. Currently, 75% of our electrical power is generated by coal-burning and nuclear power plants. Mitigates the effects of acid rain, carbon dioxide, and other impacts of burning coal and counters risks associated with nuclear energy. pollution free, indefinitely sustainable.