Four basic types of devices have emerged to produce wave power.
An oscillating water column, which acts as a piston that, drives air through single, multiple turbines or a single Wells Turbine this is connected to an electrical generator.
Wave capture devices, which channel a wave into a raised reservoir, from there the trapped water flows back down to sea level through a turbine generating electricity.
Wave profile devices (for example, Salter Ducks), which float on or near the surface and take energy from the impinging wave as it passes
And point absorbers, which take energy from a radius around a point, and are small, compared to the length of a wave.
Wind Power
This power is found in the energy of the wind and is usually converted into electricity. As with most renewable energy sources, the sun powers it. One or two percent of the sun absorbed by the earth this is changed into wind by the mechanisms of convection and coriolis forces. There are about 10 gigawatts of wind power devices in the world. The United States makes 17% of this total. Germany and Denmark have the highest in Europe. The most used wind turbines are much like the traditional windmill. The wind turbine blades work in a similar way to an airplane wing using lift instead of drag mechanisms. Wind turbines make about 750 kilowatts of energy; newer models can now produce up to 2 megawatts of energy. The main parts of a wind turbine are the rotor that drives a gearbox that then after a while drives an electrical generator.
Solar Energy
Is produced in the sun as a result of nuclear fusion reactions. It’s transmitted through space by electromagnetic radiation in quanta of energy called photons, which interact with the Earth’s atmosphere and surface. Passive solar systems capture and use solar energy without the aid of mechanical or electrical devices. Most buildings can be regarded as simple passive solar systems, taking advantage of direct gains of solar radiation through windows or skylights. As the solar radiation strikes floors, walls, and other objects within the room it is converted to heat. A good building design will use this to advantage so the house will remain warmer though out the winter and summer periods. The only commercial power stations in use to day are the solar Electric Generating systems located in California. These trap the sun’s energy into a tube containing heat transfer fluid the fluid is raised to very high temperatures to make superheated steam.
Hydro-Power
Hydro-power is made by the fall of water from a higher to a lower level. Hydro-power is extracted from waterwheels or hydraulic turbines and is a natural source. Hydro-power is available from any where, where there is a steady flow of water. To develop hydro-power on a large scale requires dams, by pass canals and storage lakes as well as large turbines and electric generating equipment. One of the disadvantages of using hydro-power is that it is very expensive to make and produce. Coal and oil are much cheaper there fore hydro-power is not as widely used as it could be if it was cheaper.
The use of water power began in ancient Greece where water wheels where used for the milling of corn, but the availability of cheap human and animal slaves prevented it from becoming widely used until the 12th Century. During the middle ages large wooden water wheels where developed with about a 50 hp power out put. Modern large scale water power owes its development to British civil Engineer John Smeaten who built the first water wheels from cast iron. In the early 19th Century water power played an important part in the industrial revolution it helped the growth of textile, leather and machine shop industries this was due to the lack of coal available at that time. By the middle of the 19th Century coal had been made on a larger scale and had become cheaper so water power was used less and less. The earliest hydroelectric plant was constructed in 1880’s in Northumberland this was to be the start of the rebirth of the water power the production of the electric generator also helped the rebirth. In the 1920’s hydroelectric plants accounted for 40% of electricity in the USA. The plants depend on a large water storage reservoir up stream of a dam where water flow can be controlled. Water flows through conduits, which are controlled by turbine gates to adjust the flow rate in line with the power demand. The water then enters the turbines and leaves them through the tailrace. The power generators are mounted directly above the turbines on vertical shafts. The design of turbines depends on the available head of water, with Francis turbines used for high heads and propeller-turbines used for low heads. Canada gets about 60% of their power from hydroelectric power. The world gets about a quarter of its power from hydroelectric sources. The leading countries are Norway 99% and Brazil 96%. Hydropower accounts for about 85% of the renewable energy sources in Europe. By 2010 the amount of hydro power used is hoped to increase from 165 to 185 billion kWh per year.
The are some advantages of using Hydro power the first and most obvious is that its clean for the environment and is a renewable energy source. It also provides Jobs workers will need to build dams. The disadvantages are that in the hotter countries such as Kenya where there is not much rain it may be harder to use such a power supply that depends on water.
In conclusion there are many different energy sources instead of fossil fuels that are a lot cleaner as well. You may be asking why don’t we use more of them this is simply because fossil fuels are much easier to produce.
