HOMEWORK RENEWABLE ENERGY <ul><li>SOLAR ENERGY </li></ul><ul><li>Solar energy means using the energy of sunlight to provide electricity, to heat water, and to heat or cool homes, businesses or industry. </li></ul><ul><li>Passive Solar Heating </li></ul><ul><li>Some buildings are designed for passive solar heating , and do not need a solar collector. passive solar heating is when opportunities are made for the sun to shine into the building to warm it up. The walls and floors are made with materials that absorb and store the sun's heat, and they heat up during the day and release the heat at night. This is called direct gain . </li></ul>Photovoltaic solar cells directly convert sunlight into electricity. Solar energy is absorbed by collector, then sunlight is focused with mirrors to create a high-intensity heat source to produce steam or mechanical power to run a generator that creates electricity.
HIDROPOWER ENERGY <ul><li>Hydropower is electrical energy derived from falling or running water. The water pressure that is created by water is used to turn the blades of a turbine. The turbine is connected to a generator, which converts the mechanical energy into electricity. </li></ul><ul><li>1. Dam </li></ul><ul><li>A barrier built across a watercourse to hold back the flow of water and create a reservoir. The reservoir that is formed is, in effect, stored energy. </li></ul><ul><li>2. Penstock </li></ul><ul><li>A pipeline used to convey water, under pressure, from the reservoir to the turbines of a hydropower plant. </li></ul><ul><li>3. Turbine </li></ul><ul><li>A machine that is turned by the force of the fast moving water pushing against its blades. Turbines convert the kinetic energy of the water to mechanical energy. </li></ul><ul><li>4. Generator </li></ul><ul><li>Connects to the turbine and rotates to produce the electrical energy. </li></ul><ul><li>5. Transformer </li></ul><ul><li>Converts electricity from the generator to usable voltage levels. </li></ul><ul><li>6. Transmission Lines </li></ul><ul><li>Conduct electricity from the hydropower plant to the electric distribution system. Transmission line voltages are normally 115 kilovolt or larger. </li></ul>
BIOMASS ENERGY <ul><li>Biomass refers to renewable energy sources from plant material.The conversion of biomass energy to electrical and mechanical energy is part of a process called cogeneration. Other agricultural industries use the plant waste of their industry as </li></ul><ul><li>the biomass energy source, such as rice husks in the rice industry. </li></ul><ul><li>Green waste is another source of biomass energy consisting of </li></ul><ul><li>council garden waste and wood waste left over from pruning trees. </li></ul><ul><li>This type of biomass is usually transported to a processing plant, </li></ul><ul><li>where it passes through a grinding machine and over screens to </li></ul><ul><li>sift out any dirt and other contaminants. </li></ul><ul><li>The different types of biomass can also be blended to create a </li></ul><ul><li>fuel blend, and then placed in a fuel storage bin where it is then </li></ul><ul><li>supplied to the boiler. </li></ul>
<ul><li>WINDNESS ENERGY </li></ul><ul><li>A wind turbine is a machine made up of two or three propeller-like blades called the rotor. The rotor is attached to the top of a tall tower. As the wind blows it spins the rotor. As the rotor spins the energy of the movement of the propellers gives power to a generator. There are some magnets and a lot of copper wire inside the generator that make electricity. </li></ul><ul><li>Because winds are stronger higher up off the ground, wind turbine towers are about 30 metres tall to allow the rotor to catch more wind energy. The turbines are built with a device that turns the rotor so that it always faces into the wind. </li></ul><ul><li>Just one wind turbine can generate enough electricity for a single house or the electrical energy to pump water or to power a mill which grinds grain. The electrical energy can also be stored in batteries. </li></ul><ul><li>Wind farms </li></ul><ul><li>Wind farms are places where many wind turbines are clustered together. They are built in places where it is nearly always windy. The electricity that is generated at a wind farm is sold to electricity companies that provide the electricity to people living in cities and towns </li></ul>
GEO-THERMAL ENERGY <ul><li>The term geothermal comes from the Greek geo, meaning earth, and therme, meaning heat, thus geothermal energy is energy derived from the natural heat of the earth. The earth’s temperature varies widely, and geothermal energy is usable for a wide range of temperatures from room temperature to well over 300°F. For commercial use, a geothermal reservoir capable of providing hydrothermal (hot water and steam) resources is necessary. Geothermal reservoirs are generally classified as being either low temperature (<150°C) or high temperature (>150°C). Generally speaking, the high temperature reservoirs are the ones suitable for, and sought out for, commercial production of electricity. Geothermal reservoirs are found in “geothermal systems,” which are regionally localized geologic settings where the earth’s naturally occurring heat flow is near enough to the earth’s surface to bring steam or hot water, to the surface. Examples of geothermal systems include the Geysers Region in Northern California, the Imperial Valley in Southern California, and the Yellowstone Region in Idaho, Montana, and Wyoming. </li></ul>