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Tidal Power The tide goes in and out into high and low tide everyday. Tidal power is harnessing this movement and using it to create power. Tidal Power is basically the same as hydro power (using dams) except the dams are built much, much bigger and is built across a river estuary. The tides movements are used to turn a turbine which then turns a generator and produces electricity. Because tides will continue to ebb and flow tidal energy is considered a renewable source. Some of the Advantages of tidal power are: • Once you build the dams the tidal power is practically free, it is not expensive to maintain, it needs no fuels and does not produce any waste (it doesn’t contribute to the green house effect • Tides are predictable, and so it produced electricity reliably Some disadvantages are: • Expensive to build • Effects a wide area • Environment is changed many miles both upstream and downstream effecting wildlife • Few suitable sites • They only provide power for 10 hours each day (when the tide is actually moving) Nuclear Power Nuclear power plants also known as atomic power plants are factories where electric power is being produced by nuclear reactors. They produce about 11% of the worlds energy needs, and are very clean and efficient to operate. Nuclear power plants use reactors made from elements with unstable bonds (for example uranium and plutonium). Nuclear fission makes heat which heats water, which makes steam which turns a turbine which turns generators which then produces nuclear power. In order to obtain uranium (which is one of the least abundant elements on earth) for the power plant, extensive mining is required. Nuclear energy from uranium is not a renewable resource. Some disadvantages of nuclear power are: • Very little waste is produced however it is very dangerous and must be sealed and buried to allow for the radio active elements to decay which takes a very long time, long past any of our lifetimes, possibly millions and millions of years. • A lot of money has to be spent on safety as a nuclear accident can be a major disaster • Mining of uranium and other elements can have sever environmental impacts such as polluting of soils and waters Some advantages of nuclear power are: • Not expensive to make • Produces huge amounts of energy from a small amount of fuel • Reliable • Does not contribute to the greenhouse effect Hydro electricity Hydro electric power stations produce about 20% of the world’s electricity. Large dams are built on rivers where water can be contained or released to ensure a reliable supply of electricity. Water from the dam is released to flow through a turbine; the turbine then turns a generator which then produces electricity. Because water constantly moves in a global cycle, hydroelectric power is considered a renewable resource. Some advantages of hydro electric power are: • That once the dam is built the energy is almost free • There is no waste or pollution produced • It is very reliable • Electricity can be generated constantly • These power stations can get to full power very quickly, by storing the water above the dam peaks in electrical demands can be met with quickly Some disadvantages of hydro electric power are: • Expensive to build • Dams flood a large area upstream eliminating wildlife habitat • Water quality and quantity downstream can be effected • Finding a suitable site can be difficult (most suitable sites have already been developed) Fossil Fuels Fossil Fuels provide 66% of the world’s electrical power. Fossil fuels are formed over millions of years from the remains of plants and animals that died and were eventually covered up by dust, dirt and rocks, heat and pressure eventually change these fossils into coal, oil and natural gas. Fossil fuels are considered non renewable resources since they take many millions of years to form. Coal is mostly used in power plants, in order to obtain coal it must be mined. In order to obtain oil we must find natural reservoirs by drilling deep into the earth and when find it, it must be pumped up by oil rigs. Then the crude oil must be refined into other products such as gasoline, diesel fuel, and oil to burn in power plants to make electricity etc.). Natural gas is lighter than air and highly flammable it is usually found near underground petroleum deposits; it is then pumped up and sent out in large pipelines. Natural gas can be used for cooking, hot water heating, drying clothes and heating your home. In order to turn the fossil fuels into electrical power first we must burn the fuel, to heat the water to make the steam which turns the turbines which then turns the generators which then makes electrical power to be sent around the country. One of the main disadvantages of using fossil fuels to create energy is that burning fossil fuels causes carbon dioxide which contributes to the green house effect. Other disadvantages are: The mining of coal can have a sever environmental impact as well as being difficult and dangerous. And burning of coal can produce sulfur dioxide which can cause acid rain. Some of the advantages of using fossil fuels to create energy are that it is not expensive, transporting the fossil fuels to the power stations is fairly easy and large amounts of energy can be generated. The power stations can be built almost anywhere (as long as you can get the fuel there). We are all used to filament light bulbs however high efficiency florescent lighting can last 8 times longer than incandescent lights and they use less then ¼ of the power. Florescent lights (which have been around for more then 20 years) now come in many shapes and sizes and are ideal for most rooms of the house. Make sure to check the packaging to be sure the type you buy can be used with a dimming switch and in an enclosed fixture. Prices for these bulbs range from $4-$15 but you can expect to save about $25-$30 a bulb in energy savings over their lifetime. It is important to dispose of these lamps properly when you are finished with them since they do contain small amounts of mercury. The hot water that we use for showers can be the largest contributor to the overall hot water usage in the home (up to 25%). A 5 minute shower can use 95 liters of hot water with a regular (conventional) showerhead, however you could save more than one half of this if you used a low-flow showerhead. By forcing the water through a very small hole which makes the flow of the water stronger and finer we use much less water. Every low-flow showerhead has a turn off valve that you press when you want to soap up so that no water comes out of the showerhead (letting you save even more money and water). The average household (3 people) have 1,000 showers per year (with the conventional showerhead) each about 10 minutes long, 190 200 liters would be used annually. If low flow showerheads were used and each shower was 10 minutes long, the amount of hot water used would be about half (95 000) saving the house $175 - $190 in savings each year. I got this information in the BChydro site. |