KS4: Unit 2 Topic 7.2: Renewable sources of energy. This worksheet will help explain the advantages/disadvantages of different types of renewable sources of energy you will need to understand for your exam. Lesson 2: Wind Power: 1.What is the name given to a group made up of single turbines working together? 2.What are the two main complaints or concerns of wind turbines? 3. Why is it more expensive to site wind turbines at sea? 4. Although it is more expensive what are the advantages of placing turbines at sea, further away from people? Advantages of wind power: Disadvantages of wind power: Modern wind turbines such as the Vestas NM82 are extremely tall. The diagram below compares a Vestas to the Eiffel Tower. The Eiffel Tower stands at 1000 feet whilst the Vestas is at least a third of its height. They are massive structures in their own right. Being so large they are capable of producing more electricity than has been produced by previous wind generators (turbines). Each Vestas can produce enough electrical power to provide the needs of 475 standard sized homes. However, the cost of construction and installation is near £ ($ ). It takes along time for the wind turbine to pay back its cost of manufacture. Wind power is generated by moving air. As the sun heats the land, the air above also warms and rises. Cold air then replaces the rising air. This creates the winds that we feel most days of the year. The diagram below shows how this ‘system’ works. Air tends to warm at a faster rate over land because the land retains its heat. Over the sea the air warms more slowly as heat by the sun is slowly cooled by the cold water. If you visit the seaside or coastal area you will probably find that the weather is more breezy or windy than inland. This is because the warm air rises over the land and cold air over the sea replaces it. Name: Group: Teacher:

Solar Power: KS4: Unit 2 Topic 7.2: Renewable sources of energy. This worksheet will help explain the advantages/disadvantages of different types of renewable sources of energy you will need to understand for your exam. Lesson 2: 1.Solar panels are quite expensive to manufacture and at the moment they are not widely used in countries such as the UK. Why do you think this is so? 2.Describe one use of photovoltaic cells within the third world or remote areas: 3.Photovoltaic cells are often used as a back up store of energy why do you think is? Advantages of solar power: Disadvantages of solar power: Modern solar panels are a combination of magnifying glasses and fluid filled pipes. The solar panel seen opposite (left) has a glass front which is specially made to focus the power of the sun on pipes behind it. The pipes carry a special fluid that heats up rapidly. They are painted black to absorb the heat from the sun. The silver reflective surface behind the pipes reflects sun light back, further heating the pipes and the fluid they contain. The reflective surface also protects anything behind the solar panel (such as a roof). The heat produced in the pipes is then used to heat a tank of water. This saves using electricity or gas to heat up the water tank. Often solar panels (sometimes called collectors) are placed on the roof of a building (shown right) where the sun’s rays are not blocked out by trees or other obstructions. Solar ________ is energy from the ____ and without its presence all _____ on Earth would end. Solar energy has been look upon as a serious source of energy for many year because of the _____ amounts of energy that are made _______available, if harnessed by modern ____________. A very simple example of power from the sun can be seen by using a ___________ glass to ______ the suns rays onto a piece of paper which would eventually burst into ________. Vast technology sun power freely life flames magnifying focus Name: Group: Teacher: Photovoltaic cells look similar to solar panels but they work in a different way. Solar panels are use to produce hot water or even steam. Photovoltaic panels convert the sunlight directly into electricity. A typical example of a device powered by photovoltaic cells is a solar powered calculator. This type of device only needs a small amount of electrical power to work and can even be used in a room with artificial light (bulbs / fluorescent light). Although we see photovoltaic cells powering small devices such as calculators they have a more practical application especially in the third world. Photovoltaic cells have been developed that will provide electrical power to pump drinking water from wells in remote villages. The diagram opposite right is a basic photovoltaic cell. The blue represents the main material, silicon. The black round and irregular shapes represent the impurities of boron or phosphorous. As the sun/light strikes the cell the impurities free up electrons which ‘bounce’ around at incredible speeds. This creates an electrical charge.

KS4: Unit 2 Topic 7.2: Renewable sources of energy. This worksheet will help explain the advantages/disadvantages of different types of renewable sources of energy you will need to understand for your exam. Lesson 2: Discuss whether you think bio-fuels have a place as an alternative energy source in our society? (6marks) Use additional paper where needed, these key word may help: conventional fuel polluting coal and oil enhancing alternative energy reducing nuclear waste productive recycling of waste ____________________________________________________________________________________________________________________________________________________________________ Bio-fuels are fuels that can be used to replace polluting fuels such as petrol, without damaging the environment. A fuel such as ‘willow’ is a good example. Willow grows quickly (as it is a softwood) on most land and it can be harvested like any agricultural crop. Whilst it is growing it absorbs carbon from the atmosphere, reducing the amount of pollution in the atmosphere. When it is burned as a fuel it releases back into the atmosphere, only the carbon it absorbs whilst growing. This means that it is a ‘green’ fuel. It does not increase the amount of pollution in the atmosphere, in fact during its life cycle it reduces these damaging gases. Using biomass to generate heat: Name: Group: Teacher: 3. The willow chippings are fed into a boiler and burned to produce heat. This replaces gas, oil or coal as an energy source. Water is heated and pumped around the building in the same way as in most heating systems. 2. The willow is processed. Each trunk is fed through a ‘chipping’ machine - the chippings are collected and packaged for distribution. 1. Willow grows quickly and is harvested. The wood is stored until transported to a processing plant for ‘chipping’ Using bio-fuel to power transportation: Methane is a gas that can be collected and burned as a fuel. This gas is produced by animal waste, as it decays. Some farms collect animal waste and store it in tanks, processing the collected gas. The resulting methane gas is then compressed in tanks/containers and distributed to customers. It can be used to heat cookers, houses and even to power car engines 1. The cycle starts with animals on a farm, grazing and producing waste. 2. The waste is collected on a regular basic. It is transferred to decomposing tanks and the methane gas is collected and stored. 3. Gases are stored in tanks and transferred to tankers. It is transported to customers or compressed and transferred to smaller cylinder tanks. 4. The methane gas can be used for household appliances such as cookers. It can also be used as the fuel for cars specially adapted to burn methane gas rather than petrol. These vehicles are less polluting although their speed and acceleration are reduced. Biomass/Bio-fuels: