1. Specification section 7.2

2. What do you need to learn? The applications and advantages/ disadvantages of using the following renewable sources of energy: Wind energy using turbines and wind farms Solar energy using solar cells and photovoltaic cells Biomass converted into biofuels for transportation Introduction video

3. Wind energy using turbines and wind farms Wind is converted into electricity using turbines. How does this happen? 1.the wind turns a rotor generating mechanical energy 2. it is then converted into electrical energy using a generator. Turbines normally need wind speeds above about 9 miles per hour to allow them to start generating electricity 7.2 Renewable sources of energy Videos Using wind to produce electricity Wind farms

4. Solar energy using solar cells and photovoltaic cells Sunlight is a renewable energy source. Solar panels convert sunlight into usable energy. Solar thermal panels use sunlight to heat water for washing and heating but solar photovoltaic (PV) panels convert sunlight into electricity. Britain's climate is unsuited to large-scale solar electricity generation so it is typically used by individual businesses, homes and even devices such as road signs to generate energy for their immediate needs. Solar panels are most effective in direct, intense sunlight so the UK isn't best suited to this method of energy. The carbon footprint of solar PV is small and shrinking, as the materials used in PV panels are increasingly being recycled.carbon footprint of solar PV However, despite various Government tariffs and incentives, solar power currently makes only a modest contribution to the UK's energy mix and is expected to contribute less than 1% to the UK renewable energy mix by 2030. 7.2 Renewable sources of energy Video 1: Spanish case study

5. Biomass converted into biofuels for transportation Biomass is organic material derived from plant or animal matter: for example, sawmill residues and parts of trees unsuitable for timber, or fast-growing crops grown specifically for the process, such as willow. It can also be sourced from the residues of food crops, such as straw, husks and kernels. Biomass can be burned to provide energy either for space heating, water heating, or to produce steam to drive turbines and generate electricity. The amount of carbon dioxide (CO 2 ) saved by using biomass instead of fossil fuels can vary depending on the emissions associated with growing, harvesting and transporting the crop, amongst other elements – but burning biomass is generally still better for the environment than burning fossil fuels. Biofuels come from Biomass and can be used to run vehicles. Brazil, for example, has the highest proportion of vehicles used to run on biofuels or from fuel cells. 7.2 Renewable sources of energy Videos What is Biomass What are biofuels and how are they made?What are biofuels and how are they made?