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Natural Sciences

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Lungile Nkosi

This document discusses renewable sources of energy, including sunlight, wind, and hydropower. It provides details on how energy from each source can be harnessed and used. Specifically, it explains that sunlight can be used to produce electricity via photovoltaic panels or solar water heaters, wind energy is captured by wind turbines to generate electricity, and hydropower harnesses the kinetic energy of moving water through dams to power generators.

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ENERGY AND CHANGE RENEWABLE SOURCES OF ENERGY
ENERGY energy is a property of matter. It can be transferred between objects, and converted in form. It cannot be created or destroyed. Energy exists in many different forms. Examples of these are: light energy, heat energy, mechanical energy, gravitational energy, electrical energy, sound energy, chemical energy, nuclear or atomic energy and so on. These forms of energy can be transferred and transformed between one another.
RENEWABLE SOURCE OF ENERGY A renewable source of energy is energy from a source that is not depleted when used, such as wind or solar power. Examples of renewable sources of energy: Sunlight Wind Hydropower
SUNLIGHT Sunlight can be used to produce electricity and to heat up water: PHOTOVOLTAIC (PV) ELECTRICITY Produces energy from the sun. PV panels only produce electricity during daylight hours. We therefore need a storage system to be able to use the energy at night or when it is cloudy Lead/acid batteries are the most common storage devices used with PV systems VERY EXPENSIVE
SOLAR WATER HEATING (SWH) A functional Solar Water Heater (SWH) must collect the suns energy and store enough hot water for desired use The SWH comprises a collector and a storage tank The SWH may be of direct design or indirect design
Some examples of SWH models
PV CELLS AND MODULES
WIND How do we Generate Electricity from Wind Energy? The movement of air is used to propel blades. These blades then turn in the wind and along with it an axle that is attached at the centre of the blades. The axle caries over the energy to a gearbox and finally to the generator where the electricity is generated. (Eskom, 2016)
WIND TURBINES
HYDROPOWER Hydro-power is energy generated by water moving downward due to gravity. Electricity is generated in Hydro-power plants. There are two systems in operation in South Africa: conventional hydro, and pumped storage systems. Power generation from these plants is limited as they rely on the water level of the dams or rivers which in turn is affected by the rainfall in its catchment area (Eskom, 2016).
Pumped storage system

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Natural Sciences

  • 2. ENERGY energy is a property of matter. It can be transferred between objects, and converted in form. It cannot be created or destroyed. Energy exists in many different forms. Examples of these are: light energy, heat energy, mechanical energy, gravitational energy, electrical energy, sound energy, chemical energy, nuclear or atomic energy and so on. These forms of energy can be transferred and transformed between one another.
  • 3. RENEWABLE SOURCE OF ENERGY A renewable source of energy is energy from a source that is not depleted when used, such as wind or solar power. Examples of renewable sources of energy: Sunlight Wind Hydropower
  • 4. SUNLIGHT Sunlight can be used to produce electricity and to heat up water: PHOTOVOLTAIC (PV) ELECTRICITY Produces energy from the sun. PV panels only produce electricity during daylight hours. We therefore need a storage system to be able to use the energy at night or when it is cloudy Lead/acid batteries are the most common storage devices used with PV systems VERY EXPENSIVE
  • 5. SOLAR WATER HEATING (SWH) A functional Solar Water Heater (SWH) must collect the suns energy and store enough hot water for desired use The SWH comprises a collector and a storage tank The SWH may be of direct design or indirect design
  • 6. Some examples of SWH models
  • 8. WIND How do we Generate Electricity from Wind Energy? The movement of air is used to propel blades. These blades then turn in the wind and along with it an axle that is attached at the centre of the blades. The axle caries over the energy to a gearbox and finally to the generator where the electricity is generated. (Eskom, 2016)
  • 10. HYDROPOWER Hydro-power is energy generated by water moving downward due to gravity. Electricity is generated in Hydro-power plants. There are two systems in operation in South Africa: conventional hydro, and pumped storage systems. Power generation from these plants is limited as they rely on the water level of the dams or rivers which in turn is affected by the rainfall in its catchment area (Eskom, 2016).