Project3
-
Upload
marinavegaortega -
Category
Technology
-
view
261 -
download
1
Transcript of Project3
Energy
Kinetic energy Gravitational potential energy
Thermal or caloric energy Chemical energy
Electric energy Light energy Sound energy
Energy is understood as a capacity to do something:
Kinetic energy Energy produced by the movement of an object. Depends on the force applied to the object and on its mass. Measured in Joules (J) More force= higher speed= more kinetic energy Can be transformed into other forms of energy
Newton´s cradle
K. E Formula
Gravitational potential energy Energy related with the height of an object above the ground.
It depends on its mass and the distance between the object and the ground.
Measured in Joules (J)
More altitude= more speed=
more G.P.E
G.P.E FormulaDam waterfall
Thermal or caloric energy Energy related with the movement and temperature of the object. (Heat
energy)
Increase on temperature= higher speed (atoms)= T.E
Can be trasmited by radiation,
conduction or convection.
Can be transformed into other
types of energy
-mechanical energy
-electric energy
Measured in Joules (J)House heated with solar energy
Chemical energy Energy related with the chemical composition of the object.
It is released in a chemical reaction and transformed into other types of energy: - Light energy - Heat energy - Electric energy Measured in Calories or Joules.
Electric energy Energy carried by the electrons in an electric conductor. It is easy to transmit and use and measured in Watt (W) or Joules. Atoms contain some electrons, their movement causes electricity. It is normally the result of another kind of energy.
Light energy It is the potencial of light to perform work. We obtain it from the sun (electromagnetic radiation) and it travels by waves. It can be converted into other types of energy:
-Heat energy
-Electric energy We can measure this waves and
their visible light with the
Electromagnetic Spectrum.
Sound energy The movement of energy through substances in longitudinal waves by a medium (Never Vacuum)
Depends on the pressure and intensity.
-Can damage our ears
-Can break glass
It is produced when a force causes an object or substance to vibrate.
Normally it has less power other forms of energy.
Measured in Pascals or decivels.
General classification of energy sources
Primary energy sources: Found in nature;
Secondary energy sources:
Not found in nature (produced using primary sources)
Sources from which energy can be obtained
Renewable energy sources
Advantages Are unlimited.
Can be replaced.
Develop industry and economy of the region they are installed in.
Not pollute the enviroment.
Disadvantages High cost (no profitability)
Availability.
Sources of energy that are UNLIMITED and can be replaced and used more and once.
Non-renewable energy sourcesSources of energy that are stored in nature during million years
and cannot be replaced once they are used.Advantages
Continuous production of abundant energy.
Easy to use.
Low cost.
No emissions of greenhouse gases during operation.
Disadvantages Are limited
Generation of harmful radioactive waste.
Pollute the enviroment.
Serious environmental disaster in case of accident.
Non-renewable energy sources We obtain fossil fuels from nature: coal, petroleum and gas.
Petroleum Coal Gas
Non-renewable energy sources We use them for:
-Making steal and fuel.
-Making gasoline for powering machines.
-Generating electricity.
-For making a lot of products such as plastics, medicines, cosmetics, synthetic fabrics, and lubricants.
Nuclear energy Nuclear Energy is used for obtaining electricity, by releasing in two ways:
-Nuclear fusion: When atoms are combined for forming a bigger one.
-Nuclear fission: When the atoms are separated.
Transformation of thermal energy into mechanical
The transformation consists of changing one type of energy into another.
For example in machines like the steam engine:
-The chemical energy inside the coal is heated so it is thermal energy.
-Is transformed into mechanical energy by heating the water transforming it into steam so that it expands and makes force moving the piston that makes the wheels move.
Steam Turbine Or the steam turbine, which work in a similar way:
-The chemical energy inside the coal is heated so it is thermal energy.
-Then the steam expands and makes the turbine move.
Internal Combstion Engine In the internal combustion engine is a group of pistons and valves. It works like this:
-First, the mixture of air goes in trough the fist vale.
-Then, it is compress by the piston.
-Later it is light up by a spark so the piston goes down by the force of the combustion.
-Finally, the gases are expelled through the second valve.
Renewable Energy Sources Rate of consumption lower than rate of production
Water and wind used by humans for thousands of years
Wheat grounded by mills powered by river currents and wind
Wind powered sailboats across seas and oceans
Solar Energy Sun is the most abundant renewable energy source
Point of origin of energy in sources such as winds, waves, firewood…
Sun produces more energy that the one we consume
Solar Thermal Power The energy of sunlight produces heat
Hot water for domestic use
1.- Cold water enters the collector
2.- Solar radiation from the panel heats it
3.- Cold water goes through the collector and goes out hot
4.- This hot water is stored in a thermal insulated tank.
Solar Thermal Power Sun is highest in the sky in the equator so at higher latitudes collectors have to be more inclined
In winter, the sun is lower in the sky than in summer and collectors have to be even more inclined
Solar Photovoltaic Power Directly transforming the energy of the Sun into electricity
This can be done with photovoltaic cells
They are to generate an electric current with sunlight
This process is called the photovoltaic effect
Solar Photovoltaic Power Photovoltaic cells are put together forming photovoltaic panels
Photovoltaic panels are connected together to get the energy
Large installations with many Megawatts are called solar farms
Solar Photovoltaic Power If the energy is stored in batteries is an Isolated Solar Installations
If it is used in the moment is a Grid Connected Solar Installations
Grid Connected Solar Installation 1. Solar radiation hits the panels and forms a continuous electric current
2. The inverter transforms the current into an alternating current so it can be used by the electrical grid of the building
3.Protection switchboard regulates the exchange of energy
Isolated Solar Installation 1. Solar radiation hits the panels and forms a continuous electrical current
2. The regulator detects if there is a need for electricity in the building and if yes, it sends the electrical current to the inverter, if not the current is stored in the batteries
3. Batteries store electrical energy so that it can be used when there is no sunlight
4. The inverter transforms the current into an alternating current so it is used by the electrical grid of the building
Solar Thermal Energy Production of electricity similarly to thermal power plants
Difference: steam is produced by the sun’s heat
A lot of water is needed to produce steam to move the turbine so solar radiation has to be very concentrated
This is achieved with mirrors that direct the rays of sun to the top of a tower
Wind Power Wind energy was used for windmills and boats
Nowadays most of its production is for electricity
The wind kinetic energy is transformed to electricity by wind turbines
Wind Turbines Turbines produce many megawatts of electricity
They are in 80m towers with a generator and three 40m rotor blades
Constant blow of wind
Speed of the wind over 6 m/s
Wind Turbines 1. The base supports the weight and stabilises the wind turbine
2. The tower supports the generator and the rotor blades at the optimum height
3. The generator transforms the rotational energy into electric energy
4. The rotation of the blades makes an axis turn inside the generator
Wind Turbines 5. The multiplier gears makes the speed to be 6 times faster
6. The generator produces an electrical current from the rotation that travels down a wire
7. A transformer makes the current able to flow to the electrical grid
Wind Turbines
Large groups of wind turbines are called wind farms Located in plains, peaks of mountains or near the sea
Wind Turbines
It affects bird population and alters the landscape Wind turbines in the sea are offshore wind farms
Biomass Used for the production of thermal and kinetic energy
Agricultural waste: Slurry and crop remains of livestock and farming
Forest waste: Tree prunings and fallen branches
Energy crops: Crops grown for energy production
Urban waste: Organic waste from homes, restaurants…
Biomass The sources have to be converted into appropriate materials
These final products are used as fuels in thermal power plants
Geothermal Energy The heat of the mantle is noticed by making a hole in the ground
This is because it is very near the mantle tre of over 3500º C
In this way we can take advantage of this heat
Geothermal Energy Using it to heat water and produce steam to move a turbine connected to an alternator, with the purpose of generating electricity in geothermal power plants
The heat is also used to directly heat water in central heating systems
Geothermal Energy 1. Water flows through a pipe inside the hot earth
2. And it transforms into steam
3. Which makes the turbine move
4. That moves the generator which produces an electric current
5. The transformer adapts the generated current to the electrical grid
6. The steam cools down in the condenser and returns to liquid state
7. Liquid water cools down in the refrigerator tower
Tidal Power The tides are how the waves are six hours nearer the coast and other six further away
It is caused by the attraction the moon exerts in the oceans and seas of the earth
Tidal Power There is a potential energy created by the highest tides at the highest point of it
We can use this potential energy to produce electric energy as in hydroelectric power plants
Tidal Power 1. When the tide rises the water enter the dike
2. At the highest point of the tide the dike is closed
3. When the tide is in the lowest point, water accumulated is released into the turbines
4. The speed of the water makes the turbines turn and this generates an electric current
Wave Energy The waves break against the coast
At any point of the sea or ocean hundreds of waves are passing over every day
We can harness this energy in the coasts where the waves are stronger
Wave Energy 1. Wave enter the air chamber
2. When the water level rises, air is pushed upwards and through a turbine, making it turn
3. When the wave falls the water level is reduced and the air chamber fills with air again
Electrical energy:
Known as the energy that has the electric current. It is the flow of electrons.
• Nuclear power plants
• Hydroelectric power plants
• Thermal power plants
Nuclear power plants Generation:
◦ Radioactive materials. (Residues of oil,coal..).
Transmission:◦ By an electrical grid. (Network which gives nergy).
Distribution: ◦ By conductive wires.
Hydroelectric power plants Generation:
By the speed of water flow.(Niagara falls).
Transmission:Energy of the sun which moves the turbines and the generators.
Distribution: The water is passed through the gate which take the water to the turbines which convert potential energy into mechanical energy, these gates are called penstocks.
Thermal power plants Generation:
◦ From the burning of certain materials , or the heating of water.
Transmission:◦ By transmission lines
Energy and the environment There are two types of energy:
◦ Renewable and non-renewable.
Energy(power plants) are causing an impact in global warming.
Energy saving and efficiencyNowadays energy is based on fossil fuels and nuclear energy.
◦ This provoke POLLUTION
◦ Save: Don´t use energy we don´t need. Turn lights off.
◦ Efficiency: Using low consuming light bulbs is an example which will save money .
This will make . the global warming and pollution to decrease , and you´ll save MONEY¡
Enviromental impact Generation of energy:
◦ Is high because people use electrical energy in their daily lifes and it pollutes
Transmission of energy:
◦ It Might be caused by oil,coal and wind.
Distribution of energy:
◦ The distribution of energy is one of the key components of infastructure , but it can damage the enviroment.