Topic 4 - Energy, materials, Systems and Devices Flashcards
are fossil fuels are finite or a non finite resource
fossil fuels are a finite resource
how are fossil fuels formed
fossil fuels are formed from the fossilised remains of plants and animals over millions of years
how are coal, oil and gas extracted
coal, oil and gas are extracted through mining and drilling
why are fossil fuels burned
fossil fuels are burned to superheat water under pressure which drives turbine
what does fracking involve
fracking involves drilling into layers of shale rock deep in the earth to release pockets of gas. water, sand and chemicals are injected into a well in order to force gas backup
what are some examples to renewable alternative energy sources to fossil fuels
wind, solar, tidal, biomass, hydroelectric
what are some disadvantages of wind turbines
very loud. damaging to the envirnment. look unnatural. interrupt birds. only work when windy
what are some advantages of wind turbines
low maintenance. clean energy. clean energy. higher winter output. low cost energy
how do photovaltic cells work
light photons hit the PV cell which allows electrons to flow, creating an electric current
what are some advantages of photovaltaic cells
low maintenance. clean energy. relatively low cost
what are some disadvantages of photovaltaic cells
seasonal fluctuations. no power generated at night. complex positioning issues
how does tidal energy work
the rise and fall of the tide forces water through turbines which drive generators to produce electricity
what is hydroelectic power
a very reliable and contrallable energy resource. thr set up costs are financially and environmentally expensive. vast areas need to be flooded to create reservoirs
how are biofuel/biomass created
biofuel and biomass are created from organic matter which is burned to generate power
what are some examples of biomass fuels
food/farm waste, compost and wood chips or compressed pellets
what pecentage of the worlds electricity does nuclear power account for
nuclear power accounts for 11% of the worlds electricity
what is an advantage of nuclear power
nuclear power provided an abundant, reliable supply of clean energy
what is energy
energy is the capacity to do work. it comes in different forms and can be stored. energy can change between forms
what are some examples of stored energy
chemical, mechanical, nuclear, gravitational
what are some examples of motion energy
movement, electricity, heat, sound, light
how is potential energy stored
potential energy is stored in objects, not in motion, that will move once released
what are some examples of potential energy
waves in s reservoir ready to turn a turbine for HEP, pressure in a fire extinguisher
what does kinectic energy involve
kinectic energy involves motion and movement
what is an example of kinectic energy
electricity when travelling through a circuit, heat radiation, sound coming from a speaker, project light, atoms vibrating
what are some examples of mechanical storage
compression, tension, motion
what are some examples of chemical storage
batteries, gases, solid fuel, food
what are some examples of pneumatic systems
they are very accurate and low maintenance
how is movement created
compressed air or gas
what are pneumatics used in
used in industry, for example with mechanical drills and on automated production lines
what might be used, instead of air, to create a powerful system
pumped and compressed liquid
what are hydraulics used in
lifting equipment, car braking systems, fire fighting cutting equipment
what is an advantage of hydroelectric power
hydroelectric power provides a very controllable supply of power
what happens when there is a surplus supply of electricity
when there is a surplus supply of electricty, water is pumped back up to the high level reservoir
in kinectic pumped storage, where is potential energy stored/ when is it used
potential energy is stored in the water at the higher level and is used when demand is high
what kind of energy do flywheels use, in order to reach optimum speed
flywheels use surplus energy to reach optimum speed
what kind of environment do flywheels rotate in
flywheels rotate in a near frictionless environment
how is electrical energy returned when needed, in flywheel energy storage
the motor used to power flywheels becomes a generator which returns the electrical energy when needed