energy2 Flashcards
What does the term ‘energy dissipation’ mean?
Whenever there is a change in a system, energy. is transferred and some of that energy is dissipated. Dissipation is a term that is often used to describe ways in which energy is wasted.
State how you would reduce energy dissipation in each of these situations Energy dissipated by friction in an engine?
for a radio or set of speakers, the electrical work is transferred into useful sound and infrared radiation is dissipated – ie wasted as heat energy
for a tumble dryer, the electrical work is transferred into useful internal (thermal) energy which helps to dry clothes and energy is dissipated as sound
State how you would reduce energy dissipation in each of these situations Energy dissipated through the walls of a house by conduction?
Heat energy is transferred from homes by conduction through the walls, floor, roof and windows.
It is also transferred from homes by convection. For example, cold air can enter the house through gaps in doors and windows, and convection currents can transfer heat energy in the loft to the roof tiles.
What is the relationship between how thick the insulation in the walls of a house is and how quickly heat is lost?
Buildings often feel too warm in the summer and too cold in the winter. In the summer, energy transfers to the building from its warmer surroundings. In winter, energy transfers from the building to its colder surroundings. It costs money to keep a building warm, so various steps are taken to reduce the rate at which energy is transferred from it by heating.
State two equations that can be used to find efficiency?
A very efficient device will waste very little of its input energy.
A very inefficient device will waste most of its input energy.
State 4 non-renewable sources of energy generation?
Coal.
Oil.
Natural gas.
Nuclear power.
State 7 types of renewable energy generation?
Solar,Wind,Hydroelectric,Geothermal,Ocean,Hydrogen,Biomass
Give two advantages and two disadvantages of using coal fired power stations?
Coal, gas, and oil are the fossil fuels responsible for most of the world’s electricity and energy demands. Coal, which is readily available in most of the developing and developed world, has been used as a major source of fuel even in ancient human civilizations. It also found its use in historic steam engines at the dawn of the industrial revolution.
Give two advantages and two disadvantages of wind electricity generation?
“Desperate times require desperate measures.” This is a quotation that most of the world is familiar with. In the current context, there are various situations all around the world that can be termed as desperate times. However, one problem that poses an equal threat for people all around the world and requires immediate action from a large number of people is climate change. Conventional fuels have been a contributing factor to the current climate crisis. Hence, there is a need to replace them. There are multiple options, like wind energy, solar energy, hydro energy, etc.
Give two advantages and two disadvantages of nuclear energy generation?
During the next five decades, humans are going to consume more energy than they have over the course of our entire recorded history. The levels of consumption for fossil fuels give us a window of 60 years or less with currently known and expected resource discovery to find a new way to produce power. If we cannot replace all of our fossil fuels with renewables, then this fact will force a lifestyle change on everyone.
Give two advantages and two disadvantages of solar energy generation?
Solar energy systems generally don’t require a lot of maintenance. You only need to keep them relatively clean, so cleaning them a couple of times per year will do the job. If in doubt, you can always rely on specialised cleaning companies, which offer this service from around £25-£35.
Also, as there are no moving parts, there is no wear and tear. The inverter is usually the only part that needs to be changed after 5-10 years because it is continuously working to convert solar energy into electricity and heat (solar PV vs. solar thermal).
So, after covering the initial cost of the solar system, you can expect very little spending on maintenance and repair work.
Technology in the solar power industry is constantly advancing and improvements will intensify in the future. Innovations in quantum physics and nanotechnology can potentially increase the effectiveness of solar panels and double, or even triple, the electrical input of the solar power systems.
The initial cost of purchasing a solar system is fairly high. This includes paying for solar panels, inverter, batteries, wiring, and the installation. Nevertheless, solar technologies are constantly developing, so it is safe to assume that prices will go down in the future.
Although solar energy can still be collected during cloudy and rainy days, the efficiency of the solar system drops. Solar panels are dependent on sunlight to effectively gather solar energy. Therefore, a few cloudy, rainy days can have a noticeable effect on the energy system. You should also take into account that solar energy cannot be collected during the night.
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