Renewable energies P1

33 flashcards · Other · by Beni

What is energy?
The capacity of doing work
Which are the 2 forms of energy?
Potential and Kinetic
Mention the types of potential energies.
Mechanical, Nuclear, Magnetic, Elastic and Chemical
Mention the types of Kinetic energy
Electrical, Light, Sonic, Therman and Motion.
Types of energy conversion explained:
Primary energy: Raw renewable and non renewable energies. Not altered in any way (Coal, crude oil, wind, sun, etc.) Secondary energy: These energies have been processed at least once (Electricity, gasoline, heat, bio fuels). Final energy: Energy that is available to the end user. Basically secondary energy in a place accessible to the end user. Useful Energy: The portion of energy that is actually available to the user after its final conversion (Light from a lamp, heat from a stove, etc.)
1st law of thermodynamics:
Energy cannot be created nor destroyed, only transformed.
Potential Energy (Related to gravity) formula:
m*g*h Mass times gravity constant times height
Kinetic energy formula:
1/2*m*v^2 A half times mass times velocity squared.
2nd Law of Thermodynamics:
The Entropy within a closed system increases or does not change due to an energy conversion.
Energy efficiency formula:
useful energy output/energy input.
Parts of an Electric generator and how they work.
An armature spins between 2 magnets. Slip rings are then used with Carbon brushes are used to direct energy to cables.
In broad terms, how does a coal power plants work?
Coal is burned to heat up some water into vapor. Then the vapor spins a turbine and generates energy.
What is the greenhouse effect?
A warming of Earth's surface and troposphere caused by the presence of greenhouse gases.
What are greenhouse gases?
Any gas that has the property of absorbing infrared radiation emitted from Earth's surface and re-radiating it back to the Earth.
Which are the 2 types of greenhouse effect gases.
Natural and Anthropogenic (Made by humans)
Which is the most affected are of global warming so far?
Europe
Which are the 2 sources of Energy?
Fossil (Gas, Coal & Oil) Clean (Wind, Nuclear, Solar, Bio, Hydrogen, Geothermal, Hydro.)
What is the trend of CO2 Global Emissions.
Co2 emissions have been steadily rising.
Advantages and disadvantages of Renewable Energies.
Advantages: Renewables will not run out. Maintenance and operating costs of rewables are less than fossil fuels. Less emission of greenhouse overall. Less foreign dependency as local energy is produced. Disadvantages: Upfront is usually higher than traditional sources. Geographic limitations Energy source intermittency Requires energy storage.
Which are the types of energy storage systems ordered? Es imprtante entender como funciona cada tipo, pero no viene en este cuestionario.
Mechanical: Pumped-storage hydroplants Compressed air energy storage Chemical: Batteries/Accumulators Hydrogen Storage Systems
Efficiency for every type of energy storage systems:
Pumped-storage hydroplants : 70-85% Compressed air energy storage: 50% Batteries/Accumulators: 80-90% Hydrogen Storage Systems: 30-40%
Which percentage solar raditation is absorbed in surface and which percentage is reflected/absorbed by clouds, atmosphere etc.
50% absorbed in surface and 50% in other parts.
Which are the 2 types of solar radiation.
Direct (Sun to solar panel) and Diffuse (Sun, reflected by something else then to solar panels).
In what parts of the world are solar panels the most effective?
Near the equator, in summer time, while it is day.
What is a photovoltaic system.
It is a power system that generates electricity by means of solar energy.
What property of silicon do the photovoltaic system s use?
semiconductors.
What are the components of a solar panel installation?
Solar panels, Inverter and Smart meter
What is the order of a silicon based cell production?
Silica --> Metallurgical grade silicon ---> Solar grade silicon ----> Silicon ingot----> Silicon Wafer ----> Solar Cell
Which are the adv and disadv of 1st generation panels
relatively high efficiency and stabillity. Widely used disadv: Rigid. Energy-intensive production
Which are the adv and disadv of 2nd generation panels
adv. Lower material consumption cheaper flexible Disadv. Lower efficiency Further development needed Evironmental issues due to some materials
Which are the adv and disadv of 3rd generation panels
Adv: Theiretical efficiency is higher Lower costs Low material consumption Disadv: Still low efficiency Not all the effects are yet documented Unstable
What is thermal energy and the 3 types of heat transfer
Energy present due to its temperature Can be transferred through: Conduction, Convection and Radiation.
How do solar heat collectors work?
Through a structure like a solar panel, but instead of a photovoltaic effect, it traps heat and uses it to warm a liquid which then heats up other things.