Wind And Solar Energy Flashcards
Historical development of wind energy
Started in the early used for sail , wind mills began in Persia and then cam to Europe . The use of these decreased tremendously with the invention of steam engines.
What is the formulae for wind power?
Wind power = 1/2 Apv^3
A=Area
p = air density
V = wind velocity.
E= mv2/2
M= A pv*t
P= E/t. P= mv2/2t. P = Apvtv2/2t
P= 1/2Apv3
What is wind power proportional to?
It is proportional to v3. This means that to achieve high wind energy you need to get a larger area (larger turbines or more turbines) and higher wind velocity
What is capacity factor in wind power?
Capacity factor = actual electricity production/ maximum electricity production
Maximum electricity production = full effect on the wind turbine all year round.
What are some design considerations for wind power ?
The blades should be placed high above the grounds because the higher the higher the wind velocity.
The generator and the rotor should be placed at the same height.
2-3 blades are much more efficient in high wind speeds than many blades are in low wind speed.
A three blade turbine is much more stable than a two blade turbine (all three blades when rotating hit a lot more angles of wind than two blades .
How does wind power operation work ?
- The wind turbine is always rotated to face the wind .
2 the rotor may spin to produce dc power which may later be transformed into Ac power - The turbine blades are rotated to maximize the power output.
Does terrain influence wind speed and how does it do that .?
Yes terrain does influence wind speed . Low lying and smooth terrains such open water , grass lands. Allow wind to flow more freely with little obstruction, hence there are higher wind speeds.
Rough terrains such as one with buildings , forests, and hills , create more friction and obstacles hence the wind speed increase with height.
Offshore vs on shore wind power
Offshore and onshore wind power refers to the location of wind energy production whether on land or at sea .
Offshore :
Wind farms situated offshore have much less visual impact and higher capacity factors (has to do with efficiency).
Less obstruction on water
Usually moderate breeze
Cons
usually more expensive
Maintenance more expensive
Long
Advantages of wind power
Produces electricity all the time.
Can be complimentary to solar as cloudy days end to be very windy as well .
No CO2 emissions after equipments has been produced .
Minor environmental impact
Renewable and is also one of the cheapest renewable energy sources.
95% of land used for wind farms can be used for other purposes such as farming.
Disadvantages of wind power
There might be a need for alternative power plants when there is no wind
When wind is substantial might cause fluctuations in grid line .
Some environmental impacts.
Maintenance is costly
What are some of the ecological impacts
Kills bats and birds
May need to roads and felling of trees
Offshore mills may disrupt sea current
Visualllupy unpleasant to look at.
A subsonic thump can be felt when blade passes the tower.
What is the projected price development ?
The prices are currently high but they are projected to go down a lot by 2050 .
What is the first step in site selection for large scale wind projects?
The first step is to find areas with adequate available transfer capability (ATC ) . ATC is the measure measure of existing capacity in an existing transmission system.
Major uses of solar energy
This type of energy has been used all humanity, with solar photovoltaics being a new innovation.
Uses
For agriculture purposes and processes
Production of electricity (can be done in two ways: concentration solar power and photovoltaics)
Space and water heating.
Solar cookers
How does solar photovoltaics panels generate electricity?
They generate electricity directly from sunlight with specialized materials.
