1. Define Wind and Mention the Properties of Wind.
• Wind is caused by the uneven heating of the atmosphere by the sun,
variations in the earth's surface, and rotation of the earth. Thus the wind
energy is a form of solar energy.
3.Sketch And Explain the Working Principal of a Vertical Axis Wind Turbine
(Darrieus). Mention its limitations.
1. Wind Blows on the Blades:
The curved blades catch the wind from any direction. As wind hits them,
they start to spin around the rotor shaft (which stands vertically, like a
flagpole).
2. Rotation is Transferred Downwards:
The spinning blades are connected to the rotor shaft, which turns as the
blades rotate.
3. Cross Arm and Guy Ropes:
The cross arm helps hold the blades in place, and the guy ropes provide
stability to prevent the turbine from wobbling or falling over.
4. Support and Bearings:
Bearings at the top and bottom of the rotor shaft help it spin smoothly
with less friction.
5. Gearbox and Brakes:
The spinning motion from the rotor shaft goes into a gearbox, which
increases the speed of rotation to the right level for electricity
generation. Brakes can stop the turbine if needed (e.g., for maintenance
or strong storms).
6. Generator Produces Electricity:
The fast-spinning motion from the gearbox turns the generator, which
converts the mechanical energy into electrical energy.
7. Electricity Goes to the Grid:
The electricity passes through switchgear and control systems, which
manage safety and performance, before being sent to the grid
connection for use in homes and businesses.
8. Foundation:
The whole structure stands on a solid foundation, which keeps it stable.
Limitations of Vertical Axis Darrieus Wind Turbine (4 Marks):
1. Not self-starting – It usually needs an external power source to start
rotating, especially in low wind conditions.
2. Lower efficiency – It generates less power compared to horizontal axis
wind turbines due to poor aerodynamic performance.
3. Mechanical complexity – The design involves high stress on blades and
bearings, making maintenance more difficult.
4. Performance issues in turbulent winds – It performs poorly in unstable
or changing wind directions, affecting power output.
5. Sketch And Explain the Working Principal of a Horizontal
Axis Wind Turbine and Mention its Advantages.
Horizontal Axis Wind Turbine :-
Rotor and Hub:
The rotor has large blades that spin when wind blows. These blades are
attached to a hub, which transfers the spinning motion inward.
Drive Train:
The hub is connected to a drive train, which increases the speed of rotation
using gears so the generator can work efficiently.
Generator:
The generator converts the mechanical spinning motion into electrical energy.
Control and Nacelle Cover:
The control system manages turbine operations like blade angle and power
output. All parts at the top (generator, drivetrain, control) are protected by the
nacelle cover.
Yaw System and Tower:
The yaw system rotates the nacelle to face the wind direction. The tower holds
everything high above the ground to capture stronger winds. Power is sent
down to the electrical system at the bottom, which is connected to the
foundation for stability.
Advantages of Horizontal Axis Wind Turbine (HAWT) –
High Efficiency:
HAWTs are more efficient than vertical types because their blades move
perpendicular to the wind, capturing more energy.
Strong Design:
The turbine design is well-developed and reliable, with modern technology
making them suitable for both small and large-scale power generation.
Better Performance at High Wind Speeds:
These turbines work very well in strong winds, especially in open areas or
offshore locations.
Easy to Install at Height:
Since HAWTs are mounted on tall towers, they can access stronger and
steadier wind currents at higher altitudes.
7.Write Shorts Notes on Wind Farm Layout Optimization.
9.Sketch And Explain the Working Principal of a Principal of Geo Thermal
Energy.
Geothermal Energy – Working Principle
Heat from the Earth (Production Well):
Hot water or steam is extracted from deep underground using a production
well. This heat comes from a low-temperature geothermal liquid-dominated
resource.
Heat Transfer in the Evaporator:
The hot fluid passes through an evaporator, where it transfers heat to another
fluid (usually one that evaporates easily). This second fluid turns into steam.
Turbine and Generator:
The steam is sent to a turbine, which spins due to the pressure. This spinning
turbine is connected to an electric generator that produces electric power
output.
Condensation of Steam:
After passing through the turbine, the steam is cooled down in a condenser,
where it turns back into liquid form.
Cooling Tower:
A cooling tower helps in further reducing the temperature of the condensed
fluid by releasing heat into the atmosphere.
Reinjection (Re-Injection Well):
The cooled geothermal fluid is then pumped back underground using a re-
injection well. This maintains pressure underground and makes the system
sustainable.
11.Sketch And Explain the Working Principal of a Flash Steam Power Plant:
Liquid Dominated: Single Flash Hydro Thermal Stations
Flash Steam Power Plant (Single Flash System) – Working Principle (6
Marks)
Hot Water Extraction (Production Well):
Very hot water (called brine) is pumped from deep underground through the
production well. This water is under high pressure.
Flash Separator:
When this high-pressure hot water reaches the flash separator, the pressure is
suddenly reduced. This causes part of the water to "flash" or instantly turn into
steam, while the rest remains liquid.
Steam to Turbine:
The dry steam from the flash separator is sent to the steam turbine, which rotates
due to the pressure of the steam.
Power Generation:
The spinning turbine is connected to a generator, which converts the mechanical
energy into electricity.
Condensation and Cooling:
After passing through the turbine, the used steam is cooled and turned back into
water in the condenser. A cooling tower may be used to release extra heat.
Reinjection and Use of Hot Liquid:
The remaining hot liquid (brine) from the separator can be used for direct heating
or is pumped back underground through the re-injection well to maintain the
geothermal pressure.
13.Explain the Fundamental Characteristics of Tidal Power.
Fundamental Characteristics of Tidal Power (in simple words):
What is tidal power?
Tidal energy is a type of water energy that uses the natural rise and fall of
sea tides to produce power, usually electricity.
Where does it come from?
This energy comes from the gravitational pull between the Earth and the
Moon, and also a bit from the Sun. That’s what causes tides.
What affects tidal energy production?
Places where tides change a lot and where the water moves faster are better
for generating more electricity from tides.
Efficiency at low speeds:
Tidal turbines can still make electricity even if the water isn't moving very
fast, which is useful in many locations.
Is it eco-friendly?
Yes, tidal power is clean and renewable. It doesn’t pollute the air or
contribute to climate change because it doesn't produce greenhouse gases.
15.Explain Harnessing Tidal Energy: Various Kinds of Tidal Power
Generation
Various Kinds of Tidal Power Generation (in simple words):
Tidal Stream Generator:
This method uses the movement (speed) of water (like underwater wind) to spin
turbines, just like how wind turbines work on land using wind.
Tidal Barrage:
A tidal barrage is a type of dam built across a river or bay. When the tide comes
in and water level rises, the dam stores water. Later, this water is released to turn
turbines and produce electricity using the difference in water height.
Dynamic Tidal Power (DTP):
This is still a concept (not widely built yet). It suggests making very long dams
straight into the sea, which would use both the height difference and flow of water
to create energy.
Tidal Lagoon:
This is a part of the sea that is surrounded by a wall or barrier (natural or built).
It works like a tidal barrage and uses the rising and falling water levels inside the
lagoon to make electricity.
