-: IMPORTANT NOTICE :-
Your answer is given in the explanation section, so please read carefully the explanation section for getting 100% in on the nptel assignment.
The capacity of a wind farm is given as 700 KW. Over an entire year, the wind farm generates 3679MW-hr of electrical energy. What is its capacity factor? (Select the value closest to your answer)
0.2
0.4
0.6
0.8
To calculate the capacity factor, we need to follow the formula:
Capacity Factor = (Actual Energy Output / (Capacity × Time)) × 100%
Given:
Actual Energy Output = 3679 MW-hr = 3679 * 1000 MWh = 3,679,000 MWh
Capacity = 700 KW (0.7 MW)
Time = 1 year = 8760 hours
Capacity Factor = (3,679,000 MWh / (0.7 MW × 8760 hr)) × 100%
Calculating this:
Capacity Factor ≈ 0.59
Among the given options, the closest value to the calculated capacity factor of 0.59 is 0.6.
So, the correct answer is: 0.6.
Which sector is consuming the maximum amount of energy in the world today?
As of my last knowledge update in September 2021, the industrial sector is typically one of the largest consumers of energy globally. Within the industrial sector, energy-intensive industries such as manufacturing, mining, and heavy machinery tend to account for a significant portion of energy consumption.
However, energy consumption patterns can vary over time and may be influenced by factors such as technological advancements, economic changes, and shifts in energy sources. It's advisable to refer to the most recent energy consumption statistics or reports to get the most up-to-date and accurate information on which sector is currently consuming the maximum amount of energy in the world.
Which country in the world has the largest renewable electrical power generation capacity?
As of my last knowledge update in September 2021, China was the country with the largest renewable electrical power generation capacity. China has made significant investments in renewable energy sources such as wind, solar, hydroelectric, and biomass, and has rapidly expanded its renewable energy capacity over the years.
Please note that the situation may have changed since then. It's recommended to consult the latest energy reports or sources to get the most current and accurate information on the country with the largest renewable electrical power generation capacity.
4. Which of these the renewable electricity generation technologies have levelized cost of electricity generation comparable or lower than fossil fuel based electricity generation in 2020?
Solar PV
Hydro power
Onshore wind
All of them
In 2020, all three of the mentioned renewable electricity generation technologies—Solar PV (photovoltaic), Hydro power, and Onshore wind—had reached a point where their levelized cost of electricity generation was comparable to or lower than fossil fuel-based electricity generation in many regions around the world.
The costs of renewable technologies, particularly solar PV, onshore wind, and hydro power, have been decreasing significantly over the years due to advancements in technology, economies of scale, and increased investment. This has led to more competitive pricing and improved cost-effectiveness compared to traditional fossil fuel sources.
It's worth noting that the cost competitiveness of different renewable technologies and fossil fuels can vary by location, specific project conditions, and changes in market dynamics. Therefore, the comparison may not hold true for all cases, but in general, these three renewable technologies have become increasingly competitive with fossil fuel-based electricity generation.
Which of the turbine types have lowest specific speed?
Among the commonly used turbine types, the Pelton turbine has the lowest specific speed.
The specific speed (Ns) of a turbine is a dimensionless parameter that helps classify turbines based on their operating characteristics. A lower specific speed indicates a turbine designed for high head (pressure) and low flow rate conditions.
Pelton turbines are typically used in high-head applications, such as mountainous regions with significant water head available. They are well-suited for situations where there is a large vertical distance between the water source and the turbine. Due to their design, Pelton turbines have a lower specific speed compared to other turbine types like Francis and Kaplan turbines, which are designed for different operational conditions.
A Power system for a define unit at a remote location requires a non-standard AC frequency of 180 Hz. A 6 pole generate will be used to generate the AC current. The power will be coming from a Pelton turbine . The angular velocity of the Pelton wheel is 40 rad/s. Determine the ratio between the angular velocities of the generation shaft and turbine shaft (i.e.ωgenωturb)?(Choose the closest value to your calculation)
0.1
10
100
1000
The formula to calculate the frequency (f) of an AC generator is given by:
f = (P * N) / 120
Where:
f is the frequency in Hertz (Hz).
P is the number of poles.
N is the rotational speed in revolutions per minute (RPM).
Given that the frequency required is 180 Hz and the generator has 6 poles, we can solve for N:
180 = (6 * N) / 120
Solving for N:
N = (180 * 120) / 6 = 3600 RPM
Next, we need to convert RPM to angular velocity (ω) in rad/s:
ω = (2π * N) / 60
Given N = 3600 RPM:
ω = (2Ï€ * 3600) / 60 ≈ 376.99 rad/s
The given angular velocity of the Pelton wheel is 40 rad/s.
Now, let's calculate the ratio between the angular velocities of the generation shaft and the turbine shaft:
Ratio = ωgen / ωturb = 376.99 / 40 ≈ 9.42
Among the provided options, the closest value to the calculated ratio of approximately 9.42 is 10.
Therefore, the ratio between the angular velocities of the generation shaft and turbine shaft is approximately 10.
Largest untapped hydro power potential lies in Africa.
True
False
True. Africa is often considered to have one of the largest untapped hydroelectric power potentials in the world due to its numerous rivers and water resources. Many countries in Africa have significant hydroelectric potential that remains undeveloped. Developing these resources could play a crucial role in providing clean and sustainable energy to the continent and contributing to its economic development.
Hydropower can generate power uniformly at its rated capacity throughout the year.
True
False
False. Hydropower generation is dependent on the availability of water resources, such as rivers and reservoirs. The power output of a hydropower plant can vary based on seasonal changes in water flow and precipitation. During periods of low water flow or drought, the power generation capacity of a hydropower plant may be reduced, and it may not be able to operate at its rated capacity. Additionally, some hydropower plants may be operated in a way that allows for better management of water resources, including storing water during periods of high flow and releasing it during periods of high demand. As a result, hydropower generation is not always uniform throughout the year.
Large hydropower installation can lead to displacement of many people from their lands.
True
False
True. Large hydropower installations, such as dams and reservoirs, can indeed lead to the displacement of many people from their lands. The construction of large dams often requires significant land area, and the resulting reservoir can flood large areas, including communities, farmlands, and natural habitats. This can lead to the displacement of local populations, loss of livelihoods, and disruption of ecosystems.
While hydropower can provide substantial benefits in terms of clean energy generation and water resource management, it can also have social and environmental impacts, including displacement and resettlement of communities. It's important to carefully consider and mitigate these potential negative effects when planning and implementing large hydropower projects.
Pelton turbines are most suitable for mountain stream, with low volumes of flow rate and high heads.
True
False
True. Pelton turbines are indeed most suitable for mountain streams with low volumes of flow rate and high heads. Pelton turbines are specifically designed to operate efficiently under these conditions.
Pelton turbines are impulse turbines, which means they work by harnessing the kinetic energy of a high-velocity jet of water. In mountainous areas, where there is a significant vertical drop (high head) in the water level, a Pelton turbine is well-suited to capture and convert the energy of the falling water into mechanical energy.
The design of the Pelton turbine, including the split buckets on the wheel and the shape of the nozzles, allows it to work efficiently with low flow rates and high heads. This makes Pelton turbines an ideal choice for harnessing hydropower in locations with mountain streams and steep terrain.
Francis Turbine is most suitable for high volume flow rate and very low head of water.
True
False
False. The Francis Turbine is best suited for medium to high head applications and moderate flow rates. It is not typically used for very low heads of water.
The Francis Turbine is a reaction turbine, which means it operates by both impulse and reaction principles. It is designed to efficiently convert the kinetic energy and pressure energy of water into mechanical energy. While it can handle a range of flow rates, it is more appropriate for moderate to high head conditions.
For very low heads of water, where the pressure energy is not significant, other turbine types like Kaplan turbines or certain types of waterwheel designs may be more suitable.
So, the correct statement is: The Francis Turbine is most suitable for medium to high head applications and moderate flow rates, not for very low heads of water.
Reaction turbines operate while completely submerged in water.
True
False
True. Reaction turbines do indeed operate while completely submerged in water. Reaction turbines are designed to work by utilizing the pressure and kinetic energy of flowing water to generate mechanical energy. They operate within a confined casing or chamber that allows the water to flow through the turbine blades, applying pressure and causing a change in the direction of the water's flow.
The pressure and kinetic energy of the water interact with the turbine blades, causing them to rotate and generate mechanical power. Because reaction turbines work by utilizing the dynamic pressure of the water, they need to be fully submerged in water to function effectively.
Examples of reaction turbines include the Francis turbine and the Kaplan turbine, both of which operate underwater to harness the energy of flowing water for power generation.
The largest growth of hydropower in the world over the last 50 years have been in China.
True
False
True. As of my last knowledge update in September 2021, China has indeed experienced the largest growth in hydropower capacity over the last 50 years. China's rapid economic development and increasing energy demand led to significant investments in various energy sources, including hydropower. China has constructed numerous large dams and hydropower projects, making it one of the world's leading producers of hydroelectricity.
Please note that the situation might have changed since then, and I recommend checking the most recent data and reports to confirm the current status of hydropower growth worldwide.
The bucket like blades of a Kaplan turbine is called as penstock.
True
False
False. The bucket-like blades of a Kaplan turbine are not called a penstock.
The term "penstock" refers to a large pipe or conduit that delivers water from a source (such as a dam or reservoir) to the turbine's runner, where the water's energy is converted into mechanical energy. It is a crucial component of a hydropower system, responsible for transporting water under pressure to the turbine.
The bucket-like blades of a Kaplan turbine are typically referred to as "runner blades" or simply "blades." The runner is the rotating part of the turbine that interacts with the flowing water and converts its energy into mechanical rotation.
In summary, the correct terminology is that the bucket-like blades of a Kaplan turbine are not called a penstock; they are called "runner blades" or "blades."