Question 1:
Which of the following is the most common form of large-scale energy storage worldwide?
Explanation: The correct answer is A) Pumped hydro storage. Pumped hydro storage is the most common form of large-scale energy storage worldwide. It involves using excess electricity to pump water from a lower reservoir to an upper reservoir, storing the potential energy. When electricity demand increases, the stored water is released from the upper reservoir through turbines to generate electricity. Pumped hydro storage offers high efficiency, long-duration storage, and the ability to respond quickly to grid demands, making it an ideal solution for grid-scale energy storage.
Question 2:
What is the primary advantage of compressed air energy storage (CAES) compared to other energy storage technologies?
Explanation: The correct answer is B) It can store large amounts of energy. Compressed air energy storage (CAES) systems can store large amounts of energy by compressing air and storing it in underground caverns or aboveground tanks. The stored energy can be released by expanding the compressed air through a turbine to generate electricity when needed. CAES offers the advantage of high energy storage capacity, allowing for long-duration storage and meeting peak demand requirements. While CAES has some energy conversion losses, its ability to store significant amounts of energy makes it a valuable solution for grid-scale energy storage.
Question 3:
What is the primary disadvantage of pumped hydro storage?
Explanation: The correct answer is B) Limited availability of suitable sites. Pumped hydro storage requires the availability of suitable sites with a significant difference in elevation to construct the upper and lower reservoirs. Such sites are limited in number, making it challenging to implement pumped hydro storage on a large scale. Additionally, pumped hydro storage projects involve high construction and operational costs, which can be a barrier to widespread adoption. While pumped hydro storage offers high efficiency and long-duration storage, the limited availability of suitable sites remains a significant drawback.
Question 4:
What is the primary advantage of underground compressed air energy storage (CAES) compared to aboveground CAES?
Explanation: The correct answer is B) It has lower air leakage losses. Underground compressed air energy storage (CAES) systems provide better air retention compared to aboveground CAES systems. The underground storage caverns offer better containment and reduce air leakage losses, resulting in higher energy efficiency. Underground CAES also has a lower environmental impact as it minimizes the visual and noise impact associated with aboveground structures. The response time of underground and aboveground CAES systems is generally similar. Overall, underground CAES is a more efficient and environmentally friendly option for compressed air energy storage.
Question 5:
Which energy storage technology relies on gravitational potential energy?
Explanation: The correct answer is D) Pumped hydro storage. Pumped hydro storage relies on the gravitational potential energy of water. It involves pumping water from a lower reservoir to an upper reservoir during periods of low electricity demand, storing the potential energy. When electricity demand increases, the stored water is released from the upper reservoir through turbines, generating electricity as it flows downhill. The gravitational potential energy of the water is converted back into electrical energy. Pumped hydro storage utilizes the concept of elevation and gravitational forces to store and release energy, making it a reliable and well-established technology for large-scale energy storage.