CCP Solar, Wind & Storage Technologies 2 — Questions and Answers
Question 1: What is the primary function of a Maximum Power Point Tracker (MPPT) in a solar PV system?
- Convert DC power to AC power
- Optimize the operating voltage to extract maximum power from the panels (Correct answer)
- Regulate battery charging cycles
- Monitor panel temperature and adjust output
Correct answer: Optimize the operating voltage to extract maximum power from the panels
MPPT controllers continuously adjust the electrical operating point of the PV modules to extract the maximum available power under varying irradiance and temperature conditions.
Question 2: Which offshore wind foundation type is most suitable for water depths between 40–60 meters?
- Monopile
- Jacket/lattice structure (Correct answer)
- Floating spar-buoy
- Gravity-based structure
Correct answer: Jacket/lattice structure
Jacket foundations (lattice structures) are preferred for intermediate water depths of roughly 30–80 meters where monopiles become structurally inefficient.
Question 3: In a lithium-ion battery, what is 'State of Health' (SoH) used to measure?
- Current charge level as a percentage of total capacity
- Remaining useful capacity relative to original rated capacity (Correct answer)
- Internal cell temperature during charging
- Rate of self-discharge per month
Correct answer: Remaining useful capacity relative to original rated capacity
SoH compares a battery's current maximum capacity to its original rated capacity, indicating overall degradation over its service life.
Question 4: What is 'curtailment' in the context of wind and solar energy?
- Deliberate reduction of renewable output to prevent grid overloading (Correct answer)
- Seasonal maintenance shutdown of wind turbines
- Increase in generation during peak demand periods
- Financial penalty for exceeding contracted capacity
Correct answer: Deliberate reduction of renewable output to prevent grid overloading
Curtailment is the intentional reduction of renewable generation output below available capacity, typically ordered by grid operators to maintain system balance.
Question 5: Which solar cell technology achieves the highest single-junction theoretical efficiency limit, known as the Shockley-Queisser limit?
- Approximately 20%
- Approximately 33% (Correct answer)
- Approximately 45%
- Approximately 55%
Correct answer: Approximately 33%
The Shockley-Queisser limit sets the maximum theoretical efficiency for a single-junction solar cell at approximately 33% under standard conditions.
Question 6: What does a wind turbine's 'cut-out speed' refer to?
- Minimum wind speed needed to start generating power
- Wind speed at which turbines shut down to prevent mechanical damage (Correct answer)
- Optimal wind speed for rated power output
- Speed at which blade pitch control activates
Correct answer: Wind speed at which turbines shut down to prevent mechanical damage
Cut-out speed (typically 25 m/s) is the wind velocity at which turbines automatically shut down to protect mechanical and electrical components from storm damage.
Question 7: Pumped-storage hydropower (PSH) currently represents approximately what share of global grid-scale energy storage capacity?
- 25%
- 55%
- 90% (Correct answer)
- 40%
Correct answer: 90%
Pumped-storage hydropower accounts for roughly 90% of global installed grid-scale energy storage capacity, making it by far the dominant storage technology.
CCP Solar, Wind & Storage Technologies 2
What is the primary function of a Maximum Power Point Tracker (MPPT) in a solar PV system?