Climate Change Renewable Energy Technologies 2 — Questions and Answers
Question 1: What is the primary advantage of offshore wind farms compared to onshore installations?
- Lower construction costs
- Stronger and more consistent wind speeds (Correct answer)
- Easier maintenance access
- Reduced environmental impact on wildlife
Correct answer: Stronger and more consistent wind speeds
Offshore wind farms benefit from stronger, more consistent winds over open water, enabling higher capacity factors than onshore sites.
Question 2: Which photovoltaic cell technology currently holds the highest certified efficiency record in laboratory conditions?
- Monocrystalline silicon
- Thin-film cadmium telluride
- Multi-junction concentrator cells (Correct answer)
- Polycrystalline silicon
Correct answer: Multi-junction concentrator cells
Multi-junction concentrator solar cells, which stack multiple semiconductor layers to capture different light wavelengths, have achieved laboratory efficiencies exceeding 47%.
Question 3: What does the term 'capacity factor' mean when applied to a wind turbine?
- The maximum power output the turbine can produce
- The ratio of actual energy produced to maximum possible energy over a period (Correct answer)
- The percentage of time the turbine is operational
- The efficiency of converting wind kinetic energy to electricity
Correct answer: The ratio of actual energy produced to maximum possible energy over a period
Capacity factor is the ratio of actual electrical energy output over a period to the theoretical maximum if the turbine operated at full capacity the entire time.
Question 4: Concentrated Solar Power (CSP) plants differ from photovoltaic systems primarily because they:
- Use mirrors to focus sunlight and generate heat to drive turbines (Correct answer)
- Convert sunlight directly into electricity using semiconductors
- Only work in desert climates
- Require no water for operation
Correct answer: Use mirrors to focus sunlight and generate heat to drive turbines
CSP plants use mirrors or lenses to concentrate sunlight into heat, which drives a steam turbine to generate electricity, unlike PV which directly converts photons to electrons.
Question 5: Which renewable energy source provides the largest share of US electricity generation as of the mid-2020s?
- Solar photovoltaic
- Geothermal
- Wind (Correct answer)
- Hydropower
Correct answer: Wind
Wind power surpassed hydropower to become the leading US renewable electricity source, generating roughly 10% of total US electricity by the mid-2020s.
Question 6: What is 'perovskite' in the context of solar energy technology?
- A type of wind turbine blade material
- A crystal structure used in next-generation solar cells (Correct answer)
- A chemical used to clean solar panels
- A government subsidy program for solar installations
Correct answer: A crystal structure used in next-generation solar cells
Perovskite refers to a crystal structure used in emerging solar cell technology that has shown rapid efficiency gains and potential for low-cost manufacturing.
Question 7: Enhanced Geothermal Systems (EGS) differ from conventional geothermal plants because they:
- Only operate in volcanic regions
- Inject water into hot dry rock to create artificial reservoirs (Correct answer)
- Use solar energy to supplement geothermal heat
- Require surface water bodies nearby
Correct answer: Inject water into hot dry rock to create artificial reservoirs
EGS technology injects water into hot dry rock formations deep underground, fracturing the rock to create a heat exchange system where no natural hydrothermal reservoir exists.
Climate Change Renewable Energy Technologies 2
What is the primary advantage of offshore wind farms compared to onshore installations?