CEA Renewable Energy Technologies 4 — Questions and Answers
Question 1: Which US federal incentive allows renewable energy project owners to deduct a percentage of system cost from federal taxes in the year the system is placed in service?
- Production Tax Credit (PTC)
- Investment Tax Credit (ITC) (Correct answer)
- Renewable Portfolio Standard (RPS)
- Modified Accelerated Cost Recovery System (MACRS)
Correct answer: Investment Tax Credit (ITC)
The Investment Tax Credit (ITC) allows project owners to deduct a percentage of eligible renewable energy system costs directly from their federal tax liability.
Question 2: What is 'net metering' in residential solar PV systems?
- Measuring both AC and DC output simultaneously
- Crediting customers for excess electricity exported to the grid (Correct answer)
- Tracking cumulative lifetime energy production
- Billing based on peak demand rather than energy consumption
Correct answer: Crediting customers for excess electricity exported to the grid
Net metering credits residential solar owners for surplus electricity sent to the grid, which offsets their future electricity bills.
Question 3: What is the main advantage of bifacial solar panels over monofacial panels?
- They are lighter and easier to install
- They capture reflected light on the rear surface for higher yield (Correct answer)
- They operate at lower temperatures to improve efficiency
- They require no inverter for grid connection
Correct answer: They capture reflected light on the rear surface for higher yield
Bifacial panels generate additional electricity by absorbing albedo (reflected) light on their rear surface, increasing total energy yield.
Question 4: What is a 'virtual power plant' (VPP) in the context of distributed renewable energy?
- A simulation tool for planning renewable projects
- A cloud-based aggregation of distributed generators and storage units controlled as a single entity (Correct answer)
- An offshore wind farm with no physical connection to land
- A backup diesel generator system for renewable microgrids
Correct answer: A cloud-based aggregation of distributed generators and storage units controlled as a single entity
A VPP aggregates distributed energy resources—solar, storage, demand response—and controls them collectively to provide grid services like a conventional power plant.
Question 5: Which wave energy converter (WEC) design uses the relative motion between a floating body and a fixed or slowly moving reference to generate electricity?
- Oscillating water column (OWC)
- Overtopping device
- Point absorber buoy (Correct answer)
- Salter's duck
Correct answer: Point absorber buoy
Point absorber buoys harness the heave and surge motion of ocean waves relative to a fixed mooring or seabed anchor to drive a linear or rotary generator.
Question 6: What does 'soiling loss' refer to in a solar PV system performance analysis?
- Power loss due to soil erosion undermining panel foundations
- Reduction in output caused by dust, dirt, or debris on panel surfaces (Correct answer)
- Inverter efficiency loss in humid conditions
- Cable resistance losses in underground wiring
Correct answer: Reduction in output caused by dust, dirt, or debris on panel surfaces
Soiling losses occur when dust, pollen, bird droppings, or other debris accumulate on PV panel surfaces, reducing light transmission and power output.
Question 7: In a pumped hydropower storage system, what determines the amount of energy that can be stored?
- The turbine blade diameter and rotation speed
- The volume of water and the vertical head between upper and lower reservoirs (Correct answer)
- The pipe diameter and flow velocity only
- The ambient temperature and elevation above sea level
Correct answer: The volume of water and the vertical head between upper and lower reservoirs
Stored energy in pumped hydro equals the product of water mass, gravitational acceleration, and vertical head (height difference) between reservoirs.
CEA Renewable Energy Technologies 4
Which US federal incentive allows renewable energy project owners to deduct a percentage of system cost from federal taxes in the year the system is placed in service?