REP Renewable Energy Technologies & Applications 3

Question 1

Which ocean energy technology converts the temperature difference between warm surface water and cold deep water into electricity?

Accepted Answer

Ocean thermal energy conversion (OTEC)

Answer

Tidal stream turbine

Answer

Oscillating water column

Answer

Salinity gradient osmotic power

Question 2

In a grid-tied PV system, what happens to power generation when the utility grid goes down (without a battery backup)?

Accepted Answer

The inverter shuts down to prevent islanding

Answer

The system continues supplying power to the home only

Answer

Power is stored in the DC bus capacitors

Answer

Output is automatically reduced to 50%

Question 3

What is the Betz limit and what value does it represent?

Accepted Answer

Maximum theoretical efficiency of a wind turbine, approximately 59.3%

Answer

Minimum cut-in wind speed required for turbine operation, 3 m/s

Answer

Maximum allowable tower height-to-rotor-diameter ratio, 2:1

Answer

Efficiency ceiling for solar PV cells, 33.7%

Question 4

Which solar cell technology currently holds the highest confirmed single-junction efficiency record for terrestrial flat-plate cells?

Accepted Answer

Gallium arsenide (GaAs) single crystal

Answer

Multicrystalline silicon

Answer

Organic photovoltaic (OPV)

Answer

Amorphous silicon thin-film

Question 5

What is 'levelized cost of energy' (LCOE) used to measure?

Accepted Answer

The average cost per unit of electricity over a plant's lifetime

Answer

The peak power output per dollar of capital investment

Answer

The ratio of renewable to fossil fuel generation in a grid

Answer

The cost of grid interconnection per kilometer

Question 6

Which type of electrolyzer technology is most suitable for pairing with intermittent renewable energy sources due to its fast response time and ability to operate at partial load?

Accepted Answer

Proton exchange membrane (PEM) electrolyzer

Answer

Alkaline (AWE) electrolyzer

Answer

Solid oxide electrolyzer (SOEC)

Answer

Molten carbonate electrolyzer

Question 7

A biomass power plant using a combined heat and power (CHP) configuration achieves what primary benefit over electricity-only generation?

Accepted Answer

Higher overall fuel utilization efficiency

Answer

Lower NOx emissions per unit of biomass consumed

Answer

Reduced need for feedstock preprocessing

Answer

Elimination of flue gas treatment requirements