REP Renewable Energy Technologies & Applications 5

Question 1

What distinguishes a 'virtual power plant' (VPP) from a traditional centralized power plant?

Accepted Answer

A VPP aggregates distributed energy resources to act collectively as a single dispatchable unit

Answer

A VPP coordinates distributed assets — rooftop solar, batteries, EVs, demand response — through software to behave as a single controllable resource visible to grid operators.

Question 2

In a tidal barrage system, electricity is generated during which phase(s) of the tidal cycle?

Accepted Answer

During ebb flow, flood flow, or both, depending on system design

Answer

Tidal barrage systems can be designed for ebb-only, flood-only, or two-way generation by controlling sluice gates and turbine operation to exploit head differences in both tidal directions.

Question 3

Which factor most directly determines the output of a wind turbine at a given wind speed?

Accepted Answer

Rotor diameter (swept area)

Answer

Power captured from wind is proportional to the swept area of the rotor (πr²), so rotor diameter is the dominant design factor determining energy capture at any given wind speed.

Question 4

What is the role of 'renewable energy certificates' (RECs) in voluntary green power markets?

Accepted Answer

They represent the environmental attributes of one MWh of renewable generation, tradeable separately from the electricity

Answer

A REC (also called SREC, I-REC, or GO in Europe) represents the non-power attributes of one MWh of renewable generation and can be sold separately from the underlying electricity.

Question 5

Which characteristic of perovskite solar cells makes them particularly attractive for next-generation PV, despite current commercialization challenges?

Accepted Answer

They can be solution-processed and have achieved efficiencies >25% in the lab

Answer

Perovskite cells have achieved laboratory efficiencies exceeding 25% (and over 33% in tandem with silicon) and can be fabricated using low-cost printing processes, but face durability and lead-content challenges.

(REP) Certified Renewable Energy Professional Practice Test

(REP) Certified Renewable Energy Professional Practice Test

REP Renewable Energy Technologies & Applications 5