Renewable Energy Technologies & Applications Flashcards

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

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

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

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

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

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.

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

Answer: Rotor diameter (swept area)

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.

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

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

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.

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

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

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.

In building-integrated photovoltaics (BIPV), what distinguishes BIPV from building-applied photovoltaics (BAPV)?

Answer: BIPV modules replace conventional building materials and serve a dual function

BIPV modules replace conventional building envelope components — roofing tiles, facades, glazing — serving both a structural/weatherproofing function and generating electricity, unlike BAPV which is added on top.

What is the primary technical reason that integrating high percentages of variable renewable energy (VRE) into a grid requires increased flexibility resources?

Answer: VRE output fluctuates with weather and does not inherently match demand patterns

Solar and wind generation varies with irradiance and wind speed rather than following load, creating mismatches between supply and demand that require flexible resources — storage, demand response, dispatchable generation — to balance.