REP Storage and Grids 5

Question 1

Which US grid interconnection region covers the largest geographic footprint, spanning 15 states across the Midwest and Mid-Atlantic?

Accepted Answer

PJM Interconnection

Answer

PJM Interconnection operates the transmission system across 13 states plus DC and manages the largest centrally dispatched electricity market in North America by load served.

Question 2

What NFPA standard governs the installation of stationary energy storage systems, addressing fire protection, ventilation, and spacing requirements?

Accepted Answer

NFPA 855

Answer

NFPA 855 (Standard for the Installation of Stationary Energy Storage Systems) provides requirements for the safe design, construction, and installation of battery storage systems.

Question 3

In power systems, what does the term 'black start capability' refer to?

Accepted Answer

The capability of a generator or storage resource to restart without drawing power from the grid after a blackout

Answer

Black start resources can self-energize and then supply power to restart other generators during grid restoration following a widespread outage, without requiring external grid power.

Question 4

Which strategy allows distributed behind-the-meter storage systems to be aggregated and dispatched as a single virtual resource in wholesale electricity markets?

Accepted Answer

Virtual power plant (VPP)

Answer

A virtual power plant aggregates behind-the-meter DERs including storage, solar, and controllable loads into a coordinated dispatchable resource that can participate in wholesale markets.

Question 5

What electrochemical phenomenon causes irreversible capacity loss in lithium-ion batteries when they are repeatedly charged to 100% state of charge?

Accepted Answer

Lithium plating and solid electrolyte interphase (SEI) growth

Answer

Lithium plating on the anode and continued SEI layer growth at full charge permanently consume active lithium and increase internal resistance, degrading capacity over time.

(REP) Certified Renewable Energy Professional Practice Test

(REP) Certified Renewable Energy Professional Practice Test

REP Storage and Grids 5