REP Storage and Grids 3

Question 1

What is the primary function of a Battery Management System (BMS) in a grid-scale BESS?

Accepted Answer

Monitoring cell-level voltage, temperature, and state of charge to protect battery health

Answer

The BMS monitors and balances individual cell parameters (voltage, temperature, SOC, SOH) to prevent overcharge, over-discharge, and thermal runaway.

Question 2

Which metric describes the ratio of actual energy delivered by a storage system over its lifetime to the total energy input over the same period?

Accepted Answer

Round-trip efficiency

Answer

Round-trip efficiency (RTE) is cumulative energy out divided by cumulative energy in over the system's lifetime, capturing all conversion and parasitic losses.

Question 3

A utility operates a grid with high solar PV penetration. Which grid challenge most commonly emerges during the transition from midday high-solar to evening high-demand periods?

Accepted Answer

Steep ramping requirement known as the duck curve

Answer

The duck curve describes the steep net-load ramp that occurs in the late afternoon as solar generation drops while evening demand peaks, requiring fast-ramping resources.

Question 4

In FERC Order 841, what action did the Federal Energy Regulatory Commission take regarding energy storage?

Accepted Answer

Required grid operators to allow energy storage to participate in all capacity, energy, and ancillary services markets

Answer

FERC Order 841 (2018) directed RTOs/ISOs to remove barriers and establish rules enabling electric storage resources to participate fully in wholesale electricity markets.

Question 5

What is the purpose of reactive power compensation provided by grid-tied inverters in renewable energy systems?

Accepted Answer

Maintaining voltage stability by supplying or absorbing reactive power (VARs)

Answer

Reactive power (VARs) support from smart inverters helps maintain voltage within acceptable limits, especially on long distribution feeders with high renewable penetration.

(REP) Certified Renewable Energy Professional Practice Test

(REP) Certified Renewable Energy Professional Practice Test

REP Storage and Grids 3