CEA Energy Storage & Grid Integration 5

Question 1

Which storage technology offers the fastest response time, making it ideal for power quality applications like voltage sag mitigation?

Accepted Answer

Supercapacitors (ultracapacitors)

Answer

Supercapacitors can charge and discharge in milliseconds, far faster than any battery chemistry, making them ideal for power quality and ride-through applications.

Question 2

What is 'virtual power plant (VPP)' technology, and how does it relate to distributed storage?

Accepted Answer

Software that aggregates and centrally dispatches distributed storage, solar, and demand response assets as a unified grid resource

Answer

A VPP uses software to coordinate many distributed assets — home batteries, EVs, smart thermostats — dispatching them collectively as if they were a single controllable power plant.

Question 3

What is the 'self-discharge rate' of a storage technology, and which technology suffers from the highest self-discharge among common grid storage options?

Accepted Answer

Rate of capacity loss at rest; flywheels have the highest self-discharge rate

Answer

Self-discharge is energy lost without output; flywheels lose energy continuously to air resistance and bearing friction, making them unsuitable for long-duration storage.

Question 4

Under the US Investment Tax Credit (ITC), what storage configuration qualifies a standalone battery project for the credit?

Accepted Answer

The battery must be charged at least 75% from a co-located qualifying renewable energy source

Answer

The Inflation Reduction Act extended ITC eligibility to standalone storage regardless of renewable pairing (effective 2023), but historically required 75% renewable charging for ITC qualification.

Question 5

What is 'islanding' in distributed storage systems, and why is anti-islanding protection required?

Accepted Answer

A storage system continuing to energize a local grid segment when the main grid disconnects; required to protect utility workers from unexpected live lines

Answer

Unintentional islanding occurs when a storage/DER system keeps a portion of the grid energized after grid disconnection, creating safety hazards for utility workers assuming the line is de-energized.

(CEA) Certified Energy Analyst Practice Test

(CEA) Certified Energy Analyst Practice Test

CEA Energy Storage & Grid Integration 5