ESCO Energy Storage Systems 2

Question 1

Ice-based thermal energy storage systems are primarily used to shift what type of building load?

Accepted Answer

Air conditioning (cooling) loads from peak to off-peak hours

Answer

Ice storage systems make ice at night using cheaper off-peak electricity, then melt it during the day to provide cooling, shifting the chiller load.

Question 2

What does 'state of charge' (SOC) represent in a battery energy storage system?

Accepted Answer

The current available energy expressed as a percentage of total capacity

Answer

SOC indicates how much energy remains in the battery at any given moment, expressed as a percentage from 0% (empty) to 100% (full).

Question 3

A flywheel energy storage system stores energy primarily as:

Accepted Answer

Kinetic (rotational) energy of a spinning mass

Answer

Flywheels store energy by spinning a rotor at high speed; the kinetic energy is converted back to electricity when the rotor decelerates.

Question 4

'Peak shaving' in energy storage refers to:

Accepted Answer

Using stored energy to reduce a facility's highest power consumption intervals

Answer

Peak shaving uses stored energy to flatten the demand profile by discharging the battery during the highest-demand intervals, reducing peak charges.

Question 5

Which battery chemistry is generally recognized for the longest cycle life among commercial energy storage options?

Accepted Answer

Lithium iron phosphate (LFP)

Answer

LFP batteries are known for exceptional cycle life (often 3,000–6,000+ cycles) due to the stability of the iron phosphate cathode chemistry.

ESCO - Energy Service Company Practice Test