Energy Storage Systems Flashcards
7 cards from real ESCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Energy Storage Systems flashcards as text
Ice-based thermal energy storage systems are primarily used to shift what type of building load?
Answer: Air conditioning (cooling) loads from peak to off-peak hours
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.
What does 'state of charge' (SOC) represent in a battery energy storage system?
Answer: The current available energy expressed as a percentage of total capacity
SOC indicates how much energy remains in the battery at any given moment, expressed as a percentage from 0% (empty) to 100% (full).
A flywheel energy storage system stores energy primarily as:
Answer: Kinetic (rotational) energy of a spinning mass
Flywheels store energy by spinning a rotor at high speed; the kinetic energy is converted back to electricity when the rotor decelerates.
'Peak shaving' in energy storage refers to:
Answer: Using stored energy to reduce a facility's highest power consumption intervals
Peak shaving uses stored energy to flatten the demand profile by discharging the battery during the highest-demand intervals, reducing peak charges.
Which battery chemistry is generally recognized for the longest cycle life among commercial energy storage options?
Answer: Lithium iron phosphate (LFP)
LFP batteries are known for exceptional cycle life (often 3,000–6,000+ cycles) due to the stability of the iron phosphate cathode chemistry.
What does 'C-rate' describe in battery energy storage systems?
Answer: The rate of charge or discharge relative to total battery capacity
C-rate expresses charge/discharge speed as a multiple of capacity; a 1C rate fully charges or discharges in 1 hour, while 0.5C takes 2 hours.
Hot water thermal storage systems are most commonly used to shift what type of load?
Answer: Water heating load from peak to off-peak electricity hours
Hot water storage tanks heat water using off-peak electricity or excess renewable energy, storing thermal energy for on-demand domestic hot water use.