Technology
The electrode in a battery that electrons come from during discharge
What is the anode?
In a grid that only uses solar and battery storage, this time period would represent the peak discharge time of the battery
What is evening?
Would freezing weather increase or decrease the round-trip-efficiency of a lithium-ion battery?
decrease
This chain reaction causes lithium-ion batteries to overheat and potentially catch fire.
What is thermal runaway?
Name three types of grid energy storage
Pumped Hydro, Batteries, Flywheels, Compressed Air, Thermal Energy
This family of battery chemistry is most commonly used in electric vehicles and grid-scale storage today.
What is a lithium-ion battery?
This is a reason that lithium-ion batteries poorly suited for seasonal grid storage
what is self-discharge during long storage periods
This term describes how much of a battery’s capacity is used in each cycle and affects its lifespan
What is depth of discharge (DoD)?
This metal, often mined in the Democratic Republic of Congo, is used in many lithium-ion batteries.
What is cobalt?
the predominant mode of energy storage on the grid in the US
This lithium-ion chemistry is known for being safer and longer-lasting but has lower energy density.
What is lithium iron phosphate (LFP)?
how batteries are able to generate revenue on the grid
what is arbitrage (buy low, sell high)?
This term describes how many times a battery can be charged and discharged before degrading significantly.
What is cycle life?
This system monitors voltage, temperature, and current to prevent battery failure.
What is a battery management system (BMS)?
This emerging battery technology replaces liquid electrolyte with a solid material for improved safety.
What is a solid-state battery?
the main current use of sodium-ion batteries
what is providing minutes of backup power between a grid outage and generators coming online
Two reasons battery energy storage is important for renewable energy adoption
Peak Shifting
Reliability
Stabilize voltage and frequency
Generate revenue
avoid need to scale up transmission networks with peaky generation
The amount of energy storage (aka capacity, in kWh) in a typical Tesla power wall
What is 13.5 kWh? (would accept 10-15 kWh)
This safer lithium-ion chemistry uses iron and phosphate instead of cobalt and nickel.
What is lithium iron phosphate (LFP)?
The round-trip-efficiency of pumped hydro
70-80%
Three advantages of sodium-ion batteries compared with lithium-ion batteries
Greater cycle life, faster charge time, lack of scarce elements
This key grid service provided by batteries helps maintain a stable system frequency (around 60 Hz in the U.S.)
What is frequency regulation?
This metric (Wh/kg) describes how much energy a battery stores relative to its mass
What is energy density?
This gas can be released during battery failure and poses a serious inhalation hazard in fires.
What is hydrogen fluoride (HF)?
store excess heat or cold in materials like water, molten salt, or rocks for later use
thermal energy storage