Energy Storage Vocabulary Quiz
12 multiple-choice questions on energy storage vocabulary: battery, capacitor, lithium-ion, pumped hydro, electrolysis, fuel cell, thermal storage, redox flow, energy density and more. C1 level.
This quiz focuses on how the target vocabulary for Energy Storage is actually used in context at C1 Level level, rather than testing bare definitions. Correct answers you will need to identify include terms such as lithium-ion, pumped hydro, fuel, electrolysis and discharge, each embedded in a full example sentence so you have to judge meaning from context, not just recognise an isolated word.
Working through all these questions and checking the explanations in the FAQ below is a quick way to spot any terms you are still unsure of. Revisiting the quiz again after a day or two, rather than only once, is one of the most reliable ways to move new vocabulary from passive recognition into words you can use confidently yourself in speaking and writing.
Keep building your energy storage vocabulary.
Energy Storage Vocabulary — FAQ
What is a 'lithium-ion battery'?
A lithium-ion (Li-ion) battery is a rechargeable battery in which lithium ions move from the anode to the cathode during discharge, and back during charging. Li-ion batteries have high energy density and long cycle life. They are used in smartphones, laptops, electric vehicles and stationary storage systems. Their invention was recognised with the Nobel Prize in Chemistry in 2019.
What is 'pumped hydro storage'?
Pumped hydro is the most widely used large-scale energy storage technology. It works by pumping water from a lower to a higher reservoir using surplus electricity, then releasing water through turbines to generate electricity when demand is high. It can store very large amounts of energy and responds quickly to grid demand.
What is a 'fuel cell'?
A fuel cell converts the chemical energy of a fuel (most commonly hydrogen) directly into electricity through an electrochemical reaction with oxygen, without combustion. The only by-products of a hydrogen fuel cell are water and heat. Unlike batteries, fuel cells produce electricity continuously as long as fuel is supplied.
What is 'electrolysis' in energy storage?
Electrolysis uses electrical energy to split water into hydrogen and oxygen gas. Using renewable electricity, this produces 'green hydrogen' that can be stored and used later as a fuel. Electrolysis is a key technology for long-duration energy storage and the production of clean hydrogen.
What is 'energy density'?
Energy density is the amount of energy stored per unit of mass (Wh/kg) or volume (Wh/L). A high energy density allows more energy to be stored in a smaller, lighter package — important for electric vehicles and portable devices. Lithium-ion batteries have a much higher energy density than older lead-acid batteries.
What is a 'redox flow battery'?
A redox flow battery stores energy in two liquid electrolyte solutions held in separate tanks. During charging and discharging, solutions are pumped through a central cell where oxidation-reduction (redox) reactions occur. Energy capacity can be increased simply by using larger tanks, making flow batteries well suited to grid-scale, long-duration storage.
What is 'grid-scale storage'?
Grid-scale storage refers to large energy storage systems connected to the electricity grid, capable of storing megawatts to gigawatts of energy. Technologies include pumped hydro, large lithium-ion systems and flow batteries. They are crucial for integrating variable renewable energy sources (wind and solar) into the grid.
What is a 'capacitor' and how does it differ from a battery?
A capacitor stores energy in an electric field between two conductive plates. Unlike a battery, which stores energy through chemical reactions, a capacitor stores energy electrostatically and can charge and discharge very rapidly. Supercapacitors offer higher power density and very long cycle life but store less energy than batteries of the same size.
What is 'thermal storage'?
Thermal storage systems store energy as heat or cold. Examples include molten salt storage in solar power plants, ice storage for building cooling and hot water tanks. Thermal storage is often a cost-effective way to shift energy demand and reduce reliance on expensive peak-time electricity.
What is a 'charge cycle' in battery technology?
A charge cycle is one complete cycle of charging a battery to full and discharging it to empty. The number of cycles a battery can complete before its capacity degrades significantly is its cycle life. A battery with a cycle life of 500 cycles can be fully charged and discharged 500 times before capacity drops below 80% of its original value.