Energy storage


The two main types of batteries that are commonly used are single-use and rechargeable. The single-use batteries, sometimes referred to as primary types, are commonly alkaline batteries, and these are readily available in supermarkets and shops.

All batteries are available in a range of sizes and shapes - tiny batteries known as button-cell batteries power calculators and hearing aids, while very large batteries power cars and trucks.

Lithium button-cell batteries displayed on a white background alongside a calculator.
Button-cell batteries in a calculator

Common forms of batteries used in homes are AA and AAA, and both typically produce around 1.5 volts (V) per battery. A larger PP3 battery, often used for smoke alarms and medical equipment, typically produces 9 volts (V) per battery.

Three batteries, AA, AAA and PP3, are shown next to each other for comparison.

Once a battery runs out it has to be replaced unless it is rechargeable, in which case it is connected to a mains power source to be recharged.

A set of four AA rechargeable batteries on charge.

Rechargeable batteries:

  • are more expensive to purchase than single-use batteries
  • can be recharged
  • are more economical in the long term
  • have a limited lifespan

Rechargeable batteries can only be recharged a number of times before they lose battery life, in the same way as smartphone batteries lose battery life over time.

Batteries can be recycled to prevent them ending up in landfill sites. Batteries contain harmful chemicals and metals that are bad for the environment if disposed of incorrectly; these elements can contaminate the ground or poison the wildlife that may eat them.

Kinetic-pumped storage systems

A kinetic-pumped storage system is a fast-acting electrical energy storage system to top up the National Grid power supply at peak times when more electricity is needed. A kinetic-pumped storage system works by having two reservoirs and a hydroelectric dam system.

During the night excess electricity is produced by other electrical energy stations, meaning the cost of the electricity is much lower, so a kinetic-pump plant will pump the water from a lower reservoir up to a higher reservoir, where the water remains. When there is a sudden need for more electricity (spike) during the daytime, the dam is opened and the water from the top reservoir passes through pipes, spinning turbines to quickly produce the electricity needed.

A kinetic-pumped storage system turning the flow of water into electricity. Water flows from a reservoir through a turbine before being pulled back up again.
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