GCSE Physics: Energy Stores and Transfers Guide

Energy stores

Energy can be stored in different ways: kinetic (movement), gravitational potential (height), elastic potential (stretched or squashed objects), chemical, thermal and others.

Energy transfers

Energy transfers between stores through four main pathways: mechanically (a force doing work), electrically (charge moving), by heating, or by radiation (such as light or sound waves).

Conservation of energy

Energy cannot be created or destroyed, only transferred between stores or dissipated (spread out, often as heat) — the total amount of energy in a closed system stays the same.

Efficiency

No energy transfer is perfectly efficient — some energy is always wasted, usually as heat due to friction. Efficiency = useful energy output ÷ total energy input, and can be improved by reducing unwanted transfers like friction.

Common mistakes

• Saying energy is "used up" or "lost" rather than transferred or dissipated.
• Mixing up gravitational potential energy (height-based) with elastic potential energy (stretch-based).
• Forgetting efficiency can never reach 100% in a real system.