Energy conservation reduces energy use by avoiding or limiting an energy-consuming activity. Energy efficiency reduces the energy required to provide the same useful output or service.
This is core content for SL and HL, within IB ESS subtopic 7.2 Energy sources: uses and management.
How the Two Approaches Differ
| Approach | Mechanism | Example |
|---|---|---|
| Energy conservation | Changes behaviour or reduces demand for an energy service | Turning off lights, lowering heating, using public transport instead of driving |
| Energy efficiency | Uses improved technology or design to provide the same service with less energy | Replacing an incandescent bulb with an LED that produces similar light using less electricity |
For example, switching off classroom lights during lunch is conservation because the lighting service is temporarily avoided. Replacing those lights with LEDs is efficiency because lighting is still provided, but less electrical energy is consumed.
Both approaches can reduce fossil-fuel consumption, greenhouse gas emissions and dependence on imported energy. They can therefore improve energy security, meaning access to affordable and reliable energy, while reducing pressure on natural resources.
However, their implementation differs. Conservation often depends on sustained behavioural change and may be viewed as reducing convenience or consumption. Efficiency usually requires an initial investment in technology, although lower operating costs may repay this over time. Policies should also consider environmental justice: low-income households may benefit from reduced energy bills but may be unable to afford efficient appliances without subsidies.
A named example is Japan's Cool Biz campaign, which encouraged lighter workplace clothing and reduced air-conditioning demand. This primarily promoted conservation, although efficient air-conditioning technology could complement it.
A common misconception is that conservation and efficiency are interchangeable. They are not: conservation reduces the amount of a service used, whereas efficiency reduces the energy input per unit of service.
Exam Technique
For the command term distinguish, state both concepts and make the difference explicit. Use one paired example, then link both strategies to energy security, sustainability and possible social or economic limitations.