Today, try this: fill your kettle (or water boiler) with only the amount of water you need before boiling.
This simple habit lowers energy use, cuts carbon emissions, and costs nothing to adopt and supports the Sustainable Development Goal 7: Affordable and Clean Engergy.
Why It Matters
- In the UK, three-quarters of households overfill their kettles, wasting energy every day.
(Source: University of Strathclyde & Energy Saving Trust study) - Research shows that boiling only the water you need can reduce the environmental impact of kettle use by about one-third.
(Source: Gallego-Schmid et al., University of Manchester) - An EU review estimated 20% or more energy-saving potential in kettle use by improving user habits like avoiding overboiling.
(Source: Electric Kettles: EU Policy Assessment)
These numbers show that behavior — not just device efficiency — is key to reducing household energy demand.
The Impact
If you usually overboil by 0.5 L:
- Each boil wastes about 0.06 kWh of electricity.
- Over a year (1 boil/day), that’s about 22 kWh saved if you stop overboiling — preventing roughly 11 kg of CO₂ emissions (based on ~0.5 kg CO₂/kWh average grid factor).
- If 1 million households adopt this habit, we save 22 million kWh and cut 11,000 tons of CO₂ annually.
How to Start (Today)
- Pick a kettle you use most.
- Mark a “one-cup” or “needed amount” line inside.
- Boil only to that line.
- Repeat daily — the savings will add up.
Bottom Line
Next time you reach for your kettle, fill it with only what you need.
A few seconds of mindfulness can save energy, cut emissions, and bring us one step closer to achieving SDG 7: Affordable and Clean Energy.