Low Impact

Even the little things we do everyday without even thinking about can have an effect on our environmental impact.

For instance, take that morning cup of tea (or coffee). Like most people, you probably shove the kettle under the tap, fill it up, turn it on, wait impatiently for it to boil, then make the actual tea. But how much water was in the kettle? A standard cup might be only 300 mls, but many people keep their jug permanently filled with around a litre or so of water. So, you’re heating up (say) 1.5 litres of water to make a 0.3 litre cup of tea - the electricity for that extra, “unused” water is wasted.

So what? There’s more to life than measuring the water in the kettle right? Still, its worthwhile looking at the numbers.

It takes around 4200 joules to heat 1 litre of water 1 degree. To keep the numbers nice and simple, lets say our kettle has 1.3 litres of water in it, to make our 0.3 litre cuppa. So, the energy we used for that extra 1.0 litres is wasted.

We’ll assume our water is a mild 20 degrees, and the kettle will heat it up to around 90 degrees. So, our waste litre requires 4200 x 70 = 294,000 joules of energy. 1 watt is 1 joule/second, so a 1500 watt kettle will take 196 seconds (or a bit over 3 minutes) to heat the wasted portion of the water. Therefore we have used 1500 x (3/60) = 75 watt-hours of electricity (with all its associated carbon-dioxide emissions at the power plant) to heat 1 litre of water that you won’t even drink!

And, over a year (assuming you have a nice cup of tea to start of each day!), thats 27.375 KwH (or around 27 kg of CO2 when your power is generated from coal sources).

Its amazing how the little things add up. So tomorrow morning, you might not want to add quite so much water to the kettle. It won’t cost you a cent to make that small change to your daily routine and as an added bonus, not only will you produce less greenhouse gasses, your kettle (and your cup of tea) will be boiled up that much sooner!

Categories: efficiency, environment, green, reduce