The Green Tau: issue 16

10th September 2021

The Appliance of Science

Heating consumes most of our household energy and consequently carbon budget. Of the remainder  some is used for heating water – for baths, showers etc – but most is used in the kitchen: about 60% on average. The typical kitchens contain a cooker, kettle, fridge and washing machine. There may also be a freezer and a tumble dryer. And then any number of smaller appliances which can take up so much space – coffee machine, blender, mixer, toaster, juicer, rice steamer, slow cooker, waffle maker, sandwich maker, bread maker, deep fat fryer, ice-cream maker, coffee grinder, electric whisk, soup maker, griddle … 

Think of an average day in the kitchen. Boil the kettle for a hot drink: approx 25g CO2 per mug of hot water; pop bread in the toaster: 75g; microwave a bowl of porridge: another 25g; run the dishwasher: 275g (70 minute programme); run the washing machine: 400g (100 minute cycle) plus 20 minutes in the tumble dryer: 250g; brew a fresh coffee with the coffee machine: 50g; bake a cake: 750g; half an hour’s ironing: 350g; make supper (eg pasta, sauce and vegetables) using three hot plates 250g; put another load through the dishwasher: 275g; boil the kettle for a bedtime hot drink: 25g. That adds up to  2750g. Meanwhile the fridge is contributing 1250g per day and the freezer 750g, giving a total of 4750g.

If we move around the home, we have the computer and the TV which might each be another 250g CO2 per day, the vacuum cleaner, mobile phone chargers (most homes have more than one), internet hub, Alexa,  hair dryer, pressure shower etc. Plus all the light fittings. 

Perhaps it is not surprising that energy consumption in our homes accounts on average for 22% of the UK’s national carbon footprint. But if we are to achieve the UN’s targeted  45% reduction on CO2 emissions  by 2030 – and net zero by 2050 – we need to find ways of reducing our personal footprint.  We can change the way we use our household appliances and next week’s Eco Tips will look at ways of making efficiency savings. 

We can use more energy efficient appliances – but is buying something new the best answer if that means throwing away equipment that is old but still working? 

Every appliance we buy, large or small, has already produced a carbon footprint  by virtue of its manufacturing, and distribution.  Information on the size of these footprints is not readily forthcoming. This may in part be because often these appliance – or their components – are manufactured elsewhere in the world. Current accounting procedures would allocate these carbon costs to the country of production and not the country of consumption. 

As well as considering the manufacturing carbon footprint of the appliance, we also need to consider the life span of the appliance. A fridge that has a life of 20 years will better repay its carbon footprint, than a fridge that is only used  for 5 years. Sadly many appliances now seem to have a very short life. Whereas a fridge or cooker might have lasted 30+ years, modern day equivalents have an expected lifespan of 10 -13 years. Even then they may not serve their full span as in out throw away society, many are discarded as part of the popular pastime of kitchen refurbishment. 

The UK has one of the highest rates of throwing away electrical appliances. In 2019 this was almost 24kg of waste per head.  Less than 20% of our electrical waste (e waste) is currently recycled  with the rest going to landfill with the potential harm of toxic chemicals leaking out, whilst at the same time failing to salvage valuable metals and other elements that could be reused. E waste will be a future topic for Green Tau. 

NB Recent EU legislation requires that electrical appliances should a, be repairable and b, that manufacturers should provide spare parts for up to ten years after a model has gone out of production. The UK introduced similar legislation in July of this year, although manufacturers have a two year window in which to bring in these changes.