Run your washing machine at 30 degC

Ariel have been running a campaign to encourage us to run our washing machines at 30°C. We switched to this as our default about 6 months ago and frankly (even though we don't use Ariel special low-temperature powder) we have noticed absolutely no difference in the results. Much to my husband's disappointment, this may be the only way in I resemble Helena Christensen.

So how much difference does this make? Ariel says 40% of your energy usage (presumably that part relating to washing clothes).

When you wash clothes, 90% of the energy is used in heating the water (according to the Centre for Alternative Technology) . As energy used to heat water is proportional to the temperature rise (energy required = mass x specific heat capacity x temperature difference), this means that Ariel are assuming that 50% of the energy is being used to heat the water from ambient to 30 deg C, and the saved 40% is the additional energy required to get the water from 30 to 40 deg C. So the ambient water temperature would be 17.5°, which sounds pretty high (I would have guessed 10-12 °), but I've just gone to check it with my oven thermometer and it is correct. The 30° cycle is shorter than the 40° cycle, so this will save even more.

But how much of my electricity bill is going on my washing machine in the first place? General estimates are around 20% (I'll try and work out a better one). So saving 40% of 20% means saving 8% of my electricity bill, or 266 kgs of CO2. Just over 1% of my personal carbon footprint. Well, it's a start, and a pretty painless step.

A few more washing machine tips...

• Always wash a full load - each load uses (and heats) the same amount of water so you might as well fill it up.
• Only use the pre-wash cycle if you really need it (uses about 15% more energy).
• Use stain treaters to avoid needing to wash at higher temperatures.
  
• Buy an energy efficient waching machine.
  

Plastic bags: give 'em up!

There are 17 billion plastic bags given out to British consumers every year. Only 1 in 200 are recycled, and the rest take from 15 to 1,000 years to biodegrade. Then there is the energy cost of producing them... (although, interestingly, plastic bags are better than paper bags) .

This is an easy one to give up.

I bought an "onya" bag today - naff name, but a great idea. They are carrier bag-sized bags made out of parachute silk with a little built-in stuff sack so they pack up super tiny, weighing only 50g - so you always have one onya - geddit. http://www.onyabags.co.uk. It was £6 in the lovely deli in Balham, or you can buy online. Cheaper than those trendy designer "This is not a plastic bag" bags...

Meanwhile, a town in Devon has banned plastic bags, and Waitrose has become the latest supermarket to announce a trial two-week ban after the success of Sainsbury's one-day ban.

Sounds great, but we could go a lot further - a 15p "plastax" plastic bag tax in Ireland has lead to a 90% reduction in use. Taiwan has not only banned plastic bags, but also all disposable plastic packaging from fast food, resulting in a 25% reduction in landfill waste. And even the US are getting involved - later in the year, San Francisco will become the first major US city to ban non-biodegradable plastic bags.

So come on UK - keep up!

Intermission

It's been a while - apologies for the gap. We were in New Zealand for 3 weeks which was fantastic (holiday pics). The best bit was hiring a little campervan so we could drive whereever we wanted and stopped overnight in some beautiful locations. Lots of fresh air, clean water and incredible views. After that, no excuse, just busy...