How many compact fluorescent lightbulbs do you have ? We've only got six, but they are in the rooms we light most often. We still have halogen lamps in the kitchen; I /think/ they tolorate being turned on and off more often than CF lights, but that's a debatable issue.
Dr Matt Prescott wrote an article about them on the bbc site recently.
Friday, June 30, 2006
Food miles
We've started getting an organic veg box delivered from Abel and Cole. They've got quite a nice website where you can place standing orders for various size boxes which they fill with in-season veg from local suppliers.
We started buying 'organic' veg when we got Jamie home, as we figured he'd had enough random chemicals in hospital without adding pesticides etc. In the supermarkets though, the tiny amount of organic stuff they have is typically imported from a long way away - Egypt, Israel and Argentina seem to be popular. It does seem silly to me to transport, say, butternut squash from 8000 miles away. Seeing as we live in Kent, it's even sillier to ship apples from more than 10 miles away - we accidentally bought some recently that had come from some far flung corner of Europe.
I read somewhere that Germany send as many potatoes to the UK as we ship to Germany - the bbc did a piece about it if you want to read more.
We started buying 'organic' veg when we got Jamie home, as we figured he'd had enough random chemicals in hospital without adding pesticides etc. In the supermarkets though, the tiny amount of organic stuff they have is typically imported from a long way away - Egypt, Israel and Argentina seem to be popular. It does seem silly to me to transport, say, butternut squash from 8000 miles away. Seeing as we live in Kent, it's even sillier to ship apples from more than 10 miles away - we accidentally bought some recently that had come from some far flung corner of Europe.
I read somewhere that Germany send as many potatoes to the UK as we ship to Germany - the bbc did a piece about it if you want to read more.
Thursday, June 29, 2006
Kettle
Here's an easy one - when using a kettle, put as much water in as you expect to use, and turn the kettle off when it's at the right temperature.
Here's the maths: for every degree temperature raised, and for every 1ml of water, you need 4.3joules of energy. So raising one litre by eighty degrees takes 1000x80x4.3=344,000 joules.
To figure a cost for that, convert to kilowatt-hours:
1 watt == one joule per second
1 kwh == 1000 joules used continuously over a period of 3600 seconds, ie, 3,600,000 joules
At about 10p/kwh, that's roughly a penny, to raise a litre of water to just under boiling point from room temperature.
Trouble is, if you actually boil the water, you use a lot of energy just to turn the water into steam - and you don't pour steam into your tea so it's just wasted.
Here's the maths: for every degree temperature raised, and for every 1ml of water, you need 4.3joules of energy. So raising one litre by eighty degrees takes 1000x80x4.3=344,000 joules.
To figure a cost for that, convert to kilowatt-hours:
1 watt == one joule per second
1 kwh == 1000 joules used continuously over a period of 3600 seconds, ie, 3,600,000 joules
At about 10p/kwh, that's roughly a penny, to raise a litre of water to just under boiling point from room temperature.
Trouble is, if you actually boil the water, you use a lot of energy just to turn the water into steam - and you don't pour steam into your tea so it's just wasted.
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