Wintry things

Winter arrived in Devil's Bridge this morning, almost as abruptly as autumn arrived, back in August. We've had a few hard frosts, but mostly it's been pretty mild, then this morning it snowed....

... and very pretty it is too, though not so nice for birds.

A pair of bullfinches came to feed on dock seeds.

When I say the weather's been mild, it's still quite cold enough to have the heating on and as usual, we're struggling to keep the house warm. The other day I did a maintenance job that I should have done ages ago. I replaced the fire rope seals around the doors on the wood burning stove.

Until I started measuring how much I needed, I hadn't even noticed that the ash flap at the bottom also has a channel to fit rope into. It's not a very big job, though slightly bigger due to the fact that it was previously fixed with cement (it shouldn't be), so I had to chip all that out first.

We couldn't believe how much difference it made! We'd always thought our second hand stove was just old and leaky but in fact, with new seals in place, it's possible to close down the air flow so much that wood stops burning. Without the flow of cool (room temperature) air into the fire box, it gets a lot hotter and radiates far more heat into the room. We're also using less wood, as it doesn't burn up so quickly. A day after I replaced the rope, Ian investigated the air inlet control, which has never had any noticeable effect before. With the ash cleared out of the vent, it works just fine, so now we have an efficient, controllable stove. It's like having a new one! It's a salutary illustration of the importance of maintenance.

Now, I'm going to go and sit by the fire, but I'll leave you with one more picture of snow, because the sun came out briefly about an hour ago.

Are dishwashers more efficient than my hand washing?

We often hear that dishwashers, counterintuitively, use less energy and water than washing the dishes by hand. No matter how many times I'm told this, I find it hard to believe, so when I finished a load of washing up today, I took a few measurements so I could compare my washing up with those that have been reported. Firstly, I bailed the water out of the bowl with a measuring jug to see how much there was, then added a bit to allow for water that had sloshed over the side. I hadn't rinsed under a running tap without catching that water in the bowl, so I didn't have to add any for that. The total amount of water was about 5.5 litres.

I know, because I've measured it before, that water that I find hot to the touch is 43°C. It's pretty chilly out at the moment, so let's say the incoming main is 5°C and round it up to 45° for washing-up temperature (all approximations here err on the side of increasing energy usage in my test). Since water is very reliable in how much energy it requires to heat up, I can calculate that this would take 256 Watt hours of energy to heat, or just over a quarter of a kWh.

I then needed to know how much washing up I'd achieved. One load for me is until either the draining rack is full or the water is too dirty to wash any more. This tends to occur at roughly the same time, though I do more rinsing under the tap towards the end of the load, as the water gets dirtier. I noted down what I'd washed:-

• 4 glasses
• 2 mugs
• 1 tin can and 1 jam jar
• 1 measuring jug (not the one I used for bailing)
• 5 plates
• 3 bowls and a basin
• pestle and mortar
• 2 saucepans
• 2 mixing bowls
• 2 plastic trays that fruit came in, for recycling
• 15 items of cutlery

One load of washing up

See those pans on the windowsill behind? I used the dirty water from this load to soak them so they'll be easier to wash when I get round to them. I do that.

Having noted down the details of my own washing up, I then needed to find appropriate figures for comparison with dishwashers. The fact that dishwashers are more efficient seems to come mainly from a study conducted at Bonn University, comparing many people actually washing up with dishwashers doing the same work. When I looked for this study I was pleased to find that they've done a follow-up with smaller loads (the original study was a full twelve place settings in one go): Our intention was to simulate the dishwashing situation in a two-person household, excellent! ... in which two place settings are used and cleaned three times per day ah, I'm not sure I wash up that frequently, ... and four additional items are soiled heavily in the food preparation processes and are washed separately. Do you wash up the pans separately? Still, we should be getting close to comparable figures.

I looked at the details of the study. One place setting consists of:-

• a soup plate
• a dinner plate
• a dessert dish
• a cup
• a saucer
• a serving dish
• a glass
• a fork, a knife, a soup spoon, a teaspoon, a dessert spoon

So that would be a three course meal with coffee to follow, three times a day?? OK, never mind how unrealistic this is. I now have some details to work with. How does my load of washing up map onto this test load?

two place settings plus pans	my washing up
2 soup plates; 2 dessert dishes	3 bowls and a basin
2 dinner plates; 2 saucers; 2 serving dishes	5 plates
2 cups	2 mugs
2 glasses	4 glasses
10 items of cutlery	15 items of cutlery
4 pans/casserole dishes	2 pans; 2 mixing bowls
not included	pestle and mortar
not included	measuring jug
not included	tin can; jam jar; plastic trays

It looks like my load of washing up was slightly more than one of their two-place-setting loads plus their food preparation load. Let's say they're roughly the same - how do the figures compare with their hand washers?

The water and energy measurements show a very wide distribution of consumption values, ranging from four to 90 l and from 0.03 kWh up to 2.6 kWh for washing a pair of place settings. Washing four heavily soiled cooking items required slightly more energy and water than two place settings.

I used 5.5 l and 0.26 kWh for a pair of place settings plus four cooking items. For water consumption I am off their scale, and I'm way down there for energy consumption too (apparently someone was happy to wash up in cold water).

How about the machines? We need to take account of the fact that you'd put more in a machine than my one load done by hand. I estimate that you'd get two to three times as much in a dishwasher, and their test used six place settings (three times as many as one of their hand-wash loads) plus the pots and pans. I think multiplying my usage by 2.5 gives a fair basis for comparison, so that's about 14 litres and 0.64 kWh. Their machines used 83 litres. With regard to energy consumption (Fig. 8), the tendencies are similar, but the difference between manual and automatic dishwashing is not as pronounced. They don't even report the figures, but examination of their Figure 8 shows almost identical energy consumption for the 6 place setting plus pots and pans; approx. 1.8 kWh.

As I'd suspected, the current emphasis on low water consumption serves to distract from high power usage. When compared with my own washing up, as best I can, I am far more efficient than a machine in both water and energy consumption.

I finish by noting a sentence from their acknowledgements section: Thanks are due to our four European manufacturers of dishwashing machines (Bosch und Siemens Hausgeräte, Electrolux, Merloni Elettrodomestici and Arcelik) for supporting this study.

Choosing light bulbs

As part of my ongoing mission to reduce our electricity consumption, I've been using low-energy light bulbs for years. We still have a few of the old-style incandescent bulbs in rooms where we switch the light on only briefly (i.e. the loo and bathroom) because the low-energy ones take a while to get going (actually, the newer ones probably aren't too bad. Ours are mostly quite old). This chimed nicely with last week's Change the World Wednesday challenge, which was to replace at least one incandescent bulb in the house with a low-energy bulb.

Having said that we only have old fashioned bulbs in rooms where they're switched on briefly, I have to confess I wasn't telling the whole truth there: We still had halogen bulbs in the kitchen. We'd been meaning to replace them with LED bulbs, but had had trouble finding any in local shops. By coincidence, in the same week as the challenge, one of the halogens blew and Ian ordered a set of four LED bulbs online (they're nowhere near as expensive as they used to be, by the way).

LED bulbs replacing halogens in our kitchen

So, challenge met with zero effort on my part! I have to say, we don't like the new bulbs very much. They're a very cold light and, being so directional, make the kitchen seem much darker than with the same amount of light more evenly spread around. I'm sure we'll get used to them in time.

This isn't the end of the story, though. The challenge prompted some very interesting discussions of the pros and cons of different types of light bulb, both in comments on the original blog post, and in linked blogs. In particular, Argentum Vulgaris had quite a lot to say about the cons of CFLs (compact fluorescent lights - like the old fluorescent tubes, but smaller), following up his earlier post on the same subject. I was quite shocked to learn that there are lots of reasons not to like these increasingly ubiquitous bulbs, and set about doing some research. Here are the various objections and what I've learned about each one.

1. They contain mercury. Do they? Well I never knew that. Not only do they contain mercury, but the way they produce light it by vapourising mercury. This poisonous chemical is their very essence! While the mercury is safely contained within the bulb, this may not be a very great concern, but what if one breaks? Mercury vapour is not something you want to be inhaling. Luckily, it turns out that the concentrations of mercury vapour in the air that might result from breakage are nowhere near high enough to do you any harm (though I probably still wouldn't bend over to clear one up straight after it had broken, just to be on the safe side).
   
   That's not the only concern, though. It seems that the main worry about mercury is that, once released into the environment, it gets into the food chain and particularly builds up in fish (presumably not good for the fish, though no-one seems terribly worried about this), which we then eat (not good for us - a major concern). So if all these CFLs that we're now fitting in our houses end up in landfill, will they release a lot of mercury pollution into the environment? One answer that I came across in various places is that the amount of mercury they'll release is outweighed by the savings in emissions of mercury from coal-fired power stations. That claim has to be worth a bit of investigation.
   
   First fact: Coal burning is the biggest human-generated source of mercury in the atmosphere. There are non-trivial amounts of mercury involved here. Estimating how much is tricky, though, because coal is not a pure substance - it's a mixture of all sorts of stuff, varying from place to place. The amount of mercury in coal varies enormously. I did manage to find some estimates, though: The amount of mercury in coal varies from 0.012 mg/g to 33 mg/g, of which 90% is released into the atmosphere. The next question is: How much coal is burned to generate one kWh of electricity? That answer is fairly easy to find: It's 0.36 kg, or 360 g of coal. Using the very lowest figure for amount of mercury in coal, we can calculate that generating 1 kWh of electricity by burning coal releases 3.9 mg of mercury into the atmosphere. Coincidentally, that's almost exactly the same as the amount of mercury in a CFL bulb.
   
   That means that if you can save just one kWh of electricity with your CFL bulb, and if your electricity comes from a coal-burning power station burning the very cleanest coal, then the CFL is releasing less mercury than the incandescent bulb. I feel a graph coming on...
   
   
   
   Electricity used by incandescent and CFL bulbs
   
   If you replaced a 100W incandescent light bulb with a 30W CFL (and that's a fairly high powered CFL on the usual equivalents), by the time you'd used the light for 15 hours you would have saved the same amount of mercury in power station emissions as the mercury you might release when you eventually throw the bulb away. Remember, that's with the very cleanest coal; the dirtiest coal contains several thousand times as much mercury as that. Of course, this only applies if your electricity is produced by a coal-fired power station. I'm not sure whether mine is or not, but this analysis persuades me that mercury is a non-issue.
2. CFLs emit electromagnetic radiation. Well if they didn't, they wouldn't be much use. Light is electromagnetic radiation!
3. CFLs emit UV radiation. OK, this is a bit more specific, and yes, they do. So does the sun. It's possible to get sunburn from CFLs if they're within about 30 cm of your skin, so you may want to consider how close you put your desk lamp.
4. In a cradle to grave analysis, CFLs use more energy than incandescent bulbs. I have to quote this one: An International Association for Energy-Efficient Lighting (IAEEL) study conducted in Denmark, explored some carbon footprint factors, but not all, showing it took 1.8 Kwh of electricity to assemble a CFL compared to 0.11 Kwh to assemble an incandescent bulb. That means it took 16 times more energy to produce a CFL. Yes, but we've already seen how quickly a kWh or two can be saved when using these bulbs. The study did not include the fact that a CFL is much heavier and is more dangerous to handle, and will thus cost more to package, to ship, and to sell. Um, much heavier and more dangerous? I don't think so. Maybe a little bit heavier, but it's not going to make that much difference. This research also did not calculate the energy required to safely dispose of a CFL and reclaim the mercury. The cost of removing mercury from the landfills was also not considered. As already discussed, the quantities of mercury involved are trivially small compared with that released by burning coal. There will be no cost of removing it from landfill. If such a study could be done, and considered all the negative contributing factors, it would show a CFL has a massive carbon footprint, one that would dwarf a regular incandescent light bulb. I doubt it.
5. The waste heat produced by incandescent bulbs makes a valuable contribution to heating our homes. Heat rises. Do you really want to heat your ceilings?
6. CFLs emit ultrasound. This is interesting. (Actually, most of the article is really annoying, but the bit at the end is interesting). Yes, it seems that CFLs have something known as electronic ballast, which turns the power on and off very rapidly to stop a runaway reaction in the bulbs, which would destroy them very quickly. This operates at a very high frequency, too high for humans to hear but within hearing of just about every other animal. Well, all I can say to this is that my cat doesn't seem overly bothered by it. On the other hand, older fluorescent tubes, which operate at a lower frequency, can be unpleasant to work under, and Mrs Green reports that they give her insomnia and dizzy spells. In my opinion, this is the only good reason for not using CFLs.

After all this research, I've found only one good reason (and there were others that I can't be bothered to go into here) for not using CFLs, and I'm lucky enough not to be affected by this. Don't fall for the scare stories!

Save energy: Clean the fridge

I'm not talking about the cleaning the inside of the fridge, here, but the back. A fridge is a heat exchanger; it takes transfers heat from the inside of the fridge out into the room. The part that sends the heat out into the room is a radiator type attachment on the back. If this is coated with an insulating layer of dust, it's going to have to work harder to get the heat out there, so the fridge is less efficient, overall.

Cleaning it is such a no-brainer that I shouldn't need any prompting to do it, but... well, I'm rubbish at housework at the best of times, and out of sight is out of mind, so this job tends to get neglected. I am therefore very grateful to Small Footprints for this week's nice, easy Change the World Wednesday challenge: Check your fridge. This gave me the nudge I needed to go and do that small job.

It really is a very small job; move fridge away from the wall, dust back of fridge, move it back. Of course it wasn't quite that easy. I used a cloth duster first, and though that removed some of the dust, there was obviously still quite a lot left. I then tried a fluffy kind of duster, which wasn't much better. I decided that what I really needed was a paintbrush to get into all the little gaps, and wondered where I'd left the brushes after the last time I used them. A bit of poking about revealed one brush on the kitchen windowsill (not sure what happened to the others). That worked much better than the dusters, so then it was a matter of a few minutes to clean the back of the fridge.

Before and after photos of the back of my fridge. As you can see, years of neglect left it seriously dusty. I don't know why the grill in the right hand photo appears lower. I didn't move it, honest.

It's not completely clean now, but there's a lot less dust trapping the heat in the grill, so hopefully my fridge is now breathing a sigh of relief that it doesn't have to struggle against this blanket as it tries to do its job.

First project on treadle sewing machine: Party dress

It may seem like an ambitious place to start, but I needed a dress to wear to my cousin's wedding. I had a dress I'd worn to another wedding earlier in the summer, but that was a) an evening dress, so not really appropriate for a daytime wedding, and b) in need of many safety pins to hold it up. So, with just under a month to go before the happy occasion, I decided to make myself a new dress.

Taking inspiration from a dress worn by a friend recently (that I've just spent, oh, far too long trying to find a photo of) I had an idea of the design I wanted. This consisted of a simple top - basically triangles over the bust, though I'd want a bit of shaping - set into a high waistband, with a skirt made of curved strips of different fabrics. Sorry I couldn't find a photo to make this clearer!

The first step was to find some suitable fabrics. As I no longer work in an office, I have no need of office-wear, so headed to my wardrobe and identified several shirts in co-ordinating colours that could plausibly be turned into a dress.

I no longer need these - they shall be sacrificed!

I decided to start at the top. I'm not sure why, but it seemed as good a place as any. When I say top, I mean bust, not straps. I chose the plain purple shirt for this bit, and the obvious place to look for fabric was the equivalent part of the shirt. Unfortunately this didn't suit, as a shirt is not entirely symmetrical, having buttons on one side and buttonholes on the other. Nevertheless, I started unpicking, and as I got to the top of the sleeves thought, That's quite a nice curved shape there. Use what you've got - that curve became the top line of my dress. Having identified my pieces of fabric, I cut them approximately to size and set to work rearranging the flat pieces to fit my not-flat chest. There was much holding of fabric against myself, pinning and adjusting. No, you don't get photos of this bit! Once I'd decided where to make darts, extensive tailors' tacks were applied to mark the positions, so I could transfer them accurately onto the other piece before stitching.

Extensive application of tailors' tacks.

Now I was ready to start sewing. Well, not quite ready. I'd found a small space in the spare room for the sewing machine...

A space for sewing

... but hadn't actually tried using it yet. Soon fixed. I picked on the cuffs as unlikely to be of any use, and tried a few lines of stitching.

Test stitching looking OK, actually

After a few goes, I was happy with it and stitched in the bust darts and moved onto the next bit. I picked the collar and cuffs of the striped purple shirt as a suitable waistband. Together, they were easily big enough and had the added advantage of a button and buttonhole to close the back (use what you've got), though I'd need another to go with that.

Opening the collar/waistband to fit the top into

By the time I'd stitched those together, I essentially had a large bra. I did try it on, but no, you're still not getting pictures! Next step was the skirt. I measured my waist, the length of the drop to somewhere below my knees, and the length needed at the hem (I looped the tape measure round my legs and adjusted until it was about loose enough). I divided two of these by six and transferred these measurements onto a piece of paper, then drew freehand curves connecting them all up.

Pattern for one of six skirt sections

As I drew, I realised that one curve was longer than the other, so I measured along that curved edge, and drew another line for the bottom edge, to make sure they'd fit together.

Adjustment to pattern so the pieces would fit together.
Quite advanced, I thought.

I'd thought that I'd need to make these pieces up in patchwork, but when I looked at the shirts I realised that if I went across the shirt, I'd be able to get the length and, get two pieces out of each shirt...

First skirt piece

... just.

Second skirt piece. Of course that fits! Who needs hems?

Right, we're really going some now! Cutting and pinning, cutting and pinning...

Skirt pieces pinned together

Pebble helped.

Once I'd got the whole thing pinned together, it was time for another fitting.

First fitting of pinned-together dress

For once, I'm glad this photo's terrible because it was at this point that I realised I'd forgotten one crucial measurement: My hips. Oops. Oh well, all was not lost. I'd been fairly generous with the hem allowances... maybe if I just moved all the pins closer to the edges it would be OK. I tried it on again, and it was definitely better. A little tight, but probably OK. I sewed it up.

I should probably say something about the experience of using the treadle at this point (given that I didn't say it earlier). Obviously it was more difficult than an electric pedal. My big problem was keeping the wheel going in the right direction. Because I was going slowly, it kept stopping and reversing, which tangled the thread round the bobbin and broke it. I found that if I put one foot right across the treadle and one with just the toes resting on the edge, I could get better control, but I still liked to keep my hand on the top wheel to stop it going backwards.

I got better at it with a little practice, and I certainly had plenty of practice with this project. The only really difficult bit now is going backwards - I need one hand on the wheel to make sure it's going forwards and one hand on the reverse button, which leaves no hand for guiding the fabric. Still, once I got into the swing of it, I was quite happy with the results.

Stitching. Not perfect, but quite tidy.

Anyway, back to the fitting. Um, no, it wasn't OK. Right then, unpick and add another bit in. Then do it again. Then tweak that seam again. Then squeeze another bit of purple in there...

There was quite a lot of unpicking involved in this project.

Unpicked thread

When I was finally happy that I had enough fabric in the skirt, it was time to hem the bottom edge. All that fiddling around made a mockery of my carefully aligned pieces, so I needed to start again with finding the length. Luckily I have a nifty little hem marker gadget. I thought I had a photo of this, but can't find it. I have a cat draped across my arm now, so I'm not getting up to take another pic. Here's an identical one that was for sale on etsy:

Don't you just love the box?

This gave me a series of white chalk dashes around the hemline...

Marking the hem

... which enabled me to sew a more-or-less straight hem.

Getting there now. At some point in the many tryings-on I noticed that the top wouldn't cover my bra at the back, so I needed more fabric there. Remember me thinking the purple cuffs were unlikely to be of any use? Wrong! They were exactly what I needed. So, more unpicking before adding another row of cuffs to the back. Straps were added, made from the lower sections of the pink collar (use what you've got), then I had to face up to the extra buttonhole.

Buttonhole fail

Hmm, that didn't go very well, did it? I gave up on that and did it by hand instead.

All I had left to do after that was to iron the dress into submission, and I think that brings me to the end of the project. No... not quite. I tried on the dress and asked Ian's opinion. Um, it does look a bit Madonna. I'd set the bust darts too close together and given myself a torpedo bra - really not suitable for a wedding! Minor last minute adjustments later, and..

...Here I am wearing the dress at the wedding, posing next to the cake that I had piled fruit on earlier that morning.

I was quite proud of that cake, if I do say so myself.
The dress was OK, too ;-)

Experiments with hay box cooking

A hay box is not necessarily a box of hay, though it might be. It's a box to put food in that's so well insulated that hot food will continue cooking with no additional input of heat. Not all types of cooking will work here, only slow cooking, the kind for which my oven has an 'S' setting, and which I use for cooking stews and beans.

Over on Selfsufficientish, Nev had posted an article on making a hay box cooker from an old cool box and some polystyrene. I had an old cool box - it used to have a mini fridge unit in the lid, but that broke in a car accident and we bought another one - so that seemed a good place to start. I'd already replaced the broken fridge unit with bubble wrap, so the lid was as well insulated as the rest of it. I also had various bits of polystyrene lying around. Yes, my house is untidy enough that I can find useful quantities of polystyrene just lying around.

Having found the insulation part, I then needed a cooking pot to actually put the food in. I was planning to try stew, so I'd usually cook this in a pyrex casserole dish (or my lovely Le Creuset dish if I'm making enough for six. Sadly, this doesn't happen very often). The trouble with my pyrex dishes is that whilst I have two dishes and two lids, neither of the lids fit either of the dishes. I have to cover the dish with foil when I'm cooking in the oven, which isn't any good for the hay box (or very eco-friendly in general).

Whilst searching for replacement lids, and wondering whether I shouldn't just give in and buy new dishes complete with new lids, which is what the manufacturers want to sell, I kept seeing picutures of these:

Pyrex dish with plastic lid

Oh yes! I thought, I've got one of those! Actually I've got two, but the smaller one hasn't got a lid. I didn't think of this for a casserole because the lids are no good in the oven (this is why my smaller dish doesn't have a lid), but it would be ideal for the hay box.

With all the pieces collected, I then had to fit them together somehow. Unlike Nev, I did not purchase the appropriate tool for cutting polystyrene and carefully cut the pieces into the right shapes. Oh no, I just cobbled together what I had.

As it happened, I had two pieces that both surrounded the pot and fitted into the cool box pretty well.

Pieces of polystyrene conveniently fitting both pot and box

I then found and cut more bits of polystyrene to fill the gaps, so I'd have a polystyrene base and various bits over the top as well. The last of these was a bag of wood shavings that had come as packaging for bulbs (plants, not lights), that would fit into the awkward shape at the top.

Pot sitting on bits of polystyrene in the box, and more bits to go on top, including a bag of wood shavings.

Again failing to follow Nev's good example, I went straight for cooking, rather than testing this out with water first. I prepared my stew, put it in the box and closed the lid at about 11:30 this morning. Come dinner time... um, that's seven hours later, not eight to twelve as recommended... I opened up the box to see what had happened.

Well, it was still warm. Not hot - I could comfortably take the pot out without oven gloves - but definitely warm. When I checked the food, there had been some cooking going on. The meat and carrots were all cooked through, but you wouldn't say the meat had been stewed. It was still pretty tough. Oops. I hadn't really left enough time to stew it properly after that.

I rescued our dinner as best I could by heating the stew up to boiling again in a pan - I'm not sure it's a good idea to eat meat that's been sitting around all day warm, even if it was in a sealed pot - and put it in the oven on a medium heat while I cooked the potatoes. The meat was still rather chewy.

The hay box experiment wasn't a great success, but I can't say it was a total failure either, as the food did cook, just not very well. I'm guessing the problem was the air gaps in my insulation. I reasoned that since my cool box was better insulated than Nev's to start with, I wouldn't need to be so fussy with the additional insulation. And I was lazy. Also, the food didn't entirely fill the cooking pot, which isn't ideal - that made another air gap, and one right next to the food, there in the pot.

I may give this another go at some point in the future. Who knows, I might even test it before using it next time!

Not switching the lights off for Earth Hour

It's coming up to the end of Earth Hour and I've been watching my electricity monitor for most of it. This is possible because I have the lights on.

About ten minutes in, the fridge happened to turn itself off, so the only things we had switched on were the lights. The other 'background' consumption, the heating, is off, mainly because it's broken. The monitor fluctuated between 19 and 27 Watts, which is not bad for four 7W bulbs. Then the fridge kicked in and the usaged jumped to around 160 Watts for the fifteen minutes until it switched itself off again. During that time, we both turned our laptops on - not a flicker on the monitor, in spite of the fact they're both plugged into the mains. If anything, the consumption dropped.

Now, as the hour comes to an end, we have both computers and four lightbulbs on, and the monitor is again fluctuating between 19 and 25 Watts.

I have very mixed feelings about Earth Hour. As you can tell from the above, we did not yield to WWF's exhortation to Switch off your lights to show you care about climate change and protecting the natural world. Is that because we don't care? No, of course not. It's because switching the lights off is purely a gesture - the lights evidently use much less power than the fridge; how many people switched their fridges off? - and I'm really not sure of the value of gestures.

Switching lights off is very visible, especially in cities (not sure anyone would notice the difference out here in rural Wales), so it's certainly an attention-grabbing gesture. Having grabbed the attention, what message does this gesture convey?

I find this question very difficult to answer. I guess the most positive possibility is that a lot of people think, We need to reduce our electricity consumption to save the Earth. I nearly wrote power instead of electricity but I think that would be over optimistic. The lightbulb is quintessentially electric; I'd be very surprised if the concept of saving power by switching them off would generalise to other forms of power. This is unfortunate, because electricity is only a medium for transporting power; its generation can come from the dirtiest of fossil fuels or the cleanest of renewables. I don't believe that targetting electricity per se is necessarily helpful.

More specific messages might be even less helpful. It's likely that focusing on light gives people the impression that lights are a relatively big consumer of electricity. If I'm to believe my electicity monitor (and I'm still not sure I entirely trust it), lights, especially modern low-powered bulbs, use relatively little power. This could easily distract people from the big energy users, and leave them thinking that regularly turning lights off will make a useful impact on their energy consumption.

As for the actual impact of Earth Hour on electricity consumption, I'd be surprised if much of the reduction was any more than displacement. For example, you could not boil a kettle during that hour by having your cup of tea either before or afterwards. You could delay putting the dishwasher on for an hour. No doubt some people charged batteries beforehand so they could use electrical devices without plugging them in during that hour.

As for carbon dioxide emissions, the effect of Earth Hour could have been to actually increase them. A friend mentioned that she was planning to use a paraffin lamp instead of electric lights, prompting me to search out this report. To save you having to read it all, I'll tell you that the interesting comparisons are found in graphs on pages 10 and 12. The first of these tells me that a pressurised paraffin lamp emits somewhat more light than an electric bulb; 180 Lux for the lamp vs. 120ish Lux for either a 15W compact fluorescent or the 60W incandescent bulb (it doesn't seem a fair comparison to look at the much more feeble hurricane lamp).

However, the difference in CO₂ emissions is far greater; 260 kg/year for the lamp vs. 80 for the incandescent bulb and only 20 for the modern, low power bulb (OK, it may not be fair, but the hurricane lamp still has higher emissions than either of the lightbulbs, in spite of much lower light output).

Earth Hour: A grand gesture that focuses a lot of attention on the issue, may distract from higher impact ways of reducing CO₂ emissions, and might have increased emissions during the hour itself. No, we're not turning off the lights for Earth Hour.

Electricity monitor

Our electricity provider has sent us a new toy to play with: A free gadget that measures and displays our electricity usage in real time. I'd been thinking of buying one of these, so I was very pleased to get one for free, but I did wonder why they'd do that. After all, the main purpose of the gadget is to help us reduce our electricity usage, which is not exactly in their interests.

Reading the small print, I thought I'd found the answer, "We reserve the right to monitor your usage, including time of day usage." (I should explain that the thing comes with a link-up to online software). Decent time-of-day usage data are highly valuable to an electricity provider, so they can optimise their output.

I've been very interested to see how much power different things use. The fridge and the central heating pump are our main 'background' users of electricity, taking 100-200 Watts each, but not all the time. I was relieved to see that the laptops use very little - about 40 Watts, and again, not all the time. Right now the monitor is displaying zero, although I have the computer plugged into the mains.

The little light by the power cable shows the laptop is plugged in and switched on, but the electricity monitor says it's drawing no power

This big users are predictable, but still startling. We all know that electric kettles use a lot of power, but seeing the monitor shoot up to 2.5 kW is a striking reminder of that fact. I'm sure it's going to encourage me to heat less water (so it's on for less time) and to make the tea straight away, so I don't have to reboil.

The washing machine also uses kilowatts, but I'm not sure I'm ready to switch to hand washing just yet. The real biggie, though, is the shower. We have an electric shower which is pathetically feeble, yet still manages to use 7.5 kW, and we use it for much longer at a time than the kettle. We really must crack on with those solar panels!

As well as power consumption, the monitor has a built in thermometer and displays the temperature. At first, I thought this was an added bonus. Most lists of tips for saving energy include advice to turn the thermostat down a degree or two, so a thermometer fits with that approach. However, this one is slightly different.

The accompanying booklet informs us that a temperature "below 17°C is considered too cold for healthy living," and "If flashing it is below 13°C, please turn your heating up." This thing is geared up to tell us to increase our heating, but will never tell us to reduce it.

Ever since it came into our house, this thing has been complaining that it's too cold:

Electricity monitor flashing warnings at me. I had trouble taking these photos, but the one on the left has no temperature information whereas if you look closely at the one on the right (or the one above), you'll see it says "too cold" and "11" in the bottom right hand corner*

Not only does it complain, but it consistently reads two degrees lower than the old fashioned thermometer we have on the wall. Call me cynical, but this company sells gas, too...

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*We do keep our house cool but I have to agree that, even allowing for the two-degree error, 13°C is on the chilly side. This is because our central heating has broken, but that's another story.