Browsed by
Tag: CO2 emissions

How green is your daily journey?

How green is your daily journey?

Given at that the eyes of the world are looking to the Climate Change conference in Copenhagen for answers to the biggest environmental challenge of our time. I thought it would be a good day to ask, How green is your daily journey? To help you work out if you are doing you bit, I have found this handy Travel footprint calculator from travelfootprint.org.

If you would like to know more about the methodology used to assess the impact of your journey, see here.   For what it is worth, my journey today resulted in the emission of approximately   46.4 g of CO2. The emission due to my writing of this post and your reading it, are another matter.

Possibly Related Posts: (automatically generated)

Let there be light

Let there be light

We recently had a new bathroom fitted and as it is an internal room lighting is important. When we first moved, in the old bathroom gave a good impression of the Black Hole of Calcutta (well more like the green and blue hole of Calcutta, an interesting colour scheme), lit by a single 40w tungsten bulb. On the first day, all the old tungsten bulbs where removed and replaced with modern low energy bulbs. In the bathroom I put in a 14w, which has a light output equivalent to a 75w tungsten bulb, a considerable improvement straight away.

Putting in a new bathroom gave the opportunity to make more radical changes. My first thought was to use halogen down lighters and flood the room with light, however there are a few issue with halogen down lighters. First off, care must been taken when fitting them into an existing ceiling, as they can be a fire risk due to the heat they generate. Secondly, all that heat is just wasted energy, with most of the energy being converted into heat rather than light. While halogen bulbs while they are more energy efficient than Edison incandescent bulbs, they are still not the most efficient means of lighting. The search was on for energy efficient replacements for the standard GU10 halogen bulb.

Most people are now aware of low energy (compact fluorescent lamps or CFL) bulbs, even if not everybody is using them. There are now CFLs which can be used to replace the old fashioned tungsten GU10 bulbs (GU10 refers to the type of fitting). They are at the present time more expensive (£5 to £6 per bulb) than the halogens they replace (£0.79 per bulb), but the CFs use less energy and last longer, but more on that later.

However I wasn’t convinced this was the most energy efficient solution. Through my interest in cycling I knew that in high end cycle lights halogen bulbs have now been entirely replaced by LED lights. Indeed the popularity of 24 hour cycle racing, where the race continues through the night (at the extreme is the Strathpuffer with 17 hours of darkness), have helped to drive development in this area, as bright and energy efficient lights are important to this sport. If you are hurtling down a forest track in the dark, you want plenty of light to find your way. Yet at the same time you don’t want to be lugging a heavy battery about, so low energy consumption is essential. The German light makers Lupine show just what can be done with their Betty 14, a 1500 lumen 22w light which can run for 6 hours on a 14.5 Ah Li-Ion bottle battery. The whole setup only weighs 810g. Ok, so it comes at a price (£685.00, just in case you want to know what I would like for Christmas) and a 1500 lumen lamp is way more brightness that the average domestic lighting system would normally use, but has any of this high end technology filtered its way down to the domestic lighting market?

Well yes it has, you can get LED lights as replacements for halogen bulbs, but there are a few differences in what is required from a bike light compared with domestic room lighting. As stated above, top end bike lights are far brighter than domestic lighting systems, also there is the colour of the light to be taken into account. As light colour and temperature can be a wee bit confusing, here is a short digression into light colour/temperature.

A lighting designer will describe white light as being cold or warm depending on whether it is towards the yellow end of the spectrum or the blue end, with yellow being warm and blue cold. On the other hand, a lighting engineer will describe white light according to its temperature in degrees Kelvin (°K), to them a “warm white” light has a temperature of 2700°K and the “cold white” a temperature of 5000°K. So why the difference? The designer gives a subjective description of the light, and we have become accustomed to the yellowish white light of the tungsten bulb in most domestic lighting situations. Before that we would have experienced the light of oil lamps or candles, which have a similar coloured light. This light is described as being warm. Whereas white light which is to the blue end of the spectrum, and is closer in colour to that of daylight, is regarded as harsh and cold. The engineer on the other hand describes light according to the level of energy required to generate it. For millennia metal workers have known that if you heat a piece of metal it will start to glow, at first red, then as you heat further straw yellow and eventually it will become white hot. At this point metals start to melt, and if you are using arc welding gear to melt the metal, you will notice that the electrical sparks give out a blue light as they are hotter still. The temperatures at which these colours are produced can be measured, hence colour temperature is given in °K. Ok so back to the subject at hand.

Most bike lights produce a “cold” white light with a temperature of about 5000°K, this is often considered too harsh and cold for use in a living area. So for domestic use there are GU10 LED lights which can replace the bog standard halogen down lighter, these usually come as a choice of either warm white (3200°K) or cool light (5000°K). Power usage ranges from 1w to 4.3w and their light output can be equivalent to 35w to 50w halogen blubs (specifications can vary between manufactures). As this is in many ways still a cutting edge technology, prices are on the high side at between £6 and £18 a bulb.

So to the big question, is it worth spending £18 on a bulb when you can get a halogen bulb for £0.79 to do the same thing? The answer depends on the time scale you look at and how much you use it, to find out it is necessary to carry out a little economic analysis. To do this I, have developed a simple tool to compare the energy usage and running cost of three different types of downlighter type lights.

Basically halogens are cheap to buy but use a lot of expensive energy and have a short lifespan (typically about 2000 hrs). Whereas LEDs are expensive to buy, but use very little energy and have a very long lifespan (typically about 50000 hrs), CFLs are somewhere in between. To see which is the better value in the longer term I chose the following scenario, using four bulb fitting, for four hours a day (OK so that is a wee bit longer that we normally use the bathroom per day) using electricity at a costing of £0.18 per kWh (a rate taken from an old bill, before the recent price hike!), what would be the total running cost per year? In the first year the total cost of the halogens would be £39.10, using CFLs would be £12.96 and using LEDs would be £4.90. This suggest that saving in energy costs of using the LEDs would repay the capital investment is a little over two years. However at the current time the cost of energy is going up and the cost LEDs is coming down, so this could soon be even shorter!

Possibly Related Posts: (automatically generated)

Food waste and climate change.

Food waste and climate change.

There was a report on the BBC Radio 4 Today programme this morning, that in Britain 6.7m tonnes of food were thrown away every year. The report went on to say “most of the waste food goes into landfill sites, where it breaks down and causes greenhouse gases”. As an ecologist (I have a BSc in Ecological Science and an M. Phil. in Plant Ecology), I immediately saw the flaw in this argument, the breakdown of food waste is a natural part of the carbon cycle and is not going to have any effect on climate change.

There is a real problem with policy makes and journalists not understanding carbon emissions and climate change. It is the release of fossil carbon, mainly from burning fossil fuels, that is causing the problems with climate change. It is the transport and storage of food that is the main contribution to carbon emissions, nagging consumers and supermarkets about food waste is unlikely to achieve much in the way of reductions. A much more effective approach would be to tax fossil carbon usage and to bring in a system of limits on fossil carbon usage, such are carbon credits and carbon trading.

Possibly Related Posts: (automatically generated)

What ever happened to Acid Rain?

What ever happened to Acid Rain?

Back in the 1980s the big environmental issue was Acid Rain, but now you never hear about instead all the talk is of climate change. So what ever happen to acid rain, was it real or just a myth?

During the 80’s I spent several summers working on a farm in Norway, where I was told about the about dead lake in the mountains. These were lakes where all the fish had died due to acidification of the water due to airborne pollution, which I was regularly told, that came from British power stations. It wasn’t just in Britain that was the culprit, in other parts of Europe, tree were dying in the Black Forest, blamed on East Germany and other countries in Eastern Europe. In Sweden and Finland there were forest and lakes were being poisoned by acid rain which came from West Germany and Eastern Europe. In North America the Canadians were complaining of acid rain from the Us of A.

So what was this acid rain and where did come from? Well acid rain or more correctly acid deposition is due to a mixture of air pollutants which can lead to acidification of freshwater and soils (for more information see the Air Pollution Information System). A major component of this long distance acid deposition is Sulphur Dioxide (SO2) is caused by the burning of high sulphur fossil fuels electricity generation, industry and domestic heating. The traditional solution to dealing smoke pollution from this type of combustion was to build a bigger chimney and move the problem further away. As air pollution is no respecter of political bounders this lead to the problem becoming transboundary which need international action to solve. So starting with the 1985 Helsinki Protocol (the “30% club”) international action was taken and a number protocols agreed leading to the UNECE Convention on Long-range Transboundary Air Pollution.

As result of these international agreements the problem of acid deposition (acid rain), in the developed world, have been greatly reduced, although there are still worries about the effects of acidification in upland areas (see Smith et al. 2000, etc for more information). In the developing world, especially in China and India acid deposition is an increasing problem as environmental legislation in these countries is not strong.

This show that where there is the political will to do something about it such transboundary, and indeed global, environmental problems can be tackled and solved. In a week when it has been made abundantly clear by the Intergovernmental Panel on Climate Change (IPCC) that climate change is a real issue and a largely man made one at that (see IPCC 4th Assessment Report), we all have a duty to do something about it.

Possibly Related Posts: (automatically generated)

Do NOT follow this link or you will be banned from the site!
%d bloggers like this: