Sunday, 25 October 2009

Who says it's green to burn woodchips?

One of the most cherished articles of faith of the green movement – that wood-fuelled power stations can help save the planet – is being increasingly challenged by campaigners and conservationists around the world.

Electricity generated by burning woodchips is on the verge of a global boom. America is planning 102 power stations fuelled by woodchips in the next few years. Europe is reported to be planning a similar, if yet unquantified, expansion. And in Britain, the next three years will see wood-fuelled power station capacity increase sevenfold, requiring, according to the campaign group Biofuelwatch, so much timber that it would need an area 12 times the size of Liechtenstein to grow it.

The power companies say the source will be "sustainable forests", but campaigners and ecologists claim that untold damage will be caused by the burgeoning market for wood. They say that, although traders in the developing world are being tempted to grub up and sell native forests, the chief danger is in the creation of monoculture plantations, where single species of trees are grown in straight rows and little wildlife can establish a home for itself.

They also challenge the "green" assumptions behind woodchip power, claiming that, far from fighting climate change, transporting large amounts of bulk wood across oceans and then burning it will increase carbon discharges by 50 per cent more than would have been caused by burning a fossil fuel like coal.
full article

Saturday, 24 October 2009

The light bulb that lasts 25

It could be the breakthrough that finally has consumers warming to the energy-saving light bulb.

A version that brightens up instantly, costs just 88p a year to run and lasts up to 25 years has gone on sale in Britain for the first time.

The only catch is that the new LED bulb will cost £30.

Manufacturers claim the Pharox is the first low-energy bulb to give off the same light quality and brightness as a conventional 60-watt traditional bulb.

They say that, despite its initial cost, each bulb will pay for itself in just three years.

After that, each one used could shave around £9 a year off a typical household electricity bill.

Unlike most of the current energy-saving bulbs, which are compact fluorescent, the Pharox can be used with dimmer switches, reaches full brightness the moment it is turned on and contains no toxic mercury.

It also looks similar to a traditional bulb, works well in freezing conditions outside and stays cool when switched on, making it ideal for children's bedside lights.

The bulb's launch comes ahead of a European ban on conventional 60-watt incandescent bulbs, due to be introduced in 2011.

James Shortridge, owner of the Ryness lighting chain, said: 'The original bulb was a 1901 design, while the compact fluorescent is a design from the 1980s that has never been perfected.

'Many people just don't like the compact fluorescents and they don't like the old bulbs being banned before a good replacement is available. But we are finally starting to get decent low energy bulbs that have the same light quality as the old variety.

'My main problem as a retailer, however, is that it lasts for more than 25 years.'

LED bulbs that produce as much light as 100-watt ones are due to go on sale at the end of next year.

full article

Save energy - just look away now

The 21st Century home is packed to the rafters with electrical devices, from labour-saving kit in the kitchen to widescreen TVs and computers.

Even the simple act of illuminating our homes requires power.

Some of the major manufacturers at the Japanese technology fair Ceatec suggest that alternative energy sources like wind and solar power could become commonplace as wind turbines and solar panels become cheaper.
But short of pulling the plug and switching off our creature comforts, reducing the amount of energy we use seems to be the goal of the big players.

Pretty much all of the consumer kit is making claims to be more energy efficient, but manufacturers are coming up with more ingenious solutions.

One particular TV set is fitted with a small camera and equipped with facial recognition software.

It is looking for a viewer's full face looking at the screen.
If the viewer looks away from the screen for a couple of seconds the image slowly fades out but the audio continues to play.

If they turn back to the screen, the image immediately returns.

TV sets require an awful lot more electricity to create pictures than they do sound, so when turned away from the screen, energy is being saved.

This TV and face recognition software are the brainchild of engineers at Hitachi and so far it remains at prototype stage but has been trumped by Sony - which already has similar technology fitted to a production TV.

You might think that features like this are no more than a gimmick, but it does help highlight the more serious green credentials of televisions.

New LCD screens are benefiting from a more efficient back lighting which uses half of the electricity of rival LCD TVs.
full article

Sunday, 11 October 2009

'Scary' climate message from past

Researchers used ocean sediments to plot CO2 levels back 20 million years.
Levels similar to those now commonly regarded as adequate to tackle climate change were associated with sea levels 25-40m (80-130 ft) higher than today.
The new research was able to look back to the Miocene period, which began a little over 20 million years ago.

At the start of the period, carbon dioxide concentrations in the atmosphere stood at about 400 parts per million (ppm) before beginning to decline about 14 million years ago - a trend that eventually led to formation of the Antarctic icecap and perennial sea ice cover in the Arctic.

If anyone still doubts the link between CO2 and climate, they should read this paper
Jonathan Overpeck
University of Arizona

The high concentrations were probably sustained by prolonged volcanic activity in what is now the Columbia River basin of North America, where rock formations called flood basalts relate a history of molten rock flowing routinely onto the planet's surface.

In the intervening millennia, CO2 concentrations have been much lower; in the last few million years they cycled between 180ppm and 280ppm in rhythm with the sequence of ice ages and warmer interglacial periods.

Now, humanity's emissions of greenhouse gases are pushing towards the 400ppm range, which will very likely be reached within a decade.
"At CO2 levels that are sustained at or near modern day values, you don't need to have a major change in CO2 levels to get major changes in ice sheets," she told BBC News.

The elevated CO2 and sea levels were associated with temperatures about 3-6C (5-11F) higher than today.
full article

Wednesday, 7 October 2009

Britain's greenest house unveiled

The special green house is set to become the most energy-efficient home in Britain, and will leave them with fuel bills of just £70 a year.

Their cosy new home in Huddersfield, West Yorks., will be finished in February next year and will be the first Anglicised version of the famous German Passivhaus.
Instead of complicated design and expensive bolt-on renewables like wind turbines and ground source heat pumps, Passivhaus creates a simple "tea cosy" effect.

It relies on simple design, orientation towards the sun, careful construction and insulation 15 times greater than required by Government building regulations. This ensures almost complete air and wind tightness.
No draughts can get in the building and no heat can leak out, but the air is never stale, thanks to a mechanical heat recovery ventilation system that brings in fresh air from outside, which is warmed used 99 per cent of the heat from the outgoing air.

The Green Building Store in Huddersfield suggested the unique design and is managing the build that uses a German computer software package to measure air tightness and energy efficiency.

full article

Saturday, 3 October 2009

Central Heating Day

The first of October is "central heating day", when many people switch on their radiators for the winter. Central heating is just another mod-con of contemporary living, but it's done much more than warm us up.
Up and down the country, radiators clank their way back to life after a summer of hibernation.
1970 West Ham United footballer Peter Grotier at home - with central heating
A radiator - a rare sight in 1970

With energy bills soaring in recent years, and more people aware of energy consumption, many make it a point of principle that their heating stays off until the start of October, which means any nippy late September mornings just have to be endured.

But given how mild the autumn has been so far, others may wait a couple more weeks before the big switch-on.

Only a small fraction of UK homes are without central heating today. In the last comprehensive survey, in 2004, it was 7% of households, and that has probably dropped further since.

Far from being a modern invention, there were forms of central heating systems in ancient Greece, and later the Romans perfected what were called hypocausts to heat public baths and private houses.

In late Victorian Britain, well-to-do houses had a form of central heating. Cragside in Northumberland, the family home of engineer Lord Armstrong, was a famous example, with ducts built into the floors to carry warm air around the building.

But it was a long time before central heating became widespread and affordable, and fired by a gas boiler.


In 1970, Martyn Jarvis, 55, was a gas fitter, installing central heating systems in the Slough area.
A terrace house without central heating
Victorian house builders kept rooms small for warmth

"Central heating was just taking off then and there was a sense of excitement. It was like getting the first colour television - 'Ooooh, I've got central heating!'

"Unless you were really well off, you didn't have any radiators. There was an awful lot of solid fuel around then, an open fire in the living room normally, which heated the water as well.

"Other houses just had a three-bar electric fire, so you needed plenty of blankets at night. I remember the 1963 winter was particularly horrendous."

By the end of that decade, and into the early 1980s, having central heating was regarded as a basic requirement, he says.

I started in 1974 and central heating was just taking off. It was quite expensive then because it was a big job.
We had to take out a lot of old-style coal fires with a back boiler to heat the hot water and an open grate at the front. But people loved it, after being cold for all those years
Michael Martindale, Peterborough

There were obvious health benefits - warmer homes helped to address winter mortality rates - but the impact was wider than that.

The design of a home changed because its inhabitants started behaving differently, says architect Harry Charrington. Today the average temperature in a home is 22C, compared with 18C in the 1950s, he says, yet people 50 years ago felt just as warm as we do today.

"People don't wear clothing to keep warm any more. One of the social norms is that people can go around in shirt sleeves at home or in the office. So central heating has changed the way people think about clothing.

"Rather than put extra clothes on, they put the heating on. It used to be that if it got cold, you put a jersey on and if it got warm you opened a window. People don't have an expectation that they will have to change the way they behave in cold weather."
full article