How green is our Silicon Valley?

Most consumers don't think very hard about what they're going to do with an old computer. They just get it out of sight, one way or another, sell it on, or leave it gathering dust in some cupboard. But for businesses, and particularly the computer manufacturers, the question of what you do with a dead computer is going to become particularly pressing. In a couple of years, an EC directive will come into force which mandates that more than 70 per cent by weight of every computer must be recyclable.

Most consumers don't think very hard about what they're going to do with an old computer. They just get it out of sight, one way or another, sell it on, or leave it gathering dust in some cupboard. But for businesses, and particularly the computer manufacturers, the question of what you do with a dead computer is going to become particularly pressing. In a couple of years, an EC directive will come into force which mandates that more than 70 per cent by weight of every computer must be recyclable.

Every year, five million computers weighing 100,000 tonnes (including associated peripherals such as printers and monitors) is being disposed of in the UK. Presently, 50 per cent is recycled. The metal from processor boards and contacts (which includes gold, lead and tin) can be melted off, separated and collected, and various plastics used in the case can be ground up and reused. Even the chips that power some machines - hundreds in a typical PC - can be removed and re-used in simpler systems such as toys and annoying greeting cards which play a tune when you open them.

But making the transition from 50 per cent recycling to 70 per cent is not going to be easy. The problem is computer monitors, whose glass is a third by weight of the waste.

At present, the only time a monitor is is any way green is when it's showing a picture of grass. "Nobody wants it," says Claire Snow, director of Icer, the Industry Council for Electronic Equipment Recycling, a cross-industry association. "You can't use it for glass in the food and drink industry because there's too much lead in the glass, but it's the wrong mix for the leaded crystal market too."

That sort of problem is typical. The computer industry is not and never has been very green. In its early days, computers were enormous things which occupied entire rooms or even floors, needing their own special power supplies. The early valves and other components were potential hazards. In those days, nobody had thought about landfills or the greenhouse effect.

Much the same applies today. The computers may be smaller, but their number has grown, so "internet hotels" (also known as "server farms") consisting simply of computers servicing companies and internet connections can cover thousands of square feet.

Equally, the power demand of computers has stayed fairly static: as engineers have found ways to incorporate better efficiency, the thirst of the central processor has risen in line with its "clock speed" - the figure usually quoted along with the principal chip's name.

In 1982, the Intel processor in the first IBM PC ran at a stunning 4.77 megahertz, or millions of cycles per second. These days, you can buy them at 800 MHz, and the processors alone suck up more than 50 watts. So making power savings at the office should include more than just turning out the lights: there's a very important reason too to turn off computers, or at least put them into a "sleep" mode.

A typical computer with a 14-inch monitor consumes about 145 watts, of which the system uses 60W and the monitor 85W. This consumption quickly adds up. At the computer company Hewlett-Packard, its 84,000 desktop PCs consume about 250W each, a total of 21 million W. That is the equivalent to 21 East Coast main line trains.

No wonder London Electricity recently warned companies thinking of setting up "server farms" that they should make their planning requests for power supplies a couple of years ahead, so the electricity grid can keep up with demand.

"Server farms"or internet hotels house computers belonging to corporate customers. These computers run websites, internet service providers' services and software applications. The advantage of the common location is that the computer operators share the cost of high-speed telecoms access to the internet, rather than having to pay for dedicated lines from their own premisis into the nearest exchange.

The demand could be very substantial: British Telecom plans to invest more than £1bn in server farms in Europe for Ignite, its internet division. A forecast by the Philips Group consultancy reckons the European market for such services could be worth $5.4bn by the end of 2001.

Yet the demand for power is still there. An office block with 1,000 people generates about 6,000 tonnes of carbon dioxide emissions a year, the equivalent of driving 1,300 petrol cars around the world. In other words, environmental problems such as global warming and the destruction of the countryside are not just down to manufacturing industries. The computer used to be one of the most prolific users of CFCs, the chemicals which damage the ozone layer. They were used to wash circuit boards before and after soldering operations (such as attaching chips). Since the mid-Eighties, they have replaced those systems with non-CFC-based production, and in closed systems to minimise pollution. (The story goes that against regulations, IBM workers used to wash their hands in CFC trays because the chemical was non-toxic and dried almost instantly.)

Last year was the deadline for developing countries to phase out their use of CFCs in manufacturing; and as most computer components (and now computers) are manufactured in such countries, the information technology industry can begin to claim green credentials.

Other advances are also helping. The price of flat-panel liquid crystal monitors has been plummeting as demand has been met by factories coming onstream. And besides taking up less space on a desk than a cathode-ray tube (CRT) monitor, an LCD uses only one-fifth as much power as its CRT equivalent, meaning it is cheaper to run over the entire lifetime. But the real problem - as Ms Snow notes at ICER - is what happens after that life is over. "The legislation is coming and it will require the recycling of all computers, including the leaded glass from any monitor," she says. "It will probably become law in the next 18 months, and implemented in a few years. Any computer made after that will have to comply."

Notably, those made before it will be exempt. The directive will also limit substances that can be used in a machine, such as cadmium and certain flame retardants.

"As far as the normal computer user goes, I'm not sure that they're really going to see any difference in the computer they buy, not the price or other aspects," says Ms Snow. "The corporate customer will, because they have to think of what it's worth to get rid of."