Green computing should learn from traditional industry

The Carlsberg brewery in Copenhagen was famous for using waste hot water to heat nearby houses

Years ago, during a tour of the old Carlsberg brewery in Copenhagen, the guide explained that homes nearby used to be highly prized. This wasn't owing to the Danes' love of the fruits of the brewery, but because the waste hot water from the plant was piped into their homes to provide free heating. It was a valuable bonus in a country where the winters are cold and hard.

I was reminded of this last week when IBM announced to great fanfare that it is building a supercomputer that will be water-cooled, and will use the waste heat to warm the building in which it will be housed. My first thought was: " What kept them?"

The system, dubbed Aquasar, will be built at the Swiss Federal Institute of Technology Zurich, and will use two IBM BladeCenter servers in one rack to run at about 10 teraflops.

The system is being designed to cut energy costs by 40 per cent, and reduce the carbon footprint by up to 85 per cent.

"Heat is a valuable commodity that we rely on and pay dearly for in our everyday lives. If we capture and transport the waste heat from the active components in a computer system as efficiently as possible, we can reuse it as a resource, thus saving energy and lowering carbon emissions," said Dr Bruno Michel, manager of advanced thermal packaging at IBM's Zurich Research Laboratory.

"This project is a significant step towards energy-aware, emission-free computing and datacentres."

As we have seen, recycling heat in this way is nothing new, so why has the technology industry been so slow in adopting methods that have been used for decades in more traditional industries?

Part of the reason is the relative immaturity of the high-tech industry. Cooling was a major problem in the early days of the computer industry, when room-sized cooling systems were required for computers that were about as advanced as the modern toaster.

But those problems were quickly solved as processors evolved. The issues only started to rear their ugly head again when we started using huge datacentres and graphics co-processors that you could fry bacon on.

Last year's spike in power costs may have subsided somewhat, but it provided a taste of things to come. Power prices are going to carry on rising, and the smart datacentre designer needs to be aware of this and to build more efficient systems in the future.

If companies baulk at this as an unnecessary expense, they need to be put straight. This short-sighted approach needs to be countered, not least by pointing out that it makes great PR as well as good economic sense.

As the world continues to live outside its means, we are going to have to get used to reusing everything we can, and heat is one of the easiest commodities to recycle.