The popularity of cloud computing is rising faster now than at any time in the past. And it’s no wonder; accessing services and applications through the Internet rather than storing the necessary data on your own computer makes sense now that links are so fast and reliable.

However, cloud computing has some significant drawbacks. Instead of localizing failures as conventional Internet computing does, the cloud makes failures system wide, say Alexandros Marinos at the University of Surrey and Gerard Briscoe at the London School of Economics, both in the U.K.. If the cloud goes down, as happened earlier this year with Gmail and last year with Amazon’s S3 service, entire companies and the industries associated with them can grind to a halt.

So Marinos and Briscoe have come up with an alternative: community clouds in which individuals offer a portion of their computing resources to a virtual cloud. That’s not unlike distributed computing ventures such as SETI@home and Folding@home that use processing cycles on idling personal computers to carry out intensive data analysis.

A virtual cloud would be more demanding but could have substantial benefits. Marinos and Briscoe say that Wikipedia might be an ideal test bed on which to try out the idea. At the moment, Wikipedia depends on substantial donations to keep its servers running and to keep the service free of advertisements. An interesting alternative might be a virtual cloud based on computing resources donated by users around the world.

Marinos and Briscoe point out that a virtual cloud should also be greener than the rapidly expanding data centers that are springing up all over the world. The combined carbon footprint of data centers is expected to exceed that of the world’s airlines by 2020. Even now, these facilities are challenging the capacity of power grids to deliver enough power to keep them going.

That alone may provide the necessary vision and momentum to get an idea like this off the ground.

Ref: arxiv.org/abs/0907.2485: Community Cloud Computing