City governments can show Green ICT leadership. Here is what Paul Kronberger is CIO of Madison (WI-USA), a city of 270,000 residents, tells me the municipality has done to improve the sustainability of its own operations.

Liquid cooling was once a staple of large-scale computing, but has largely been replaced by air cooling. We identified several efforts to bring liquid cooling to the server world in our first version of this post a year and a half ago. Here is an update featuring a UK company.

Microsoft has announced plans to spend $5.5 million to build a zero-carbon data center pilot project in Wyoming. A source of very low carbon electricity is key to such projects. Microsoft's power generation fuel? Municipal sewage!

Traditional ICT facilities consume as much energy cooling their gear as powering it the first place. One solution is to re-use the waste heat.

Microsoft researchers have proposed that "servers can be sent to homes and office buildings and used as a primary heat source. We call this approach the Data Furnace or DF. Data Furnaces have three advantages over traditional data centers: 1) a smaller carbon footprint 2) reduced total cost of ownership per server 3) closer proximity to the users." Data centers are already being used as heating sources in Europe, 'data furnaces' takes the concept to the distributed residential level.

Helsingin Energia (Helsinki Energy) uses the graphic on left to illustrate how it harnesses seasonal climate cycles to provide district cooling. Now, its applying this approach to cool the "world’s most eco-efficient computer hall" (data center), as illustrated on right. Nordic Energy Solutions reports that the data center "has the capacity to heat 500 large single-family houses." Helsingin Energia tells me that its ISP partner in the project, Academica, expects to have the center operational in May 2010.

Municipal heating/cooling districts are most common in northern Europe, but this model could be implemented at universities and government complexes in North America, many of which which have both large ICT infrastructures and campus-wide heating/cooling systems.

More on unique approaches to data center cooling.

A datacenter built by IBM Switzerland for GIB-Solutions AG, announced in 2008 and completed in 2009, incorporates a number of innovative features.