If they are to firmly establish themselves, smart grid and the broader category of green technology will have to reach down and reuse many legacy technologies that are deeply engrained in telecom networks and IT systems.

The smart grid concept, for example, potentially covers the vast distribution infrastructure from the utility to the thermostats and appliances in homes and businesses. Of course, utilities and telecommunications companies have had their eyes on remote management and similar cost-saving and efficiency-driving applications for decades. What’s happened over the past year or so is that images of glaciers melting like Italian ices left in a backseat of a hot car has led this sporadic and tactical interest to coalesce into a cohesive and potentially huge mainstream business category.

The focus on green energy usage -- which includes data center efficiency, more efficient mobile workforces, smart grid and many other elements -- is something to behold. It all seems new and shiny, but the reality is that digging down so deeply into the nooks and crannies of the way IT and telecom works requires the use of a lot of technology that already is there, though it may be tweaked to do things slightly differently.

Smart grid, for instance, is giving a second chance to broadband over powerline (BPL), a technology that was, as the kids say, an epic fail on its go-round. Automatic meter reading (AMR) technology gets to morph into a proactive management suite that is new and exciting. And, as this earth2tech story suggests, smart grid also will reinvigorate digital subscriber line (DSL) technology. DSL still is mainstream, of course. But the ascent of fiber and higher bandwidth wireless technologies suggests that it is well on its way to niche status. Another example of how green can push mundane – if not fading -- technology is in the data center, where Google is realizing record breaking efficiencies on the backs of boring commodity servers.

Of course, there will be a lot of cutting edge technology in the move to green technology. It’s a bit ironic, however, that green technology is a great deal for older technologies as well. In April, I wrote a feature about the ramifications of smart grids on the telecommunications network. One of the interesting comments was that the amount of data that must be trafficked in order to smarten up the grid isn’t great: Turing up the AC a couple of degrees isn't as demanding as downloading The Matrix in HD. Indeed, legacy 2G and 2.5G networks can do the job fine.