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  • Getting to Green

    An administrator pushes, on a shoestring budget, to move his university and the world toward a more sustainable equilibrium.

The best idea yet for greening campus IT
January 29, 2009 - 8:52am

When I do a sustainability audit for departments on campus, one of the things I look for is "converters" or "chargers" or external power supplies. You know, those big bulky boxy plugs that go into the wall socket and are then connected to the electronic whatever by a thin electrical cord. The cord is thin because what comes out of the converter isn't 120 volt alternating current any more, it's direct current at a much lower voltage. All electronic equipment -- computers, monitors, telephones, etc. -- runs on low-voltage DC. We plug it into high-voltage AC because that's what we have available. Equipment manufacturers like external power supplies because (among other reasons) the definition of "high voltage AC" differs in various parts of the world; with the power converter external, the same basic appliance can be sold into multiple markets by just swapping the converter it ships with.

Sustainability folk, however, hate external power supplies. The reason is simple -- there's no switch and no logic controlling the external charger, it simply runs (and draws electricity) all the time. If you're not using your telephone, it's still drawing power. If you switch your speakers off, they're still drawing power. Lots of sustainability administrators have initiated campaigns to teach people to plug their power converters into surge suppressors or other power strips and then use the switch on the power strip, which really does turn the damn thing off.

Now there's a better idea. It will take a while to work the details out and even longer to get the infrastructure in place, but it's basically a flash of brilliance. So much of the electricity consumed on campus goes into various electronic appliances (using the term in its broadest sense). Each of them has its own, individual power converter, and the simple act of converting the AC to DC accounts for about 20-30% of the electricity used. But remember, we have to convert the power from high-voltage AC because that's what we have available in every office.

Meanwhile, campuses are installing solar arrays and wind turbines and other means of generating electricity. Solar panels generate low-voltage DC, which has to be converted to high-voltage AC before it can get fed into the campus electrical network. Wind turbines can generate AC or DC equally well, but the more voltage they're required to generate, the more wind you need. (See where this is going?)

Why not have a separate electrical network across campus, which delivers appropriate low-voltage DC to offices and (maybe) residence halls. There'd need to be standards worked out, but even if some voltage step-up or step-down were required some of the time, the losses would be far less than in the AC-to-DC scenario we're now facing. And campuses are locales where a separate network could (relatively) easily be installed. And DC could be generated effectively and efficiently on more campuses than can AC. And the DC network could include significant power storage to smooth out the power available, as well as a (centrally converted, larger scale hence more efficient) feed from the electrical grid to assure power availability even at the end of long stretches of sunless, windless days and nights.

Look, I'm not saying that this would be easy or quick, but all the technology is available, mature, and relatively cheap. It's kind of outside the box, but thinking inside the box is what got us into this mess. It's well suited to the campus environment, and if Greenback could save 20-30% on a significant portion of our electric bill, the savings would pay for a significant capital project.

What's not to like?


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