Electricity: Lost in Transmission; Saved by Distribution

Thursday, December 8, 2011

image There’s no record at the moment, but there had to be a few homeowners in Vermont or New Hampshire at the end of October who were lucky. They came out when the freak snowstorm at the end of October was over, swept the snow off their solar panels, turned the heat back on and went on with their lives. Much of the rest of the state had to wait for days in early winter weather before the linemen of their electric companies were able to reconnect the power lines to their homes and businesses.

Enough sunlight falls on the earth every eight minutes (by one estimate) to power the world. Enough wind blows to generate all the energy we need. Of course a lot of that sunlight falls on mountains, oceans and swamps, and wind comes and goes. Batteries to store the energy and fuel cells to generate it are not as efficient and cheap as they need to be. So it’s hard for a building to rely on one or the other alone. But that is why we need to think of electricity as a two-way source.

Currently, almost all the electricity we use in the U.S. travels one way: from the power company to us. Power is generated at about 2500 plants distributed around the country, and delivered to our homes and businesses through wires that are slung above ground and run through underground conduits. Over the last half century, the power companies organized themselves into intelligent regional grids, allowing each company to draw on the common supply to meet local needs.

But the system is old, and it is relatively inefficient. Most of the plants are well over 50 years old, and so is much of the wiring that connects them together. Outside of cities, most of the wiring is above ground and subject to wind and weather. Well over half of the electricity generated is lost to the heat and energy of generation, and close to half of what is left is lost in its passage along the transmission lines.

In response to this massive, wasteful dated system, innovators like Daniel Nocera at MIT set the goal of making "each home its own power station." Nocera and his colleages have developed an artificial leaf in which a photocatalyst splits water to create a functioning fuel cell. Nocera estimates that if they can make their system economically feasible, a gallon of water could power a home for a day. For the moment the “leaf” system remains a laboratory experiment, although one with possibilities.

But even when this or a similar system is developed, most individual buildings will probably find themselves connected to some kind of local micro-distribution network, because they are more likely to have power if their own system fails. Such a system consists of multiple power-generating units tied together locally. It can include a group of homes and businesses that are tied together via a local microgrid to each other and a local electric plant that will most likely have two or more alternative power systems: not only solar or wind, but possibly fuel cells and other sources. The idea for the future is that it operates on renewable energy sources and is locally self-sufficient, generating all the power its town or its neighborhood needs.

One Response to “Electricity: Lost in Transmission; Saved by Distribution”

  1. editor

    Betty: I don’t know of a single site where you can get useful information on solar panels in terms of deciding whether or not to install them. I am, of course, a champion of alternate energy, but the truth is that most homes and commercial and industrial buildings have so many ways they can conserve electricity that they haven’t used that installing a solar system is like putting a rolls engine in an old Chevvy. For example, most people have refrigerators that are well over 10 years old. Refrigerators made after 2001 use so much less energy that you’ll see the effect on your electric bill immediately. Most homes leak so much air around windows, doors and electrical outlets that half your heating or cooling are wasted. Updating your appliances and sealing your home are inexpensive ways to take a big conservationist leap — which might also get you a tax break. Come to think of it, there’s a post.

    #2583

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