Locavolts or Super Grids ?  

Alex Steffen has a post at WorldChanging on relying local power generation (aka locavolts) versus large scale renewable energy delivered via a "supergrid" - Locavolts or Super Grids? Where to Source Clean Energy?

Should clean energy be distributed energy made locally and connected to a smart grid, or should it be gathered from the windiest and sunniest places on the planet and shipped to us in giant new super grids? The answer may prove critical to solving our greenhouse gas problems.

Ian Bowles, the secretary of energy and environmental affairs for Massachusetts, argues that smart grids should make local power the preferred option:

Unlike our federal highway system, which is needed to transport goods across the country, or the “information superhighway” of the Internet, which is the fastest way to carry information around the world, long-distance transmission lines have no inherent value. On the contrary, the farther electricity is transported, the more of it is dissipated. “Line loss,” as this is called, gobbles up an estimated 2 percent to 3 percent of electricity nationally.

And of course, the longer the power line, the more expensive it is to build. In New England, we estimate the cost per mile at $2 million to $10 million. The closer electricity is generated to where it’s used, the better.

There are many benefits to building a smart, distributed energy system. One problem with distributed energy is that is people don't necessarily live where clean energy resources are most abundant; another is that wiring together many different parts can impose regulatory costs that could make deploying distributed energy more difficult, and can be a hassle for homeowners (one of the reasons various schemes to rent or lease people home solar power packages remain popular).

That's why some smart folks argue for putting the power generation where the power resources are and then building a new international grid of transmission lines to carry that clean energy from wind farms and solar fields to distant cities. The model of centralized production and distant consumption suffers particularly from the "line losses" of electricity wasted while transmitting it. One possible solution is the "ultra high voltage" direct current power line, which delivers large amounts of power over long distances with relatively little power loss.

It's not a perfect fix, since there are both technical problems (like the conversion of that direct current to the alternating current used in homes and businesses) and cost issues (it's expensive to build big infrastructure, no matter how efficient). Still, China is planning 15 long-distance UHV lines while there is growing support for a plan by the European commission's Institute for Energy to use UHV lines to build a "super grid" to bring Saharan solar power to Europe. (You can wonk out more on transmission options here.)

Given the severity of the crisis we face, when presented a choice between two approaches to providing clean energy, the answer must be "both, please." But in this debate, as in every other, there are trade-offs, and it's worth thinking about when we want our volts local, and when being hooked into the super grid makes the most sense.