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Smart Grid Promises Substantial Carbon Abatement

Laboratory's estimates depend on full implementation of all smart grid technologies, a big if

3 min read

The Pacific Northwest National Laboratory  has issued a report in which carbon savings from introduction of smart grid technologies are estimated, looking ahead to the year 2030. PNNL, located in Richland, Washington and operated by Batelle for the U.S. Department of Energy,  puts direct carbon savings from equipment like smart meters at 12 percent, and indirect savings from things like stronger grid support for renewable electricity generation at 6 percent.

Studies like PNNL's must of course be treated with a degree of skepticism, first of all because their estimates depend on a large number of uncertain factors, and second, in this particular case, because the whole subject of the smart grid gives rise to a certain breathlessness. "With smart grids, there should be no need to send out lorries and ring door bells when the power fails," Britain's Economist predicted. "A few mouse clicks may do the trick, or the equipment may even fix itself."

Tell that to the Philadelphia linesmen who risked their lives last week restoring power to homes, following what was in that part of the world the snow storm of several centuries.

Still, the PNNL report meticulously explains its methodology and procedures, and is useful if only for the rather complete laundry list it provides of smart grid technologies and connections. Positive aspects of the smart grid include energy conservation resulting from real-time consumer feedback; more effective efficiency and demand response programs; building diagnostics; load shifting to lower-carbon generation; charging support for electric and plug-in hybrid vehicles; advanced voltage control; and enabling of wind and solar generation.

Of the 6 percent reduction in energy and carbon that the report credits as an indirect effect of smart grid technology, 5 percentage points are from greater use of wind and solar. Support for EVs and hybrids is expected to account for a quarter of the 12 percent carbon reduction from direct effects, that is, 3 percent.

The report's estimates assume that smart grid technologies are "fully implemented by 2030. For equipment like smart meters, which are being installed by the tens of millions in the United States and many other advanced industrial countries, that assumption seems warranted. But for technologies such as EV and hybrid charging, high obstacles must be surmounted if the technology is fully implemented, even assuming that electric and hybrid vehicles mature as hoped.

In an article that appeared last year in the March-April issue of IEEE's Power and Energy magazine, Ali Ipakchi and Farrokh Albuyeh pointed out that "plug-in vehicles will represent a significant new load on the existing primary and secondary distribution networks, with many of these circuits not having any spare capacity and no monitoring and automation capability." Typically, they say, charging a vehicle will more than double an average household's electric demands on the grid.

The PNNL report itself concedes on p. 76 considerable uncertainties in its estimates for hybrid and electric vehicles, because of factors such as choice of reference vehicles, postulated duration and intensity of charging, and assumptions about demands on baseload versus peak generation.

In detail, the PNNL report contains many insightful observations. On p. 52, for example, it points out that considerable carbon savings can be realized if smart grid technologies facilitate load shifting from peak to baseload generation. This is partly because, it says, natural gas peaking plants are about as carbon-intense as coal-fired plants--even though, as is well known, large baseload gas plants emit only about a third or half as much carbon as baseload coal plants.

Will the PNNL's estimated carbon savings largely materialize by 2030? If you had asked me fifteen years ago whether technologies based on the new high-temperature superconductors would be revolutionizing power generation and distribution by 2020, I would have answered in the affirmative, with confidence. But here we are in 2010, with little sign that any of the HTSC technologies are market-ready.

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