Brittle Power- PARTS 1-3 (+Notes) - Natural Capitalism Solutions

124Disasters Waiting to Happenpressures. In the electric grid, everything happens much faster. Controlresponse is often required in thousandths of a second, not in minutes orhours. Reliance on computerization, farflung telecommunications networks,and specialized skills—already cause for concern in oil and gas grids—is evengreater in electric grids, and becoming ever more so.The electrical and petroleum grids are also vulnerable in many of the sameways. Power lines, like pipelines, are long, exposed, and easily severed bysimple means. Like refineries, many vital electrical components depend oncontinuous supplies of cooling water, pump lubricants, and so forth. Just asrefineries have a risk of explosion from hydrogen (used to hydrogenate carbon-richmolecules into light products), so big electrical generators are oftencooled with hydrogen (whose small molecules reduce friction). Many keycomponents of electrical systems, ranging from turboalternators to maintransformers, are special-order items with long delivery times. Repair of substationsand transmission lines has many features in common with repair ofpipelines and pumping stations—but the electrical components tend to be costlier,more delicate, and less available than their oil and gas counterparts.Electrical grids and their components seem to be far more frequently attackedthan oil and gas grids—perhaps because power failures are so much more immediateand dramatic than interruptions of oil or gas supply, and offer so fewoptions of substitution in the highly specialized end-use devices. This chapterexamines the vulnerabilities—of individual components and of the power grid asan interrelated whole—which make such sabotage tempting and effective.The major components of power grids are, in their broadest categories,•power stations;• transmission lines with their associated switchgear and transformers (whichraise generators’ output to very high voltages for long-distance transmission,then reduce the voltages again for distribution);• distribution systems, including further voltage-reducing transformers andswitches; and• the control and communication systems which these components require towork together.These will now be considered in turn.Power stationsAbout twelve percent of the domestically generated electricity supplied to theUnited States comes from about twelve hundred hydroelectric dams. Aboutthree hundred sixty of these produce more than twenty-five megawatts each.