Checking out the competition

In a bit of a change of pace from the normal fare, I thought I'd post some pictures from a visit today to TVA's Norris Dam. At 130 MW peak generating capacity, it is perhaps the one source out there that can truly compete with nuclear in terms of marginal unit cost as well as dispatchability: hydro.

Norris Dam from the western overlook

Norris Dam serves a dual purpose, being designed both to provide large amounts of reliable electricity as well as providing flood control along the Clinch River (which winds through east Tennessee, eventually joining with the Tennessee river).

Norris Dam and power station

Hydro represents one of the most interesting sources of electric power, in terms of its flexibility - its economics are similar to nuclear in certain respects (in that it is capital-intensive yet very low marginal unit cost, meaning it is the first energy source to be dispatched for demand), yet by its nature it is easily suited to baseload generation (low marginal cost), as well as load following and peak generation (i.e., given the ease at which floodgates can be opened or closed). Nuclear is also capable of load-following, which is commonly done in France, although much less so in the United States (due to economics) save for where nuclear exists is high concentrations; typically load-following is accomplished through fast-response natural gas turbines.

In other respects, hydro shares some similarities with other renewables - the energy output of a hydroelectric plant is fundamentally tied to nature - namely by the reservoir level (which in turn is influenced by rainfall levels). Unlike wind and solar however, hydro represents relatively "smooth" and predictable power output - while meteorology is far from a perfect science, rainfall patterns are generally quite predictable, meaning output levels from hydroelectric dams can also be readily planned for in advance.

The view from the top of Norris Dam

Clinch River valley, past the impoundment

More photos here.

Unfortunately, at least as far as the U.S. goes, most of the "prime" hydroelectric capacity has already been tapped - meaning we've got about as much as we're going to get from this source.

Happy Memorial Day to our U.S. readers - we'll be back to our regular scheduled programming later this week.