Capacity Credit, Fuel Saving and Need For Extra Back-up
Many commentators concentrate on whether or not wind has any "capacity credit" without defining what they mean by this and its relevance. Wind does have a capacity credit, using a widely accepted and meaningful definition, equal to about 20% of its rated output (but this figure varies depending on actual circumstances). This means that reserve capacity on a system equal in MW to 20% of added wind could be retired when such wind is added without affecting system security or robustness.
UK academic commentator Graham Sinden, of Oxford University, argues that this issue of capacity credit is a "red herring" in that the value of wind generation is largely due to the value of displaced fuel, not any perceived capacity credit – it being well understood by the wind energy proponents that conventional capacity will be retained to "fill in" during periods of low or no wind. The main value of wind, (in the UK, 5 times the capacity credit value) is its fuel and CO2 savings. Wind does not require any extra back-up, as is often wrongly claimed, since it uses the existing power stations, which are already built, as back-up, and which are started up during low wind periods, just as they are started up now, during the non availability of other conventional plant. More spinning reserve, of existing plant, is required, but this again is already built and has a low cost comparatively.
Read more about this topic: Intermittent Energy Source
Famous quotes containing the words capacity, fuel, saving and/or extra:
“Rice and peas fit into that category of dishes where two ordinary foods, combined together, ignite a pleasure far beyond the capacity of either of its parts alone. Like rhubarb and strawberries, apple pie and cheese, roast pork and sage, the two tastes and textures meld together into the sort of subtle transcendental oneness that we once fantasized would be our experience when we finally found the ideal mate.”
—John Thorne, U.S. cookbook writer. Simple Cooking, “Rice and Peas: A Preface with Recipes,” Viking Penguin (1987)
“It is now many years that men have resorted to the forest for fuel and the materials of the arts: the New Englander and the New Hollander, the Parisian and the Celt, the farmer and Robin Hood, Goody Blake and Harry Gill; in most parts of the world, the prince and the peasant, the scholar and the savage, equally require still a few sticks from the forest to warm them and cook their food. Neither could I do without them.”
—Henry David Thoreau (1817–1862)
“Oh that my Pow’r to Saving were confin’d:
Why am I forc’d, like Heav’n, against my mind,
To make Examples of another Kind?
Must I at length the Sword of Justice draw?
Oh curst Effects of necessary Law!
How ill my Fear they by my Mercy scan,
Beware the Fury of a Patient Man.”
—John Dryden (1631–1700)
“Celebrity is a mask that eats into the face. As soon as one is aware of being “somebody,” to be watched and listened to with extra interest, input ceases, and the performer goes blind and deaf in his overanimation. One can either see or be seen.”
—John Updike (b. 1932)