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:
“Information about child development enhances parents’ capacity to respond appropriately to their children. Informed parents are better equipped to problem-solve, more confident of their decisions, and more likely to respond sensitively to their children’s developmental needs.”
—L. P. Wandersman (20th century)
“Beware the/easy griefs, that fool and fuel nothing./It is too easy to cry “AFRIKA!”/and shock thy street,/and purse thy mouth,/and go home to thy “Gunsmoke,” to/thy “Gilligan’s Island” and the NFL.”
—Gwendolyn Brooks (b. 1917)
“We black women must forgive black men for not protecting us against slavery, racism, white men, our confusion, their doubts. And black men must forgive black women for our own sometimes dubious choices, divided loyalties, and lack of belief in their possibilities. Only when our sons and our daughters know that forgiveness is real, existent, and that those who love them practice it, can they form bonds as men and women that really can save and change our community.”
—Marita Golden, educator, author. Saving Our Sons, p. 188, Doubleday (1995)
“When we leave our child in nursery school for the first time, it won’t be just our child’s feelings about separation that we will have to cope with, but our own feelings as well—from our present and from our past, parents are extra vulnerable to new tremors from old earthquakes.”
—Fred Rogers (20th century)