When it comes to energy, it’s important to understand the difference between the potential and the capacity of a given energy source.
Case in point: U.S. Interior Secretary Ken Salazar was quoted on April 6 as saying that ocean winds along the East Coast could generate as much as 1 million megawatts of power – roughly the equivalent to the output of 3,000 medium-size coal plants.
Press accounts (which I am sure the anti-coal activists will seize upon) say that, according to the secretary, if wind power were fully developed, it could generate enough electricity to replace most, if not all, the coal-based power plants in the U.S.
But wait (as the late Paul Harvey would say)…there’s more. The secretary’s spokesman said that his remarks were misrepresented. From the Washington Post:
A spokesman for Salazar said Monday evening that the secretary does not expect wind power to be fully developed, but was speaking of its total potential if it were.
In fact, in the same article, Secretary Salazar expressed the need to keep all energy options open, saying “we need to look at all forms of energy as we move forward into a new energy frontier.”
So what’s the deal? What’s the difference between wind potential versus actual capacity and why is it important?
Wind’s greatest challenge is intermittency. In fact, public utility commissions (in regulated states) generally require that you build 300 megawatts of installed wind capacity for every 100 megawatts of required capacity that you need to meet. Why? Because wind is rated at basically 1/3 reliable (in most cases) due to intermittency (only producing power when there is sufficient wind speed).
So does that mean we shouldn’t expand wind power? Not at all. We’ve said many times before that it’s going to take all of our domestic energy resources to meet our growing energy demand (again, echoing the comment made by Secretary Salazar yesterday). But we need to get off the idea that wind and coal are competitors—they’re not. They’re complimentary energy sources.
UPDATE 4-8-2009: The Wall Street Journal's Environmental Capital blog echoed our sentiments on this topic. An excerpt:
[Secretary Salazar] contends that the offshore wind potential just in the Atlantic—the easiest region to develop–totals about 1,000 gigawatts.
Let’s put that in context. The entire electricity-generation capacity of
the U.S., including coal, gas, nuclear, hydropower and other
renewables, is just over 1,000 gigawatts. There are only about 1,400
coal plants in operation in the U.S., accounting for about 336
gigawatts of power. So that would indeed be a lot of wind.
[B]ut wind power, even offshore wind power, isn’t the same as coal or
nuclear. Offshore wind farms in Europe are lucky to generate 40% of their listed capacity. So that limits that mid-Atlantic resource to about 74 gigawatts. And that doesn’t even consider the technical and economic hurdles that still dog offshore wind power and make it less competitive than its onshore cousin.
UPDATE 4-10-2009: Late yesteday, Wyoming Gov. Dave Freudenthal discounted Sec. Salazar's statement. From USA Today:
The governor said coal plays a critical role in the nation's energy, despite any creative hypotheticals by those in the Beltway.
"That potential (for wind energy to replace
coal) is never going to be realized," Freudenthal said. He also noted
that Salazar's comment was out of step with other messages from the
The federal economic stimulus package includes
millions of dollars to develop technology for clean coal programs and
for carbon capture and sequestration.