As I understand it -- and I'm definitely not an expert --
the nuclear plants are considered so fragile that nobody
even dreams of black start capability. In the event of a
disturbance in the grid, the nuclear plants are always the
first to go down and the last to come back up.
I think fossil-fueled power plants also don't dream of black start
capability. When starting a large generator, one often first thinks of the
"exciter" power needed to energize the field magnets of the generator.
While it is true that power is needed to provide the excitation field, power
plants using steam turbines require a lot of additional power. It takes
substantial electricity to run the boilers (to provide the fuel feed,
operate blowers, pump cooling water, etc.). It also takes power to operate
the various control systems and computers. In the Wiki article on "black
start" it suggests that a fossil-fuel power plant can require 10% of the
generator power output just to run the generator and boilers and control
systems. A diesel-powered black-start-able generator would need to be huge
(and expensive) in order to start a typical-sized coal-fired generator. I
can imagine it would take nearly as much power to black-start a coal-fired
plant as to black-start a nuclear plant.
The Wiki-article states that hydroelectric power plants are the ones that
are easiest to black-start from a diesel generator because you only need
excitation power plus sufficient power to open and moderate the water intake
gates. This makes a lot of sense, but not all areas of the continent are
flush with hydroelectric power plants. The question then becomes, do we
collectively spend some big bucks to gain black-start capability at some key
coal-fired plants, or do we spend money to improve the grid to reduce the
likelihood of widespread blackouts like the one that happened in 2003, or
perhaps some of both?
Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Chair, Division of Natural and Applied Sciences
Bluffton University
1 University Drive
Bluffton, OH 45817