Fade to Blackstart
May 26 - Power Engineering
The Blackout that plunged much of the country into darkness this past August caused millions to question the integrity and reliability of the nation's power grid. The bulk of the criticism has fallen on the lack of enforceable reliability requirements, ineffective vegetation management practices, and poor communication. An area that has escaped much attention - primarily because it appears to have performed effectively in the immediate aftermath of the Blackout - is blackstart capability, which enables the grid to re- energize without external power. Blackstart capability, however, occupies an uncertain position in the system reliability framework, caught between the "obligation to serve" element associated with conventional utility operation and the "market commodity" element associated with deregulation and evolving power markets. Resolving this dual master status warrants attention.
In mid-March, Exelon Power completed upgrades at its 350 MW Southeast Chicago
combustion turbine peaking plant to enhance its blackstart capabilities - adding
three 2 MW diesel generators to start the fuel gas compressor and the first
combustion turbine starting motor. The upgrade enables Exelon to be a reliable
source of power should a major system blackout occur. To its credit, Exelon
Power saw the need for additional blackstart capacity and acted accordingly. In
fact, Exelon initiated the project in December 2002, well in advance of the
Blackout of 2003.
Somewhat surprisingly, at least to me, there has been little formal activity
in developing, or at least evaluating, the need for beefed-up blackstart
capability elsewhere post-August 14. Perhaps this is a reflection of the more
serious issues associated with the Blackout, such as enforceable reliability
standards. Or perhaps it's a reflection of the "success" of the
restoration process on August 15 and 16 - blackstart capacity wasn't even needed
in many cases. FirstEnergy was able to draw on pumped storage hydro plants on
the Ohio River that didn't trip off-line, and, in New York, NYISO was able to
draw on the Niagara and St. Lawrence hydro plants to support and re-energize the
grid after the Blackout.
Still, one would think the Blackout would jump-start a more detailed analysis
of blackstart capabilities within utility service territories, control areas,
and wider interconnection regions, to at least ensure there is enough capacity,
in the right places, operating under the same procedures and requirements. The
U.S.- Canada Power System Outage Task Force's final report on the Blackout,
issued on April 5, does acknowledge the importance of blackstart functions, but
with a muted sense of urgency. The Task Force recommended that NERC evaluate the
blackstart and system restoration performance following the August 14 outage and
report back to the NERC board within one year. Within six months of that date,
each of the reliability councils would then be required to re- evaluate their
procedures and plans to assure an effective blackstart and restoration
capability within their region.
The reliability councils and regional transmission organiza- lions (RTOs) do
have guidelines in place regarding blackstart capability. According to PJM's
Emergency Operations Manual, for example, PJM has the ability to completely
restore power from a shutdown state within 24 hours, with 80% restoration
achieved within 16 hours. PJM acknowledges, however, that because of current
scheduling strategies, the amount of nuclear units operating, direct purchases,
and system conditions before and after the outage, these restoration times may
be difficult to achieve.
Beyond the Blackout, there are other factors at play with respect to
blackstart capability. "The recent issue which has probably had the
greatest impact on the industry's thinking with regard to blackstart capability
is deregulation," says Richard Barker, president of Quad Resources, an
engineering, management and consulting firm based in Atlanta. "Since
generation has become a mar- ket-based business, utilities are asking who will
pay for blackstart capability. The most prevalent thinking seems to be that
transmission line customers and users should pay a blackstart capability charge
in order to have it available. But blackstart capacity was not among the
so-called ancillary services mandated by FERC, so how this will shake out
remains to be seen. Further, because deregulation has made line loadings and
power flows less predictable than they once were, on what criteria will the
decisions of how much and where blackstart capacity should be built be
based?"
Questions such as these are beginning to force the operating ISOs and RTOs to
evaluate the changing role of blackstart capability in a deregulated market. PJM
Interconnection, for example, recently filed a tariff revision with FERC to
provide more flexibility in the recovery of fixed costs associated with
providing blackstart services. Rather than just compensating owners for costs
attributed to existing resources, the revised tariff would enable recovery of
costs required to provide new blackstart resources, to replace existing
resources that may be retired or removed from blackstart service, or to make
capital investments to retain or increase a generator's blackstart capabilities.
"While the August 14th Blackout has not directly caused us to make changes
with respect to blackstart, it certainly highlighted the need for proper
preparation, particularly as older blackstart units are retired," said PJM
spokesman Ray Dotter.
I'm not claiming that insufficient blackstart capacity is currently
imperiling the nation's power network. Whether or not sufficient blackstart
capacity exists is a matter for the power system ', engineers to determine, not
me.
The point I'd like to make is that the incremental cost of making
strategically located power plants blackstart-qualified is modest - particularly
in comparison to the avoided economic impact of a fade to black.
BY BRIAN K. SCHIMMOLLER, MANAGING EDITOR
Copyright PennWell Publishing Company May 2004