POWER June 2014 - 72

ELECTRIC POWER 2014 ROUNDUP
Fuel Flexibility Is the Gift That
Keeps Giving
Against the backdrop of low-priced natural gas and increasing renewable capacity,
finding ways to stay competitive as operating costs continue to rise at coalfired
power plants is getting increasingly difficult. Fuel flexibility can help keep
coal plants in the mix.
Aaron Larson
A
ll power plants must continually strive
to control operating expenses, but it is
particularly important for coal-fired
facilities to cut costs these days to stay competitive
while meeting ever-more-stringent
environmental requirements. By some estimates,
the addition of a modern air quality
control system (AQCS)-including activated
carbon injection, selective catalytic
reduction, flue gas desulfurization (FGD),
and baghouse components-can result in a
50% increase in operating expenses due to
the cost of consumables, such as activated
carbon, ammonia, and lime, as well as additional
labor to operate and maintain the extra
equipment.
Worse yet, these estimates don't take into
account catalyst or bag and cage replacements;
additional steam, water, and auxiliary
power usage; or by-product transport costs.
With the additional overhead expenses, finding
savings in other areas is imperative. Developing
a fuel flexibility strategy is one way
some companies have found to save a significant
amount of money.
During the ELECTRIC POWER Conference
& Exhibition (EP) held in New Orleans
this April, Daniel Donochod, PE, fuel
1. Fuel diversification. Daniel Donochod,
PE of Duke spoke about fuel flexibility.
Source: POWER/Aaron Larson
flexibility strategy manager for Duke Energy
(Figure 1), gave a presentation entitled
" Keeping Coal Competitive-Fuel Flexibility. "
In it, Donochod explained how Duke
Energy has diversified its fuel mix and, in the
process, positioned itself for better environmental
compliance.
Duke Energy is the largest electric utility
in the U.S., with about $114 billion in assets
and roughly 58 GW of generating capacity.
Like many companies, its generation portfolio
has changed dramatically since 2005.
Back then, coal accounted for about 55% of
total output, but the company estimates that in
2015 coal will fuel only 38% of its electricity
output. During the same period, natural gas-
fired generation is expected to increase from
5% to 24%, essentially picking up all of the
lost coal generation and more.
Although Donochod noted that there aren't
PRBCUG Focuses on Safe Coal Handling
Andy Dobrzanski, Mark Collett, and Dave
Markle were among the presenters at the
Powder River Basin Coal Users' Group (PRBCUG)
annual conference held Mar. 31 to
Apr. 3, 2014, in conjunction with the ELECTRIC
POWER Conference in New Orleans.
The PRBCUG provides in-depth presentations
and discussions promoting the
safe, efficient, and economic use of PRB
coals by companies that currently use,
or are considering the use of PRB coals.
While several speakers mentioned housekeeping's
important role in the safe operation
of facilities, other topics were also
covered in depth.
One was fly ash-handling systems and
PRB coal ash. Dobrzanski, fuel supply
manager for DTE Energy's Monroe Power
Station, noted that PRB coal fly ash size is
typically finer than bituminous fly ash and
normally has very low unburned carbon due
to the reactivity of the fuel. The majority
of the ash is removed as fly ash-70% to
90% of the total quantity-in a baghouse
or electrostatic precipitator.
Although Dobrzanski said that bottom
ash systems at Monroe are still wet systems,
problems such as the Dan River ash
spill are putting pressure on the industry
to move toward dry ash systems. " There
72
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are different types of systems-hydraulic,
mechanical, pneumatic, and vibratory systems-that
collect bottom ash dry, " Dobrzanski
said. " Those are some of the items
that we need to look at going forward to
meet the standards that I'm sure will be
developed very shortly. "
Mark Collett, director of mining and
minerals for River Consulting, discussed
electrical standards and area classifications.
" There should be an electrical classification
drawing for every substation in
the plant so you can always look on that
and see how an electrical area is classified, "
said Collett. " If you don't know
what the classification of the areas of the
plant are, there's something wrong. "
Hot work procedures were also a " hot "
topic, but one can't talk about hot work
without discussing fire protection. Duke
Energy's Dave Markle noted that the only
guidance that the Occupational Safety
and Health Administration provides coal
plants is that if they have decided to have
a fire protection system, then it must be
maintained. " We are responsible for fire
protection ourselves, " he said. " There's no
guidance for it, except if you have it, you
maintain it. " In other words, just like so
many things, " It's up to us! "
POWER | June 2014
http://www.powermag.com
POWER June 2014

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