Comment Log Display

Thank you for the opportunity to comment on the draft “Expanded
List of Early Action Measures to Reduce Greenhouse Gas Emissions –
Recommended for Board Consideration”.  Reliant Energy, Inc. is an
independent power producer that owns and operates five natural
gas-fired power plants in California.  All of our facilities were
constructed before 1980.  We offer the following comments to
EJAC-22 (CARB staff summary B21) and EJAC-27 (staff summary B26).

EJAC-22 – Relatively Inexpensive Energy Savings Measures with
Relatively Short Payback Times for Fossil Fuel Power Plants Built
Prior to 1980

We agree with ARB staff that this measure is not appropriate to
consider as an Early Action.  We also question whether further
discrete study of this idea is warranted within the context of the
Scoping Plan.  As an experienced power plant operator and
competitor with other experienced operators, Reliant thinks much
about efficient fuel use and is continuously implementing cost
effective fuel efficiency measures.  Fuel is our largest power
production cost by far, therefore a significant incentive already
exists to use fuel wisely and gain an edge over our competitors. 
Rather than discrete ARB regulations or policies which force
uneconomic efficiency measures on knowledgeable facility owners, a
market-based system for AB 32 implementation (e.g., a cap and trade
system) and it’s resulting carbon price signal would be a more
efficient and economic means of uncovering further GHG emission
reductions from increased fuel efficiency.

EJAC-27 – Phase-out of Pre-1980 Power Plants Generating at Least
100 MW and  Provide Incentives to Replace them with Clean Energy

We agree with ARB staff that this measure is not appropriate to
consider as an Early Action.  We also question whether further
discrete study of this idea is warranted within the context of the
Scoping Plan without the benefit of the comprehensive electric
sector recommendations to be made by the joint CEC and CPUC
process currently under way.

In addition, ARB staff assumes that retired pre-1980 generating
units would be replaced by new CCGT plants of identical capacity.
However, older traditional steam boiler plants play an important
role in grid reliability that baseload CCGTs cannot match.  Many
of the older steam generators can “swing” down to very low loads
and operate there for extended periods in compliance with air
quality permits, and expeditiously swing back up to higher loads
when the grid demands it.  In contrast, modern CCGTs with dry low
NOx combustors would not be able to operate at significantly
reduced loads because they cannot achieve permitted limits for NOx
emissions at below 60-70% of rated output.  For example, a 500 MW
CCGT would not be able to operate below approximately 300-350 MW. 
This is because the very lean fuel-to-air mixture in the turbine
combustors which is effective at reducing NOx at high loads
creates combustion instability at part loads.  A less lean firing
mode mitigates the instability at approximately 60-70% output and
prevents combustor flameout, but also increases NOx emissions
excessively relative to permit limits.  Thus, if grid reliability
calls for a relatively small amount of generation, the class of
baseload CCGTs likely envisioned by CARB staff for replacement
generating capacity would not be flexible enough to swing down and
serve that need.  

As noted by staff, the impact on emissions from this idea is
potentially minimal.  We believe the risk to the stability of the
electric grid from shutting down these plants outweighs the
benefits of the GHG reductions that would be gained thereby.