摘要：The possibility of using electricity dispatching strategies to achieve a 50% nitrogen oxide
(NOx) emission reduction from electricity generating units was examined using the grid
of the Electricity Reliability Council of Texas as a case study. Simulations of a
hypothetical policy demonstrate that imposing higher NOx prices induces a switch from
some coal-fired generation to natural gas generation, lowering NOx emissions.
The simulation is for a day with relatively high electricity demand and accounts
for transmission constraints. In addition to the lowering of the NOx emissions,
there are co-benefits of the redispatching of generation from coal to natural gas,
including reductions in the emissions of sulfur oxides (24%–71%), Hg (16%–82%) and
CO2 (8.8%–22%). Water consumption was also decreased, by 4.4%–8.7%. Substantial reductions
of NOx emissions can be achieved for an increased generation cost of 4–13%,
which is due to the higher fuel price of gas relative to coal (assuming a price of
$3.87 per MMBTU (MMBTU: million British thermal units) for natural gas, and
$1.89 per MMBTU for coal). However, once the system has reduced NOx emissions by
approximately 50%, there is little incremental reduction in emissions due to further
increases in NOx prices.
