Using market-based dispatching with environmental price signals to reduce emissions and water use at power plants in the Texas grid




Alhajeri, Nawaf S.
Donohoo, Pearl
Stillwell, Ashlynn S.
King, Carey W.
Webster, Mort D.
Webber, Michael E.
Allen, David T.

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IOP Publishing


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.


Nawaf S. Alhajeri is with UT Austin, Pearl Donohoo is with Massachusetts Institute of Technology, Ashlynn S. Stillwell is with UT Austin, Carey W. King is with UT Austin, Mort D. Webster is with Massachusetts Institute of Technology, Michael E. Webber is with UT Austin, and David T. Allen is with UT Austin

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N.S. Alhajeri, P. Donohoo, A.S. Stillwell, C.W. King, M.D. Webster, M.E. Webber, and D.T. Allen, "Using Market-Based Dispatching With Environmental Price Signals to Reduce Emissions and Water Use at Power Plants in the Texas Grid," Environmental Research Letters 6 (9pp) (2011) 044018.