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

• Published in: Environmental research letters 2011-10, Vol.6 (4), p.44018
• Main Authors: Alhajeri, Nawaf S, Donohoo, Pearl, Stillwell, Ashlynn S, King, Carey W, Webster, Mort D, Webber, Michael E, Allen, David T
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Coal; Electric power demand; Electric power generation; Electricity; Emissions control; Industrial plant emissions; Natural gas; Nitrogen oxides; Photochemicals; Power plants; Sulfur; Sulfur oxides; Water consumption; Water use
• ISSN: 1748-9326; 1748-9326
• DOI: 10.1088/1748-9326/6/4/044018

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.