Estimation of Annual Reductions of NOx Emissions in ERCOT for the HB3693 Electricity Savings Goals

Abstract

Increasing the level of energy efficiency in Texas, as proposed by House Bill 3693, an Act related to energy demand, energy load, energy efficiency incentives, energy programs and energy performance measures, would reduce the amount of electricity demanded from Texas utilities. Since approximately eighty-eight percent of electricity generated in Texas is from plants powered by fossil fuels, such as coal and natural gas, this decrease would also reduce the air pollution that would otherwise be associated with burning these fuels. This report presents the potential emission reductions of nitrogen oxides (NOx) that would occur in the Electric Reliability Council of Texas (ERCOT) region if new energy efficiency targets for investor owned utilities are established for 2010 and 2015. These energy efficiency targets are the subject of a feasibility study as prescribed by Texas House Bill 3693. This report describes the details of the methodology, data and assumptions used, and presents the results of the analysis. The total energy savings targets for utilities within ERCOT are 745,710 megawatt-hours (MWh) by 2010 under the 30 percent reduction of growth scenario and 1,788,953 MWh by 2015 under the 50 percent reduction of growth scenario. The total projected annual NOx emissions reductions from these electricity savings are 191 tons in 2010 and 453 tons in 2015, or converting the annual totals into average daily avoided emissions totals, 0.5 tons per day by 2010 and 1.25 tons per day by 2015. The average avoided emission rate is approximately 0.51 pounds (lb) of NOx reduced per MWh of electricity savings. While House Bill 3693 is an Act related to energy and does not target emissions levels, the energy efficiency improvements would achieve air pollution benefits that could positively affect air quality and human health. The emissions reductions projected to result in 2010 and 2015 are comparable to the Texas Emission Reduction Program (TERP) Energy-Efficiency Grants Program, which does target emission reductions and estimated 2005 annual NOx emissions reductions of about 89 tons. While the projected emissions reductions are small compared to the total emission reductions needed to bring the state’s non-attainment areas into attainment of the national ambient air quality standards for ozone, they can be a part of an overall strategy to reduce emissions and improve human health in Texas.