Due to low natural gas prices and the environmental advantages of natural gas combined cycle (NGCC) compared to coal, NGCC is replacing coal generators as the inframarginal providers of electricity. However, on average, NGCCs are running only 54 percent of the time. Utilizing excess NGCC capacity, as a substitute for coal generation, is a short-term policy solution for reducing greenhouse gases. In this research, we evaluate the impact of a carbon tax on substitution of natural gas for coal in the U.S. electricity sector. Through fixed effects regression and counterfactual calculations, we analyze data from 2003 to 2017 to evaluate the impact of a carbon tax on NGCC utilization, carbon emissions, and federal tax revenue between 2020 and 2030. We find the highest marginal increase in NGCC utilization happens with a carbon tax priced at $10/ton. Depending on future estimated changes in natural gas capacity, a $10 carbon tax would reduce carbon emissions between 1.39 and 1.55 billion metric tons per year and generate $106.47 to $118.33 billion in net revenue. The carbon tax we propose would be simpler to implement than an economy-wide policy and would still lead to significant carbon reductions and federal tax revenue in the short-run.

由于天然气价格低廉以及天然气联合循环 (NGCC) 与煤炭相比的环境优势，NGCC 正在取代燃煤发电机成为边际电力供应商。然而，平均而言，NGCC 的运行时间仅为 54%。利用过剩的 NGCC 产能替代煤炭发电，是减少温室气体排放的短期政策解决方案。在这项研究中，我们评估了碳税对美国电力部门天然气替代煤炭的影响。通过固定效应回归和反事实计算，我们分析了 2003 年至 2017 年的数据，以评估碳税对 2020 年至 2030 年间 NGCC 利用率、碳排放和联邦税收的影响。我们发现 NGCC 利用率的最高边际增长发生在碳税价格为 10 美元/吨。根据天然气产能未来估计的变化，10 美元的碳税将每年减少 1.39 至 15.5 亿公吨的碳排放量，并产生 106.47 至 1183.3 亿美元的净收入。我们提议的碳税比整个经济范围的政策更容易实施，并且在短期内仍会导致显着的碳减排和联邦税收收入。