Research Publications

Although widespread deployment of negative emission technologies (NET) is crucial for achieving aggressive mitigation pathways (including nearly all 1.5 degrees Celsius pathways), few studies examine the impacts of adoption of NET on the electric power sector. A key gap among these studies is understanding the impact of planning for NET deployment under different timelines. Generating this information is pressing given ongoing decarbonization activities by utilities across the United States and globe. In this paper, we fill these critical gaps by quantifying power system impacts of planning for NET deployment at different points along decarbonization pathways under net-zero and negative emission scenarios. We test the robustness of our results by conducting sensitivity analyses to explore how differences in decarbonization constraints, NET planning timelines, and capital costs of key technologies can influence costs and capacity investment decisions. We use the Electric Reliability Council of Texas power system as our case study and focusing on direct air capture and sequestration (DACS) as our chosen NET. We find that planning for DACS early leads to the lowest cost in all scenarios due to significant displacements of wind, solar PV, and expensive long duration storage capacity investments, as well as less required DACS deployment. Specifically, under a net-zero emission target, planning for DACS beginning in 2020 lowers total costs by 1.3billion, or 62.8 billion, or 3% compared to planning for DACS in 2050. The value of planning for DACS early increases when there is a high electrification of end-use demand, due to complete displacement of expensive advanced nuclear investment in this scenario. Specifically, planning for DACS early lowers total cost by 24% under a net-zero emission target and by 5% under a negative emission target. As demand becomes more electrified, planning for DACS early leads to more similar capacity investment decisions under both a net-zero and a negative emission system. Our results demonstrate the importance of planning for NET early regardless of emission target scenarios, uncertainties in technological costs, and decarbonization constraints.