We are especially grateful to Walter Short who first envisioned and developed the WinDS and ReEDS models. We also thank the NREL analysts who provided input on the technology costs, assumptions, and methodologies in ReEDS, including

Department of Energy (DOE) reports produced after 1991 and a growing number of pre-1991 documents are available free via www.OSTI.gov.

We gratefully acknowledge the many people whose efforts contributed to this report. The ReEDS modeling and analysis team at the National Renewable Energy Laboratory (NREL) was active in developing and testing the ReEDS model version 2019. We also acknowledge the vast number of current and past NREL employees on and beyond the ReEDS team who have participated in data and model development, testing, and analysis. We are especially grateful to Walter Short who first envisioned and developed the Wind Deployment System (WinDS) and ReEDS models. We thank

Recent developments in India and Nepal highlight new opportunities for increased cross-border energy trade (CBET). This study builds on several prior analyses of CBET in South Asia to explore potential trading opportunities among India, Nepal, Bangladesh, and Bhutan. Uniquely, this study uses a detailed 1-year, 1-hour resolution unit commitment and economic dispatch model of the South Asia power system in the year 2022 to examine the technical and economic impacts of CBET under different assumptions about hydropower development in Nepal and regional trade agreements. The study finds that although Nepal might have the physical capacity to increase annual exports to India if development of domestic hydropower is accelerated (to 4,500 megawatts ), much of this increase would be uneconomic to export if current market inefficiencies between the two countries remain. But the economics of trade can improve dramatically with institutional changes. If market and system operating rules are revised to treat transactions with Nepal the same as transactions between Indian states, our findings suggest that annual net exports to India could increase threefold (to 9.0 terawatt hours), hydro curtailment in Nepal would decrease, and production costs for electricity in both countries would fall $359 million. These factors-the level of hydropower development in Nepal and the ease of crossborder trade-are the biggest drivers of potential CBET in South Asia. The study also examines the impact of CBET on renewable energy development in India, a supply contract between Nepal and Bangladesh, and fully coordinated market operations across Bangladesh, Bhutan, India's eastern region, and Nepal. Although this study does not provide a complete characterization of system operations within each South Asia country, it does capture many previously unconsidered intertemporal operational constraints. Additional work can include more detailed representations of the Bhutan and Bangladesh power systems and alternative trading arrangements with these countries, which could be especially fruitful in light of the benefits measured in this study. iv This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. This analysis was funded by the U.S. Department of State's Bureau of South and Central Asian Affairs Regional Connectivity Program.Although the study identifies many previously unconsidered impacts on CBET between India, Nepal, Bhutan, and Bangladesh, including local impacts in different Indian states and regions and intertemporal operational constraints, it does not provide a complete characterization of system operations within the entire region. Future work could include detailed modeling of the Bhutan and Bangladesh power systems to examine the impact of CBET on these systems in greater detail. Complementary analysis could identify policy and regulatory pathways to remove nontechnical barriers to CBET and capture the benefits identified in this study.viii This report is available at no cos...

Department of Energy (DOE) reports produced after 1991 and a growing number of pre-1991 documents are available free via www.OSTI.gov.