The Net Zero America study aims to inform and ground political, business, and societal conversations regarding what it would take for the U.S. to achieve an economy-wide target of net-zero emissions of greenhouse gases by 2050. Achieving this goal, i.e. building an economy that emits no more greenhouse gases into the atmosphere than are permanently removed and stored each year, is essential to halt the buildup of climate-warming gases in the atmosphere and avert costly damages from climate change. A growing number of pledges are being made by major corporations, municipalities, states, and national governments to reach netzero emissions by 2050 or sooner. This study provides granular guidance on what getting to net-zero really requires and on the actions needed to translate these pledges into tangible progress.
The global move towards a net-zero emission energy system focuses on reducing CO2 emissions, driven by technological advances and a shift to renewable energy. The U.S. aims to transition from fossil fuels to low-carbon sources, while addressing social and economic aspects for equitable community support. Advances in wind, solar, nuclear power, energy storage, and carbon capture are key. Major emission reductions are expected in electricity, transportation, and home heating, though decarbonizing sectors like aviation and heavy industry remains challenging. This shift is crucial for climate mitigation, potentially cutting global CO2 emissions by 10% and improving health. The U.S. targets net-zero by 2050, in line with global emissions mitigation goals. This report highligts the role of National Academies of Sciences, Engineering, and Medicine in overseeing this transition, advocating diverse energy solutions and inclusive policies, highlighting the importance of technological, economic, and social changes for an equitable transition.
Mitigating climate change while fueling economic growth requires decarbonizing the electricity sector at reasonable cost. Some strategies focus on wind and solar energy, supported by energy storage and demand flexibility. Others also harness “firm” low-carbon resources such as nuclear, reservoir hydro, geothermal, bioenergy, and fossil plants capturing CO2. This paper presents a comprehensive techno-economic evaluation of two pathways: one reliant on wind, solar, and batteries, and another also including firm low-carbon options (nuclear, bioenergy, and natural gas with carbon capture and sequestration). Across all cases, the least-cost strategy to decarbonize electricity includes one or more firm low-carbon resources. Without these resources, electricity costs rise rapidly as CO2 limits approach zero. Batteries and demand flexibility do not substitute for firm resources. Improving the capabilities and spurring adoption of firm low-carbon technologies are key research and policy goals.
The electric power sector is currently undergoing several important transitions, which individually and collectively have the potential to transform the design, operation, and characteristics of electricity systems, including: decarbonization of electricity supplies; increased adoption of variable renewable energy and distributed energy resources; digitization of power systems; and electrification of greater shares of heating, transportation, and industry. In the face of these transformations, many conventional electricity resource capacity expansion models are no longer adequate for rigorous decision support and policy analysis. This working paper describes the formulation of “GenX,” a highly-configurable electricity resource capacity expansion model that incorporates several state-of-the-art improvements in electricity system modeling to offer improved decision support for a changing electricity landscape. GenX is a constrained optimization model that determines the mix of electricity generation, storage, and demand-side resource investments and operational decisions to meet electricity demand in a future planning year at lowest cost subject to a variety of power system operational constraints and specified policy constraints, such as CO2 emissions limits. The appropriate level of model resolution with regards to chronological variability of electricity demand and renewable energy availability, power system operational detail and unit commitment constraints, and transmission and distribution network representation each vary for a given planning problem or policy question. As such, the GenX model is designed to be highly configurable, with several different degrees of resolution possible on each of these three key dimensions. The model is capable of representing a full range of conventional and novel electricity resources, including thermal generators, variable renewable resources (wind and solar), run-of-river, reservoir and pumped-storage hydroelectric generators, energy storage devices, demand-side flexibility, and several advanced technologies such as high temperature nuclear reactors and carbon capture and storage. The model has been implemented in Julia Language.