Negative CO2 Emission Transition Roadmap (NECTAR): A Rapid Decision Support Tool for Negative CO2 Emis-sion Hybrid Energy System Development and Analysis

The Biden Administration set a goal to reduce 50% of greenhouse gas emissions by 2030, which supports the existing goal to create a carbon free electric power sector by 2035 (https://www.whitehouse.gov/briefing-room/statements-releases/2021/04/22/fact-sheet-president-biden-sets-2030-greenhouse-gas-pollution-reduction-target-aimed-at-creating-good-paying-union-jobs-and-securing-u-s-leadership-on-clean-energy-technologies/). This massive and continued investment in decarbonization will include hybrid energy systems that combine one or more primary energy sources with carbon capture. One such technology is direct air capture and carbon storage (DACCS) coupled with CO2 neutral sources of heat, which is a hybrid system because it uses electricity and heat to provide negative CO2 emissions. As discussed in our narrative, DACCS could provide tens of billions of dollars per year or more of cost savings for decarbonization because it places a ceiling on decarbonization cost, but there are many unknowns about DACCS adoption at various scales within the clean-energy economy. For example: to what heat and electricity sources should DACCS be coupled (process-scale); how will DACCS integrate and change the design of regional CO2 transportation and storage infrastructure that fossil-fuel and biomass power plants with CO2 capture also need to reach climate warming goals (regional-scale); and what policies appropriately incentivize DACCS adoption as a component of the decarbonization portfolio (national-scale)? We propose to develop NECTAR (Negative CO2 Emission Transition Roadmap) to directly ad- dresses these challenges, with a focus on the FOA’s need for Decision Support Tools for Decarbonization, including developing and applying a decision support tool that directly utilizes the capabilities of IDAES to help enable a widespread use of models and simulations for expansion planning to inform future investments for decarbonization. As requested by the FOA, the target end user for NECTAR is utilities and regulators, to aid in the evaluation of different decarbonization scenarios and technologies to inform policy and investments. Our NECTAR partners, including the Electric Power Research Institute (EPRI), Southern Company, and Carbon180, demonstrate there is support for NECTAR across these two stakeholder groups; see letters of commitment and support. As requested by the FOA, NECTAR will visualize how the negative emission transition may occur across the United States with a user-friendly graphical user interface that will allow the user to change process-, regional-, and systems-level factors related to hybrid DACCS systems, thus incorporating user feedback in real time directly. The data visualized will be generated by directly utilizing the Institute for the Design of Advanced Energy Systems (IDAES) computational plat- form, which supports this multi-scale optimization. More specifically, IDAES will be to used to quantitatively evaluate how DACCS should be coupled with other primary energy sources of heat to design optimal negative emissions hybrid energy systems. In addition to IDAES, developing NECTAR will also require using SimCCSPRO and REGEN. SimCCSPRO is Carbon Solutions LLC software that can be used to determine CO2 pipeline networks that optimally connect sources of CO2 to locations where that CO2 can be sequestered. REGEN is EPRI’s economy-wide expansion planning model that is being developed out of their Low Carbon Resources Initiative.