The value of low- and negative-carbon fuels in the transition to net-zero emission economies: Lifecycle greenhouse gas emissions and cost assessments across multiple fuel types

Impacts of the Inflation Reduction Act on the Economics of Clean Hydrogen and Synthetic Liquid Fuels

“…The time frame for relevant IRA credits, their values for different carbon intensity products, and other relevant statutory requirements are summarized in Table S1. Building on details provided in our previous study, 22 the performances and costs of technologies prospectively commercially deployed in the early 2030s are summarized in Table 2. Table S2 provides additional details.…”

“…where subscript p refers to a specific SLF pathway (P7−P15), CAPEX, CRF, FOM, VOM, and Seq are analogously defined as for eq 2, F is the annual cost of feedstock ($; for biomass, ethanol, or H 2 , where the H 2 cost is determined by eq 2), V SLF S3). The lifecycle GHG emissions for P1−P6 (assuming GWP 100 for non-CO 2 GHGs) are adopted from our previous analysis, 22 and 142 GJ HHV /kg of H 2 is used to convert from kg of CO 2 e/GJ HHV in ref 22 to kg of CO 2 e/kg of H 2 . The IRA credits shown here are expressed as derated values to account for project economic lifetimes longer than the IRA-stipulated durations over which incentives are available, e.g., the $1/kg of H 2 and $3/kg of H 2 45V credits are derated to $0.8/kg of H 2 and $2.…”

“…The IRA and other policy support is aimed at helping clean options gain early footholds in markets, scale up commercial deployment, and achieve cost reductions via economies of scale, experience, and incremental innovation, which support policies have previously achieved for other technologies, e.g., wind generation. 21 In our previous study, 22 we analyzed technologies for H 2 and Fischer−Tropsch liquid (FTL) production and determined their environmental and economic performance in the context of an assumed universally applied carbon tax. Here, building on that work, we seek to provide a timely and nuanced analysis of specific provisions of the IRA that affect the cost-competitiveness of low-carbon and negative-carbon hydrogen and SLF production relative to carbon-intensive fossil fuel equivalents.…”

“…The 45Y clean electricity PTC is incorporated into the electricity price that is assumed in our analysis. The input electricity price after applying the 45Y subsidy is $21.5/MWh (see Table S3), and the capacity factor for electrolysis is 0.55. , f The biomass used here is assumed to be agricultural residue, and we treat its biogenic CO 2 to be carbon-neutral, which is consistent with its treatment in the billion-ton study . Upstream (nonbiogenic) emissions of 5.08 kg of CO 2 /GJ (Table S4) are assumed from harvesting, transport, and preprocessing.…”

Assessing capacity to deploy direct air capture technology at the country level – an expert and information entropy comparative analysis

“…Therefore, in order for direct air capture to be a net-CDR solution, DAC needs to be paired with reliable long-term carbon storage mechanisms -for example, geological sequestration in disused oil wells and unmineable coal seams distributed globally, or mineralisation in rock formations [25,26] Notwithstanding technical considerations, significant uncertainty remains with regards to the economic viability across the various DAC technologies being explored. The DAC company Climeworks in 2019 quoted costs of US$500-600/tCO 2 , while commercial forecasts for long-term costs point to pricing of below US$100/tCO 2 [27][28][29]. In spite of the uncertainties around cost and the early stage of technical development, DAC is receiving an increasing amount of attention, particularly as companies developing the technology approach commercialization.…”