Future Prospects of Direct Air Capture Technologies: Insights From an Expert Elicitation Survey

Abstract

Direct air capture (DAC) technologies are promising but speculative. Their prospect as an affordable negative emissions option that can be deployed in large scale is particularly uncertain. Here, we report the results of an expert elicitation about the evolution of techno-economic factors characterizing DAC over time and across climate scenarios. This is the first study reporting technical experts' judgments on future costs under different scenarios, for two time periods, for two policy options, and for two different DAC technologies. Experts project CO2 removal costs to decline significantly over time but to remain expensive (median by mid-century: around 200 USD/tCO2). Nonetheless, the role of direct air capture in a 2°C policy scenario is expected to be significant (by 2050: 1.7 [0.2, 5.9] GtCO2)1. Projections align with scenarios from integrated assessment model (IAM) studies. Agreement across experts regarding which type of DAC technology might prevail is low. Energy usage and policy support are considered the most critical factors driving these technologies' future growth.

The cost of direct air capture and storage: the impact of technological learning, regional diversity, and policy.

“…As a result, several studies have attempted to estimate the current cost of DACS, [8][9][10][11][12][13][14] or project the cost of DACS into the future. [14][15][16][17] However, these studies all use methods inconsistent with the nature of the cost development of early-stage technologies, whose costs tend to rise during the research, development, and deployment (RD&D) phase up to the first deployed commercial scale plant, i.e., the first-of-a-kind (FOAK) plant, and then start falling as a function of deployment, as demonstrated in Figure 1. A recent method for the costing of advanced CO2 capture technologies was postulated by Rubin and co-workers.…”

Inequality repercussions of financing negative emissions

“…No leakage is considered from the geological sites. 32 and decrease with learning-by-doing. Total cost of DAC is assumed, in the central projection, to start from 780$/ton CO2 removed, and the floor cost is set at 214 $/ton CO2.…”

The cost of direct air capture and storage: the impact of technological learning, regional diversity, and policy.

“…For example, an expert elicitation study showed that experts currently predict that the costs today lie between ~$100-2000 t-CO2 -1 falling to ~$50-1500 t-CO2 -1 by 2050 depending on future policy scenarios. 15 Furthermore, there is little to no information on the cost of DACS in locations outside the US (and perhaps Europe), and on how government policy may support the deployment and cost development of DACS projects.…”