working paper

Direct Air Capture: Assessing Impacts to Enable Responsible Scaling

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Endnotes

  1. 1Beuttler et al. (2019) reports energy needs for capturing 1 MtCO2 are expected to be 2,000 kilowatt-hours (kWh) in the long term, or 230 megawatts (MW). In the near term, we assume this value is closer to 2,400 kWh, or 270 MW.
  2. 2This comparison is only intended to contextualize scale using current, relatable numbers and is not a projection of future market share.
  3. 3Community engagement resources include Forbes et al. 2009; Groundwork USA 2021; and Katsonis 2019.
  4. 4OSHA specifies the maximum noise level for workplace fans is 85 decibels (dB) at 5 feet (ft) distance. Given sound drop off, the plant would need to be 500 ft from a residential neighborhood for sound to drop to 45 dB, which is considered maximum for nighttime noise level (WHO 1999).
  5. 5Beuttler et al. (2019) reports energy needs for capturing 1 tCO2 are expected to be 2,000 kWh in the long term, or 230 MW for 1 MtCO2/yr. In the near term, we assume this value is closer to 2,400 kWh/tCO2, or 270 MW for 1 MtCO2/yr.
  6. 6This comparison is only intended to contextualize scale using current, relatable numbers and is not a projection of the future market share.
  7. 7Other energy sources could potentially help power DAC, including nuclear, hydropower, waste heat, and hydrogen.
  8. 8With this strategy, DAC would not directly compete with decarbonizing the grid and could make use of surplus renewable electricity. After midcentury, these natural gas plants would reach the end of their life, and the deployment experience from using them would help reduce the cost of DAC. Energy sources for DAC could then be reevaluated and ideally shift to nonfossil resources. This would create a systems approach that leverages stranded natural gas assets, scales up renewables, and supports scaling up DAC over the next three decades.
  9. 9Of note, the U.S. banned imports of products made with silicon from Xinjiang, China, where there is “reasonable” indication of use of forced labor (Kaplan et al. 2021).
  10. 10A family-sustaining wage is defined by the Massachusetts Institute of Technology (MIT) Living Wage Calculator as a wage that is higher than $22/hour.
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