Integrated assessment model (IAM) scenarios examining pathways to achieve the goals of the Paris Agreement stress the necessity of deploying carbon dioxide removal (CDR) methods, of which direct air capture (DAC) is viewed as one of the most promising. This study undertakes both a geospatial analysis and techno-economic assessment of potential heat sources for DAC to examine the economic impact of different renewable heat source systems on the capture costs of large-scale LT-DAC plants. It does this by determining the location of these plants through the paradigm of identifying the ideal geographic and economic environment for the selected heat sources. Thus, the research aims to answer the following research questions: What heat sources are optimally suited for low-temperature (LT) DAC and what conditions are feasible for setup? Which geographic locations represent the ideal environment within Europe for each heat source? How do the selected heat sources and geographic locations impact the economic viability of LT-DAC? Drawing on Climeworks’ LT-DAC approach as a focal case, the heat sources of geothermal energy, parabolic trough collector (PTC), industrial waste heat (IWH), and high-temperature heat pump (HTHP) were chosen, to be separately deployed in Iceland, Spain, Germany, and Norway, respectively. Spain emerged as a highly promising location for the PTC, IWH, and HTHP systems while Iceland is most suitable for the geothermal, IWH, and HTHP systems. Norway is a promising country mostly for deploying a HTHP system, whereas Germany faces primarily environmental and legal barriers. The techno-economic assessment identified great variation in the LCOD costs for the different heat source systems, with the geothermal energy system exhibiting the lowest costs at 175.63 €/tCO2 followed by the IWH, PTC, and HTHP systems. Future LCOD costs could potentially see a significant reduction of up to 66 % depending on the heat source system based on projected decreases in DAC CAPEX costs. A cost comparison revealed that current carbon price levels within the European Emission trading scheme are not expected to be sufficiently high enough to drive large investments in the development and scaling of LT-DAC. Cost levels of CCS technologies and LT-DAC could however be comparable, in particular for the geothermal energy system.

中文翻译：

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欧洲低温直接空气捕获可再生热源的地理分析和技术经济评估


研究实现《巴黎协定》目标的途径的综合评估模型 （IAM） 情景强调了部署二氧化碳去除 （CDR） 方法的必要性，其中直接空气捕获 （DAC） 被视为最有前途的方法之一。本研究对 DAC 的潜在热源进行了地理空间分析和技术经济评估，以检查不同可再生热源系统对大型 LT-DAC 工厂捕获成本的经济影响。它通过确定所选热源的理想地理和经济环境的范式来确定这些工厂的位置来实现这一点。因此，本研究旨在回答以下研究问题：哪些热源最适合低温 （LT） DAC，哪些条件适合设置？哪些地理位置代表了欧洲每种热源的理想环境？所选的热源和地理位置如何影响 LT-DAC 的经济可行性？以 Climeworks 的 LT-DAC 方法为重点，选择了地热能、槽式集热器 （PTC）、工业余热 （IWH） 和高温热泵 （HTHP） 的热源，分别在冰岛、西班牙、德国和挪威部署。西班牙成为 PTC、IWH 和 HTHP 系统的非常有前途的地点，而冰岛最适合地热、IWH 和 HTHP 系统。挪威是一个很有前途的国家，主要部署了 HTHP 系统，而德国主要面临环境和法律障碍。技术经济评估确定了不同热源系统的 LCOD 成本差异很大，其中地热能系统的成本最低，为 175。63 €/tCO2，其次是 IWH、PTC 和 HTHP 系统。根据 DAC CAPEX 成本的预计降低，未来的 LCOD 成本可能会显著降低高达 66%，具体取决于热源系统。成本比较显示，欧洲排放交易计划内的当前碳价水平预计不够高，不足以推动对 LT-DAC 开发和规模化的大量投资。然而，CCS 技术和 LT-DAC 的成本水平可能相当，特别是对于地热能系统。