Direct air capture (DAC) is widely investigated to capture CO2 emissions from decentralised sources . As an alternative to geological storage, CO2 from DAC can be reacted with H2 from water electrolysis driven by renewable energy to produce synthetic CH4, increasing the penetration of renewable energies and leading to a circular carbon economy . In the DAC methanation, Tregambi et al estimated total project cost (TPC), levelized cost of CO2 removal (LCCR), and levelized cost of methane (LCOM). The process involved the hydrogenation of CO2 sourced from DAC, H2 generated from water electrolysis, and renewable PV sources, culminating in the production of synthetic methane (CH4). The results indicated that cities with varying solar energy distribution might have to invest heavily in H2 storage tanks. The major cost contributors were found to be the electrolyser, followed by the PV field, H2 storage, and reactors . The LCOM was estimated at 4.9-8.2 USD•kgCH4 -1 using integration with the DAC plant investigated, while 3.1-3.9 USD•kgCH4 -1 when utilizing integration with point source carbon capture. Such the LCOM analysis found that the DAC process costs higher than the prevailing market price of methane, suggesting the need for technical improvements or economic incentives to increase the competitiveness of this powerto-gas technology . The study presents a promising yet currently expensive option, highlighting the need for technical advancements and economic incentives.