Techno-economic assessment of e-methane production via plasma-catalytic CO2 methanation

The transition to net-zero energy systems requires scalable and flexible pathways for converting and storing surplus renewable electricity. Power-to-gas (P2G) technologies that convert CO 2 and H 2 into synthetic methane (e-CH 4 ) offer a long-duration energy storage solution compatible with existing natural gas infrastructure, yet their economic viability remains uncertain. Here, we present a comprehensive techno-economic assessment of plasma-catalytic CO 2 methanation and benchmark its performance against a conventional thermal catalysis route. At a CO 2 processing capacity of 2000 kg/h and an electricity price of 50 €/MWh, plasma catalysis achieves a break-even selling price (BESP) of 2208 €/tonne e-CH 4 when process heat recovery is integrated, which is ∼10% lower than that of thermal catalysis (2427 €/tonne). Although plasma catalysis requires higher specific power consumption and additional downstream separation requirements, it benefits from ∼45% lower capital costs. Sensitivity analyses indicate that plasma catalysis remains economically competitive at electricity prices up to 100 €/MWh and exhibits a markedly lower sensitivity to load factor than thermal catalysis, making it intrinsically better suited to variable renewable electricity supply. Under projected future renewable energy cost trajectories, plasma-based e-CH 4 production could reach 1845 €/tonne in regions with high solar potential and 1235 €/tonne in regions with strong wind resources. This work demonstrates plasma catalysis as a flexible and complementary pathway for decentralized P2G systems, particularly under intermittent renewable electricity supply. • Plasma-catalytic CO 2 methanation offers a flexible power-to-gas pathway. • Plasma catalysis reduces capital costs by ∼45% compared to thermal methanation. • The break-even selling price of e-CH 4 is ∼10% lower with plasma catalysis. • Plasma catalysis is less sensitive to load and suits variable renewable electricity. • Competitive e-CH 4 costs are achievable in high solar and strong wind regions.