Decarbonisation Technology August 2025 Issue

efficiency is still developing. Burning methanol in a turbine for power works with some modifications, but using methanol in fuel cells is still in the experimental stage (often requiring on-board reformation to hydrogen). These approaches are promising, but not yet proven at scale for grid use. Key points – methanol: ● Efficiency: ~30-35% round-trip (similar to hydrogen, slightly lower due to the extra conversion step). ● Best use: Long-duration storage and fuel flexibility (days to months of storage, transportable fuel for electricity or other uses). ● Pros: Liquid fuel at ambient conditions – easy to store in tanks and transport using existing fuel infrastructure; much higher volumetric energy density than hydrogen gas; can be carbon-neutral if made from captured CO₂ and renewable hydrogen; enables multi-week or seasonal storage in any location (no special geology needed); leverages existing fuel industry infrastructure and can serve multiple purposes beyond electricity. ● Cons: Moderate efficiency (~one-third of energy retained); depends on a CO₂ source and carbon capture to be climate-neutral; the overall process is complex and not yet proven at scale. Conclusion: the future storage mix No single storage technology will solve all the needs of a decarbonised grid – instead, each will play a role in a diversified energy storage ecosystem. Lithium-ion batteries will continue to excel at short-duration and rapid-response tasks, keeping the grid stable from minute to minute and shifting solar energy over a few hours from daytime peak generation to evening peak usage. Carnot thermal storage and similar technologies can take on the middle-duration role, handling daily peaks or buffering a couple of days of cloudy weather. For the truly long gaps – multi-day wind lulls or seasonal fluctuations – chemical energy storage in the form of fuels becomes key. Hydrogen and methanol represent this class of ultra-long-duration storage options. Hydrogen is likely to be favoured in places where it can be stored easily in huge volumes (like regions with

salt caverns) and where it also supports other hydrogen-based industries. Methanol, on the other hand, offers a compelling solution where geographic or infrastructure constraints make hydrogen difficult: it allows the storage of renewable energy in liquid form anywhere you can put a tank, effectively creating a strategic energy reserve that can be transported and used as needed. Methanol neatly bypasses hydrogen’s density and storage challenges by converting it into a more manageable liquid, albeit by accepting some efficiency loss. In summary, as we push toward an electric grid dominated by renewables, a portfolio of storage technologies will likely be deployed. Fast, high-efficiency batteries will cover seconds-to-hours needs. Thermal storage might cover the multi-hour to day-scale needs in an economical way. For the weeks-to-months scale, energy-dense “ Public and private sectors around the world are already investing in pilot projects for all of these solutions – from new 100-hour batteries to hydrogen hubs and e-fuel plants ” molecules will be crucial – hydrogen where it is practical, and methanol or similar synthetic fuels where it is not. This combination ensures reliability through all seasons: the surplus wind of spring or sun of summer can be stored in chemical form and released in the depths of winter. Public and private sectors around the world are already investing in pilot projects for all of these solutions – from new 100-hour batteries to hydrogen hubs and e-fuel plants. By 2030, grid operators may routinely juggle a mix of batteries, heat storage, and renewable fuels to keep the lights on. This diversified approach will boost resilience and, through competition and innovation, help drive down costs.

Vaibhav Desai vaibhav.desai@konsciousplanet.com Ashish Gupta ashish.gupta@konsciousplanet.com