Solar-to-X enables industrial defossilization turning power to molecules or materials

<p class="p1"><span class="s1">The industry sector is most challenging to defossilize, due to high energy and feedstock demand, large and continuously running production plants, hard-to-abate process emissions, and infrastructural challenges. In public discourse, hydrogen is discussed prominently for industry, but its role may be overestimated. Solar PV as the least cost source of electricity may bring the electrification of industry to the next level.</span></p><p><strong>Electrons versus molecules in industry: Key insights from a comparative study</strong></p>
<p>A public debate similar to the transport (battery electric vehicles versus fuel cell electric vehicles) and heat sector (heat pumps versus hydrogen boilers) may emerge soon for energy-intensive industries. While direct electrification is clearly superior for heat and transport, the picture for industry is more complicated. <a href="https://www.sciencedirect.com/science/article/pii/S0196890425006697">A new study from LUT University & RLS-Graduate School</a> challenges existing narratives on large hydrogen quantities and highlights the possibilities of direct electrification. Using multi-criteria decision analysis as a methodological framework, with five different weighting strategies, the study compares direct electrification and hydrogen technologies for four industry segments, including e-ammonia and e-methanol. The overall results show that hydrogen is technically easier to implement, but suffers from high energy costs, limited process flexibility, potentially lower efficiency, and higher land impact than its electron-based alternative. Still under lab-scale development but highly promising are the electrocatalysis routes for ammonia and methanol production that avoid high temperatures, high pressures and energy losses during the production of green hydrogen as an intermediate step and synthesize the final products directly from water and nitrogen or carbon dioxide, for ammonia and methanol, respectively.</p>
<figure class="wp-caption aligncenter" id="attachment_316594" style="width: 600px;"><img alt="" class="size-medium wp-image-316594" height="395" src="https://www.pv-magazine.com/wp-content/uploads/2025/09/Bild1-600x395.png" tabindex="0" width="600" /><figcaption class="wp-caption-text">Technology comparison for basic chemical production with direct electrification (yellow) and hydrogen-feedstock (blue) <p><i> Image: LUT University & RLS-Graduate School</i></p>
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<p><strong>The bigger picture: Mapping the landscape of industrial solutions</strong></p>
<p>The set of technologies is huge, and some are more promising than others. <a href="https://www.sciencedirect.com/science/article/pii/S1364032124007494">A previous study</a> identified 28 technologies across all considered energy-intensive industries. Iron and steel is the sector with the highest emissions and energy demand, but also the best researched one, with a growing body of studies.</p>
<figure class="wp-caption aligncenter" id="attachment_316601" style="width: 600px;"><img alt="" class="size-medium wp-image-316601" height="285" src="https://www.pv-magazine.com/wp-content/uploads/2025/09/PIcture31-600x285.png" tabindex="0" width="600" /><figcaption class="wp-caption-text">Technology comparison for basic chemical production with direct electrification (yellow) and hydrogen-feedstock (blue) <p><i> Image: LUT University & RLS-Graduate School</i></p>
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<p>Development of research articles published on industry defossilisation from 2012 &#8211; 2022. Source: <a href="https://doi.org/10.1016/j.rser.2024.115023">LUT University & RLS-Graduate School</a></p>
<p>Currently, the world is waiting for the first hydrogen direct reduction plants in Sweden (Stegra) and Germany (Thyssenkrupp) to start large-scale green steel production. However, direct electrification is a considerable option for each industry segment: most prominently for low-and medium-temperature heat supply via heat pumps and electric boilers across all industries or by simply replacing fossil with renewable electricity for already electrified processes (such as aluminium smelting). Additionally, direct electrification can be implemented in technically advanced approaches such as plasma-fired heating in rotary cement kilns, full electric glass melting with submerged electrodes, or new electrolysis or electrocatalysis approaches for steel and chemical production, respectively. Most importantly, the study demonstrated that most industries could benefit from increased use of already available technologies for secondary production and recycling to electrify processes, increase efficiency and reduce pressure on material availability.</p>
<p><strong>Electrification pathways for primary steelmaking</strong></p>
<p>Researchers expect steel recycling using electric arc furnaces to play an increasingly prominent role. However, primary steelmaking using reduced iron ore, i.e., pig/sponge iron, will still be needed for high-quality steel production. Aside from the hydrogen direct reduction route, direct electrolysis of iron ore via electrowinning may be an opportunity for direct electrification of sponge iron production. Previous <a href="https://doi.org/10.1016/j.jclepro.2022.134182">LUT University research</a> indicated that, assuming technical maturity in 2040, steelmaking via electrowinning may be the least cost steelmaking technology at an electricity price of €16 ($18.7)/MWh, well achievable by solar PV and CO₂ emissions costs of €30/tCO₂.</p>
<p>Anticipating hydrogen direct reduction in the short term, companies have made investments to produce sponge iron in regions with abundant renewable energy resources, particularly solar PV, along with iron ore deposits to supply electric arc furnaces in regions with limited land availability or less abundant renewables. Such projects are currently underway in Namibia, Algeria, and Mauritania to produce green iron that can be used in Europe’s electric arc furnaces. <a href="https://doi.org/10.1016/j.energy.2023.127236">New supply chains</a> may then emerge with sponge iron being a heavily traded commodity due to the significant share of hydrogen production costs in total steelmaking costs. Technical development of electrowinning may allow for higher shares of self-sufficiency across the steelmaking supply chain, as total steel production costs would be less sensitive to electricity prices.</p>
<p><strong>Global supply chains for hydrogen-based chemical feedstocks</strong></p>
<p>For chemical production, hydrogen-based feedstocks of <a href="https://www.sciencedirect.com/science/article/pii/S0306261920315750">e-ammonia</a> and <a href="https://pubs.rsc.org/en/content/articlelanding/2024/ee/d3ee02951d">e-methanol</a> are most commonly considered as the major platform chemicals to produce downstream chemical products. Indeed, <a href="https://doi.org/10.1039/D3EE00478C">chemical industry transition research</a> has estimated that upwards of 33 PWh of electricity may be required to defossilize chemical feedstock production. Given the high electricity requirements to produce hydrogen before chemical synthesis, low-cost solar PV may be the key to producing economically viable electricity-based feedstocks. Analogous to steelmaking, significant trading of electricity-based methanol and ammonia feedstocks may occur, with research on a <a href="https://doi.org/10.1016/j.enconman.2024.118295">power-to-plastic supply chain</a> from Chile and Morocco to European countries finding that feedstock imports lead to comparable plastic production costs for importing final plastics. For regions with large chemical industries, such a supply chain strategy may be viable to retain chemical production capacities, as electrocatalytic routes may not be available until 2045. Global <a href="https://www.sciencedirect.com/science/article/pii/S1364032123002770">e-fuels and e-chemicals trading</a> investigation indicates a strong and rising competitiveness for sunbelt countries.</p>
<p><strong>Energy system modelling for industrial needs in 100% renewable energy systems</strong></p>
<p>More energy system models include industry to complement energy system modelling in <a href="https://ieeexplore.ieee.org/document/9837910">100% renewable energy systems</a> research and to represent all energy and feedstock demand for creating full demand and supply insights while covering all energy-industry <a href="https://doi.org/10.1016/j.rser.2025.115383">system flexibility</a>. Existing studies with a full energy-industry system representation, such as for <a href="https://doi.org/10.1016/j.energy.2025.134888">Finland</a>, <a href="https://www.sciencedirect.com/science/article/pii/S0306261920316639">Kazakhstan</a>, <a href="https://ieeexplore.ieee.org/document/10726607">Americas</a>, and the <a href="https://ieeexplore.ieee.org/document/10869466">United States and Canada</a>, clearly indicate a high solar PV share with industrial demand driven by three key factors: low-cost electricity, seasonal resource complementarity in particular with wind power, and flexibility benefits in the shorter term with batteries and in longer term with hydrogen-based demands. For the Americas and the United States and Canada, industrial Solar-to-X characteristics can be found.</p>
<p><strong>Solar-to-X as an industrial strategy</strong></p>
<p>In most regions in the world, solar PV is already the <a href="https://doi.org/10.1016/j.apenergy.2025.125856">least cost source of electricity</a>, with excellent resource availability opening new industry opportunities for countries in the sun belt region. While large investments in new plants will be necessary, the already low and still decreasing costs of solar PV and batteries will open the door for large-scale industrial production, with directly electrified processes, or by using green e-hydrogen as a transition option. These countries, often located in the global South, can <a href="https://doi.org/10.1016/j.egyr.2024.08.011">become exporters</a> of either green bulk e-chemicals (ammonia, methanol, ethylene) or other intermediate or final products such as e-steel or e-aluminium. Countries in the global South also benefit from reduced seasonality, ensuring continuous production enabled by a synergetic interplay of large- and small-scale batteries and solar PV. While the global industry transition is still in its early stages, the promising technical opportunities for green industrial production and low-cost electricity are ideal preconditions for a Solar-to-X-based industrial leap &#8211; one that allows emerging economies to position themselves as key players in a defossilized global supply chain.</p>
<p><em>Authors: Philipp Diesing, Gabriel Lopez, Dominik Keiner, and Christian Breyer</em></p>
<p><em>This article is part of a monthly column by LUT University.</em></p>
<p><em>Research at </em><a href="https://www.lut.fi/en"><em>LUT University</em></a><em> encompasses various analyses related to power, heat, transport, industry, desalination, and negative CO₂ emission options. Power-to-X research is a core topic at the university, integrated into the focus areas of </em><em>Planetary Resources, Business and Society, Digital Revolution, and Energy Transition</em><em>. Solar energy plays a key role in all research aspects.</em></p>
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