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Beyond Tomorrow -- Electrification of Hard-to-Abate Sectors
Jonas Huber, Johann W. Kolar
TL;DR
Hard-to-abate sectors present a challenge for net-zero electrification, and the paper surveys selected direct-electrification pathways and their power-electronics needs. It identifies application-specific converter and system-level research needs, alongside examples such as a 1 MW DC induction-heating demonstration exceeding 80% efficiency.
Problem
Hard-to-abate sectors require electrification, but their diverse industrial processes leave power-converter requirements, grid integration, and energy management to be clarified.
Source: §III · pp. 11–12Method
The article reviews selected direct-electrification technologies and research from neighboring disciplines, highlighting power-electronics opportunities and challenges.
Source: §I · p. 3, §II · p. 3, §III · p. 12Results
The review identifies application-specific converter needs, including fast-control high-voltage plasma supplies, low-voltage high-current electrochemical loads, and unresolved high-power grid and energy-management issues.
Source: §III · p. 12Takeaways & Limitations
Clarifying converter requirements for electrified industrial processes calls for close interdisciplinary work, including co-development or integration with process-specific technologies.
Source: §III · p. 13
Abstract
from arXiv · showhide
Reaching net-zero greenhouse-gas (GHG) emissions requires deep electrification beyond ground transportation, buildings, and conventional industry automation. This article discusses direct electrification pathways for hard-to-abate sectors, which today account for 30% of global GHG emissions and include steel, cement, chemicals, aviation, and shipping. Whereas indirect electrification via hydrogen and synthetic fuels will remain indispensable for some applications, direct use of electricity is generally preferable from an efficiency perspective. We review selected emerging opportunities for power electronics in industrial process electrification, including steelmaking through hydrogen plasma smelting reduction or molten-oxide electrolysis, electrified cement production, high-temperature process heat, plasma-assisted chemistry, and electrochemical synthesis. Across these examples, power converters must interface with highly application-specific loads, ranging from low-voltage high-current electrolysis cells to dynamic plasma reactors and megawatt-scale induction heating systems. In addition, high-power grid interfaces and in-plant energy management/buffering solutions must be clarified. Thus, future electrified industrial processes open new "beyond-tomorrow" research challenges for power electronics in close interdisciplinary collaboration with scientists from neighboring disciplines.
I. INTRODUCTION
Net-zero targets call for rapid emissions reductions, but hard-to-abate sectors still rely on fossil fuels for high-temperature heat and process emissions. The article surveys direct electrification opportunities, especially in industry, and the power-electronics research they require.
I. INTRODUCTION
- Around 30% of today’s GHG emissions come from hard-to-abate sectors, where emissions include both high-temperature fuel use and process emissions.The article notes that reaching net zero also requires indirect electrification for applications that do not lend themselves to direct electrification.Source: §I · p. 2, Figure 1 · p. 2
- Direct electricity use is preferable to indirect electrification through hydrogen or synthetic fuels from an efficiency perspective.Source: §I · p. 2
- The article highlights power electronics opportunities and research directions for direct electrification, focusing particularly on industrial processes.It situates this need within a transition toward renewable electricity and growing power-converter use.Source: §I · pp. 2–3
II. DIRECT ELECTRIFICATION OF HARD-TO-ABATE INDUSTRY SECTORS
The article offers selected examples of established and emerging direct-electrification technologies as entry points for power-electronics engineers to identify research challenges.
II. DIRECT ELECTRIFICATION OF HARD-TO-ABATE INDUSTRY SECTORS
- The article surveys selected established and emerging electrification technologies rather than attempting a comprehensive review.Source: §II · p. 3
- Its examples progress from transportation, steel, and cement to process heat, electrified chemistry, and system-level challenges.Source: §II · p. 3
A. Transportation
Direct battery-electric transport is demonstrated on short maritime routes, while battery limitations and long-range aircraft concepts leave roles for hydrogen and synthetic fuels.
A. Transportation
- Scandinavian electric ferries operate on itineraries of up to one hour using around 4.5 MWh batteries.Battery weight and space limit this approach to short coastal routes, not long-haul freight shipping.Source: A. Transportation · p. 3
- Long-range aircraft concepts typically rely on liquified hydrogen, unlike small short-range aircraft.Source: A. Transportation · p. 3
- Renewable-electricity electrolysis remains relevant for producing hydrogen, including as a precursor to more readily stored and transported synthetic fuels such as ammonia.Research explores pulsed-DC and plasma-assisted electrolysis, creating power-supply research opportunities.Source: A. Transportation · p. 3
B. Steel
Steelmaking can be electrified through scrap-melting furnaces, hydrogen plasma reduction, and molten-oxide electrolysis, each imposing distinct process and power-supply requirements.
B. Steel
- Conventional blast-furnace steelmaking releases CO2 through iron-ore reduction and also incurs heating and raw-material preparation emissions.The resulting pig iron contains around 4% to 5% carbon before oxygen conversion reduces it to below 2%.Source: B. Steel · pp. 3–4, Figure 2 · p. 4
- Modern DC electric arc furnaces melt scrap with better energy efficiency, lower electrode consumption, and better grid friendliness than legacy three-phase AC designs.Their low, nonlinear arc voltage varies with arc length, temperature, and slag conditions, requiring tailored supply design and stabilization.Source: B. Steel · p. 4, Figure 2 · p. 4
- Hydrogen plasma smelting reduction supplies both reduction chemistry and thermal energy, with water vapor as its only core-reaction byproduct.The process avoids carbon release, but scaling up non-thermal microwave hydrogen plasma remains challenging.Source: Figure 2 · p. 4, B. Steel · p. 5
- A typical 100 MW-class EAF supply uses 24-pulse thyristor rectifiers and constant arc-current control, while an IGCT chopper alternative enables constant-power control.The former requires compensation for active and reactive power fluctuations to prevent flicker.Source: Figure 3 · p. 5
- Molten-oxide electrolysis reduces iron oxide with externally supplied current and an inert anode, yielding pure oxygen without carbon release.Industrial-scale development targets kiloampere cell currents, around 2.6 V, and operating temperatures near 1600 °C; lower-temperature alkaline alternatives remain at the research stage.Source: Figure 2 · p. 4, B. Steel · pp. 5–6
C. Cement
Cement production emits CO2 both from limestone calcination and from fossil-fuel heating. Directly electrifying heat offers several alternatives, including electrically heated calciners and plasma-heated rotary kilns.
C. Cement
- About 600 kg of CO2 are released per ton of clinker: around 40% comes from fossil-fuel heating, while 60% is inherent to limestone calcination.Conventional production heats the calciner to around 900 °C and the rotary kiln to around 1400 °C.Source: C. Cement · p. 6
- An electrified alternative uses resistance or induction heating for the calciner and plasma torches for the rotary kiln.Electric calciner heating can yield a high-purity CO2 stream that facilitates carbon capture and use; a 300 kW plasma-heated kiln using recycled CO2 as process gas was demonstrated in 2025.Source: C. Cement · p. 6, Figure 5 · p. 7
- Electric arcs are also considered for calciner heating, while microwave heating has not advanced beyond the research state.A pilot factory in Sweden using electric arcs was scheduled to open in 2027.Source: C. Cement · p. 6
D. High-Temperature Heat
Industrial process heat spans applications beyond heat-pump temperatures, with technologies ranging from resistance and induction heating to plasma and dielectric heating. Their temperature and power capabilities vary, and a 1 MW DC induction demonstration addressed efficiency limits for conductive billets.
High-Temperature Heat
- High-temperature process heat is used across many industries, and the section surveys electric heating options rather than providing a comprehensive technology review.The referenced overview covers typical temperature ranges and power capacities expected by 2035.Source: D. High-Temperature Heat · p. 7, Figure 6 · p. 7
Heating technologies
- Heat pumps are limited to 200 °C, while resistance heating provides rapid, accurately controlled temperatures well beyond 1500 °C.Heat-pump systems reach power ratings in the tens of megawatts by paralleling individual units.Source: D. High-Temperature Heat · pp. 7–8
Induction Heating
- Induction furnaces can reach 3000 °C and 20 MW, with higher-frequency operation enabling greater specific furnace power.Induction heats volumetrically through eddy currents; frequency selection depends partly on the heated material’s skin depth.Source: D. High-Temperature Heat · p. 8
- More than 80% efficiency was reached by a 1 MW DC induction heating demonstration for aluminum or copper billets, compared with around 60% for conventional AC induction heating.The DC concept rotates billets in a very high DC magnetic field generated by a coil made from high-temperature superconducting tape.Source: D. High-Temperature Heat · p. 8
Plasma Torches and Electric Arc Furnaces
- Transferred-arc electric arc furnaces can exceed 90% overall efficiency, whereas plasma torches heat process gas to temperatures up to 5000 °C and more.The EAF arc burns between an electrode and the material, improving heat transfer by about an order of magnitude versus a plasma torch; plasma torches face cooling and electrode-lifetime challenges.Source: D. High-Temperature Heat · p. 9
Dielectric Heating
- Microwave dielectric heating offers selective, local volumetric heating that can improve reaction rates, yields, completeness, and selectivity.Microwave heating has reached 2200 °C in ceramic heat treating and sintering; magnetrons have conversion efficiencies up to 85% but limited lifetimes.Source: D. High-Temperature Heat · p. 9
E. Chemistry
Electrification in chemistry includes volumetric heating, non-thermal plasma reactions, and electrochemical processes. These pathways create application-specific power-converter challenges, especially where plasma dynamics or pulsed high-current, low-voltage supplies are involved.
Chemistry
- Volumetric heating can provide selective heating with spatial or temporal resolution, supporting rapid heating and quenching along non-equilibrium thermal pathways.The section frames these as chemistry applications beyond heat generation.Source: E. Chemistry · p. 10
Plasma-Assisted Chemistry
- Non-thermal plasma can support applications from CO2 upcycling and methane-emission reduction to recycling and water splitting.Unlike thermal plasma used for heating, non-thermal plasma has much hotter electrons than heavier ions and typically interacts with gases or material surfaces rather than bulk material.Source: E. Chemistry · p. 10
- Plasma generation’s fast, unstable dynamics demand converters with very high regulation bandwidth and controlled output impedances.The instability is associated with positive feedback between temperature and current consumption.Source: E. Chemistry · p. 10
Electrochemical Processes
- Electrochemical processes can directly electrify emission-intensive chemistry, including nitrogen fixation, for which 50% lower CO2 emissions and 75% lower energy usage are reported.Other examples include high-purity silicon production and electronic-waste recycling.Source: E. Chemistry · pp. 10–11
- Electrochemical CO2 reduction can produce multi-carbon chemical feedstocks, with millisecond pulsing motivating high-current, low-voltage supplies and possible supply-reactor co-design.The text also identifies pulsed proton-exchange-membrane electrolysis and an externally supplied current for PFAS decomposition as emerging pathways.Source: Figure 9 · p. 10, E. Chemistry · p. 11
F. Summary
Power electronic conversion systems could enable direct electrification of industrial processes through electrochemical processes and plasma applications. The research agenda also includes system-level interfaces and energy management, requiring collaboration with process-specific science.
F. Summary
- Power electronic energy conversion systems are an opportunity to enable direct electrification of chemical and metallurgical industrial processes.Examples include electrochemical processes and plasma applications.Source: F. Summary · p. 11
- Future research should address grid integration, mains interfaces, in-plant power distribution, and energy management for fluctuating supply and demand.Source: F. Summary · p. 11
- The area is an interdisciplinary research interface between power electronics and process-specific science.Electrification of auxiliary systems such as motor-drive pumps is also important, although its pathways are relatively clear.Source: F. Summary · p. 11
III. CONCLUSION AND OUTLOOK
The article surveys emerging options for directly electrifying hard-to-abate sectors, where direct electricity is preferable whenever possible. It identifies application-specific converter requirements and interdisciplinary research as priorities for future power electronics.
III. CONCLUSION AND OUTLOOK
- Direct electrification is preferable whenever possible, although synthetic fuels will remain part of net-zero energy systems for some applications.The article frames electrification of hard-to-abate sectors as necessary for reaching net-zero carbon-emission targets.Source: §III · p. 11
- Power converters face distinct requirements, including fast-controlled high-voltage plasma supplies, low-voltage high-current electrochemistry, and strategies for very high power levels.Thermal management, reliability, grid integration, and energy management also remain research needs.Source: §III · p. 12
- Fig. 11a frames beyond-tomorrow challenges as an exploratory research phase that ramps up activity before handover to industry.The article places process-industry electrification within this research outlook.Source: Figure 11 · p. 12, §III · p. 12
- The authors identify hard-to-abate-sector electrification, particularly in the process industry, as an upcoming beyond-tomorrow research challenge for power electronics.They describe it as a source of interdisciplinary research questions.Source: §III · p. 12
- Interdisciplinary work with neighboring disciplines is needed to clarify converter requirements and optimize electrified industrial processes through co-development or close integration with process-specific technology.A 2026 workshop aimed to connect process-industry experts with power-electronics researchers to address these known unknowns.Source: §III · pp. 12–13