Start with the load, not the technology
Temperature is the first filter. The process medium, heat-transfer path, operating schedule, and product specification decide whether a nominally capable heater is useful.
| Route | Useful domain | Advantage | Binding constraint |
|---|---|---|---|
| Industrial heat pump / MVR | Usually <160°C commercial; higher systems emerging | COP >1 by upgrading waste or ambient heat | Temperature lift, working fluid, heat-source availability |
| Electric boiler / resistance | Steam and broad direct-heating range | Simple, precise, near-unity device conversion | Electricity price, connection size, element and refractory life |
| Induction | Conductive workpieces; melting and heat treatment | Rapid, local, high power density | Part geometry, coupling, frequency, coil design |
| Infrared | Surface heating, drying, curing | Fast response; avoids heating some furnace mass | Line of sight, surface absorption, penetration depth |
| Microwave / radio frequency | Dielectric and wet materials | Volumetric and selective heating | Field uniformity, material response, scale-up |
| Electric arc / plasma | Melting and very high-temperature duty | Extreme flux and direct energy delivery | Electrodes, refractories, power quality, product chemistry |
| Thermal battery | Steam to high-temperature process heat | Moves electricity purchase in time | Cycles, discharge rate, heat exchanger, utilisation |
Heat dominates the factory energy balance
The first project is often not a new heater. It is insulation, air-leak reduction, condensate recovery, heat integration, or using waste heat as the source for a heat pump.
Low temperature rewards moving heat
A resistance element cannot convert more than one electrical unit into one thermal unit. A heat pump can deliver several because most output is upgraded heat recovered from air, water, refrigeration, exhaust, or another process stream.
Carnot sets the direction, integration sets the COP
The ideal heat-pump ceiling falls as the lift between source and sink widens. Real machines also pay for finite heat-exchanger approaches, compressor losses, pumps, and pressure drop. A plant with warm wastewater and a 90°C hot-water demand is a different proposition from one making 150°C steam from winter air.
IEA's 2026 monitor places commercial industrial heat pumps primarily below 160°C and estimates that currently available systems could technically supply around 20% of global industrial heat demand. Technical potential is not adoption: industrial heat pumps supplied under 1% of light-industry heat in 2025.
Read longitudinally, that gap is the curve: under 1% deployed (Measured) against roughly 20% technically servable with today's machines (Projected), a diffusion curve, not a physics curve. The conversion floors are already in place, so the distance between them is closed by integration, tariffs, and plant economics rather than by a new physical result.
Electricity supply
The cheapest annual average can be unusable if the process cannot stop during expensive hours.
- Specify
- Energy price, carbon intensity, firmness, tariff, and power quality
- Acceptance test
- Product quality and throughput at operating duty
Grid connection
A large furnace can require a site-scale substation before it requires a new heating element.
- Specify
- MVA capacity, transformer, switchgear, protection, and lead time
- Acceptance test
- Product quality and throughput at operating duty
Power conversion
Transformers, drives, rectifiers, and power electronics add cost, loss, harmonics, and failure modes.
- Specify
- Voltage, current, frequency, waveform, and controllability
- Acceptance test
- Product quality and throughput at operating duty
Heat generation
Heat pumps, resistance, arcs, induction, infrared, microwave, and plasma solve different loads.
- Specify
- COP or conversion efficiency, temperature, flux, and turndown
- Acceptance test
- Product quality and throughput at operating duty
Thermal storage
Cheap storage media still need expensive heaters, insulation, heat exchangers, and process interfaces.
- Specify
- MWhth, discharge rate, temperature, losses, and cycles
- Acceptance test
- Product quality and throughput at operating duty
Heat transfer
A hot element is not useful unless energy reaches the product at the required rate and uniformity.
- Specify
- Conduction, convection, radiation, phase change, or volumetric absorption
- Acceptance test
- Product quality and throughput at operating duty
Furnace or reactor
Removing combustion changes gas volume, mixing, moisture, chemistry, and sometimes the product.
- Specify
- Geometry, refractory, atmosphere, seals, material flow, and residence time
- Acceptance test
- Product quality and throughput at operating duty
Controls and quality
A lower energy bill is irrelevant if colour, strength, purity, cure, or metallurgical structure changes.
- Specify
- Temperature distribution, recipe, yield, throughput, and rejects
- Acceptance test
- Product quality and throughput at operating duty
Operations
Continuous plants price an hour of lost production differently from a batch oven.
- Specify
- Availability, maintenance, backup, restart, and retrofit downtime
- Acceptance test
- Product quality and throughput at operating duty
A flame does more than provide joules
Combustion establishes gas flow, pressure, moisture, oxygen potential, mixing, and radiative conditions. Replacing it can alter the reaction even at the same measured temperature.
Near-unity conversion is not near-unity system efficiency
Resistance heating is already close to its device-level physical floor: nearly all electrical input becomes heat. The remaining frontier lies outside the element: reducing shell loss, avoiding hot exhaust, shortening warm-up, transferring energy directly into the workpiece, recovering rejected heat, and improving yield.
For an electric furnace, the next efficiency gain is often a better process rather than a better resistor.
Electromagnetic methods can change the boundary. Induction deposits heat inside conductive material; microwave and radio-frequency fields can couple volumetrically to suitable dielectrics; infrared can heat a surface without first heating a large air volume. Each can save energy and time, but only when the product's geometry and electromagnetic properties cooperate.
Radiation rises as absolute temperature to the fourth power
High temperature increases radiative heat-transfer potential rapidly, which is useful for moving intense heat into a load. The same law increases radiation through openings and to furnace walls. Refractories, seals, electrode penetrations, insulation, and view factors become system components, not incidental construction.
Store heat if the product needs heat
Converting electricity to heat, storing it in brick, particles, salt, water, or another medium, and delivering heat directly avoids paying for a second conversion back to electricity.
Storage is a power-and-energy system
These figures have different labels: target, planned subsystem demonstration, and measured prototype outlet. None alone establishes delivered industrial-heat cost.
Four quantities must be priced separately
Charging power
Heaters and the grid connection set how quickly cheap electricity can be absorbed.
Stored energy
Media, container, insulation, and allowable temperature swing set duration and loss.
Heat delivery
Fans, steam generators, heat exchangers, and ducts must meet process temperature and flux.
Utilisation
A low-cost store cycled rarely can add more per delivered MWh than an expensive store used every day.
The hotter the process, the less temperature alone tells you
Arcs and plasma can exceed the temperatures of industrial flames. The frontier is delivering that intensity over the required volume and residence time without destroying electrodes, refractories, or product quality.
Electric arc steelmaking
Electricity already melts scrap at industrial scale. Feedstock quality, not attainable temperature, limits which steel products the route can make.
Measured industry operationInduction and resistance
Widely used in melting, heat treatment, silicon, glass boosting, and specialty manufacture where material coupling and geometry fit.
Commercial, not universalHigh-temperature storage
Commercial projects and public demonstrations are moving from steam toward hot air above 1,000°C.
Vendor targets remain targetsElectric kilns and crackers
Cement, chemicals, and mineral processes must reproduce reaction atmosphere, solids flow, and continuous throughput, not only peak temperature.
Pilot evidenceThe cheapest heater can be the expensive project
Equipment cost is visible. Lost production, site works, grid connection, and requalification are often larger and more uncertain.
Downtime
Tie-ins, demolition, refractory cure, commissioning, and product requalification can cost more than the heater. Plan conversion around a major turnaround.
Footprint and access
An electric unit may be smaller, but transformers, storage, ducting, heat exchangers, and construction access require real estate the existing plant may not have.
Steam architecture
A central boiler serves many pressures and users. Electrifying one load may be easy; retiring the shared header requires every remaining user to move.
Product qualification
Food safety, pharmaceutical validation, coating cure, glass colour, metallurgical structure, and cement mineralogy can make the process recipe a regulated asset.
Reliability
A continuous plant needs redundancy, black-start behaviour, spares, trained maintainers, and an answer for grid interruption.
Asset age
A greenfield furnace can be designed around electric heat. A young fuel-fired asset carries unrecovered capital and geometry optimised around a flame.
Greenfield changes the equation
A new plant can place transformers beside the load, match voltage to heaters, eliminate a steam loop, reuse cooling duty as a heat-pump source, design refractory and airflow around electric heat, and reserve room for storage. Retrofitting inherits every old boundary. This is why asset age belongs in an electrification map beside temperature.
The energy-price ratio can overwhelm equipment efficiency
Heat pumps divide the electricity price by COP. Resistance does not. Storage substitutes a flexible electricity price but adds capital, loss, and cycling requirements.
Electricity price sets the curve; COP bends it
Compare four simplified ways to deliver one thermal megawatt-hour. Change energy prices, utilisation, carbon price, and heat-pump performance. Grid upgrades, retrofit downtime, and process modifications sit outside the boundary.
Gas boiler
- Gas boiler
- $25/MWh
- Resistance / electric boiler
- $92/MWh
- Industrial heat pump
- $41/MWh
- Stored electric heat
- $66/MWh
Calculation, capital assumptions, and evidence labels
Gas includes fuel at 85% boiler efficiency, EPA's 53.06 kg CO₂/MMBtu combustion factor, a carbon price, $110/kWth illustrative capex, and fixed O&M. Resistance uses 98% device conversion and $180/kWth capex. The heat pump uses the selected COP and $900/kWth capex. Stored heat uses the flexible electricity price, 90% round-trip heat efficiency, $25/kWh-thermal storage in the base case, 300 cycles a year, and $250/kWth charging and heat-delivery equipment. Capital is annualised at 10%.
All equipment and storage costs are editorial assumptions intended for sensitivity analysis, not quotations or market averages. The energy-price anchors are measured national averages; DOE's $15/kWh-thermal figure is an R&D target, not the model's claimed installed cost.
A gas pipe and a power line are not interchangeable
A continuous heat load becomes a large electrical load. Heat pumps reduce it where temperature lift permits; diversity and headroom increase the connection required.
Direct resistance draws 51.0 MWe at the heater. A heat pump at the selected COP draws 14.3 MWe before auxiliaries. Storage can change when power is drawn, but not the energy that must cross the meter.
Who is building what
Thermal batteries, high-temperature industrial heat pumps, and electric boilers electrify process heat across temperatures from 100°C to over 1500°C. Search the record, or filter by technology.
Rondo EnergyRondo Heat BatteryElectric resistance heating elements warming refractory clay bricks up to 1150°C, delivering continuous high-pressure steam or superheated air
- Reported evidence
- Commercial 2 MWh unit operating continuously at Calgren Renewable Fuels in California; expanding industrial installations in Europe and the US.
- Announced next step
- Gigawatt-hour annual production capacity supplying zero-carbon steam to chemical, food, and cement manufacturing.
- Unresolved risk
- High volumetric footprint inside existing space-constrained factories and electricity price spreads against cheap pipeline natural gas.
Antora EnergySolid Carbon Thermal BatterySolid carbon/graphite blocks heated by resistance to 1500°C+, discharging power via high-efficiency thermophotovoltaics (TPV) and high-temp heat
- Reported evidence
- Inaugurated commercial manufacturing facility in San Jose, California; commissioned first commercial thermal battery at a Fresno industrial site.
- Announced next step
- Simultaneous delivery of industrial steam and on-demand firm electricity from a unified modular thermal battery.
- Unresolved risk
- TPV cell production yield and preventing carbon oxidation through vacuum and inert gas hermetic sealing over decades.
Electrified Thermal SolutionsJoule HiveElectrically conductive refractory ceramic bricks that act as their own heating element via direct Joule heating up to 1800°C
- Reported evidence
- Demonstrated core brick conductivity and thermal stability; selected for a $35M DOE industrial demonstration grant.
- Announced next step
- Direct replacement of fossil burners in cement kilns, glass melting tanks, and metal forging furnaces.
- Unresolved risk
- Ceramic element degradation under rapid cyclic thermal shock and long-term electrical contact stability at ultra-high temperatures.
AtmosZeroBoiler 2.0Modular, drop-in industrial air-source heat pump boiler producing saturated steam up to 165°C with high seasonal coefficient of performance (COP)
- Reported evidence
- Piloting commercial units with New Belgium Brewing; closed Series A funding to establish domestic manufacturing.
- Announced next step
- Direct drop-in replacement for standard fossil-fuel package boilers across breweries, pharmaceuticals, and food plants.
- Unresolved risk
- Refrigerant performance degradation and lift limits when ambient air temperatures drop during severe winter extremes.
Turboden / HeatexLarge-Scale Steam Heat PumpsCentrifugal compressor industrial heat pumps capturing low-grade industrial waste heat (40–80°C) to generate process steam up to 200°C
- Reported evidence
- Multi-megawatt installations operating in chemical plants and paper mills in Scandinavia and Central Europe.
- Announced next step
- Replacing fossil boilers with systems achieving COPs between 2.5 and 4.0 using industrial effluent heat.
- Unresolved risk
- Compressor design constraints for high-temperature working fluids and site-specific engineering requirements.
Babcock & Wilcox / Vapor PowerElectric Electrode BoilersHigh-voltage electrode boilers passing current directly through water to produce high-pressure steam at nearly 100% electrical efficiency
- Reported evidence
- Operating in district heating and industrial facilities globally with ramp rates from standby to full steam output in under one minute.
- Announced next step
- Rapid grid-balancing steam services utilizing curtailed renewable power during negative pricing events.
- Unresolved risk
- Operating cost: pure resistance boilers have a COP of 1.0, requiring electricity to be cheaper per MWh than natural gas to compete.
Boston MetalMolten Oxide ElectrolysisDirect electrochemical reduction of metal oxides at 1600°C using an inert iridium-based anode, bypassing fossil combustion completely
- Reported evidence
- Inaugurated commercial plant in Minas Gerais, Brazil, for high-value critical metals extraction; testing steel-scale electrolytic cells in Massachusetts.
- Announced next step
- Licensing commercial MOE cells for multi-million-tonne green ironmaking by 2026–2030.
- Unresolved risk
- Refractory corrosion and anode lifetime in corrosive molten oxide slag baths at extreme operating temperatures.
US DOE Industrial Heat ShotFederal Decarbonization InitiativeFederal R&D funding targeting an 85% reduction in greenhouse gas emissions from industrial heat by 2035 through electrification and clean fuels
- Reported evidence
- Disbursed billions under the Bipartisan Infrastructure Law and IRA for advanced industrial heat demonstration pilots.
- Announced next step
- Cost parity between electrified heat solutions and fossil fuels across low-, medium-, and high-temperature industrial processes.
- Unresolved risk
- Policy reversals, industrial inertia, and delays in connecting heavy industrial power loads to electrical substations.
Thermal battery efficiencies describe electricity-to-heat recovery under continuous operation. Standby thermal losses (1–3% per day) become significant during prolonged factory shutdowns.
The new bottleneck
Abundant electricity moves scarcity into the factory
Once clean power is cheap, the binding work is delivering its heat at the required flux, cleanliness, continuity, and product quality while a live plant keeps shipping.
Recover and upgrade
Map waste heat, lower required temperatures, and use heat pumps where source and sink align.
Electrify the simple loads
Hot water, low-pressure steam, batch ovens, and direct electromagnetic processes establish operating experience.
Redesign the process
High-temperature continuous assets need furnace, material-flow, grid, storage, and product engineering together.
There is more than one finish line
- Temperature-capableThe heater reaches the nominal process temperature.
- Flux-capableIt transfers enough heat into the real product to preserve throughput.
- Quality-capableAtmosphere, uniformity, residence time, and control preserve yield and specification.
- Plant-capableConnection, reliability, maintenance, footprint, and downtime fit the site.
- Cost-competitiveDelivered heat wins under the actual tariff, utilisation, financing, and production boundary.
The fuel-price ratio and temperature decide the first conversions
IEA’s 2025 industrial-heat review says commercial large heat pumps can serve up to roughly 150°C and electric boilers can make steam up to about 350°C. Those are equipment capabilities, not proof of integration into every food, paper or chemical site. High-temperature steel and cement process steps need different equipment and have separate chemical emissions. In its 2026 monitor, IEA estimates existing industrial heat pumps could technically serve about 20% of global industrial heat, while Japan’s roughly 650 MW of installed industrial heat-pump capacity in 2024 covered only about 1% of light-industrial demand.
For a resistance boiler, each kWh of heat needs about one kWh of electricity. At a 90% gas-boiler efficiency, the electricity price must be near or below 1.11 times the gas price per kWh of fuel to match the energy bill, before capital and carbon cost. A heat pump at COP 3.5 tolerates an electricity-to-gas price ratio of about 3.89. IEA’s 2024 country comparison reports standalone electric-boiler running costs about four times gas in the United States and twice gas in China on its example assumptions. That is why a heat pump or waste-heat recovery may clear first even when an electric boiler is technically simple.
China’s electricity share of final energy reached 28% in 2024, versus 27% in 2023, though this economy-wide measure is not an industrial-heat share. The meaningful plant-level diffusion metric is fossil heat displaced by temperature band, with measured electricity use, output quality, connection lead time and delivered cost.
The global heat curve is still early
IEA estimates electricity supplied about 4% of global industrial process heat in 2024 and models 12% in 2030, with China representing more than half of the projected growth in renewable electric process heat. The 2030 figure is a scenario, not installed thermal-battery capacity. Rondo reports a 100 MWh heat battery entering operation in 2025; that is company-reported site capacity, with no public audited installed $/kWh-th for a cross-vendor cost curve.
IEA describes industrial heat pumps reaching roughly 200°C in emerging applications, beyond its narrower commercial mainstream range around 150°C. The industrial price test must include tariff demand charges and utilization as well as energy $/MWh; a site with short process runs can lose an apparent COP advantage to capital recovery and connection costs. Cement clinker and virgin steel reduction still require separate chemistry and high-temperature solutions, covered in the cement and steel reports.
Sources, method, and boundaries
Temperature points in the explorer are representative screening values. The cost model keeps measured energy-price anchors separate from editorial equipment assumptions. Technology temperatures describe reported commercial or demonstration boundaries, not universal material limits. Company and funded-project targets are explicitly labelled.
- Measured
- An observed energy price, operating statistic, or completed test reported by a primary source.
- Derived
- A calculation whose inputs and boundary are shown in the model.
- Projected
- A modeled future outcome, such as a technical-potential or scenario figure.
- Target
- A future cost, temperature, efficiency, or emissions objective.
- Editorial inference
- A maturity or integration judgement synthesised from the evidence.