Sustainability Atlas
Clean Energy·16 min read··...

Interview: the builder's playbook for Industrial heat & high-temp electrification — hard-earned lessons

A practitioner conversation: what surprised them, what failed, and what they'd do differently. Focus on retrofit workflows, grid impacts, and incentives that move adoption.

Industrial heat accounts for approximately 20% of global energy consumption and represents a $1 trillion market opportunity for decarbonisation. Yet until recently, electrifying processes above 400°C—steel reheating at 1,200°C, cement kilns at 1,450°C, glass furnaces at 1,600°C—seemed technically impossible at scale. That changed in 2024-2025. The high-temperature industrial electric heating market reached $11.3 billion in revenue with 4,136 MW of capacity additions in 2024, and Guidehouse Research projects this will nearly triple to $30.6 billion by 2033. We spoke with engineers, project developers, and operations leaders across European and North American facilities to understand what's actually working, what's failing, and how practitioners are navigating the most challenging retrofit environments in the energy transition.

The lessons are often counterintuitive. Grid connection timelines, not technology readiness, determine project viability. Unit economics depend more on electricity price structures than equipment costs. And the companies capturing value are those building integrated solutions—combining thermal storage, power flexibility, and process redesign—rather than selling standalone electrification hardware.

Why It Matters

Heavy industry—steel, cement, chemicals, glass—generates roughly 30% of global CO₂ emissions, with process heat representing the dominant energy demand. Traditional approaches rely on burning natural gas, coal, or petroleum coke at temperatures ranging from 500°C to 2,000°C. Electrification eliminates direct combustion emissions, but until recently, electric technologies couldn't economically reach these temperatures at industrial scale.

The urgency is accelerating. The EU Emissions Trading System carbon price exceeded €80/tonne in 2024, adding €50-100 per tonne to steel production costs. The US Inflation Reduction Act provides substantial tax credits for industrial decarbonisation, while the EU Carbon Border Adjustment Mechanism (CBAM) will impose tariffs on carbon-intensive imports starting in 2026. Manufacturers that fail to electrify face both regulatory penalties and competitive disadvantage as customers increasingly specify low-carbon materials.

For European engineers, the business case extends beyond compliance. Industrial electricity prices have stabilised after the 2022-2023 crisis, while natural gas remains volatile. Electrification enables integration with on-site renewables and participation in demand response programmes that generate revenue rather than incurring fuel costs. The question is no longer whether industrial heat will electrify, but how quickly practitioners can execute retrofits without disrupting production.

Key Concepts

Thermal Batteries and Energy Storage

The breakthrough enabling high-temperature electrification is thermal energy storage—systems that convert electricity to heat, store it in solid media, and discharge on demand. Unlike electrochemical batteries, thermal batteries use inexpensive materials like carbon blocks, refractory bricks, or specialised firebricks to store heat at 1,000-1,800°C.

"The elegance is in the simplicity," explains a project engineer who led a 100 MWh deployment. "We're heating rocks with renewable electricity when it's cheap, then extracting that heat as steam or hot air when the process needs it. Round-trip efficiency exceeds 97% because there's no conversion back to electricity—we're delivering heat directly."

Three architectures dominate:

Brick-based systems (Rondo Energy) store heat in stacked refractory bricks using resistive heating, delivering steam or superheated air up to 1,000°C. The modular design enables rapid deployment alongside existing gas boilers.

Carbon-block systems (Antora Energy) store heat at 1,500-1,700°C using solid carbon, with optional thermophotovoltaic conversion to generate electricity. The higher temperature range addresses steel, cement, and glass applications.

Conductive firebrick systems (Electrified Thermal Solutions) use electrically conductive E-Bricks that can cycle to 1,800°C—the highest temperature in the industry—targeting the most extreme process requirements.

Retrofit Workflow Realities

Practitioners consistently emphasise that technology selection is the easiest decision in industrial heat electrification. The hard work involves site assessment, grid connection, and process integration.

"We spent eighteen months on grid interconnection for a facility where the thermal battery installation took four weeks," notes an operations director at a European chemicals manufacturer. "The equipment arrived, we bolted it down, connected the steam lines, and it worked. The utility paperwork nearly killed the project."

Standard retrofit workflows involve:

  1. Heat audit and process mapping: Characterising temperature requirements, duty cycles, and integration points. Most facilities have multiple heat loads at different temperatures—matching electrification technology to specific applications rather than attempting whole-site conversion.

  2. Grid capacity assessment: Determining whether existing electrical infrastructure can accommodate new loads. High-temperature processes require significant power—a 50 MW thermal load may require 15-20 MW of electrical input, potentially exceeding substation capacity.

  3. Hybrid system design: Integrating electric heating with existing fossil fuel systems to provide redundancy and manage peak demands. Most practitioners recommend phased transitions rather than complete replacements.

  4. Utility negotiation: Securing interconnection agreements, negotiating demand charges, and structuring power purchase agreements. Time-of-use pricing and demand response participation significantly affect project economics.

Grid Integration Challenges

Industrial electrification is occurring against a backdrop of unprecedented electricity demand growth. Global electricity consumption grew 4.3% in 2024—the fastest rate in years—driven by data centres, EV charging, and industrial expansion. The IEA projects demand will increase by 3,500 TWh between 2025 and 2027, equivalent to adding one Japan per year.

For industrial facilities, this creates both opportunity and constraint. Opportunity because grid operators need flexible loads that can absorb surplus renewable generation. Constraint because infrastructure bottlenecks limit new connections.

"The US has 1,650-2,000 GW of renewable projects waiting for grid connection—almost double current installed capacity," observes an energy analyst. "Connection wait times exceed four years for transmission lines. Data centres build in 18-24 months. The mismatch is creating stranded projects."

European grids face similar pressures. Transmission investment is growing at 16% annually, but 70% of US grid infrastructure is over 25 years old, and transformer lead times have nearly doubled since the pandemic. Power transformer prices have increased up to 2.6x pre-pandemic levels.

The lesson for practitioners: grid connection is the critical path. Begin utility engagement before finalising technology selection. Consider behind-the-meter generation (solar PV, on-site storage) to reduce interconnection requirements. Design systems with grid flexibility as a core feature, not an afterthought.

What's Working

Rondo Energy at Calgren Renewable Fuels

In October 2025, Rondo Energy commissioned the world's largest industrial heat battery at Calgren Renewable Fuels in Pixley, California. The 100 MWh system stores heat above 1,000°C in refractory bricks, charged by on-site solar PV, and delivers steam to power fuel production 24/7.

The project demonstrates several principles practitioners are applying:

Zero production disruption: The thermal battery operates alongside existing gas boilers, providing supplemental heat without requiring process modifications. "We didn't ask them to change anything about how they make fuel," explains a Rondo executive. "We just gave them cheaper, cleaner steam."

Heat-as-a-Service model: Calgren pays for steam delivered, not equipment purchased. Rondo retains ownership and operational responsibility, eliminating capital expenditure barriers for the industrial customer.

On-site generation integration: By co-locating solar PV and thermal storage, the project avoids grid interconnection delays and captures the full value of low-cost renewable electricity.

Antora Energy at Summit Materials

In March 2024, the US Department of Energy selected a consortium including Antora Energy and Summit Materials to build four low-carbon cement plants. Antora's carbon-block thermal batteries will provide kiln heat, targeting approximately 1.1 million tonnes of CO₂ reduction annually.

The partnership addresses cement's unique challenge: calcination requires sustained temperatures above 1,400°C while also releasing process CO₂ from limestone decomposition. Electrification alone cannot eliminate emissions—carbon capture or alternative chemistries are also required—but eliminating fuel combustion addresses roughly 40% of cement's carbon footprint.

"We're proving that electric kilns can reach and maintain the temperatures cement requires," notes an Antora engineer. "The carbon blocks store heat at 1,500°C and deliver it on demand. Once operators see that temperature stability actually improves product consistency, adoption accelerates."

Electrified Thermal Solutions and ArcelorMittal

In September 2025, ArcelorMittal—the world's largest steelmaker—announced a partnership with Electrified Thermal Solutions to validate its Joule Hive thermal battery technology at ArcelorMittal's GasLab facility in Asturias, Spain. The agreement includes potential pilot deployment across ArcelorMittal's global steel operations.

The partnership signals that major industrials are moving beyond laboratory curiosity to commercial evaluation. ETS's technology can reach 1,800°C—sufficient for virtually any industrial process—and has achieved Technology Readiness Level 6 with DOE validation.

"ArcelorMittal operates facilities that consume more energy than many countries," observes an industry analyst. "When they commit to validating a technology, it signals to the entire supply chain that this is becoming real."

What's Not Working

Grid Interconnection Timelines

The single most common failure mode practitioners report is grid interconnection delays. Facilities with adequate on-site electrical capacity can deploy thermal batteries in months. Those requiring grid upgrades face multi-year timelines that undermine project economics.

"We had a project in the Midwest where the technology was ready, the customer was ready, financing was secured—and the utility told us five years for interconnection," recounts a project developer. "The customer's capital allocation cycle is three years. The project died."

The root causes are structural: utility planning processes designed for gradual load growth cannot accommodate rapid industrial electrification. Transmission queues are congested with renewable generation projects. Skilled workers for grid construction are in short supply.

Practitioners are responding by prioritising behind-the-meter solutions, designing hybrid systems that minimise peak electrical demand, and engaging utilities earlier in project development. Some are locating new facilities based on grid availability rather than traditional site selection criteria.

Electricity Price Volatility

While natural gas prices are famously volatile, electricity prices—particularly in markets with high renewable penetration—can swing even more dramatically. Negative pricing during sunny or windy periods creates opportunity; price spikes during low-generation periods create risk.

"We modelled a project assuming average electricity prices," explains a financial analyst at an industrial developer. "Then we ran it against actual hourly prices from the past two years. The variance was enormous. Projects that look marginal at average prices become highly profitable with thermal storage arbitrage—or deeply unprofitable without it."

The lesson: thermal storage provides optionality that electric heating without storage lacks. Systems that can charge during low-price hours and discharge during production reduce exposure to price spikes. But modelling must account for realistic price distributions, not annual averages.

Equipment Durability at Extreme Temperatures

High-temperature electric systems face material challenges that fossil fuel systems avoid. Glass industry practitioners report that electric furnaces wear approximately twice as fast as gas-fired alternatives, reducing asset life and increasing maintenance costs.

"We're heating materials to 1,600°C with electrical elements that are themselves at even higher temperatures," notes a glass manufacturer's engineering director. "The thermal cycling, the corrosive atmosphere, the mechanical stresses—it's a demanding environment. We've had element failures that shut down production."

Suppliers are addressing durability through improved materials (silicon carbide, molybdenum disilicide) and system designs that reduce thermal stress. But practitioners should budget for higher maintenance costs and shorter replacement cycles during early deployment phases.

Workforce Knowledge Gaps

Industrial electrification requires expertise that spans electrical engineering, process engineering, and controls—a combination rarely found in traditional operations teams trained on combustion systems.

"Our operators have decades of experience managing gas-fired furnaces," explains a plant manager. "The electrified system has completely different failure modes, different control strategies, different safety considerations. We underestimated the training investment required."

The Renewable Thermal Collaborative and ACEEE launched an Industrial Heat Pump Buyers Bootcamp in 2025, recognising that procurement and operations teams need structured guidance. Similar efforts are emerging for thermal battery technologies.

Key Players

Established Leaders

  • ArcelorMittal — World's largest steelmaker with hydrogen-DRI facilities in Germany, Belgium, and Spain. Investing in Electrified Thermal Solutions for high-temperature electrification validation across global operations.

  • Heidelberg Materials — Global cement leader operating the world's first industrial-scale CCS facility at Brevik, Norway. Exploring electrification technologies for calcination.

  • BASF — Chemical giant with extensive process heat requirements. Partnering with thermal battery developers for pilot deployments at European manufacturing sites.

  • Saint-Gobain — Major glass manufacturer evaluating electric melting technologies. Operating pilot electric furnaces targeting 80% emissions reduction.

Emerging Startups

  • Antora Energy — San Jose-based developer of carbon-block thermal batteries storing heat at 1,500-1,700°C. Raised $150M Series B in February 2024, manufacturing at 50,000 sq ft facility. Deploying with Summit Materials cement consortium.

  • Rondo Energy — Alameda-based brick thermal battery company. Commissioned world's largest 100 MWh industrial heat battery in October 2025. Expanding manufacturing capacity to 90 GWh/year with Siam Cement Group.

  • Electrified Thermal Solutions — MIT spinout developing Joule Hive conductive firebrick systems reaching 1,800°C. Selected for over $40M DOE funding. Partnering with ArcelorMittal for steel industry deployment.

  • Sublime Systems — Boston-based developer of electrochemical cement production eliminating kilns entirely. ASTM C1157-compliant product achieving 90% CO₂ reduction.

Key Investors & Funders

  • Breakthrough Energy Ventures — Bill Gates-backed climate fund investing in Antora Energy, Rondo, and other industrial decarbonisation startups.

  • Temasek/BlackRock Decarbonization Partners — Co-led Antora's $150M Series B. Targeting industrial climate solutions.

  • US Department of Energy — Providing over $40M to Electrified Thermal Solutions, $14.5M ARPA-E funding to Antora, and supporting Summit Materials cement consortium.

  • EU Innovation Fund — Funding ELECTRA project for high-temperature electrification of cement and lime at MW-scale. Supporting industrial heat demonstration projects across Europe.

  • ArcelorMittal XCarb Innovation Fund — Corporate venture arm investing in ETS and other steel decarbonisation technologies.

Action Checklist

  1. Conduct a comprehensive heat audit: Map all thermal loads by temperature, duty cycle, and process criticality. Prioritise electrification candidates based on temperature range (start with processes under 1,000°C), existing electrical capacity, and production flexibility.

  2. Engage utilities immediately: Begin interconnection discussions before finalising technology selection. Understand substation capacity, demand charge structures, and time-of-use pricing. Grid connection is typically the longest lead-time item.

  3. Model realistic electricity price scenarios: Use hourly historical data, not annual averages. Evaluate thermal storage options that provide arbitrage value. Include demand response revenue in project economics.

  4. Design hybrid systems: Plan for parallel operation with existing fossil fuel equipment during transition. Maintain backup capacity until electric systems demonstrate reliability. Phase implementation to manage risk.

  5. Evaluate Heat-as-a-Service models: Consider operational expenditure structures that shift technology risk to vendors. Companies like Rondo offer steam purchase agreements that eliminate capital barriers.

  6. Invest in workforce development: Budget for operator training on electric systems. Establish relationships with OEM service teams. Consider hiring electrical engineering expertise in addition to traditional combustion specialists.

  7. Track regulatory incentives: Monitor IRA tax credits, EU Innovation Fund opportunities, and national industrial decarbonisation programmes. Incentives can shift project economics from marginal to compelling.

  8. Join industry consortia: Participate in the Thermal Battery Alliance, Renewable Thermal Collaborative, or Third Derivative Industrial Innovation Cohorts. Shared learnings accelerate deployment and reduce individual project risk.

FAQ

Q: What temperature ranges can current electric technologies achieve, and which industries do they serve?

A: Commercial thermal battery systems now reach 1,500-1,800°C, addressing virtually all industrial processes. Rondo's brick-based systems deliver heat up to 1,000°C, suitable for chemicals, food processing, and pulp and paper. Antora's carbon-block batteries operate at 1,500-1,700°C for steel reheating and cement precalcination. ETS's Joule Hive technology reaches 1,800°C, enabling glass melting and the most extreme metallurgical applications. Industrial heat pumps serve lower-temperature processes (under 200°C) in food, beverage, and pharmaceutical manufacturing. The technology gap that made high-temperature electrification seem impossible five years ago has effectively closed.

Q: How do grid constraints affect project viability, and what strategies are practitioners using?

A: Grid interconnection is the primary bottleneck for industrial electrification. US interconnection queues exceed 2,000 GW of waiting projects with four-plus year timelines. Transformer lead times have doubled, and skilled labour is scarce. Successful practitioners are responding by: (1) prioritising behind-the-meter solutions with on-site solar PV and thermal storage, reducing grid upgrade requirements; (2) designing systems with load flexibility that minimises peak demand charges; (3) engaging utilities during site selection, not after technology decisions; (4) considering co-location with existing industrial facilities that have excess electrical capacity. Projects that treat grid connection as an afterthought frequently fail.

Q: What are realistic payback periods for industrial heat electrification, and how do incentives affect economics?

A: Payback periods vary significantly based on electricity prices, fuel costs, carbon pricing, and incentive availability. In Europe, with carbon prices exceeding €80/tonne and natural gas volatility, projects targeting medium-temperature processes (500-1,000°C) are achieving 3-5 year paybacks. Higher-temperature applications (greater than 1,200°C) typically require incentive support to reach acceptable returns. US IRA tax credits for industrial decarbonisation can cover 30-40% of capital costs, dramatically improving economics. Heat-as-a-Service models eliminate capital expenditure entirely, converting the decision from a payback calculation to an operating cost comparison. Practitioners recommend modelling multiple scenarios with and without incentives to understand exposure.

Q: Should facilities pursue complete electrification or hybrid approaches?

A: Experienced practitioners overwhelmingly recommend hybrid approaches for initial deployments. Parallel operation with existing fossil fuel systems provides backup during the learning curve, enables gradual operator training, and reduces risk of production disruption. Rondo's deployment at Calgren operates alongside gas boilers; Antora's cement consortium maintains conventional kiln capacity. Complete electrification may be appropriate for greenfield facilities or processes where electric systems demonstrate superior performance (temperature stability, process control). But for retrofit environments—which represent the vast majority of industrial heat opportunities—hybrid design provides optionality that pure electrification lacks.

Q: How is the Thermal Battery Alliance shaping industry standards and deployment?

A: Formed in January 2025 by Antora, Electrified Thermal Solutions, Rondo Energy, and RedoxBlox, the Thermal Battery Alliance coordinates industry efforts on standardisation, policy advocacy, and market development. The Alliance is working with regulators to establish performance standards, with utilities on interconnection procedures, and with industrial customers on procurement specifications. By presenting a unified industry voice, the Alliance aims to accelerate the regulatory and infrastructure changes that individual companies cannot achieve alone. For practitioners, Alliance resources provide vetted guidance on technology selection, system design, and deployment best practices.

Sources

The electrification of industrial heat represents one of the largest decarbonisation opportunities of the coming decade—a $30+ billion market addressing 20% of global energy consumption. The technology barriers that made high-temperature electrification seem impossible have fallen. The remaining challenges are infrastructure, economics, and execution. Practitioners who master grid integration, design flexible systems, and build operational capability will capture disproportionate value as heavy industry transforms. The playbook is emerging from deployed projects, failed pilots, and hard-won lessons. The window for competitive advantage is now.

Topics

industrialheatstandardsDERbenchmark KPIsriskunit economics

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