Green goals for heavy industries in the energy transition

We have looked at the impacts of three of the most ‘hard-to-abate’ sectors and what alternatives may look like from the perspective of their emissions, costs and practicalities.(Courtesy: Shaah Shahidh/Unsplash)

By David Stent — Climate Council Digital Producer & Content Manager

Our emissions crisis is often defined in simplistic terms, often focusing on the more obvious carbon-intensive sectors of oil and gas production, shipping and aviation or the ‘carbon footprint’ of the individual. Intentional or not, this fails to provide a full picture of the circumstances that have led us to the brink. Entire societal structures have been built on the pretense of continued and lasting growth, through the use of fossil fuels. And while renewables are now extremely competitive for electricity production, they cannot (yet) fulfil the needs from industrial and manufacturing demand.

To continue to achieve “growth”, society must expand, build and develop the environment to facilitate business. This requires infrastructure of buildings, electrical networks, sewerage, roads, transport networks etc – the point being, that we can rarely access “growth” without construction and development.

Yet these sectors that we have become so reliant upon, are the very same that weigh us down as we seek to new paths to a cleaner, net-zero society. We have looked at the impacts of three of the most ‘hard-to-abate’ sectors and what alternatives may look like from the perspective of their emissions, costs and practicalities.

A session called Funding the New Energy Paradigm: Innovative Financing Mechanisms & Clever Capital Structures will be presented during the POWERGEN Leadership Summit in Dallas, Texas on January 28, 2022. 

Green Steel

The unfortunate reality of steel production, is that it is one of the single largest contributors of total global CO² emissions, accounting for roughly 6-7%. Such hefty carbon impacts onto the atmosphere are entirely unsustainable, and while we seek wholesale changes to energy procurement, there are few avenues that can abate the emissions of steel production.

Steel is made using incredibly high heats that demand incredibly high quantities of energy throughout the production process. In simplistic terms, steel is created through the melting of iron ore with coke (superheated coal to remove oil, tar, hydrogen, nitrogen and sulfur) and limestone – essentially making an alloy of iron and carbon.

From the mining of iron ore, to the crushing of coal to make coke, the heating of furnaces for prolonged periods – all contain huge emissions profiles. For every one tonne of steel made, 1.85 tonnes of carbon are emitted.

As the capital and political pressures increase for industries to decarbonize their processes and prove a commitment to Paris Climate Goals, there is a genuine threat to the sector as steel comes under increasing scrutiny. A report by McKinsey found that “14 percent of steel companies’ potential value is at risk if they are unable to decrease their environmental impact”.

Process to make green steel

The highest carbon emission aspect of steel production, is the reduction of iron ore into ‘pig iron’. The speed of replacing this traditional process with low-carbon alternatives, namely ‘molten oxide electrolysis (MOE) and hydrogen direct reduction (HDR)’, has been slow as they are not commercially viable at scale yet. But in terms of emissions impacts, HDR has the same CO² impact than the most efficient blast furnaces (BF).

Hydrogen can effectively replace coal as the reagent in the reduction of iron ore, yet they require the use of electric arc furnaces (EAFs) that use electricity to power the furnace (instead of fossil fuels in a BF). The concern herein is the source of electricity powering the furnace. Wind, solar, hydropower or green hydrogen would radically and rapidly reduce the emissions impacts of steel.

The Rocky Mountain Institute established how, “For one ton of crude steel produced from iron ore, the hydrogen generation requires 2,633 kWh of power, and in addition, the direct reduction and EAF plants consume 816 kWh. Assuming global average CO2 intensity of 0.48 tCO2/MWh for the power, each ton of crude steel generates emissions of 1,713 kgCO2. This should be compared with a blast furnace, which emits a total of 1,714 kgCO2 for each ton of crude steel.”

Case study –

  • “In 2016, SSAB, LKAB (Europe’s largest iron ore producer) and Vattenfall (one of Europe’s largest energy companies) joined forces to create HYBRIT”, resulting in the world’s first delivery of ‘green steel’ to Volvo late last month.

Green Cement

Similarly to steel, cement is one of the undercover anchors weighing down progress in the energy transition and just like steel, accounts for roughly 8% of global emissions. The essential role cement plays in making concrete (and in turn, the wider construction indsutry) ensures a longevity that we cannot yet see an end to, unlike fossil fuels.

Another McKinsey report showed that, as a product, the quantity of emissions cement produces in terms of, kilograms of CO² per revenue dollar – at 6.9kg of CO² is easily one of the most carbon intensive sectors. For comparison, iron and steel produce 1.4kg of CO² and oil and gas 0.8kg of CO² per revenue dollar.

While cement only accounts for 12% of the mix in concrete, ‘it is almost exclusively responsible for the resulting CO2 emissions’. And similarly to steel, the enormous energy inputs to fire the kilns, together with the chemical reactions produced, create emissions on a scale that should entail global reconsideration of its use. With global cement growth rising 2.5% per year to 2050, the current production of 2.55 billion tonnes per year will rise to 4.5 billion tonnes per year. And for each one these billion tonnes of cement produced each year, for every 1 tonne of cement, 0.6 tonnes of carbon emissions occur.

Process to make green cement

Abating cement emissions is not wasy or straight forward, as many of the individual steps of the process have significant risk profiles. As such, much of the task in creating ‘green’ cement is to isolate and replace the burdensome elements, from; using industrial waste product of ‘fly ash’ and ‘slag’, or recovering ‘waste heat’ and by using renewable-powered electrical kilns (alone could replace 10% of cement emissions).

The reinvented cement production process, adding calcined clay and powered limestone, has the additional benefit of producing a stronger cement with less porosity. Moreover, the carbon impact is reduced by 40%.

Case Studies:

Heavy-duty transport

The global nature of existence has entrenched the human need for products from far, far away. But for our enjoyment to occur, first they must travel thousands of kilometers to arrive at our local shop or even at our doorstep in the cargo holds of container ships, planes and heavy-duty trucks. Each of these pose their own concerns in how to successfully mitigate their emissions profiles, but they are part of the same ecosystem.


According to the International Maritime Organisation, the maritime transport sector, “emits around 940 million tonnes of CO2 annually and is responsible for about 2.5% of global greenhouse gas (GHG) emissions”. The IMO believes that without urgent and practical reductions in emissions, the sector’s impact will increase by between 50-250% by 2050. For a sector that already accounts for 2.5% of GHG emissions, such an increase would radically change the sectors emissions contribution. Some of the major alternatives proposed are the use of hydrogen-based fuels (ammonia), synthetic fuels or bio- and waste-based fuels.


Aviation emissions probably attract the greatest attention of the heavy-transport sector due to the frequency in which people use planes, creating an emissions impact of 915 million tonnes per year. This figure the EPA says accounts for roughly 2.4% of total global emissions. Passenger planes are the worst offenders, producing 81% of aviation emissions with the other 19% coming from air freight.

While aviation fuels are far more efficient these days, with Sustainable Alternative Fuels from algae or waste by-products increasingly coming into the fray and reducing a portion of emissions impacts, there remains significant hurdles to overcome. The IEA “estimates aviation oil demand to rise will increase more than 50% by 2040”. Practical alternatives such as hydrogen fuels are constrained by the much lower energy density than traditional jet fuel, requiring larger and more complex fuel storage.

Heavy-Duty Trucks

Heavy-duty trucking is the link that ensures all freight sent by sea or air reaches its final destination, and due to the relatively smaller capacities, the energy requirements are reduced.  In turn, this allows for fuel cells, batteries and alternative/bio-fuels to effectively replace fossil fuels by utilizing pre-existing networks to refueling stations – albeit with some upgrades.

The IEA reports that global emissions from heavy-duty trucks account for 1856 million tonnes of CO² per annum, or roughly 2% of global CO² emissions, with 2.6% yearly growth in CO² emissions impact since 2000. The EU’s regulation has mandated that trucks reduce their emissions by 15% by 2025, and 30% by 2030 – with 70% of new trucks now sold in regions with fuel economy and emissions standards in place. While these are encouraging signs, the full potential for electrification or net-zero buses, medium and heavy-duty transport is far from being realized.

Case studies:

  • Ship
    • “The European innovation project Flagships will deploy the world’s first commercial cargo transport vessel operating on hydrogen, plying the river Seine in Paris. Commercial operations are set to commence in 2021.”
    • Being developed by Norway, the EU and a range of industrial partners, “The Nordic Green Ammonia Powered Ships (NoGAPS) project will pave the way for the first ammonia-powered vessel.” They expect first demonstration of operations in 2025.
  • Planes
    • The groundbreaking Airbus ZEROe (H2) is set to re-introduce hydrogen-powered flight in an exciting new aircraft. “All three ZEROe concepts are hybrid-hydrogen aircraft. They are powered by hydrogen combustion through modified gas turbine engines. Liquid hydrogen is used as fuel for combustion with oxygen.”
    • Boom Supersonic has re-introduced another form of air travel, supersonic flight. And all while using Sustainable Aviation Fuels, effectively reducing GHG emissions and flight times – having the capacity to make “an 80% reduction in lifecycle CO2 over conventional jet fuel”.
  • HDVs
    • While not released yet, the Tesla Semi appears to be pushing the boundaries of what is possible for heavy-duty electrification. Achieving ranges of between 300 – 500 miles, it outperforms most competitors and matches the cost of high-end diesel-powered 18-wheelers.
    • eRoadArlanda, has taken a vastly different approach to electrification by focusing on the road rather than the vehicle. The “solution is based on conductive technology that enables cars, buses and trucks to be recharged while drive,” using electrified tracks and a movable arm, similar to how a train track would.


  • John Engel is the Content Director for Renewable Energy World. For the past decade, John has worked as a journalist across various mediums -- print, digital, radio, and television -- covering sports, news, and politics. He lives in Asheville, North Carolina with his wife, Malia. Have a story idea or a pitch for Renewable Energy World? Email John at

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