Trucks and Buses

Not on track
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About this report

After dipping during the pandemic, in 2021 emissions from trucks and buses rebounded to roughly their previous level. As a result, emissions in this sector need to peak within the coming few years and begin to rapidly decline within the coming decade to reach Net Zero Scenario milestones. This equates to a fall of 16% by 2030 relative to their current level. 

CO2 emissions

Given historical trends and the rebound in 2021, emissions from trucks and buses are set to continue increasing, reaching record levels in the coming years. More countries need to adopt, strengthen and harmonise heavy-duty vehicle fuel economy standards and zero-emission vehicle (ZEV) mandates. Adoption of electric and hydrogen fuel-cell electric heavy-duty vehicles (HDVs) is needed now to enable emissions reductions in the 2020s and 2030s.  

Tracking progress

CO2 emissions from trucks and buses, 2000-2021, and 2030 in the Net Zero Scenario


Where practical, logistical improvements and modal shift to rail or ship can be even more effective at achieving decarbonisation; however, a successful rollout of zero-emission (i.e. battery and fuel cell electric) vehicles will also reduce overall energy consumption via efficiency advantages over internal combustion engines. There is an immediate need to deploy electric buses, which are already cost-competitive in many applications, and to demonstrate and scale up markets for battery electric and hydrogen trucks. Doing so in line with the Net Zero Scenario can see electricity, which currently accounts for less than 0.5% of sectoral energy, and hydrogen (negligible share today), increase to around 7% and 2% of sectoral energy by 2030 respectively – only eight years from now.  

Global final energy demand for trucks and buses by fuel, 2000-2021, and 2030 in the Net Zero Scenario

Technology deployment

Sales of electric buses increased by 40% in 2021 and electric truck sales more than doubled, even while total sales remained approximately the same as in 2020. China accounted for over 90% of these, although registrations in Europe and the United States also increased. 

The sale of more than 91 000 electric buses in 2021 brought the fleet total to 670 000, 4% of the global bus fleet; the total stock of electric trucks now stands at 66 000, representing 0.3% of new registrations in 2021, but just 0.1% of the fleet. In 2030 in the Net Zero Scenario, zero-emission buses comprise over 25% of the total stock and zero-emission trucks more than 10%. 


To date, buses have been the most amenable HDV to electrification; however, as manufacturers scale up production and battery technology improves in terms of cost, energy density and durability, the availability of electric trucks is also increasing. CALSTART’s Global Drive to Zero ZETI tool provides details on current and announced models. The market is particularly dynamic in China, where zero-emission truck and bus manufacturers are developing and commercialising new models to satisfy domestic and international demand. 

Current and announced zero-emission commercial vehicle models by type, release date and range, 2019-2023

Current And Announced Zero Emission Hdv Models By Segment Release Year And Powertrain In Major Markets 2020 2023
Current and announced zero-emission commercial vehicle models by type, release date and range, 2019-2023
Current And Announced Zero Emission Hdv Models By Segment Release Year And Powertrain In Major Markets 2020 2023
Supporting infrastructure

Work on megawatt-scale charging systems is ongoing at CHAdeMO in Asia and the NREL in the United States, and at CharIN, a global group developing the Megawatt Charging System of up to 3.75 MW. Meanwhile, a high-flow rate heavy-duty hydrogen refuelling station in the United States has demonstrated filling a 40 kg tank in less than three minutes. 

In order to decarbonise trucks via electrification, extensive upgrades to the associated grid infrastructure must also be considered, as well as additional renewable electricity supply. The costs and lead times of these have the potential to hamper progress. 

Alternatives to fast charging are being demonstrated in various parts of the world. China leads the way on battery swapping, with a number of pilots underway and joint projects between GCL Energy Technology and Deepway Technology. Europe is leading on the development of electric road systems, where Germany has various demonstrations and Sweden is building its first permanent system; demonstrations have also been announced in the United States and the United Kingdom.   


Over 75% of trucks sold in 2021 were covered by fuel economy or vehicle efficiency regulations, up from 60% in 2016.  

In 2021, 15 countries1 endorsed the Global Memorandum of Understanding on Zero-Emission Medium and Heavy-Duty Vehicles, with Portugal as the latest signatory. The ambition is for 30% of new truck and bus sales to be ZEVs by 2030 and 100% by 2040, adding to the push for ZEV deployment in the HDV sector.  

In the European Union an emissions trading scheme for transport and changes to the Alternative Fuels Infrastructure Regulation will aid ZEV deployment. The Green Deal commits to reviewing the CO2 emissions standards for HDVs, likely revising them upward from the current levels of a 15% and 30% reduction by 2025 and 2030 respectively, with incentives for achieving ZEV sales targets. Recent reports by CALSTART and the ICCT provide further details on ZEV policies in the HDV sector.  

International collaboration

Collaboration across leading markets on heavy-duty ZEV infrastructure is critical for encouraging these vehicles’ innovation, accelerating their production and facilitating their adoption. It is also essential for establishing the interoperability of electric vehicle chargers.  

The Hydrogen Heavy Duty Vehicle Industry Group seeks to develop global-standard high-flow hydrogen fuelling hardware components, while the PRHYDE project aims to develop a series of hydrogen fuelling protocols for acceptance into international standards.  

Private-sector strategies

Of the largest HDV OEMs, 21 have made commitments to ZEVs and carbon reductions, ranging from a 90% reduction in CO2 emissions in driving operation by 2050, to 90% ZEV sales by 2040 (Scania). These commitments mostly focus on electrification.  

Elsewhere, stakeholders from government, manufacturers, fleet operators and infrastructure providers have signed CALSTART’s Drive to Zero pledge. This pledge commits to enabling and accelerating the growth of ZEVs with the “vision that zero-emission technology will be commercially viable by 2025 and dominate by 2040 in specific vehicle segments.” OEMs are also recognising the need to kickstart investment in charging infrastructure.  

In China, where fuel cell trucks are seeing far greater deployment than anywhere else, SAIC Motor is commissioning a fuel cell truck production facility to satisfy demand. However, activity levels are higher in battery electric trucks, including from large players such as Volvo, MAN and others.  

Recommendations for policy makers

California and other governments around the world have placed obligations on automakers requiring a share of HDV sales to be ZEVs. Their success has led to them being followed by five other US states, and similar such policies should be enacted elsewhere. The latest Energy-saving and New Energy Vehicle Technology Roadmap 2.0, drafted by the Society of Automotive Engineering in China, proposes that the share of new energy vehicles (which are equivalent to ZEVs) in the heavy-duty segment should be 12% by 2025, 17% by 2030 and 20% by 2035.  

Fleet purchase requirements such as the Clean Vehicle Directive2 can also send strong signals to automakers that there is demand for heavy-duty ZEVs. 

Policies such as fuel taxes and road pricing can enhance the attractiveness of ZEVs. Purchase incentives and/or favourable loan terms encourage their adoption, as evidenced by California’s HVIP scheme, which has funded over 9 000 vehicles to date.  

London’s Ultra Low Emission Zone ostensibly targets air quality, but the daily fixed charge also encourages ZEV adoption. Similar schemes exist in Paris, Milan, Beijing and others, but they can be as simple as differentiated road tolling. More stringent zero-emission zones are being considered in many places and will further favour ZEVs. 

High-power charging infrastructure should be deployed both by fleet operators and at publicly available stations (e.g. along major freight corridors). This will require coherent, collaborative effort between government and industry, including data sharing. Lead times for medium- and high- voltage lines and substations are long, and so heavy-duty charging needs must be anticipated. Notably, abundant high-power infrastructure can reduce the need for large battery capacities, which can lower vehicle purchase costs and improve vehicle efficiency similarly to electric road schemes. 

Recommendations for the private sector

Financing is a high barrier to ZEV adoption and so manufacturers should explore more innovative financing models. Hyundai has introduced a pay-per-use model, packing the complete service into a flat rate per kilometre. Penske and Scania have similar leasing options that simplify battery electric vehicle ownership. Proterra enables electric bus purchase for a price comparable to a fossil-fuelled bus by maintaining ownership of the battery pack. Manufacturers could also lease and manage the vehicles directly.  

  • Felipe Rodriguez, ICCT, Reviewer 
  • Owen MacDonnell, CALSTART, Reviewer 
  • Sacha Scheffer, WVL, Reviewer 
  • Matteo Craglia, ITF, Reviewer 
  1. Austria, Canada, Chile, Denmark, Finland, Luxembourg, Netherlands, New Zealand, Norway, Scotland, Switzerland, Republic of Türkiye, United Kingdom, Uruguay and Wales. Together these countries represented roughly 5% of global HDV sales in 2021. 

  2. Note, however, that the Directive’s definition of clean vehicles is broader than ZEVs.