Electric buses and HGVs face big engineering challenges in batteries, charging, and maintenance. Discover how SOE supports engineers leading this transition.
The UK’s road transport sector is entering a decisive decade. As cities commit to cleaner air targets and operators prepare for net zero deadlines, the transition to electric buses and heavy goods vehicles (HGVs) is no longer a distant ambition but a pressing engineering challenge. While the environmental benefits of electrification are clear, the technical, operational and regulatory obstacles are complex, demanding innovative solutions from engineers across the sector.
Battery technology and range limitations
The most immediate challenge is energy storage. Batteries powerful enough to move 18-tonne trucks or double-decker buses over long distances remain heavy, costly and prone to limitations in range. Unlike cars, which can rely on overnight charging, commercial vehicles require sustained power over long duty cycles, often with minimal downtime. Engineers are tasked with balancing energy density, charging times, and vehicle payload, as each trade-off affects operational efficiency.
Thermal management is also critical. High-capacity batteries generate significant heat, which raises safety risks and accelerates degradation. Developing cooling systems that can maintain optimal battery performance under real-world conditions is a priority for vehicle manufacturers and maintenance engineers alike.
Charging infrastructure and grid demand
For electric buses and HGVs to be viable, charging must be fast, reliable and accessible. Depot charging can support overnight replenishment, but high-powered rapid charging is essential for vehicles operating on continuous shifts or long-haul routes. This raises a significant engineering challenge: ensuring the UK’s electricity grid can handle the surge in demand.
Upgrading substations, integrating renewable energy, and managing peak loads will require close collaboration between transport engineers, utility providers and policymakers. Engineers must also design systems that allow interoperability across fleets and regions, preventing operators from being locked into proprietary technologies.
Vehicle weight and payload capacity
The addition of heavy battery packs increases the gross vehicle weight of buses and HGVs, often cutting into payload capacity. For operators, this creates a difficult balance; fewer passengers on buses, or reduced cargo on lorries, can undermine the economic case for electrification.
Lightweight materials and innovative chassis designs are being explored to offset this issue. However, these introduce their own challenges in terms of durability, crashworthiness and lifecycle maintenance. Engineers must therefore optimise structures that are both lighter and stronger, which is no easy feat when vehicles are expected to endure high mileage and tough working environments.
Maintenance and skills
Electrification is reshaping the skillset required within workshops. Traditional diesel mechanics are highly skilled at managing combustion engines, gearboxes and exhaust after-treatment systems, but electric drivetrains demand expertise in high-voltage systems, battery diagnostics and software integration.
The Society of Operations Engineers (SOE) has long highlighted the importance of Continuing Professional Development (CPD) to keep pace with technological change. The shift to electric fleets reinforces this need: without upskilling, operators risk knowledge gaps that could compromise both safety and efficiency. Professional registration offers engineers a structured route to demonstrate competence in these emerging fields.
Cost and total cost of ownership
While electric buses and HGVs have lower running costs due to fewer moving parts and cheaper energy per mile, the upfront capital cost remains high. Operators face uncertainty around battery lifespan and replacement schedules, which affects long-term planning. Engineers play a crucial role in reducing whole-life costs by designing components for modular replacement, improving energy efficiency, and developing predictive maintenance systems that minimise downtime.
Policy and regulation
Government policy is a powerful driver of electrification. The UK’s Zero Emission Vehicle (ZEV) mandate is accelerating the adoption of electric buses and HGVs, with incentives and deadlines shaping investment decisions. Engineers must ensure vehicles meet not only environmental standards but also evolving safety and operational regulations.
This includes testing charging systems to international standards, managing electromagnetic compatibility in high-power drivetrains, and ensuring vehicles comply with weight and dimension limits. Such regulatory demands highlight the critical role of professional engineers in bridging the gap between policy ambition and technical delivery.
Looking ahead
Despite the hurdles, progress is accelerating. Battery chemistries are improving, hydrogen fuel cells are being trialled for longer-range applications, and advances in digital simulation are helping engineers design vehicles with greater efficiency. Collaborative projects between OEMs, universities and operators are pushing the boundaries of what is possible.
For engineers, this transition is not just about swapping diesel engines for electric motors. It is about re-engineering entire systems from depots and supply chains to maintenance and workforce training. It represents one of the most complex and exciting engineering challenges of our time.