Electrifying HGVs ─ what are the options?

By 2040, all new heavy goods vehicles (HGVs) sold in the UK must be zero-emission. Advances in green energy technology mean this is possible, but automotive manufacturers are still in disagreement about what type of power source is best.

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There are two main types of electric vehicle, categorised by their power source. Battery electric vehicles (BEVs) rely on a lithium-ion battery for power. Fuel cell electric vehicles (FCEVs) on the other hand use a fuel cell, which combines hydrogen gas with oxygen to generate electricity.

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? Hydrogen power

Hydrogen is the most abundant element in existence, so future supply is not an issue. Hydrogen power also has a much higher energy density than batteries, allowing HGVs to carry much heavier payloads ─ up to an extra two tonnes or more depending on the vehicle.

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The main problem with hydrogen fuel remains with its production. Most hydrogen produced currently is generated using methane from natural gas, producing about ten times more carbon dioxide than hydrogen.

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And while greener methods of hydrogen production are available, they generally come at a higher cost ─ though predictions do suggest that prices will fall to more competitive levels within the next decade or so.

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?? Refuelling and recharging

Another hot area for debate is refuelling. FCEVs take only around three to five minutes to refuel, meaning lorries can get straight back onto the road with minimal downtime.

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In contrast, BEVs can take anywhere between 30 minutes to ten hours to recharge, depending on the voltage of the charger and the battery size. Rapid chargers operating at a higher voltage can give access to much faster recharging times, but they will still not be as quick as FCEVs to refuel.

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?? Preserving battery life

In response to these issues, manufacturers should be looking for ways to ensure that their HGVs can get the maximum value out of their fuel.

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One of the ways this can be achieved is through regenerative braking. This technology allows the excess kinetic energy generated by braking to be put back into the battery rather than wasted.

But what happens when the battery is already full? Excess electricity can lead to component damage, overheating and even brake failure in extreme cases.

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To dissipate the excess electricity safely and prevent this from happening, a dynamic braking resistor, or DBR, can be used. Choosing a lightweight DBR like Cressall’s EV2 helps to reduce the overall weight of the HGV, maximising its payloads while improving its fuel efficiency.

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There’s still a long way to go to providing cost-effective and sustainable fuel for heavy vehicles, but boosting battery life can go a long way in meeting overall demand. By implementing technologies like regenerative braking, even the largest of road vehicles can benefit from cleaner, greener fuel.

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You can learn more about Cressall’s range of DBRs on our website, or get in touch with a member of the team on +44 (0) 116 273 3633.?