Opinion: The problem with solar powered trucks

by Andrew Bell

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Automatic platooning and self-driving trucks are two of the most hotly anticipated next steps in mobile asset technology, with industry leaders such as Jens Bjoern Andersen claiming that we could see the latter on the road in as little as 5 – 10 years’ time. The highly ambitious prospect of solar powered “heavy-duty trucks and high passenger-density urban transport” was also recently proposed by Elon Musk in his much publicised ‘Master Plan, Part Deux’.

How realistic is this prospect of solar powered trucks given the current state of solar technology however? Indeed, the idea of trucks energised by light is an exciting one, eventually promising a cheap and environmentally friendly mobile asset solution. The difficult reality, however, is that light powered vehicles today tend to be lightweight, streamlined and fitted extensively with costly solar panels. Indeed, while the advantages associated with solar trucking would be vast, there are a series of underlying issues that would need to be addressed in order for this to be a serious industry proposition.

Firstly, the amount of time it takes to convert sunlight into a sufficient amount of energy to power an entire truck is substantial, meaning that a solar truck would not be able to drive and recharge at a sustainable rate when pushing a substantial load. This problem is compounded by the fact that access to sunshine is severely restricted in certain countries, with time of day and seasonality also playing their parts in restricting the amount of light energy available depending upon the time of day or year.  

Another one of the most pressing issues associated with the solar vehicle is energy storage. Battery technology is not yet advanced enough to store a sufficient amount of electrical energy relative to battery size, particularly on substantial journeys lasting several days. Indeed, limited battery capacity means that heavy trucks would need to either stop to recharge at electrical stop points or would need to switch between multiple batteries. Carrying multiple large batteries is also undesirable however as additional batteries would require trucks to carry extra weight, consuming yet more electricity to push along.

Solar panels are also still prohibitively expensive, running up to $100,000 for high grade solar cells, which would in turn require a large immediate investment on the part of logistics companies when purchasing new vehicles.

In any case, so far our light powered vehicles have been designed to transport little less than one or even a few people, not thousands of tonnes of cargo. Therefore until engineers are able to dramatically improve the pace at which solar power is converted into electric energy, advance the capacity of batteries and reduce the pricing of cells significantly, it seems the promising notion of solar powered trucks will stay a distant dream.