Royal Mail considered shifting its fleet of small vans in London to electric vehicles but concluded that doing so would lead to a power meltdown at its central hub in the capital.

Speaking at a Parliamentary hearing about electric vehicles, Andrew Benfield, group director of transport at the non-profit Energy Saving Trust, revealed Royal Mail contemplated switching all its petrol guzzlers to an available electric alternative.

"Assuming they could get them from the manufacturer – which is another problem – they [worked out it] would melt the substation at Mount Pleasant in London where they are based, because there isn't the power available to charge the vehicles that they would need to run."

Last year Royal Mail began trials in London of nine electric vans with ranges of up to 100 miles, produced by Oxfordshire-based car maker Arrival. It had also ordered another batch of 100 electric vans from Peugeot.

The company's fleet is made up of roughly 49,000 vehicles.

Given the concerns around power capacity, The Register asked Royal Mail when it would in fact be feasible to shift its entire fleet, but did not receive a response.

During the hearing, MPs heard that a number of factors are preventing the uptake of electric vehicles, including lack of charging methods and not enough range of vehicles (only 80 are predicted to be on the market by 2025).

Other factors included the expense – Tesla's entry-level Model 3 vehicle is $35,000 (£28,500) and there's no second-hand market. All these issues mean the electric car won't become "a thing" for some time.

However, the government is keen to boost the sector, unveiling a £400m charging infrastructure fund in the last Budget, along with an extra £100m in plug-in-car grants, and £40m in charging R&D. ®