Fast E.V. Charging.

A significant infrastructure rethink will be needed to meet the current targets using electric lorries  - as is obvious from looking at the same consideration the other way - the rate of delivery of chemical potential energy at a conventional  fuel station at a motorway services compares with a small power station. (assume the calorific value of diesel or petrol is 45 Mega joules per litre,and then ask how many seconds to pump a litre of fuel, and how many pumps are running.)  There is an advantage that electric vehicles convert less of their fuel into waste heat, but it is only a factor of 2 or 3, not tens or hundreds.

1. Charge the batteries away from the vehicle - i.e. filling stations just swap battery modules rather than charging the battery while the vehicle waits. Batteries could then be charged more slowly (usually better for battery chemistry, especially for full charges) and at a time more convenient for the national grid. If the battery module included charging circuitry - then it could have a standardized 230V or 400V a.c. interface regardless of battery chemistry and perhaps a bit of logic to oversee performance and communication with the vehicle and charging system. Battery fade then becomes the responsibility of the "fuel" supplier, rather than the vehicle owner. In time an automated system (I'm imagining something between a car-wash and a juke box) could replace several modules probably faster than a liquid fuel fill up.

• Or do like I'm told the Swiss have done - ban long distance goods movement by HGV and move the goods by rail instead. The power is then picked up direct from overhead cables and all this messing about with batteries is completely avoided.

A significant infrastructure rethink will be needed to meet the current targets using electric lorries  - as is obvious from looking at the same consideration the other way - the rate of delivery of chemical potential energy at a conventional  fuel station at a motorway services compares with a small power station. (assume the calorific value of diesel or petrol is 45 Mega joules per litre,and then ask how many seconds to pump a litre of fuel, and how many pumps are running.)  There is an advantage that electric vehicles convert less of their fuel into waste heat, but it is only a factor of 2 or 3, not tens or hundreds.

1. Charge the batteries away from the vehicle - i.e. filling stations just swap battery modules rather than charging the battery while the vehicle waits. Batteries could then be charged more slowly (usually better for battery chemistry, especially for full charges) and at a time more convenient for the national grid. If the battery module included charging circuitry - then it could have a standardized 230V or 400V a.c. interface regardless of battery chemistry and perhaps a bit of logic to oversee performance and communication with the vehicle and charging system. Battery fade then becomes the responsibility of the "fuel" supplier, rather than the vehicle owner. In time an automated system (I'm imagining something between a car-wash and a juke box) could replace several modules probably faster than a liquid fuel fill up.

• Or do like I'm told the Swiss have done - ban long distance goods movement by HGV and move the goods by rail instead. The power is then picked up direct from overhead cables and all this messing about with batteries is completely avoided.