On 13/06/2020 9:07 am, Tom Worthington wrote: > On 12/6/20 11:50 am, Stephen Rothwell wrote: > >> ... recharging is possible (most of the time) in a >> few hours even from a 10A 240V circuit. ... > > That assumes you have a parking space with mains power. If you park on the > street, > or in an complex with allocated parking, there may not be power to charge > from.
Sure - In which case, an EV may not be useful to you. But for a majority of people living in urban areas, who do park their vehicle somewhere with access to a power point, and do the majority of their trips <300km/day, an EV would be useful, That is a very large proportion of the population. A particular solution or technology need not be able to be taken up by every single individual, to be useful to many/most. To bring it back on topic regarding chargers, rather than EVs - Liquid fuel stations work because the dwell-time for pulling in, filling up, and leaving is very short - 5 minutes or so. With 6 - 9 pumps or so, an average suburban fuel station can service a large stream of cars - say ~1.5/minute, or 100/hour (possibly gated by the departure rate pulling back on to the main road) - queuing theory and Ehrlang measures apply. Generally, you can pull in to the next one, and be assured you won't have to queue behind more than one or two others waiting for each lane at most, and you'll be filled and out in under 10-15 minutes. The same rough dwell-time applies to the air-hose for tyres, generally only one bay available. An EV charger needs at least 30 mins to several hours to accept a meaningful charge, depending on the charge rate accepted by the EV. To service a reasonable number of vehicles, and to have a reasonable expectation when you pull into a service station that there will be at least one charging bay available, the service station would need to have a very much larger number of charging bays than fuel pumps - and physical real-estate to have all those cars parked, and able to safely move past each other to arrive and leave. Again, queuing theory calculations can apply. Very few service-stations have that required surface area on their aprons to serve enough cars per hour to make it worthwhile. Don't get me wrong - the more charging stations the better. But for many reasons, current fuel-stations are not useful locations for them. P. _______________________________________________ Link mailing list [email protected] http://mailman.anu.edu.au/mailman/listinfo/link
