meetis said:
I think one of the big assumptions of night time charging is that it will be a slower charge rate knowing that there is going to be 4 hours or more to charge the vehicle. Kind of like with the battery chargers for a car there are different charge rates for how fast you wish to charge the battery. The same could be done for a all electric car. Slower charge rates would have less of a impact on the grid Especially if the cars battery is not fully discharged needing only a partial charge.
You would make a
small dent in the impact by using more efficient (possibly?) slow charging, but if your system is designed and optimized for quick charging charging slow will likely not make an appreciable efficiency difference.
Neither quick nor slow charging addresses the impact of the increase in demand. With all those cars requiring electricity, demand will increase and the "cheap" night rates will likewise increase. You would see a kind of equalization between day and night time demands, with the heavy demands of manufacturing and climate control and other power-hungry applications during the day being balanced at night by the charging of the population's commuting vehicles.
Plugging the cars in during the day to "sell back" some of your unnecessary power would only serve to increase this homogenization of day and night demand, by allowing energy companies to run closer margins between constant power generation capacity and peak generation capacity. With the plants running at their constant capacity during the day to supply energy needs and the car batteries to supply the peak power loads throughout the day, the generation capacity will again be running at that same constant output during the night as it charges up all its various "mobile battery packs."
End result? No more cheap night rates, 'cause the generators are doing the same amount of work day and night.
Personally my idea for a all electric nation includes the idea of electric filling stations so to speak and a makeing things more standardized. We have a power distribution network nation wide all that would be needed would be a standard way to connect the high current lines and standardized charging system Then there would be no discussion about how far can the car go on 1 charge or where do you recharge. the answere would be at any filling station and it could be done in a manner to charge the car up in a very rapid manner if batteries or large capacitors were used at the stations for large amounts of current to flow.
You'd also need to upgrade the nation's electrical grid and generation capacity to handle the additional load and provide redundancy. Brownouts and even blackouts are common occurences in portions of the country, caused most frequently by the grid and generation capacity being overloaded and overdrawn, respectively.
With the electrical grid now supplying transportation energy, you'd need to engineer redundancy into the system to ensure that if one option goes down, you have other options to obtain your power. Redundancy exists in the present setup in that if one station runs out of gas or one distributor goes down, there are other distribution companies to supply that company's client stations with fuel, and there are other, competing fueling stations that can still supply fuel because their supply is not dependant on their neighbor's supply.
With "filling" stations all tied to the national electricity grid, a problem with the grid in an area would knock out
all of the stations tied to that grid. You couldn't go across the street to a competitor, they're tied to the same power plants and distribution grid. End result? You're SOL if a portion of the network gets overstressed, struck by lightning, hit by a terrorist attack, goes critical and melts down, whatever have you.