"Our case is based on science, while the opposition is based on political philosophy. When a nation whose welfare is highly dependent on technology makes vital technological decisions on the basis of political philosophy rather than on the basis of science, it is in mortal danger."— Bernard L. Cohen
Using Pierre's numbers, 1 gallon of diesel equals 10kWh, so the overnight charge would be 7kWh equals about three quarts.The EIA says a gallon of diesel is 137452 BTU, or just over 40 kWH(th). Converted to work in your typical light-duty engine you might get 16 kWh out of it. Your usual "convenience cord" is capable of 1440 W (120 VAC @ 12 A) so a 7-hour charge can yield as much as 10 kWh from a standard wall outlet. PHEV batteries have widely varying capacities; the Prius+ has just 4.4 kWh, the Ford Energi models started out at 7.6 kWh and are going up to 9 kWh next year, and the Pacifica plug-in has 16 kWh. These figures correspond to just over a quart, just under half a gallon and a gallon, respectively.
you spend 18 hours charging to get energy equivalent to roughly 1.2 gallons of diesel per day.If you had a Chrysler Pacifica charging off a standard wall outlet for 18 hours a day, you'd get up to about 1.6 gallons-equivalent. Vehicles with smaller batteries would reach full charge and have to stop; the Fusion reaches full in about 5 hours from your garden-variety wall outlet and about 90 minutes on a Level 2 charger.
To compete with IC, you need to be able to drive hundreds of miles, with a heater blasting hot air, then fuel up in a few minutes and do it again. To get a 300 mile range, you need ten times that amount of energy, or more.You don't need to compete with IC to replace most of your fuel. Most trips are short trips, and engines are very inefficient when cold. If you electrify most or all of the short trips and eliminate most of the cold starts, you've eliminated most of the fuel consumption with it. If you delay the engine starts until the vehicle has left the city, you get rid of the pollution generated in the city. The engine also warms up faster if run under load, improving the efficiency.
Our existing grid is generally pretty heavily loaded.Back in 2004 it would have taken ~180 GW to replace all US gasoline and diesel with electricity. Average electric consumption last year was 458 GW but nameplate generating capacity was 1074 GW. Some of that is unreliable wind and PV and more is loaded-to-max nuclear and limited hydro, but finding 180 GW in that 616 GW difference wouldn't be all that hard. Ironically, it would probably be hardest in California which has lots of vehicles but not much electric demand anymore after chasing out so much industry.
Labels: The Energy Collective
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