johnrhansen wrote:I don't get what's wrong with good old gasoline. It's simple, it's cheap, and even if you use a range extender powered by it once in awhile, you still are emitting far less carbon than you would be by having to rent a gas car .
Not true, you are better renting an efficient gas car or even better a hybrid, either choice will be more economical in fuel consumption.
I don't think that would be true. A properly designed generator gets to run at a set RPM constantly and therefore should be more effecient than any gas car, or even a hybrid that has to run through the rev range at various loads and sacrafice a lot of efficency for smooth and quiet operation. In an interview I read with a volt engineer they said they could have improved fuel economy while running on gas by holding a higher rpm but the noise and vibration was deemed to be unacceptable. If you run the generator putting out a higher output than required to simply move the car then the rest goes into the battery and eventually you will reach full charge and run without gas again. In any rental car eventually you will stop, idle, and have 0% efficency. Even with stop start there will be times when you just start, or are coasting down and have 1% efficency. A generator will never dip below a certain efficency and get down close to 0% unless something is wrong.
If the generator is in a trailer noise and vibration are a non issue, if the generator is a turbine or rottary noise and vibration can be cut down a lot and can be placed inside a car. The problem with placing it inside the car is the extra cost in packaging space and weight to lug it around when you never need it. Plus you then have to buy it up front instead of paying a rental fee to use it when you know you'll need it.
And for this purpose nothing is wrong with good old gasoline. Since I doubt we will ever see the commercial industry on 100% electric there will always be cheap liquid or gas fuel available to us be it gasoline, diesel, hydrogen, propane or natural gas.
To get back to the original post I think that if the tow truck industry switched over to hybrid trucks there may an option to set up DC to DC fast charging from the tow truck. It would be much safer to just pull over at the side of the road, hook up a chamedo/frankenplug and give you a fast charge than it would to tow to charge. With the time it takes just to hook up a tow truck to charge while pulling you could get a good enough charge from running the tow truck engine as a generator.