John in CR said:
An electric bike, even a high powered one like mine, uses so much less energy that it doesn't matter,
I just don't think you are right about that, hp-for-hp. What you have in effect is a hybrid, with the fossil-fueled engine at the the power plant. The best coal-fired steam turbine plant is about 50% efficient. You lose efficiency bringing the brown coal (not a very energy-dense fuel) to the plant, and then lose some more in the electrical generator and even more (about 10%) in the lines getting it from the plant to your house's plug. Then you lose more converting the voltage in your charger, and more again turning the charger's energy into battery charge. Then under optimum conditions you get 3/4 of the battery's charge out of the controller and motor if you have good ones.
Let's disregard the wasted energy moving coal to the power plant, since gas vehicles need their fuel transported too. And let's disregard transmission and tire losses, because those apply whether you're using ICE, electric, or muscle. And then let's take our best case numbers for the electric system-- let's assume you have a really good motor and controller that combine to deliver 75% efficiency, and that your charger and battery are both 90% efficient in the real world. And let's assume that your local utility is using a state-of-the-art steam turbine for power generation, and a state-of-the-art electrical generator and generator system that delivers 90% efficiency,
50% from the power plant's turbine X 90% from the power plant's generator X 90% from the power lines X 90% at the charger X 90% at the lithium ion battery X 75% from the bike's controller and motor = 24.6% total efficiency, or about the same as what you get from a good gasoline engine under favorable operating conditions. Only your bike is running on coal.
The way an electric vehicle becomes more efficient than its ICE equivalent is by using less power, as in less actual horsepower to the ground. And that means going slower than the ICE vehicle, because as I just demonstrated, horsepower for horsepower the electric does not improve on the efficiency of a good modern gasoline engine. Just like human power, the efficiency and small resource footprint of an electric vehicle is predicated on its low power and speed. Make an EV like a Tesla or the two-wheeled equivalent, and your pollution and resource depletion are going to be directly comparable to their ICE counterparts per kWh. Higher, if you figure in the energy sunk in manufacturing the batteries, which I know you don't like to do.
The beauty of an EV is that one with 1/2hp or 2hp works every bit as well as one that makes 100hp. Probably better, in fact. ICE engines give up thermodynamic efficiency as you scale them down, which is a technical disincentive to making really small ones. So the real efficiency promise of EVs is in making them smaller and slower than ICE vehicles, in a regime where ICE vehicles can't offer comparable performance per kWh and in which household-level power generation makes sense. Start making 20kW e-bikes and those advantages disappear.
Compared to a 20 kW e-bike, a 20kW gas bike is just about as efficient per calorie of fossil fuel, costs less to make and buy, and lasts much longer than the most expensive and energy-intensive part of the e-bike (the battery). A 1kW e-bike bests a 1kW gas bike in most ways, though. And in a real city, a 1kW e-bike gets you there in almost the same elapsed time as a 20kW bike, but with a small fraction of the power consumed.
Chalo