Quote:
Originally Posted by Phoenix'97
No, electricity is not free, unless you build a network of Tesla's Wardenclyffe Towers!
I am trying to figure out how to give my gasoline engine the constant electric assist that I would like for it to have, beyond the energy neutral task of stopping and then using the saved energy to move the car at the same momentum that it had prior to stopping.
If I am anal about fuel consumption, going pure battery pack and having to charge it up after driving is what I will need to do. So, how big of a battery pack would I need then if recharging is out of the question? There is no way to slowly charge the system with minimal fuel economy loss and hence the owner is responsible for charging the battery back up after the car is no longer in use?
There has to be a way to solve this problem or satisfy it enough to make it practical.
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The Wardenclyffe towers needed huge engines turning generators to make that electricity too.
The devices that captured the field essentially put a load onto the towers, which in turn loaded the generators. There's no such thing as a free lunch. The problem with these towers was that it was impossible to make people pay for the energy they were using, so the cost of running the tower fell entirely on someone else.
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You have a limited number of places to take energy from to propel your car down the road, and all of it has to come from outside of your car. Either you put more gasoline in it (lower gas mileage, fill up more often) or you have a battery pack, which is effectively a second gas tank. You can choose to fill your battery pack from your gasoline tank, but you're not helping by doing that.
There are two kinds of hybrids that work:
1) Non plug-in hybrids, like the Prius and Insight. These have systems that basically only capture energy lost when you slow down, and use it to accelerate you again. With this in place, a gen4 Prius can get more than 50mpg city, whereas an equivalent car without the system would probably only get about 30mpg city. Don't underestimate how much energy is needed to accelerate the entire mass of your car.
These cars have lithium batteries which could fit inside a lunchbox, because they really only need to store enough energy for a couple of "launches", usually between 0.8kwh and 1.5kwh.
2) Plug-in hybrids, which have large packs designed to continuously provide assist (or even entirely electric propulsion) for many miles and hours at a time. Depending on how large your portion of electricity you use, your gas mileage can actually be infinite - if you never start the gas engine. Battery packs for these vary; the Chevy Volt's is about 19kwh and the size of a large suitcase. It's capable of pushing the car down the highway at highway speeds entirely on its own for over 50 miles. The Prius Prime has a ~9kwh battery capable of about 25 miles. Both of these cars also capture energy when you slow down, but their programming is designed so that they're assisting basically all the time, and you really only need to start the gas engine if you want to drive past what the battery's range is.
EDIT: I would like to stress that with both systems, you get the added acceleration of the electric motors. The plug-in just uses electricity longer, and displaces more of the gasoline you have to burn.