What Really is Holding Back Plug-In Hybrid Electric Vehicles

[Michael Redman]

I don't know if this belongs in a new thread, but what about ditching the batteries and powering more vehicles with overhead or hot rail supplied power, like trains, trolleys, and buses do in many places? Anyone know about the efficiency of this type system?

 

[technoextreme]

I don't know if this belongs in a new thread, but what about ditching the batteries and powering more vehicles with overhead or hot rail supplied power, like trains, trolleys, and buses do in many places? Anyone know about the efficiency of this type system?

That is impossible from a logistical standpoint. Wires hanging would be impossible to place everwhere. You can't have hot rails on the ground where people have to walk.

 

[luchog]

So you plug it in to recharge off of cheap electricity, (really cheap if you are living in France), if you don't drive more than 100K you don't need to buy gas, and if the power goes out, you run your house off of your car.

And if you don't get cheap electricity? In the US, there would not be a significant enough cost savings, since the electricity is costly enough, and the storage inefficient enough, to erode the difference between an all-petrol fuel engine, and a plug-in hybrid.

Add to that that the off-peak electricity is as cheap as it is specifically because it is just that, off-peak. If there was a wide uptake of plug-in hybrids, with the overwhelming majority of charging done during what are currently off-peak times, electricity-use curves would flatten due to the increase in demand resulting in a dramatic reduction in off-peak surplus electricity. The price curve would similarly flatten, increasing the cost of the electricity used to charge the batteries, reducing the operating cost differential between hybrid and traditional IC vehicles.

I can see Oil Executives pulling out their hair, (if they have any), because even the most die hard scoffer can see what this would lead to.

There are no "Oil companies" anymore. There are Energy companies, diversified organizations which include Oil as one of their main, but not sole, products. They are also the biggest investors in alternate energy sources.

This was possible in 1975, actually, it was done in 1975. Is it any wonder the gas and oil companies didn't jump on that bandwagon?

If it ws possible, it would have been done. Why was there no consumer demand for it? Cost. It was economically unfeasible with 1975 technology.

What really is holding back a plug-in hybrid car? It certainly isn't technology.

No, it's cost and convenience. That's why, despite the availability of hybrids, there has been very little uptake.

There is still no strong indication that this is anything other than a dead-end, or at best supplemental, technology.

So far the best bet for the future is biofuels. A biofuel hybrid is probably the most likely scenario once battery technology improves sufficiently.

Fuel cell tech is stalled until someone manages to devise a way to 1) generate hydrogen in commercially viable, positive-net quantities without relying on fossil fuels (commercial hydrogen is currently derived from cracking natural gas); and 2) overcome the considerable storage and transportation hazards for the hydrogen, while retaining sufficient convenience for consumer application.

 

[qayak]

And if you don't get cheap electricity? In the US, there would not be a significant enough cost savings, since the electricity is costly enough, and the storage inefficient enough, to erode the difference between an all-petrol fuel engine, and a plug-in hybrid.

Plus, a plug-in hybrid is dirtier than a traditional vehicle. In the US 65% of electricity comes from coal fired generators. With everyone charging plug-ins overnight, they will need to significantly increase the amout of coal burned.

No savings and more damage to the environment . . . that's an improvement.

 

[tracer]

Another problem limiting Electric cars is the Patents are being bought and then not used. Electric car technology has been around since the early 90's. Why is it only now that there starting to make a comeback?

They've been around longer than that. In 3rd Grade, I remember reading an article in the My Weekly Reader about a guy who was driving an electric car with a top speed of 50 miles per hour. It looked about the same as a normal car of the time ... which was early 1973.

Incidentally, the reasoning for wanting an electric car in early 1973 wasn't because it didn't use petroleum products, but because it was quieter than internal combustion engine powered cars.

 

[Ziggurat]

I don't know if this belongs in a new thread, but what about ditching the batteries and powering more vehicles with overhead or hot rail supplied power, like trains, trolleys, and buses do in many places? Anyone know about the efficiency of this type system?

Buses are the only comparable system, but it wouldn't work, regardless of the efficiency. It's only cost-effective to run the lines in dense urban settings, which means cars running on these power lines are useless outside the network. Furthermore, attaching from the car to the power lines would be a serious problem. The connections on the top of a bus are out of reach, but that's not true on a car, so what happens if a kid climbs on top of your car? And you can't make a car that can run on or off the network either: the last thing you want is consumers trying to connect and disconnect their cars to high-voltage power lines that could kill them if they screw up.

 

[Michael Redman]

Buses are the only comparable system, but it wouldn't work, regardless of the efficiency. It's only cost-effective to run the lines in dense urban settings, which means cars running on these power lines are useless outside the network. Furthermore, attaching from the car to the power lines would be a serious problem. The connections on the top of a bus are out of reach, but that's not true on a car, so what happens if a kid climbs on top of your car? And you can't make a car that can run on or off the network either: the last thing you want is consumers trying to connect and disconnect their cars to high-voltage power lines that could kill them if they screw up.

Much of the commuting done in the US is on limited access freeways, where pedestrians are not allowed anyway. The additional danger of electricity would not add much to the danger of getting run over by vehicles.

Trains seem to have no problem running on electricity when available, and switching to diesel when needed. Engineers don't get out of the train to connect and disconnect the power lines. A system of supplied power, either overhead, or more likely from below, that functions automatically and safely, is certainly not beyond our technical ability.

A great deal of fuel is wasted in traffic congestion on American freeways during rush hours, and much of urban smog is a result. Electrifying just the freeways leading into cities would make a big difference. The question is whether it would make enough of a difference to be worth the cost of enhancing the grid and building the infrastructure.

 

[Cuddles]

The connections on the top of a bus are out of reach, but that's not true on a car, so what happens if a kid climbs on top of your car?

And how would roofracks work?

 

[Ziggurat]

Much of the commuting done in the US is on limited access freeways, where pedestrians are not allowed anyway. The additional danger of electricity would not add much to the danger of getting run over by vehicles.

Much, but not all. People aren't interested in buying two cars when one will do (and why should they?). And if you need to go from off a network to on a network, how will the connection and disconnection be handled? Those overhead bus wires don't connect automatically.

Trains seem to have no problem running on electricity when available, and switching to diesel when needed.

Trains opperate on fixed tracks. You know exactly where a train is going to be, you can spend a lot of money on the track itself because it's not a very extensive network, and you can wire near the ground. You can't run high-voltage electrical connects near the ground on a freeway. You'll notice that electric trains use a third rail, to the side of the track, which is slightly elevated and covered to protect it from rain. The train cannot cross over this third rail, if the rail needs to be on the other side of the train, then a new rail starts on the other side of the train and the old rail stops. You can't do the same thing with a car on a multi-lane freeway.

In short, it's an entirely different problem, and the solutions for trains will not work with cars.

A great deal of fuel is wasted in traffic congestion on American freeways during rush hours, and much of urban smog is a result.

Sure. Wider roads would help considerably.

Electrifying just the freeways leading into cities would make a big difference.

But you can't do that. You can't lay the electric lines into the road itself (it'll short every time it rains), and you can't elevate them because then cars can't change lanes.

 

[Michael Redman]

Much, but not all. People aren't interested in buying two cars when one will do (and why should they?).

Who said anything about separate cars?

And if you need to go from off a network to on a network, how will the connection and disconnection be handled? Those overhead bus wires don't connect automatically.

Have you ever watched trains connect and disconnect from overhead wires on the fly? Sure, a solution would have to be more complex for vehicles that aren't set on tracks, but so what? Are we out of engineers?

Trains opperate on fixed tracks.

Freeways are fixed tracks.

You know exactly where a train is going to be, you can spend a lot of money on the track itself because it's not a very extensive network, and you can wire near the ground. You can't run high-voltage electrical connects near the ground on a freeway. You'll notice that electric trains use a third rail, to the side of the track, which is slightly elevated and covered to protect it from rain. The train cannot cross over this third rail, if the rail needs to be on the other side of the train, then a new rail starts on the other side of the train and the old rail stops. You can't do the same thing with a car on a multi-lane freeway...

In short, it's an entirely different problem, and the solutions for trains will not work with cars.

Obviously. I didn't suggest we could incorporate current technology wholesale. So we would have to employ some engineers and designers to solve some of these problems. That's how progress happens.

Sure. Wider roads would help considerably.

And they have the added bonus of destroying parts of the city, thereby reducing density.

But you can't do that. You can't lay the electric lines into the road itself (it'll short every time it rains), and you can't elevate them because then cars can't change lanes.

Here's one idea off the top of my head: Only the inside lane has electricity, and you do it like a third rail.

Here's another idea: electric conductors are inside grooves cut into the road. A computer controlled probe could track the grove against the vehicle's movement and keep it in contact with the conductor. The computer could lift the probe when you change lanes and reinsert into the next lane's groove.

Getting actual experts working on the problem (rather than just saying it can't be done because there isn't currently a working solution) would likely lead to better, and perhaps unpredictable solutions to these issues.

The real question not whether it is possible, but whether there will be benefit enough to outweigh the cost.

 

[Ziggurat]

Who said anything about separate cars?

Lots of people, if not you specifically. The point being, the car needs to be gas-powered, even if it's capable of running off of an electric grid. So for any scheme to work, it's got to be evolutionary, it's got to be backwards compatible, it's got to provide advantages when implemented on a small scale, and it has to provide significant advantages over conventional hybrids to justify the costs.

Have you ever watched trains connect and disconnect from overhead wires on the fly? Sure, a solution would have to be more complex for vehicles that aren't set on tracks, but so what?

But so what? That's not a trivial difference, it's critical. I don't think what you're proposing can be done for cars at an affordable price.

Freeways are fixed tracks.

No, they aren't. Cars can zoom all over them, and across lanes at will. You cannot count on a car being in a particular location on a freeway. You can with a train. That difference is not trivial.

Here's one idea off the top of my head: Only the inside lane has electricity, and you do it like a third rail.

Again, we're not dealing with fixed track, which means cars can and will crash into the sides, with some regularity. It's not acceptable to have cars crashing into your high-voltage third rail, but you can't prevent it.

Here's another idea: electric conductors are inside grooves cut into the road. A computer controlled probe could track the grove against the vehicle's movement and keep it in contact with the conductor. The computer could lift the probe when you change lanes and reinsert into the next lane's groove.

Putting it under the road won't prevent it from shorting in the rain. What it will do, though, is create an opportunity for serious maintenance problems (for both the road and for cars) as soon as pebbles start to fall in the groove. If that groove gets clogged up from depris, what do you think happens to the car's probe when it hits at 70 mph?