Huh? Heating and cooling your home isn’t doing useful work?
This makes no sense. Do you think that heating or cooling your home doesn’t require energy? Geothermal doesn’t work because ‘it’s a more efficient exchange medium than the air’ - it works because it’s a different temperature than the air. The air is heating or cooling your home. It takes energy to counteract this. Since the ground is at a temperature closer to what you want, you run water through it and extract the energy resulting from the temperature differential and use that to heat or cool your home. Energy is energy.
I have no idea what your point is now. Electric vehicles aren’t desirable because they are cheap to drive, they are desirable because you can run them without burning fossil fuels and without giving off emissions. The point about plug-in hybrids is that they do this nearly as well for a fraction of the cost and without having to change the infrastructure. And OF COURSE if gas were dirt cheap there would be no market for these. But gas isn’t dirt cheap, and therefore people will switch to them out of self-interest because it will save them money.
I can’t imagine how heat and air conditioning would work on an electric car. Seems like a decent air conditioner would seriously undermine your range.
That is a serious concern in a place like Atlanta, where the temperature is set on broil by mid-July.
For that matter, I would think heat would suck a lot of power on an electric car, since you don’t get to “cheat” by borrowing the heat created by an internal combustion engine.
I notice that the Tesla has heat and A/C (judging from the dials in the cockpit) but I can’t imagine that the performance would be very good.
What about all this talk about hot rocks? Current geothermal installations are in areas where underground water is naturally turned to steam by geological processes and is currently only viable in areas you mentioned. However, there is research underway to drill deep holes and pump water down into them, and convert that to steam. Similarly, I believe some people are looking into using fluids with lower boiling points than water so that the holes don’t have to be as deep and also using existing oil wells that are played out. The downside is that this can apparently cause earthquakes.
One question I have about PHEVs: If they achieve mass-market acceptance, could they ever have a total cost of ownership equivalent to what, say, my '98 Chevy Prizm had at 1998 gas prices? IOW, will transportation costs ever get back to where they were or is the idea to keep them from getting a lot worse. You can assume some sort of biofuel, too, but let’s factor out subsidies for the moment.
I also want to know if it would be practical to run a generator off the exhaust of the gas engine of a hybrid. I understand that there is a lot of energy there, or at least enough to run a turbocharger.
That’s the kind of thing I came here to talk about. What about the stereo and headlights? My big “what ifs” about cars like the Volt are not only those questions about heating and air conditioning, lighting and sound systems, but;
How does the battery hold up under adverse weather and temperature? Is it as efficient and stable at 110 degrees as it is at the -40 we have here in Minnesota a couple of times a year?
Oh sure, “40 mile range” under optimum conditions. But what about when it’s dark and 40 below zero? What about when it’s 110 in the shade? How far am I going to be able to get and how comfortable am I going to be trying to get there?
All of that stuff consumes power, but not as much as you’d think, compared to the amount of energy required to move the car.
The Chevy Volt has a 16 kWh battery, of which 8 kWh is usable (you don’t want to run the battery dead or you’ll lower its lifespan). You could run a 500W heater off that for 16 hours. HiD headlamps consume about 35 watts each. Toss in another 100W for your stereo, and let’s say 25 watts for all the peanut bulbs, tail lamps, etc. Call it 200W for all the accessories plus heater. (I’m actually not sure how much power things like the computers in the car would use, so feel free to bump this number up a bit).
Now, the Volt can go 40 miles on those 8 kWh, or about 200Wh per mile. So it looks to me like running all those accessories for an hour would cut about 3-4 miles off your range. So if you’re going 20 mph, your range would drop from 40 miles to maybe 30-35, depending on what’s running.
I’m more worried about extremely low temperatures, like we get here in Canada half the year. Not only would you have to run the heater, but the batteries will lose efficiency, lubricants will be sludgy causing more drivetrain losses, there’s more rolling friction through snow, etc. I wouldn’t be surprised if the Volt lost more than half its range under those conditions. Even so, a 20 miles range would get me to work and back without using a drop of gas. So a Volt or something like it willl definitely be on my shopping list when it comes time to retire the Ford Escape I have now.
Running pipes underground to use the Earth as a heat resevoir is a practical idea, but I’m not sure it’s technically geothermal. And no matter what you call it, it’s not going to help recharge the batteries in your car (or crack hydrogen for fuel cells, or whatever), which was the question at hand. And I’ve heard ideas about deep geothermal for some time now, but that’s all they ever seem to be: Ideas. I haven’t heard that anyone’s making any real progress with it.
If it were practical, they’d be doing it already. The smaller the temperature differences get, the less efficient an engine you can run off of it, and the fumes going out your tailpipe are a heck of a lot closer to ambient temperature than they are inside the cylinder.
Sure it is. If you heat and cool your home by using the earth as a heat reservoir, that’s energy you’re not buying from the power or gas company that you can use to power your vehicle. According to the Manitoba Gov’t, geothermal heating of homes in that province has saved as much energy as taking 10,000 cars off the road. That seems a little extreme to me, but that’s what they say. Anyway, another way of looking at it would be to say that using geothermal heat has diverted enough energy to power 10,000 hybrid vehicles. And that means the infrastructure doesn’t get stressed, either. Total consumption consumption is lower by 10,000 vehicles. Exactly the same as if the energy had come from hot geothermal.
And that’s why it’s currently only practical for small heating applications like private homes. The thermal gradient is shallow, and so you need to use it in a highly efficient way, and you need a relatively large amount of underground surface area to extract enough energy. But there’s no doubt that this technology is entering the marketplace in very rapid fashion. With oil at $100/bbl, it makes good economic sense for many people. It’s an increasingly common option offered by homebuilders.
Well, I will buy they’d be doing it if were practical, but while the fumes going out the tailpipe may be much cooler, the fumes coming out of the exhaust port are pretty hot. Aren’t turbochargers attached very near the exhaust port?
“Harnessing energy” for “useful work” implies being able to gather energy and distributing it to where you want it for the purpose that you want it. Bona fide geothermal power, for example, uses the Earth’s heat to generate electricity to be used anywhere for anything. Geothermal HVAC doesn’t do this. It’s not powered by the Earth’s heat. It’s merely a run of the mill heat pump that is made more efficient by the difference in temperature between the earth and the atmosphere, i.e., I works precisely because it’s a more efficient exchange medium than the air. Consider any old regular heat pump – are you going to say that it’s harnessing atmospheric energy? Perhaps you don’t realize that for a regular heat pump (including an AC only-unit), the exchange medium is the air?
So which is it? Are they desirable because you don’t need fossil fuels, or out of self-interest because it will save them money? The sole attraction as far as the teeming masses are concerned is that it will save them money. No one cares about fossil fuels per se. Look, my point is dirt simple, all CO2 politics and fossil fuels aside: if you advertise that a car will get 200 mpg, it damned well better have the operating costs of a car that gets 200 mpg, otherwise you’re being deceptive. But a plug-in hybrid will never, ever get 200 mpg. When operating with then engine, it will get essentially what they get today, 30 to 70 mpg. You’re not getting better mpg because you plug in; you’re just using energy from a different source, energy that has to be paid for. You’ve got to describe what that energy use is, and mpg is a useless figure for such.
We don’t have the grid to handle a lot of people using electic cars, do we? Seems like we have problems meeting electricity demands on hot days in the summer. Wouldn’t masses of people plugging their cars in for recharging result in blackouts?
WA idea but wouldn’t they be able to make say the roof of the car a solar panel and while you’re car is parked at work or home it’s charging the battery? Not foolproof but something.
Folks would generally charge their cars at night. In fact plug-in hybriods represent a distributed storage technology that allows folks to charge their cars at night, when energy use and costs are low and then plug their cars into the system to use that energy on the grid during the premium daylight hours.
At 100% efficiency, there’s only about 1kW / square meter of solar power available at the earth’s surface. Current panel efficiency is around 20%, so if the Chevy Volt takes 200Wh/mile then 6 hours of sunlight will give you 6 miles of charge (for a 1 sq. meter roof area, which seems about right).
The majority of our electricity is produced by burning fossil fuels such as oil and coal. So when using electicity you are burning some “gas”. This has to be taken into the equation. It might be true that eletrical plants don’t burn gasoline directly, but they do burn polluting fossil fuels.
Using a heat exchanger buried in the ground /= “geothermal”.
It’s two completely different sources of energy. What you’re talking about is powered by the sun (more specifically, the resulting temperature differential between the sun and the insulated ground)
True geothermal is powered by gravitational energy from the earth’s interior (and the resulting temperature differential between that and the surface) if your HVAC system was using a hot springs, geyser, or magma vent, THAT would be geothermal. Otherwise, no.
Well, that’s because you’re in San Diego, CA. Here in Minnesota, they are fairly common in parking areas. (But used for engine tank heaters in winter.) Many apartment complexes offer a parking spot with an electric outlet (for a higher rent, of course). Some hotels also offer this. I worked at a company where the executive parking spaces were wired with outlets. I’ve even heard of some downtown parking garages that are considering coin-operated timer controlled outlets in some spaces.
It would just shift to other businesses – smart ones would adapt. Sit-down restaurants and movie theatres might offer this service. It could be an additional option offered at the beauty parlor. Shopping mall parking spots might be equipped to offer recharges for a small fee while you are shopping. Any business where you are likely to spend a longer time could see this as an opportunity.
That’s a quality control problem, not an obstacle specific to electric vehicles. It’s no different than getting a defective gasoline engine that breaks down in the middle of nowhere, or getting tainted gasoline that causes your car to break down in the middle of nowhere.
Well, the latter example is better than the former example, but what are the chances of getting bad gas that causes more than a little knocking? You would need to get the defect rate of the ultracap down to that level over the course of its rated life. Also, how many charged caps would the average station have to keep on hand? What would keep attendants from giving you an old one claiming that rated life is a bunch of bullshit perpetrated by overcautious engineers? One thing I don’t know is how many single points of failure an ultracap would have, and of course until they commercialize a design, no one else will either.
BTW, I think ultracaps are cool, but I don’t think they will make all electric vehicles practical unless someone comes up with solutions to the above problems.
Or, you could just instead of single big one put three smaller semi-independent batteries in your car. Critical failure of one of them would just mean that you get red control light lit and could continue happily along your way, keeping in mind that you should visit workshop soon.
Market forces. Supply and demand. As much, as needed.
Built-in chip in every ultracap containing log of whole history of that piece and hardwired limits into vehicle. They can do it with laser printers, why wouldn’t they do it with cars? You put ultracap into your vehicle, you get reading on the display “produced at that-and-that date, loaded that-and-that many times” and then your vehicle computer chimes in with “Battery had more loading cycles than advised. Using it would void your car warranty. Would you like to continue? Yes/No”.
Here, I came with solution to your problems. Does that mean that electric vehicles are practical now?
