[Maxer]

Mihai, I have a question on how air conditioners effects the efficiency of and electric vehicle, I live in a very humid and hot climate, so air conditioning is a must.

[Peter Shupe]

It is possible! You just use more electricity, which will cost you more! Just like a car that runs on gas! More gas to run a car with air conditioning!

[Mihai]

Mihai, I have a question on how air conditioners effects the efficiency of and electric vehicle, I live in a very humid and hot climate, so air conditioning is a must.

There was this question and reply on the Tesla blog:

Andy Schulteis wrote:
“I have to ask, just what does 250 miles per charge mean when your sitting in a traffic jam, with the AC running, stereo blasting, and it’s night with the lights on? ”

The stereo and lights probably use a maximum of 150 watts. I’ll guess the AC uses 850 watts so I can get a round 1kw for everything you’ve listed. The battery holds 45kwh of energy. If you sat in trafic for, say, 2 hours, you’d only use 2kwh of energy, or about 5% of the battery capacity. You’ve only lost 12 miles of range. If it’s night, I’d imagine it wouldn’t usually be hot enough to require running the AC full blast, so you’d probably use less than 5% of the battery.

[Maxer]

That's good to know since sitting in traffic for 2 hours during the day isn't something that's out of the question here in Texas. Just curious but what would it cost to charge a car that drove let's say 1400 miles per month?

[Mihai]

Well for example, since the Tesla holds 45kWh of energy, which allows you to drive approximately 250 miles, find out how much you pay for 1kWh of electricity and you can figure out your monthly cost to drive 1400 miles. Even better you can charge it at night when electricity is cheaper.

[Thomas An.]

This is a very interesting technology indeed, but I imagine for it to catch on, it would require battery technology that can give at least 500miles per charge and 5-10min rapid recharge cycle (sort of a sweat spot of battery performance). Also, not everyone owns a house (and have a garage) ... so the people who live in apartments would need extension cords running across the sidewalks or something.

[Mihai]

If the car can run 500 miles on a charge, I don't see the need for very fast charging times. I mean you drive all day, and sleep while the car is charging. Also i think as with laptop batteries, you can have very quick 50% recharge time, but if you want to charge it 100%, you have to leave it a few hours.

For those without garages, I can imagine if hopefully we'll see more electric cars on the streets, the infrastructure needed to make electric charging stations in parking lots, supermarkets, work places for example is nothing compared to the infrastructure needed to make everybody use hydrogen.

Besides the car batteries can actually be recharged using a standard outlet, ofcourse then it would take longer, but for many people it would be sufficient. There's not many days in the week most people need to drive 250 miles. So even if it will take 5-6 hours to charge on a standard outlet, it's largely sufficient.

[Mihai]

Something else to add

How to get free electricity? Solar panels. A few years ago it was an option too expensive for most people but recently the prices have been dropping, and they will drop considerably with new technologies. For example Nanosolar is a company that in 2007 will build the worlds largest thin film solar panel factory in the US, with a price about 1/10th of silicon based panels.

In a few years we'll also see much more efficient panels, see here http://www.rosestreetlabs.com/RSL%20Energy.htm

They have licensed tech from Cornell and Berkeley to make panels more than 48% efficient, meaning half of the solar energy that falls on a given surface can be converted into electricity. Current panels are about 14-22% efficient. I read somewhere that enough solar energy falls on Earth every minute to cover the entire planets energy needs for a whole year!

So it's not at all impractical, even now, not in 10 years, to install solar panels on your roof, and you esentially have free fuel. These panels last for more than 30 years, and the whole system requires virtually no maintenance. No valves, no mechanical moving parts, no filters, fluid changes....

[andrebaros]

You can't turn your head for a minute without Google getting involved these days. They're going solar too.

http://www.eetimes.com/news/semi/showAr ... =193303166

[Peter Shupe]

It has to come down to the economy of scale! How expensive is a solar car now? How much is maintenance?

The 250 miles on 45 kWh of energy seems a little too good to be true. Here in Southern Ontario, Canada we pay about $0.06/kWh. So that would cost me about $2.70, which would cost me about $40.00 in my gas car. Even if it were 5x that expensive, for good heater, air conditioning, and a little more trunk space, it would be well worth it. There must be some pretty hefty cons to this that we are not aware??

Regards Peter.

[glebe digital]

So it's not at all impractical, even now, not in 10 years, to install solar panels on your roof, and you esentially have free fuel.

Something tells me our oil-economies are not going to like that.........how long until the technology is bought up by 'them' and hidden in a drawer somewhere.

[Maxer]

That is exactly what I was thinking, the oil and gas companies are going to fight any new technology that increases fuel economy or gets rid of gasoline all together. In America the average fuel economy of cars has gone from 20 MPG in the 1970's to 21 MPG in 2006. I find it hard to believe that since the 1970's they have only been able to increase the average fuel efficiency a little more than 1 MPG. Now that gas has become more expensive I believe this is going to change but it's very apparent that the auto makers and the oil companies are not very interested in making it cheaper for us to drive our cars, not to mention making it cleaner.

[Peter Shupe]

Look at all the electronics that cars have today. They have power everything. The engines themselves may be much more fuel efficient but how much power is consumed by all the power components? Doesn't hurt to have everything power so that there is more money in repairs when your seat heater, or power windows stop functioning.

Here in Canada the power is subsidized. Don't ask me why! It would make generation for alternative sources a lot more feasible if we paid the actual price of eletricity. We also don't pay less for power off peak times. We are just having "smart meters" phased in now over the next 5 - 10 years. And we are also supposed to be able to generate power and feed it back onto the grid. But you only get what you are being charged, and with subsidies I guess a lot of people wouldn't think it worth it.

[Mihai]

Not worth it to have free electricity for at least 25 years? I think many would find it interesting

You have to remember the return on investment is calculated on current prices for electricity, and even so a solar installation today pays for itself in 7-8 years. So for another 20-25 years, even more, you'll have free electricity. With new panels the return on investment drops below 5 years, in many cases as little as 2. But as we know, electricity today won't cost the same in 15 years from now, so your real savings are even better.

The situation for batteries has changed thanks to laptops, they require more and more power every year, so batteries have developed to keep up with them.

There's an interesting story about Nickel Cadmium batteries, the patents were bought by Chevron, and they wouldn't give licenses if you wanted to build one for car use...

But now it's not one company that makes Li-Ion batteries, it's many companies, and there are several types of Li-Ion batteries. Plus there's not only one tech with possibilities to improve batteries, there are several.

The 250 miles on 45 kWh of energy seems a little too good to be true. Here in Southern Ontario, Canada we pay about $0.06/kWh. So that would cost me about $2.70, which would cost me about $40.00 in my gas car. Even if it were 5x that expensive, for good heater, air conditioning, and a little more trunk space, it would be well worth it. There must be some pretty hefty cons to this that we are not aware??

I haven't even finished mentioning the rest of the pros
The "con" would be that governments and car manufacturers are pushing so hard for hydrogen, ethanol, biodiesel and all that stuff when every study shows an electric car is the most efficient. Hydrogen is without a doubt the dumbest idea of all. Ofcourse they don't want you to see that because then they wouldn't be able to sell you the fuel, and all the replacement parts needed for the engine and transmission. Everybody knows an honest mechanic is worth his weight in gold.

Several other pros for an electric car:

- while you're stuck in traffic and not moving, the car isn't consuming a lot of energy, it's only when you move the electric motor needs to spin. With a gasoline car you waste a lot of fuel being stuck in traffic for 2 hours.

- electric motors have great torque, from almost 0 rpm, unlike an ICE which reaches it's max torque value at pretty high rpms. What this means is you have great acceleration in an electric vehicle, at any speed. Tesla couldn't have shown it better, with an electric motor weighting about 45kg it accelerates their car faster than a Ferrari (0-100km in 4 seconds).

[michaelplogue]

Well, I've taken this even further. Having just moved back to Washington DC, with it's high taxes and expensive parking problem, I sold my car and got one of these:

http://www.nycewheels.com/go-ped-esr-750.html

I now have just a 15 minute commute to work (30 minutes by subway), and no longer have to pay for gas, tags, insurance, or parking ($250 a month at my apartment, not counting parking expenses near work). My little scooter paid for itself in just a couple of months.

I don't miss my car the least bit!