Darell! Seen this yet? :)
- Thread starter Tomas
- Start date
highlandsun
Enlightened
The latter. A 35W HID puts out about 2-3x as much light as a 65W halogen after it's started. Startup is heavy, but only takes a few seconds.
Darell
Flashaholic
[ QUOTE ]
highlandsun said:
Will be interesting to see the LiIon Tzero results. And as a technology car goes, I don't see them talking about HID headlights or LED signal lights. Shame on them.
[/ QUOTE ]
A. None of that is unique technology
B. Just 'cause they don't talk about it doesn't mean the car doesn't have it /ubbthreads/images/graemlins/wink.gif
highlandsun said:
Will be interesting to see the LiIon Tzero results. And as a technology car goes, I don't see them talking about HID headlights or LED signal lights. Shame on them.
[/ QUOTE ]
A. None of that is unique technology
B. Just 'cause they don't talk about it doesn't mean the car doesn't have it /ubbthreads/images/graemlins/wink.gif
highlandsun
Enlightened
Very little of what's in these cars is unique technology. The Tango is after all, mostly off the shelf parts. For an electric vehicle, where basically every watt counts (because every accessory you turn on is directly lowering your cruising range) it would seem to be a worthwhile point to mention... Now, as they've mentioned the use of waste heat and Peltiers for cabin heating, I wonder how much waste heat the drive system produces, and how much electricity can be generated from it? (Recalling the 1kW TEGs powered by the heat from a diesel truck's exhaust stack.)
I wouldn't mind building up a car like this from a kit for my next vehicle, it could be a fun project. Especially if I can replace some of the parts and tweak the physical design, add some PV film to the body panels and glass, etc. If you're gonna make a "statement" car, go all the way.
I wouldn't mind building up a car like this from a kit for my next vehicle, it could be a fun project. Especially if I can replace some of the parts and tweak the physical design, add some PV film to the body panels and glass, etc. If you're gonna make a "statement" car, go all the way.
brightnorm
Flashaholic
- Joined
- Oct 13, 2001
- Messages
- 9,027
Darell
Flashaholic
[ QUOTE ]
highlandsun said:
Very little of what's in these cars is unique technology. The Tango is after all, mostly off the shelf parts.
[/ QUOTE ]
Right. And the Tango is not being built as a technology car. But anyway... If you want unique, look no further than the EV1 and the Tzero. They are both comprised mostly of purpose-built pieces.
[ QUOTE ]
For an electric vehicle, where basically every watt counts (because every accessory you turn on is directly lowering your cruising range)
[/ QUOTE ]
Yes, every watt counts, but maybe not for as much as you'd expect. Having traditional headlights on for one hour of driving would reduce the range of the Rav4, at most, by about 3,000 feet (out of 65 miles). The AC is the biggest energy consumer after the traction, and it is certainly optimized. You get serious cooling for a measly 2-3 amps. For the heat side of the heat pump, all electronic waste heat is scavenged because it is an easy task - but it still amounts to VERY little.
[ QUOTE ]
I wonder how much waste heat the drive system produces
[/ QUOTE ]
Damn little. The extra weight and expense of capturing it would likely never pay off. Same with using PV to help boost charge. If you covered all horizontal areas with PV, it would literally take all day to generate a mile or two worth of charge. The extra weight and cost would severely offset any small advantage.
Kits would be fantastic, as these would be so much easier to build than a traditional ICE vehicle.
highlandsun said:
Very little of what's in these cars is unique technology. The Tango is after all, mostly off the shelf parts.
[/ QUOTE ]
Right. And the Tango is not being built as a technology car. But anyway... If you want unique, look no further than the EV1 and the Tzero. They are both comprised mostly of purpose-built pieces.
[ QUOTE ]
For an electric vehicle, where basically every watt counts (because every accessory you turn on is directly lowering your cruising range)
[/ QUOTE ]
Yes, every watt counts, but maybe not for as much as you'd expect. Having traditional headlights on for one hour of driving would reduce the range of the Rav4, at most, by about 3,000 feet (out of 65 miles). The AC is the biggest energy consumer after the traction, and it is certainly optimized. You get serious cooling for a measly 2-3 amps. For the heat side of the heat pump, all electronic waste heat is scavenged because it is an easy task - but it still amounts to VERY little.
[ QUOTE ]
I wonder how much waste heat the drive system produces
[/ QUOTE ]
Damn little. The extra weight and expense of capturing it would likely never pay off. Same with using PV to help boost charge. If you covered all horizontal areas with PV, it would literally take all day to generate a mile or two worth of charge. The extra weight and cost would severely offset any small advantage.
Kits would be fantastic, as these would be so much easier to build than a traditional ICE vehicle.
Darell
Flashaholic
The Tzero specs on the site are from test done on the first unit that was built. Each subsequent car has out-performed the previous one... and this next one will blow doors. Pretty nice *beginning* performance numbers, huh?
Tomas
Banned
Question, Darell, that I'm possibly too lazy to figure out for myself when you might have it off the top of your head.
Ny current motor vehicle usage burns between 8 and 12 gallons of gasoline a month in a vehicle that gets 21 MPG on a good day.
With PV/s on the roof of an EV the size and shape of, say, a Mini (probably 1 1/2 sq. yd of roof), do you think it just might be able to keep itself charged?
In other words, would a yard and a half of PV's be good for 200 miles a month in the norther temperate zone?
A vehicle like that would do me just fine. Nothing fancy, and a 60 mile range at one go would be just fine, etc. I'm not sure recovery time would always be OK, so there would have to be an auxiliary commercial power charge system no matter what. I guess what I'm asking is: For a low-use vehicle could it be at least "nearly solar powered."
Ny current motor vehicle usage burns between 8 and 12 gallons of gasoline a month in a vehicle that gets 21 MPG on a good day.
With PV/s on the roof of an EV the size and shape of, say, a Mini (probably 1 1/2 sq. yd of roof), do you think it just might be able to keep itself charged?
In other words, would a yard and a half of PV's be good for 200 miles a month in the norther temperate zone?
A vehicle like that would do me just fine. Nothing fancy, and a 60 mile range at one go would be just fine, etc. I'm not sure recovery time would always be OK, so there would have to be an auxiliary commercial power charge system no matter what. I guess what I'm asking is: For a low-use vehicle could it be at least "nearly solar powered."
Darell
Flashaholic
Well, my math typically sucks, but let me see what I can do.
Today's standard panels are, interestingly enough, about 1.4 sq yards, so let's call that the surface of a car. For that 1.4 sqyd, you'd be able to generate about 1kWh on a good day with a premium panel (assuming 5 hours at 200W). As a side note: My 20-panel array of 150W panels is generating more than 15kWh/day.
Let's say you burn 10 gallons at 20mpg. You travel ~200 miles per month, and you need to do it on 30x1kWh = 30kWh/month. The bad news is that at 3 miles/kWh (about what my EV1 does) we're only looking at being able to travel 90 miles/month. These are mostly best-case scenario numbers too. In the winter, you'd pretty much be able to drive to the end of your driveway and back. /ubbthreads/images/graemlins/smile.gif This ignores all the charging inefficiencies. Realistically, I think you'd be able to travel about 1 mile/day for a year-'round average. This is why nobody (beyond the extreme, non-road-worthy solar racers) has wanted to put PV on an electric car. Just doesn't make practical or economic sense.... yet. Who knows what sort of panels we'll have in ten years.
The City of Vacaville (who helped with my lease/purchase) has installed enough PV to power all of City hall, and 16 EV chargers. THAT's the way to do it.... it just takes a giant roof - the entire roof of city hall.
But this has me thinking that for all the golf carts running around Florida - this might make some sense. Build a big, ugly, flat sunshade up over the cart and install two full panels, and you'd never have to plug the things in (or worse - burn gas!).
I love questions like that... thanks for asking.
Today's standard panels are, interestingly enough, about 1.4 sq yards, so let's call that the surface of a car. For that 1.4 sqyd, you'd be able to generate about 1kWh on a good day with a premium panel (assuming 5 hours at 200W). As a side note: My 20-panel array of 150W panels is generating more than 15kWh/day.
Let's say you burn 10 gallons at 20mpg. You travel ~200 miles per month, and you need to do it on 30x1kWh = 30kWh/month. The bad news is that at 3 miles/kWh (about what my EV1 does) we're only looking at being able to travel 90 miles/month. These are mostly best-case scenario numbers too. In the winter, you'd pretty much be able to drive to the end of your driveway and back. /ubbthreads/images/graemlins/smile.gif This ignores all the charging inefficiencies. Realistically, I think you'd be able to travel about 1 mile/day for a year-'round average. This is why nobody (beyond the extreme, non-road-worthy solar racers) has wanted to put PV on an electric car. Just doesn't make practical or economic sense.... yet. Who knows what sort of panels we'll have in ten years.
The City of Vacaville (who helped with my lease/purchase) has installed enough PV to power all of City hall, and 16 EV chargers. THAT's the way to do it.... it just takes a giant roof - the entire roof of city hall.
But this has me thinking that for all the golf carts running around Florida - this might make some sense. Build a big, ugly, flat sunshade up over the cart and install two full panels, and you'd never have to plug the things in (or worse - burn gas!).
I love questions like that... thanks for asking.
highlandsun
Enlightened
The batteries on the Tango provide 300V at 55Ah so 16.5kWh of power and they spec the range as 80 miles. So, only .206kWh per mile. A 1kWh solar panel would thus add 5 miles/day to your range. Noticable, but not great.
Darell
Flashaholic
[ QUOTE ]
highlandsun said:
The batteries on the Tango provide 300V at 55Ah so 16.5kWh of power and they spec the range as 80 miles. So, only .206kWh per mile. A 1kWh solar panel would thus add 5 miles/day to your range. Noticable, but not great.
[/ QUOTE ]
.... BUT, the roof is probably smaller than the area we're talking about, and as I mentioned - I used all "best case" numbers. 1kWh generated by the panel will never put 1kWh into the batteries. Still, the Tango is quite the efficient little vehicle. Very little frontal area for one thing...
Of course, regardless of vehicle, these rosy numbers also assume full-sun days, and never parking indoors!
highlandsun said:
The batteries on the Tango provide 300V at 55Ah so 16.5kWh of power and they spec the range as 80 miles. So, only .206kWh per mile. A 1kWh solar panel would thus add 5 miles/day to your range. Noticable, but not great.
[/ QUOTE ]
.... BUT, the roof is probably smaller than the area we're talking about, and as I mentioned - I used all "best case" numbers. 1kWh generated by the panel will never put 1kWh into the batteries. Still, the Tango is quite the efficient little vehicle. Very little frontal area for one thing...
Of course, regardless of vehicle, these rosy numbers also assume full-sun days, and never parking indoors!
highlandsun
Enlightened
Well, in Southern California, you'd get a worthwhile percentage of full-sun days... I generally would park indoors 'cause otherwise the car interior gets unbearably hot. Would a car shrouded in PV panels convert enough solar energy into electricity to prevent the interior from baking?
Sorry, that just got me into my thermoelectrics searching again. Check this out...
http://www.darpa.mil/dso/trans/energy/briefings/18Steve.PDF
Sorry, that just got me into my thermoelectrics searching again. Check this out...
http://www.darpa.mil/dso/trans/energy/briefings/18Steve.PDF
Darell
Flashaholic
[ QUOTE ]
highlandsun said:
Well, in Southern California, you'd get a worthwhile percentage of full-sun days... I generally would park indoors 'cause otherwise the car interior gets unbearably hot.
[/ QUOTE ]
Yeah - there's the rub, alright! If it is sunny enough to generate electricity, nobody wants to park in the sun. /ubbthreads/images/graemlins/smile.gif
[ QUOTE ]
Would a car shrouded in PV panels convert enough solar energy into electricity to prevent the interior from baking?
[/ QUOTE ]
Only if you cover the windows! Seriously, most heat enters via the glass. Something else to consider is that solar panels get hotter than the roof they're installed on because they are specifically designed to absorb the very solar radiation that contains heat. The nice part about home roof mount, is that there is an air gap, so the net result is a cooler roof. But unless you wanted a REALLY wacky looking vehicle, you'd need to mount them directly to to the roof, and then you've back to baking...
The link is an interesting one. There sure are a lot of ways to make power without burning anything, huh? /ubbthreads/images/graemlins/grin.gif
highlandsun said:
Well, in Southern California, you'd get a worthwhile percentage of full-sun days... I generally would park indoors 'cause otherwise the car interior gets unbearably hot.
[/ QUOTE ]
Yeah - there's the rub, alright! If it is sunny enough to generate electricity, nobody wants to park in the sun. /ubbthreads/images/graemlins/smile.gif
[ QUOTE ]
Would a car shrouded in PV panels convert enough solar energy into electricity to prevent the interior from baking?
[/ QUOTE ]
Only if you cover the windows! Seriously, most heat enters via the glass. Something else to consider is that solar panels get hotter than the roof they're installed on because they are specifically designed to absorb the very solar radiation that contains heat. The nice part about home roof mount, is that there is an air gap, so the net result is a cooler roof. But unless you wanted a REALLY wacky looking vehicle, you'd need to mount them directly to to the roof, and then you've back to baking...
The link is an interesting one. There sure are a lot of ways to make power without burning anything, huh? /ubbthreads/images/graemlins/grin.gif
How about a non-visible air gap a'la Airbake. Maybe it would still bake though, a'la Airbake.
Maybe if the panel was decent enough it could run an interior fan, not the whole system, but a fan.
Since the sky is the limit on money why not make the windows out of that sandwiched LCD stuff. Clear when driving, fully tinted when parked.
Maybe if the panel was decent enough it could run an interior fan, not the whole system, but a fan.
Since the sky is the limit on money why not make the windows out of that sandwiched LCD stuff. Clear when driving, fully tinted when parked.
highlandsun
Enlightened
Yes, I understand that. But are you saying that a solar panel is less reflective than a roof? Because if not, then a roof would absorb all of that light and turn it into heat anyway. Given a solar panel with the same surface area as the roof, and thus receiving the same amount of light as would otherwise hit the roof, if its reflectivity is about the same or higher, then the energy that remains will result in a cooler surface overall because some percentage of the absorbed solar energy turned into electricity, not heat.
As I recall, one of the common problems with solar panels is that they're too reflective, and so I would expect less heat getting to the base overall.
Re: window glass - that's what Sanyo See-Thru Amorton is for. Get stylish-looking gray window tint and PV electricity generation all at the same time. Again, for a Technology Statement vehicle, go all the way.
Given that a car interior can hit 180F on a sunny day (ambient 95F), there's gotta be a way to turn all that waste heat into usable power and in so doing, keep things cooler overall. Thermoelectric or maybe a Stirling engine, I'm not sure which, but there's gotta be something here.
(Sorry, am I hijacking this thread? I'd really like a solution here. It's enough of a problem that you could probably market it too; look at all those solar-powered ventilation fans and other inadequate solutions on sale.)
As I recall, one of the common problems with solar panels is that they're too reflective, and so I would expect less heat getting to the base overall.
Re: window glass - that's what Sanyo See-Thru Amorton is for. Get stylish-looking gray window tint and PV electricity generation all at the same time. Again, for a Technology Statement vehicle, go all the way.
Given that a car interior can hit 180F on a sunny day (ambient 95F), there's gotta be a way to turn all that waste heat into usable power and in so doing, keep things cooler overall. Thermoelectric or maybe a Stirling engine, I'm not sure which, but there's gotta be something here.
(Sorry, am I hijacking this thread? I'd really like a solution here. It's enough of a problem that you could probably market it too; look at all those solar-powered ventilation fans and other inadequate solutions on sale.)
Tomas
Banned
Just two thoughts on roofs and solar power:
1) I would assume, then, that the flat roof over my carport would probably have enough area to actually provide most, if not all, the power needed by an EV if I owned one. Interesting ...
2) As to heat absorption with a "normal" roof, the roof of this apartment building ("satellite picture" thread) is not white as I mistakenly said in that thread. The roof is actually a very reflective metallic aluminum coating over an insulating layer with a 4 foot airspace below then 12 inches of blown-in insulation before you get to the ceiling of the uppermost apartments. I have NO idea what the architects were thinking putting that here in the northwest instead of somewhere in Arizona ...
Weird building in many ways.
Oh, one more "thing." I had a small solar powered fan unit that fit in the narrow slot at the top of a slightly open car window - about 1/2 inch required. When there was sun, it exhausted air from the interior right at roof level. Leaving the low-mounted vents in the car open, it did actually help keep the temp within reason.
/ubbthreads/images/graemlins/hahaha.gif
1) I would assume, then, that the flat roof over my carport would probably have enough area to actually provide most, if not all, the power needed by an EV if I owned one. Interesting ...
2) As to heat absorption with a "normal" roof, the roof of this apartment building ("satellite picture" thread) is not white as I mistakenly said in that thread. The roof is actually a very reflective metallic aluminum coating over an insulating layer with a 4 foot airspace below then 12 inches of blown-in insulation before you get to the ceiling of the uppermost apartments. I have NO idea what the architects were thinking putting that here in the northwest instead of somewhere in Arizona ...
Weird building in many ways.
Oh, one more "thing." I had a small solar powered fan unit that fit in the narrow slot at the top of a slightly open car window - about 1/2 inch required. When there was sun, it exhausted air from the interior right at roof level. Leaving the low-mounted vents in the car open, it did actually help keep the temp within reason.
brightnorm
Flashaholic
- Joined
- Oct 13, 2001
- Messages
- 9,027
Aspen, Colo post office has been PV powered for years. Looks good too.
Brightnorm
Brightnorm
highlandsun
Enlightened
I have one of those solar car window vent fans too, it's not effective enough for my black car in SoCal.
Mebbe I should just get a Tyvek car cover and forget about it... http://www.tyvek.com/na/covers/english/carcovr2.htm
But it'd be much more neato to do something with the power...
These guys have a solar reflector that can concentrate the energy to levels high enough to make a TEG worthwhile. Hmmm... http://www.cleardomesolar.com/
Mebbe I should just get a Tyvek car cover and forget about it... http://www.tyvek.com/na/covers/english/carcovr2.htm
But it'd be much more neato to do something with the power...
These guys have a solar reflector that can concentrate the energy to levels high enough to make a TEG worthwhile. Hmmm... http://www.cleardomesolar.com/
Darell
Flashaholic
[ QUOTE ]
Tomas said:
1) I would assume, then, that the flat roof over my carport would probably have enough area to actually provide most, if not all, the power needed by an EV if I owned one. Interesting ...
[/ QUOTE ]
Easily... especially for your low mileage. I figure the surface of a standard single-space car port would support about 40 EV miles/day. I don't have much more surface area than that covered with my panels, and I'm making ~15kWh/day.
Tomas said:
1) I would assume, then, that the flat roof over my carport would probably have enough area to actually provide most, if not all, the power needed by an EV if I owned one. Interesting ...
[/ QUOTE ]
Easily... especially for your low mileage. I figure the surface of a standard single-space car port would support about 40 EV miles/day. I don't have much more surface area than that covered with my panels, and I'm making ~15kWh/day.
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