# Solar Powered Electric Vehicle



## Ziggythewiz (May 16, 2010)

crucifier said:


> 1. Its has to be a 2 Seater
> 2. It should atleast run for 30-50 kms in one full charge.
> 4. The solar panel should charge the battery in a max time of 6hrs.
> 
> ...


Sorry, does not appear possible to meet your specs. A typical car could hold enough solar panels for about 2 miles of range after 6 hours.

Try searching here for other solar threads, the topic has been pretty well discussed.

As for your specification questions, it will all depend on the vehicle you use as your donor.


----------



## Sunking (Aug 10, 2009)

It is not possible to do what you want.

If you could achieve the very elusive efficiency of 125 watt hours/kilometer (200 wh/mile) would require about a 60 watt panel. To go 30 kilometers requires about a 1800 watt panel as long as it does not weigh anything. a 1800 watt panel requires about 12 square meters of surface area. 

Realistic efficiency of a professional manufactured EV is around 250 wh/kilometer, and you have very little chance of achieving that high of an efficiency on a student budget.


----------



## crucifier (Sep 7, 2011)

Ziggythewiz said:


> Sorry, does not appear possible to meet your specs. A typical car could hold enough solar panels for about 2 miles of range after 6 hours.
> 
> Try searching here for other solar threads, the topic has been pretty well discussed.
> 
> As for your specification questions, it will all depend on the vehicle you use as your donor.





Sunking said:


> It is not possible to do what you want.
> 
> If you could achieve the very elusive efficiency of 125 watt hours/kilometer (200 wh/mile) would require about a 60 watt panel. To go 30 kilometers requires about a 1800 watt panel as long as it does not weigh anything. a 1800 watt panel requires about 12 square meters of surface area.
> 
> Realistic efficiency of a professional manufactured EV is around 250 wh/kilometer, and you have very little chance of achieving that high of an efficiency on a student budget.




Thanks to u both for the reply...

So what i get from your replies is that either we have to increase our charging time...(which means some days) to achieve that distance or we reduce the distance...


At the same time it comes to my mind, can we add a plug-in charge option too??
That just expands our range of using the vehicle and keeps the it efficient and non polluting??

I hope this is possible...

So now i would need the specs for a the motor and the battery specifically...

Am waiting!!!!


----------



## Sunking (Aug 10, 2009)

crucifier said:


> So what i get from your replies is that either we have to increase our charging time...(which means some days) to achieve that distance or we reduce the distance...


You cannot increase your charging time with Solar , the SUN GOD will not allow it. With a vehicle you cannot even achieve 6 sun hours.

A trap people fall into is they think if the sun shines 14 hours in a day, a solar panel will produce rated power for 14 hours. That is far from the truth and not even close to real world application. In the lower 48 USA the highest solar insolation is Tuscon AZ is 8.1 sun hours in the month of June at a tilt angle of 0 degrees. In December with the same 0 degree tilt angle is 3.2 Sun Hours.

At the other extreme is Seattle WS June Sun Hours 5.1 Sun Hours in June and 0.9 in December

Depending on what type of charge controller and battery combination you use, efficiency on the low end using a series type charge controller (PWM) and lead acid batteries is 50%, at best with MPPT charge controller and lithium batteries as high as 80%.

So a 100 watt panel in Tuscon in June can produce as much as 650 watt hours using MPPT and Lithium. Or as little as 45 watt hours in Seattle WS using a PWM controller and lead acid battery. Reality is neither is acceptable and way to low. It goes to from horrible to non existent.


----------



## Ziggythewiz (May 16, 2010)

crucifier said:


> Thanks to u both for the reply...
> 
> At the same time it comes to my mind, can we add a plug-in charge option too??
> That just expands our range of using the vehicle and keeps the it efficient and non polluting??
> ...


You can do an EV conversion like most of the members here, and add some novelty solar panels for a slight range increase. You will primarily charge the car via the plug, and the panels may cover 5-10% of your charging needs.

Another option is to just use solar to charge your 12V system, as I have done. No 12v charger or DC - DC converter needed, so the panel pays for itself in both cost and weight.


----------



## steven4601 (Nov 11, 2010)

solar powered, 30kph, 2 seater, ultra low-weight. Sounds like a solar challenge vehicle. 
Your primary focus will be drag (air and rolling) and following that is mass (lacking it)


If using perfectly flat roads, i think its possible. If its to be used in everyday traffic, it is not likely to work out. Harsh acceleration, erratic stopping etc drive up the watt/hour per distance unit.

edit:just What about un-folding a large pv panel? That way you're not restricted entirely by surface area.


----------



## Sunking (Aug 10, 2009)

Ziggythewiz said:


> Another option is to just use solar to charge your 12V system, as I have done. No 12v charger or DC - DC converter needed, so the panel pays for itself in both cost and weight.


It is impossible for solar battery systems to ever pay for themselves, especially in a mobile system. It will cost you a minimum of 10 times more than commercial power.


----------



## Ziggythewiz (May 16, 2010)

Sunking said:


> It is impossible for solar battery systems to ever pay for themselves, especially in a mobile system. It will cost you a minimum of 10 times more than commercial power.


I'm not talking about the energy cost savings, I'm talking equipment. What is the average cost of a 12V charger or DC-DC converter?


----------



## Sunking (Aug 10, 2009)

Ziggythewiz said:


> I'm not talking about the energy cost savings, I'm talking equipment. What is the average cost of a 12V charger or DC-DC converter?


Fair question. 

A quality 12 VDC 10 amp AC charger cost $50 to $75. It can supply full power 24x7x365. 

A 12 volt solar panel that can supply 10 amps for a couple of hours per day (140 to 200 watt panel) cost $150 to $400, plus the cost of a charge controller which cost about the same as the AC charger.

Any questions?


----------



## Ziggythewiz (May 16, 2010)

Sunking said:


> Fair question.
> 
> A quality 12 VDC 10 amp AC charger cost $50 to $75. It can supply full power 24x7x365.
> 
> ...


The 5 watt solar panel I bought for $20 or $25 provides more than the 45 whrs per day I use in the 12v system. Running lead there's no need for a charge controller for a small panel.

So for a low-draw electrical system, solar can provide the necessary power at half the cost without needing to steal anything from the traction pack. I'm sure you'll happily tell me what's wrong with that.


----------



## Sunking (Aug 10, 2009)

Ziggythewiz said:


> The 5 watt solar panel I bought provides more than the 45 whrs per day I'm sure you'll happily tell me what's wrong with that.


I will be happy too, the math cannot work. No place on earth has 9 Sun Hour Days. Well maybe around the equator, but no place in the USA, not even Arizona or Hawaii

If this is a standard 36 cell panel made for 12 volt battery systems connected directly to the battery, then you have turned it into a 3.5 watt panel by operating the panel below Vmp of 18 volts. Lastly once you take Lead Acid charging efficiency into account (80%) about all you could get is 10 to 15 watt hours out of it on a good summer day. Winter non existent.


----------



## Ziggythewiz (May 16, 2010)

Regardless of what you think the numbers should be, this 5 watt panel is the only power my 12v system has received since April. Maybe it's because solar insolation in TX is likely at record highs, or maybe the panel was underrated at 5w, but it works.

Also, trickle charging is more efficient than other charging due to absorption rates. It's like a sponge soaking up water from an eyedropper vs a hose.


----------



## crucifier (Sep 7, 2011)

Hmmmm....


Did not have time to quote for replies...


So now my understanding of ur comments suggests me that i have to have a parallel charger(plug-in type) along with the solar panel.

Could you please first tell me *how many batteries* would be required & *what spec* to run the car 50kms.???
& also gimme a *suggestion for the motor* too....


----------



## Ziggythewiz (May 16, 2010)

> So now my understanding of ur comments suggests me that i have to have a parallel charger(plug-in type) along with the solar panel.
> 
> Could you please first tell me *how many batteries* would be required & *what spec* to run the car 50kms.???
> & also gimme a *suggestion for the motor* too....


Correct. The types of batteries and other gear you need will depend on the vehicle you use. Do you have a car in mind? 

30-50 km would be much easier had using lithium batteries as opposed to lead acid, what kind of budget do you have available?


----------



## crucifier (Sep 7, 2011)

Ziggythewiz said:


> Correct. The types of batteries and other gear you need will depend on the vehicle you use. Do you have a car in mind?
> 
> 30-50 km would be much easier had using lithium batteries as opposed to lead acid, what kind of budget do you have available?



I am thinking of making a fresh chassis out of steel pipes.
No donor car needed. Would start afresh

my budget is somewhere around Rs.1,20,000/- or US$2500

out of which, the chassis would take up around Rs.30,000.

so i need to find the motor and batteries in the amount of Rs. 60,000.

Waiting for your reply...


----------



## Ziggythewiz (May 16, 2010)

What is the intended purpose of this vehicle? Street driver? At least in the US, it is far more expensive to build from the ground up than to use a pre-built, used vehicle.


----------



## crucifier (Sep 7, 2011)

Ziggythewiz said:


> What is the intended purpose of this vehicle? Street driver? At least in the US, it is far more expensive to build from the ground up than to use a pre-built, used vehicle.


No. I just want to build it as a showcase vehicle. It would be driven mostly in the university where I study,n once will be displayed at the New Delhi Auto Expo in 2012.

Thats all.
But it should be reliable.


----------



## Ziggythewiz (May 16, 2010)

So it needs to be reliable. Does it need to be legal? Are there standards you have to build to?

What are your performance needs?
You said 30-50km, is that necessary for a show vehicle?
Max speed?
Acceleration?


----------



## crucifier (Sep 7, 2011)

Ziggythewiz said:


> So it needs to be reliable. Does it need to be legal? Are there standards you have to build to?
> 
> What are your performance needs?
> You said 30-50km, is that necessary for a show vehicle?
> ...


does not need to conform to any standards
the range is required.
max speed need not exceed 30kmph
accelaration should be just what is required.


----------



## Ziggythewiz (May 16, 2010)

With the budget you have you'll need to find some cheap used stuff, maybe a forklift motor or golf cart. Any voltage 48 or higher should be able to get the speed you need, but of course, move voltage = more fun.

Look at the vendors here to get ideas of typical prices for new equipment, then hit up google/ebay/etc to see what good stuff you can find used.


----------



## crucifier (Sep 7, 2011)

Ziggythewiz said:


> With the budget you have you'll need to find some cheap used stuff, maybe a forklift motor or golf cart. Any voltage 48 or higher should be able to get the speed you need, but of course, move voltage = more fun.
> 
> Look at the vendors here to get ideas of typical prices for new equipment, then hit up google/ebay/etc to see what good stuff you can find used.


should I use a BLDC Motor or some other kind???
is a 48V 5KW BLDC motor good??

and how many batteries and of what power ratings would be required??

will any of these motors suffice?? http://www.rotomag.com/pdf/d_c_traction_motors.pdf
or these http://www.rotomag.com/pdf/battery_operated_pmdc_motors.pdf
(The links are not for BLDC Motors)


----------



## Ziggythewiz (May 16, 2010)

Many of those higher voltage ones would probably work fine. I don't know anything about BLDC motors though, check some of the other threads here.

For batteries it will depend on what your vehicle weighs and how aerodynamic it is. You'll likely get around 200 wh/mile for a light, low speed vehicle. That would require 8 6V batteries at ~200ah each to do 40km.


----------



## crucifier (Sep 7, 2011)

Ziggythewiz said:


> Many of those higher voltage ones would probably work fine. I don't know anything about BLDC motors though, check some of the other threads here.
> 
> For batteries it will depend on what your vehicle weighs and how aerodynamic it is. You'll likely get around 200 wh/mile for a light, low speed vehicle. That would require 8 6V batteries at ~200ah each to do 40km.


People suggest that a BLDC Motor can be used,but its not what everyone is using.
people are mostly using series wound DC motors which run at 48V.
Would a *48V series wound DC motor rated at 3HP/2240W with a torque of 144Kg-cm* do it for me assuming that the car weighs 150kg including the motor??


----------



## Ziggythewiz (May 16, 2010)

crucifier said:


> Would a *48V series wound DC motor rated at 3HP/2240W with a torque of 144Kg-cm* do it for me assuming that the car weighs 150kg including the motor??


Probably, but your car will not weigh 150 kg. Unless you use lithium, your batteries alone will weigh significantly more than 150 kg.

You probably need at least double that, but check out the garage to see what other low power vehicles are running: http://www.diyelectriccar.com/garage/cars/index/max_power/ASC


----------



## dtbaker (Jan 5, 2008)

crucifier said:


> Hello everybody,
> 
> I am new here....
> 
> ...



looks to me like you are asking folks here to do your homework for you. I think you'll get much better response if you come up with preliminary plans and ask for review along the way.


----------



## Searching (Sep 13, 2011)

Just putting this out there.

What about using the solar cells and plug in to convert water to hydrogen gas, then burn that for fuel. which will power the vehicle well at the same time make more hydrogen gas from the motors own power out put.

From the sound of it you should want 3-10 HP which is 2,237.09
to 7,456.9 watt range. If you wish to get your 30 kmph (just under 19mph) you should want to be around the 4000-5000 watt range but if possible I would go higher. It might be a good idea tho to use an infinitely variable transmission similar to that of a snowmobile to lower the amperage needed and boost your range. Most of your power is used when starting out, So if you can gear the motor down for starting out and then let it spin up at speed you would get more range and more speed. Keep in mind Heat is loss. Go for higher voltage and avoid anything that makes the motor heat up and that will boost your range. so it is a good idea to have some form of a speed selector.

To run purely on solar you would have to keep it under 50-100 lbs and then use an electric bike hub motor that used very little power. but you wouldn't get the speed or distance you want from just solar. a small 1-2hp gas motor to turn a 10-15 amp stator would probably help you a lot.

Anyway those are my thoughts on the idea.


----------



## Sunking (Aug 10, 2009)

Searching said:


> Just putting this out there.
> 
> What about using the solar cells and plug in to convert water to hydrogen gas, then burn that for fuel. which will power the vehicle well at the same time make more hydrogen gas from the motors own power out put.


OMG I cannot believe you just said that. Another above unity gain NUT who has no understanding of physics.


----------



## Searching (Sep 13, 2011)

Sunking said:


> OMG I cannot believe you just said that. Another above unity gain NUT who has no understanding of physics.


my my my... Yet vehicles are running off of this.. If they are then it works. don't be stupid.


----------



## Searching (Sep 13, 2011)

By the way I was really good at physics in school. Do your research before you say something. electrolysis works. The only thing i might be wrong on is if the storage of power is lower then that of a battery. However running on water does work.

If you really believe it does not that wow... Idk what to say to you other then research it.

Next time think first please.


----------



## Sunking (Aug 10, 2009)

Searching said:


> my my my... Yet vehicles are running off of this.. If they are then it works. don't be stupid.


You are out of your mind.


----------



## Searching (Sep 13, 2011)

Sunking said:


> You are out of your mind.


I've done it and seen it work. you split the water then burn it. you can use solar to split it well the vehicle is off. it will not however make enough to run the vehicle but it can bank some well not is use.

You however are lacking in common knowledge. Many many things run on hydrogen.


----------



## Sunking (Aug 10, 2009)

Searching said:


> You however are lacking in common knowledge. Many many things run on hydrogen.


No you are having Green dream. Sure you can make hydrogen and once you burn it or recombine it in a DIY system you are lucky to get 5% efficiency, and 95% is lost forever.


----------



## Searching (Sep 13, 2011)

Sunking said:


> No you are having Green dream. Sure you can make hydrogen and once you burn it or recombine it in a DIY system you are lucky to get 5% efficiency, and 95% is lost forever.


What makes you think i care about green, burning oil is great for plants. it makes them grow better.

Anyway the key here is that water is free. the system once built would have almost no cost to run other then rods, lubrication oil, tires, water filters, ect.

Anyway your taking one small suggestion I made at the start, the rest of my post was about electric then a suggestion at using a small gas motor to turn a charger, not hydrogen.


----------



## Sunking (Aug 10, 2009)

Searching said:


> suggestion at using a small gas motor to turn a charger, not hydrogen.


That is called a hybrid vehicle that just about every auto manufacture has at least one for sale.


----------



## zeroexcelcior (Aug 2, 2011)

Searching said:


> What about using the solar cells and plug in to convert water to hydrogen gas, then burn that for fuel. which will power the vehicle well at the same time make more hydrogen gas from the motors own power out put.


I feel the way this is worded, it sounds like a perpetual energy machine. I'm fairly sure that's not what you're describing so I'll move on. I think it may be within the limitations of this project to use solar cells to generate electricity (even then use that electricity to separate distilled water into hydrogen and oxygen), but I think the best application would be a large, stationary solar array with an energy storage system to hold on to the energy it gathers (via lead, lithium, H2, or maybe even something completely different) and then use that to charge a small, lightweight, aerodynamic electric vehicle. Most importantly, however, I feel that *burning* hydrogen is the last thing you want to do, and I feel you explain it best in your own words.


Searching said:


> Keep in mind Heat is loss.


I believe one would be better off using reverse electrolysis instead so as to better utilize the hydrogen's potential energy, should the decision be made to use it.




Searching said:


> a small 1-2hp gas motor to turn a 10-15 amp stator would probably help you a lot.


This would certainly extend the range of the EV, however I believe this would also defeat the fundamental point of building a *solar powered* vehicle, and as you've said,


Searching said:


> Keep in mind Heat is loss.


and internal combustion engines excel at making heat well above any other function.




Searching said:


> It might be a good idea tho to use an infinitely variable transmission similar to that of a snowmobile to lower the amperage needed and boost your range. Most of your power is used when starting out, So if you can gear the motor down for starting out and then let it spin up at speed you would get more range and more speed.


CVTs are wonderful things but unfortunately they have mass. I would not be opposed to such an idea, I just think that for this particular project the added weight would not be able to justify itself. That said, it may well be something worth considering and I think you bring about a good point.




Searching said:


> I've done it and seen it work. you split the water then burn it.


You're right, it does work. I've been on a bus that burned hydrogen for fuel and I am of the opinion that it not only works but works quite well, but I don't think this project would benefit from it. This is only my opinion, however, and because it is the OP's project it is his decision to make.

Anyway, just my unabridged $0.02


----------



## Searching (Sep 13, 2011)

zeroexcelcior said:


> I feel the way this is worded, it sounds like a perpetual energy machine. I'm fairly sure that's not what you're describing so I'll move on. I think it may be within the limitations of this project to use solar cells to generate electricity (even then use that electricity to separate distilled water into hydrogen and oxygen), but I think the best application would be a large, stationary solar array with an energy storage system to hold on to the energy it gathers (via lead, lithium, H2, or maybe even something completely different) and then use that to charge a small, lightweight, aerodynamic electric vehicle. Most importantly, however, I feel that *burning* hydrogen is the last thing you want to do, and I feel you explain it best in your own words.
> 
> I believe one would be better off using reverse electrolysis instead so as to better utilize the hydrogen's potential energy, should the decision be made to use it.
> 
> ...


Thank you.. Someone that knows what they are talking about.. All your points I did consider but i don't know if he is strictly limited to just solar. I put the ideas out there. What he does it up to him.


----------

