Solar power deserves its own section on SEVA Forum, even if this is Seattle

[lenapralos]

Okay,

Perhaps I'm alone on this one and I would be the only one to post on it, but really believe that "Solar Vehicles" or atleast solar power should have a section at SEVA.  I doubt many people here would agree because of all the reasons it is not feasible to put solar panels on an EV, but I believe the reasons you should, outweigh the reasons you shouldn't.  (Obviously)

You've got wind drag, added weight, little extra added power from massive amounts of surface area, dc to dc step up complications because most panels are around 17 volts and most EV pack are around 120, high cost of solar panels....etc, etc.

But........

on the other hand.....

You don't have to plug in or pay anything when the sun is shining thus making you CARBON FREE and although this is Seattle..., Case and Point: Boeing builds their airplanes in one of the cloudiest places in the U.S., not because it's fun to fly in the clouds but because their planes don't stay in WA just like a solar powered vehicle probably won't stay in WA FOR very long.

The added weight of a panel is not that much.  A Kyocera 130 watt solar panel weighs 25lbs.  One trojan 6v battery can weigh easily more than 60lbs.

THe little added power of mounting 4 170 watt 24volt(35rated) panels on the back of a truck for an extra panel weight of around 120lbs. would result in approx. 7amps constant charge in direct sunlight for a 120volt pack.  THat's not bad considering it is more than half of the amps coming from many conventional 120v AC chargers.

FOr small voltage panels such as mine I simply run the power from the panels into a charge controller(xantrax $120----> small SLA ($25)------>inverter------>5 small 3amp soneil 24v chargers in series.   There are power losses, but there are also more creative ways to do it.

Yes solar panels are expensive, but Gosh last time I checked those high voltage Kanekas were still cheap at $213 for 60 watts

http://store.oynot.com/kak6060wasop.html

THose panels are 67 volts(90v open circuit) so with a diode and maybe a few other safety items you could run the voltage of just 2 of these panels into a 120v or maybe even 144 volt battery pack.  Maybe mount just one atop a 72 volt Geo conversion, but I haven't tried it yet.

Anyways......these are my thoughts and I'm stuck in this house for the time being...dreaming of solar and how Germany gets over 20% of all there power from the sun.

-j

[leitmotif]

Yes you are definitely in a minority.
I think there may be enough interest to justify it.

DOWNSIDE The other kids argument - those that advocate geothermal, heat pumps, underfloor heat and their mini hydro plants will want their own forum too.  After all you got yours.  THEN the argument goes where does it stop?
I find it interesting I am the only one to respond after it has been posted for a day.  Maybe there is not enough interest??

I propose IF ten people respond within two weeks then it gets a slot.

Solar (phovoltaic) is fantastic stuff and definitely has a place ideally off grid as a standalone power supply. 
I cant see it on the vehicle (unless incorporated into the skin) but I can definitely see it at home where it supplements the house and maybe vehicle recharge at night.  Since I prefer to work nites then solar recharge at home would fit right in.

[aviken]

I have always been intrigued by the thought of utilizing solar panels on vehicles. It's always been with the notion that you'd never get enough power to go with solar alone, but the idea of making the car that much less expensive to operate.

It's similar to those who worry a lot about the aerodynamics; drag, etc. And the weight. And I hear people removing the clucth to save 17 lbs...so the car can go farther on a charge...it can be more efficient. If you are from the "I want it super efficient" school, than I would say that solar must be considered. Don't tell people you charge up from the sun and drive all day...but maybe keep your accessory battery fully charged, and you don't have need for a dc to dc converter. Maybe you switch all the lights - internal and external - to LEDs, lowering electrical requirements. Not much for sure, but probably as much as saving 17 lbs on a 2400 lbs vehicle. Who knows, maybe the solar panel could power the battery warmers that some are quite fond of...anything that takes a little electricty here or there - remove that from the traction batteries, and you will get better range.

Think of it this way - can the energy created offset the weight, and is the excess generated worth it? Most will say not, I don't know the calculations, but I would think almost any net gain would be a win in my book.

Another way to consider this is if an ice car gets 32MPG, wouldn't it be better if it got 33? It's not much more, but it is better. If you take the best of breed, and find say 5 things that increase mpg by 1mpg each, you can now take it from 32 to 37mpg. Same theory with EVs. Although electricity is cheaper, range is limited, so I think we should give consideration to these ideas.

Where do I stand on the whole thing? I think it's a cool idea, but I don't think it will get you lots of power. But that's okay, it can make your ride go farther, one way or another. A Seva related forum Category? I don't like that idea - I think it is too obscure - especially for the number of members we have actively posting in the first few months.

So yeah to your thinking, nay to the new forum category. My 2 cents.

Ken

[StorminN]

I think solar PV's should be filed under "Misc. parts", or perhaps somewhere under "charging systems".

I believe the best place for PV panels is either the roof of your house, or on a pole in your yard, with a tracker on top... and of course, in both cases, grid connected. But, I also understand that they can provide a incremental charge if mounted on the vehicle.

It sounds like you've got panels on your truck. Perhaps a PV MPPT charge controller like the Outback MX60 could be rewired or reprogrammed to have an algorithm for charging 120V battery packs. In your case, this would eliminate some of the equipment, (SLA battery, inverter, five chargers) and increase the efficiency... the MX60's run at 96%+. The standard MX60's will take up to 140VDC input and output to battery packs from 12V to 60V. Perhaps if the output is pulsed (I've never scoped it) it could be as simple as a 1:2 step-up transformer... this would be a question for the guys in Arlington.

Of course, you could always go with those small single-panel charge controllers, and have a panel for each battery in your vehicle... hmmm...

-Norm.

[ev-supply]

DOWNSIDE The other kids argument - those that advocate geothermal, heat pumps, underfloor heat and their mini hydro plants will want their own forum too.  After all you got yours.  THEN the argument goes where does it stop?

Okay, I have to ask - who puts geothermal, heat pumps, underfloor heat or mini hydro plants in/on their EV?  Solar panels, without a doubt, are a legitimate EV topic, when used in the context of vehicles.  That is clearly what he is saying.  If he was talking about solar water heaters, then I would have to agree that it really does not have any application here.

[leitmotif]

Okay, I have to ask - who puts geothermal, heat pumps, underfloor heat or mini hydro plants in/on their EV?  Solar panels, without a doubt, are a legitimate EV topic, when used in the context of vehicles.  That is clearly what he is saying.  If he was talking about solar water heaters, then I would have to agree that it really does not have any application here.

THose topics except hydro were the rage on the EV mail list several months ago.

Dan Bentler

[aviken]

I can see both sides of this, and here is my take -

SEVA is the Seattle chapter of the Electric Vehicle Association. The main topic is of course EVs. It's ok for members to sometimes chat about similar interests - be it Solar, recycling, microhydro or wind power. This is a rather geek heavy group of folks, and they do more than drive cars. That being said, the "off" topic or ones with very little interest, should be limited in scope and fall under one of the related categories already existing or be placed in the general category. That's what it is for. If someone is looking for detailed information on how to reprogram an outback charger controller, they will likely have better luck in a solar / off grid type of forum...but it's still okay to pose the questions / ideas here - mainly because of the intent of putting in an EV. 

If you ask me, we already have PLENTY of categories. There are two that seem appropriate, but still have no posts in yet:

Electric Motorcycles and other unique high speed vehicles.
EV Racing and the National Electric Drag Racing Assoc (NEDRA)

IMHO, I think we should atleast put the electric bikes & electric motorcycles  / other unique vehicles in the same category.

The thing I love about forums and deciding categories, is that it is a self regulating sort of system. You can ask for a whole new category, but if there are no posts for it already, it's probably not gonna happen. If we get lots of posts in general that seem to be related to a specific area, we would certainly consider creating a new category for it.

To summarize, we can chat about stuff that is related, but it does not always need a new category - and I like this topic, but don't think it is worthy of it's own category on this forum.

THose topics except hydro were the rage on the EV mail list several months ago.

This is one of the main reasons why I had dropped from the list when I got busy - I didn't have time to deal with all the emails, and they are intersting to me (some of them), but again, I'm not signed up for solar / wind / etc....I would like to see 90% of all SEVA be EV related, and not OT. I am back on the list now I am back from vacation etc - but I still have hopes of swaying more folks to use this forum to get their opinions out - and heard. It's a great place to have a discussion.

[Eletruk]

Well, putting solar panels on my truck is something that I constantly am considering. One of the biggest issues is how to hook the power into the system. The Ford Ranger EV has the charger tightly integrated with the overall system, and the range is based on how much was put in while charging. The main problem is that the Ranger system can only handle 100AH in the software. So adding more energy may not neccesarily result in greater range. It's weird I know, but it has come up with Ranger owners that have replaced the NiMH batteries with Lithium. Even with the lower weight and greater energy storage, they can't get more mileage. And nobody has a clue how to reprogram the system. I guess I could just go ahead and tie some panels to the batteries and see if I get anything useful out of the system. The problem is how to get the voltage up to 320V to charge the batteries. I could buy a bunch of individual cells and series them all together, which might be the easiest. Otherwise, I would need a DC-DC converter that would up the voltage from 12V (or whatever the panel outputs) to the 320V I need to charge the batteries. If I can find such a device, it might be the better way to go, since it would (should) have circuit protection. I think the power output would be low enough that I don't have to be concerned about the battery cooling, NiMH batteries can get warm when charging, but if you are trickle charging, I don't see that as an issue. Anyways, as you can see, adding solar panels isn't as straightforward as it seems.

Roger

[srloper]

I think solar power is a viable source of interest its just many are involved in lots of other areas and just haven't taken the time to get involved as much as they need to.I personally feel that an ample mix of the resources could make SEVA a better tool for all involved..Solor could be incorporated into the battery backup systems to prolong the milage range of all ev's.
Steve