Solar cover?

JBee

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While the question wasnā€™t to me, my reply would be:

1.) Significantly important (IMO) that if Tesla offers it, then the vehicle has to already be configured to accept it. Thatā€™d be a biggy for me.

2.) I (personally) would be happy with something that covers parasitic draw, plus hopefully banking a few miles a day. Anything past that would be gravy, and would become less useful as price, bulk, and complexity increased.


Having the ability to park in a remote location without the nagging worry that your charge is dwindling while youā€™re there would be great, and the less hassle involved would be even better.
I agree that some sort of PV input connection should be available on off-road EV's. Probably all EVs in fact.

But there is also a lower limit to a PV size that produces enough to be a meaningful improvement.

"If" you want a plug in stationary solar charging setup, you can already buy those as well. They are just a inverter that plugs into the NACS and connects to the solar modules. No batteries required. But practically this is less than ideal.

I think there are a couple of things to consider to "do solar right" on a EV. For example the PV system should be able to charge whilst travelling as well as when stopped in traffic, or whilst parked, or whilst charging from the grid too.

So whatever it's connected to, should operate all the time and not need much, if any interaction to function. Obviously a deploying solar array should be activated, but this could become a part of the vehicle locking routine if it has collision and light sensors, for when parked under a roof or tree.

This leaves the question of where the best place is to connect an always on solar array. In the case of the CT the ideal situation would be if Tesla would include a MPPT DC-DC connection.

"If" the "power feed" in the roof, apparently there for the lightbar, would be bidirectional DC converter for example, then that would offer 2.3kW of solar input on the roof. Now 2.3kW seems very high for a lightbar, but about right for a decent size solar array over the rear roof, so maybe it has this capability in hardware already? Even a non-MPPT PWM type solar charger would work. But MPPT is simple to implement if you already have a microcontroller for the DC converter.

This leads to the next "possibility" being that the inverter and DC converters used in the CT are in fact a derivative of the Powerwall V3. This is because it too operates at 48V on the DC side, and 120/240V on the AC side. The question is how it would integrate with the 400/800V side, but this step up is also required for L1 and L2 charging on any EV, so I'd expect this would be a seperate setup to the 48V.

We also know that there is a 48V battery to backup the SbW, and that there a redundant DC converters as well. I don't think we know the size of the battery yet, but there might also be a slim chance to charge that to add power to the CT. For example if the HVAC is also 48V that could run off that too. But it would be at a fairly limited capacity I think, and it too would need to be bidirectional so that it could add more power back to the main 800V pack.

That leaves us with the extension pack connection point. That would have nearly unlimited power input capacity, in the 100kWs, given that the motors and SC4 level charging would require it.

The only issue is that it would be at the higher pack voltage but it would not be an issue to wire up the custom PV array in series to get the right voltage, and use a common high voltage MPPT to regulate it. This is probably the best way to integrate larger PV arrays with the CT and if it is not already included in the 48V DC converter setup already, would be how they solve an array connection as well. At some point it has to make its way into the main pack for bulk storage, so this would be the way of least conversion losses.

That then leaves the question of how to add an array in such a way that it increases functionality but keeps loss of range to a minimum. As described above, I think the combination of different functions without adding much mass, nor extra air resistance, let alone the capability of extending towing range, without any extra batteries is the best way to go.
 
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SpaceYooper

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Large retail stores, malls, etc will eventually have most of the superchargers. I fully expect solar and battery farms to be installed at places like Walmart and target. It will lower their costs tremendously and give people a good reason to spend 15-30 minutes in their stores.
Although those locations will be useful in general to all EVs, they won't really help me when I need the extra battery capacity or solar option to charge. Week long camping scenarios in CO, mid November and later, cold weather.
 
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My question was more about why you need the solar cover, as in what necessary purpose does it have?
Hunting season. It will be cold. Generally very close to 0 overnight. Sometimes colder. Maybe 30 during the day. I don't have a great way to charge overnight. I can not arrive with a full charge. I'll be there a week.

I drive about 60 miles a day during that week. Typically driving before sun up, and driving again after sun down. The truck is usually (not always) parked in areas that get sun most of the day.

Anyone who has spent much time in CO knows we get a lot of sun and our sun is intense. An reasonable solar option that gave me 15 miles a day would be great.
 

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Although those locations will be useful in general to all EVs, they won't really help me when I need the extra battery capacity or solar option to charge. Week long camping scenarios in CO, mid November and later, cold weather.
With a truck bed you can carry a whole pallet of solar panels šŸ˜€
 


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With a truck bed you can carry a whole pallet of solar panels šŸ˜€
True, except my bed will often have other stuff in it. And setting up and tearing down a panel system 2 times a day in the dark sounds terrible....unless it's extremely easy to do. Like plug it in and roll it out. Unplug and roll it up.
 

JBee

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Hunting season. It will be cold. Generally very close to 0 overnight. Sometimes colder. Maybe 30 during the day. I don't have a great way to charge overnight. I can not arrive with a full charge. I'll be there a week.

I drive about 60 miles a day during that week. Typically driving before sun up, and driving again after sun down. The truck is usually (not always) parked in areas that get sun most of the day.

Anyone who has spent much time in CO knows we get a lot of sun and our sun is intense. An reasonable solar option that gave me 15 miles a day would be great.
Right.

Are you planning on staying in the CT overnight with the heater running as well? If so solar will not be able to provide enough power for this in winter, without an array several times the footprint of the CT.

A small silenced 2-3kW ICE generator would produce as much in under an hour of winter sun in CO. If you need heat you can also get a little Diesel hot air heater for $100 instead. You could also insulate the CT to retain heat better etc. In effect the camper module proposed would do all of these things as well.

But let me temper your solar expectations here a bit so it aligns with solar isolation at CO latitudes.

The "15mile range" was a best case scenario on a long summer day in a lower latitude, say Texas or Florida.

The difference alone for winter, even in those locations, is that a winter day is less than half of that, often only a third of that in available sunlight on a winters day.

So that means 15miles in Florida in Summer, and 5-7 miles in winter.

In CO you would be starting from a lower base, and reducing it even more than that.

Note this assumes full exposure during the entire day without shading from trees etc.

This is not because of the CT or the solar panels poor performance in those conditions, but rather from the fact there is simply not enough solar energy coming down from the sun for a long enough period in winter to achieve that range.

If you did it in summer you would get closer, and wouldn't need to worry about heating as well.

So of all situations that probably represents one of the worst sets of conditions, and is not actually feasible with a little bit of Tesla integrated solar on the CT at all.

If you tell me a rough location I can run some numbers to see what you can expect to solar charge there at what times of the year.

Let me know.
 
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Are you planning on staying in the CT overnight with the heater running as well?
Definitely not. I do bow season sleeping in the truck 1 or 2 nights at a time. No way I'm doing a week in colder temps that way.

A small silenced 2-3kW ICE generator would produce as much in under an hour of winter sun in CO. If you need heat you can also get a little Diesel hot air heater for $100 instead. You could also insulate the CT to retain heat better etc. In effect the camper module proposed would do all of these things as well.
Yup. Considering those options... actually I haven't considered insulation for the CT.
But definitely considering generators to add range overnight. I just wasn't sure if the solar route could get me enough during the day to avoid the generator route.

If you tell me a rough location I can run some numbers to see what you can expect to solar charge there at what times of the year.

Let me know.
Roughly...Rocky Mountain National Park area.
 
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With a truck bed you can carry a whole pallet of solar panels šŸ˜€
Or within the bed a roller with pivot to house a long roll of polymer based solar panels.
Or four smaller rolls mounted off the track that could be electrically retracted and act as an awning or extended in any suitable direction? Just thinking out loudā€¦ā€¦.
 


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Or within the bed a roller with pivot to house a long roll of polymer based solar panels.
Or four smaller rolls mounted off the track that could be electrically retracted and act as an awning or extended in any suitable direction? Just thinking out loudā€¦ā€¦.
Yep! I'm really excited for us to break the barrier of affordable and pliable panels. I don't think most people have any idea how much our world will change when that starts to take off.
 

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Would it not be logical for the solar cover to plug into the connections on the top and rear of the truck?
 

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Definitely not. I do bow season sleeping in the truck 1 or 2 nights at a time. No way I'm doing a week in colder temps that way.


Yup. Considering those options... actually I haven't considered insulation for the CT.
But definitely considering generators to add range overnight. I just wasn't sure if the solar route could get me enough during the day to avoid the generator route.



Roughly...Rocky Mountain National Park area.
So if you are not staying in the vehicle overnight, isn't there any option to charge at your accommodation? Maybe take something with to the location to charge overnight while you sleep?

I think overall, if your main concern is off-grid charging and your doing this in the cold of a Colorado winter, with short days, and overcast and low sun angle days, you won't be able to add any meaningful charge using solar without installing a solar array some 4-6times the area of the CT. Any onboard system will likely add nothing useful. Just stick with a decent silenced liquid fuel generator, maybe just hire one as needed when you head out.
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