DC Solar trailer used for charging my M3

[MobileClimate]

Get the EVTV esp32 controller and 4 model s batterys put them in a safe enclosure ,,i get 240 40 amps with the 2 sunny island inverters for about 2 hrs with those batteries ..its awesome charging off the sun .. i have mine mounted in a 20 ft container ..you need to install a load shedding contacter 48 volts I use micro inverters ..they put 240 right into the model 3 on a sunny day ..the battery is the grid ..and the power from solar panels goes directly into the model 3 240 ..when the model 3 is not using the 240 volts it gets rectified right back into the battery ..its what jack would say selfish solar

 

[timk225]

Sounds good but needs more solar panels for more charging capacity.

 

[crazyrudy]

Fair enough. As I mentioned "because I can" is certainly valid, lol. I dont need to convinced about solar, I have rooftop solar, powerwalls and a model 3.

Then I think you should know better than to create a post where you cite the price the power company sets as the cost of grid power. That is the exact wrong thinking that keeps people from renewable energy. The cost of that energy may be priced at $0.10 by Rocky Mountain Power, but we all know that is not the true cost. It has no respect for externalities like CO2 production, which is going to make the planet uninhabitable. If we are going to accelerate the transition to renewable energy, we must stop thinking in the terms that you post. The answer to your question about how long it will take to pay for these panels and batteries is: 1 millisecond.

 

[crazyrudy]

Sounds good but needs more solar panels for more charging capacity.

These panels put out 1k per side at 240v. How much more power are you thinking?

 

[crazyrudy]

Get the EVTV esp32 controller and 4 model s batterys put them in a safe enclosure ,,i get 240 40 amps with the 2 sunny island inverters for about 2 hrs with those batteries ..its awesome charging off the sun .. i have mine mounted in a 20 ft container ..you need to install a load shedding contacter 48 volts I use micro inverters ..they put 240 right into the model 3 on a sunny day ..the battery is the grid ..and the power from solar panels goes directly into the model 3 240 ..when the model 3 is not using the 240 volts it gets rectified right back into the battery ..its what jack would say selfish solar

That is a convolution that only a Tesla owner could think of. I congratulate you sir!

 

[crazyrudy]

Here is that actual power production at mid-day today....View attachment 619011

The Sunny Islands were not on when this picture was taken. The actual power production is much higher per side, about 1k per.

 

[jjrandorin]

Then I think you should know better than to create a post where you cite the price the power company sets as the cost of grid power. That is the exact wrong thinking that keeps people from renewable energy. The cost of that energy may be priced at $0.10 by Rocky Mountain Power, but we all know that is not the true cost. It has no respect for externalities like CO2 production, which is going to make the planet uninhabitable. If we are going to accelerate the transition to renewable energy, we must stop thinking in the terms that you post. The answer to your question about how long it will take to pay for these panels and batteries is: 1 millisecond.

Not eveyone cares about "accelerating the adoption of renewables" nor, "CO2 production" etc. For most people, the choice to go solar or not boils down to dollars and sense. Is it going to save me money, and how long is it going to take to save me money?

Solar is way past having only "eco warriors" support them, so the price one pays is the most important to most people. One has to have a lot of money to be able to care about the other stuff you are talking about.

The actual answer to "how long will it take those panels to pay for themselves" in your situation is "never, but I dont care because that wasnt my criteria for buying them" and thats totally fine.

 

[AlanSubie4Life]

I recently bought at auction the DC Solar trailer. All in it was just over $5k (bid was $4400). I limit my home charging to 20A no matter the source. I installed a NEMA1450 receptacle, and boom. I achieved the magic four words..."it charges my Tesla".View attachment 618464

I see a tiny amount of shadow on those second set of panels in this picture. Doesn't that completely kill the panel output, or are they unlike many house solar panels, where as soon as you shade even a small portion of them, the output of the panel drops by 80% (or whatever)? Or is that only my house panels, lol? I thought this was inherent to panels, since each one is like a bunch of current sources in series, with some bypassing mechanism, but it's been a while since I've looked at panel designs, so maybe they've changed the designs to make individual panels more resilient to partial shade?

 

[jjrandorin]

I see a tiny amount of shadow on those second set of panels in this picture. Doesn't that completely kill the panel output, or are they unlike many house solar panels, where as soon as you shade even a small portion of them, the output of the panel drops by 80% (or whatever)? Or is that only my house panels, lol? I thought this was inherent to panels, since each one is like a bunch of current sources in series, with some bypassing mechanism, but it's been a while since I've looked at panel designs, so maybe they've changed the designs to make individual panels more resilient to partial shade?

Panels with optimizers or micro inverters are much more tolerant of shade, but I dont know what this OP has. The equipment on his rig is worth quite a bit more than he paid for it though.

 

[crazyrudy]

Panels with optimizers or micro inverters are much more tolerant of shade, but I dont know what this OP has. The equipment on his rig is worth quite a bit more than he paid for it though.

I see a tiny amount of shadow on those second set of panels in this picture. Doesn't that completely kill the panel output, or are they unlike many house solar panels, where as soon as you shade even a small portion of them, the output of the panel drops by 80% (or whatever)? Or is that only my house panels, lol? I thought this was inherent to panels, since each one is like a bunch of current sources in series, with some bypassing mechanism, but it's been a while since I've looked at panel designs, so maybe they've changed the designs to make individual panels more resilient to partial shade?

Each panel is equipped with its own micro inverter, which helps. This is the winter solstice so the sun is very low at mid-day which exaggerates the shading in this photo. Remember that these panels rotate to wherever you want the angle to be. The trailer can likewise be leveled or angled in such a way that the shading is eliminated. I have noticed a small drop in solar production when one panel bank shades another, but it is not a deal or current killer.

 

[AlanSubie4Life]

Each panel is equipped with its own micro inverter, which helps. This is the winter solstice so the sun is very low at mid-day which exaggerates the shading in this photo. Remember that these panels rotate to wherever you want the angle to be. The trailer can likewise be leveled or angled in such a way that the shading is eliminated. I have noticed a small drop in solar production when one panel bank shades another, but it is not a deal or current killer.

I have Enphase microinverters on my panels and they die on an individual basis (200W down to 50W or whatever) as soon as the shade hits. Not a deal killer.

Was just curious given that shading is a given at this sun angle with this array spacing whether they did anything special with the panel design.

 

[nwdiver]

Panels with optimizers or micro inverters are much more tolerant of shade, but I dont know what this OP has. The equipment on his rig is worth quite a bit more than he paid for it though.

When you shade the panels across all the cell groups like that it doesn't matter what you have... the output goes to ~0 (About ~20w... still).

 

[AlanSubie4Life]

(About ~20w... still).

Yeah, I tried to look it up on my Enphase page before posting to get the number right, but at least on the phone app they don't seem to let me plot power vs. time anymore! I have a chimney shadow that hits the array at a particular time so it's pretty easy to see the instant drop. So, 50W was definitely a high estimate; I didn't want to overstate the drop. I do think 20W from a panel that would otherwise be at 200W is about what I would expect.

Here are my panels midsummer when the tiny shade of the chimney starts to hit one panel in the southeast array. 187W to 20W (would otherwise have been about 180W) over 10 minutes. There's only a very small amount of shading of the panel to create this near complete cutoff of energy production (it's less shading than what is shown in the picture in the OP).

 

[nwdiver]

I do think 20W from a panel that would otherwise be at 200W is about what I would expect.

Depends on how the shade hits. If only one cell group is in shade which can be up to 33% of the panel you'd only lose ~33%. If you shade 10% of the panel but the shade covers all 3 cell groups you lose >90%. If the panel is in series with unshaded panels you lose 100%. That's why the 'shade tolerance' claims of micros and optimizers annoy me. If one cell group is shaded there's no benefit. If all cell groups are shaded you gain ~20w.... yay?

 

[jjrandorin]

Yeah, I tried to look it up on my Enphase page before posting to get the number right, but at least on the phone app they don't seem to let me plot power vs. time anymore! I have a chimney shadow that hits the array at a particular time so it's pretty easy to see the instant drop. So, 50W was definitely a high estimate; I didn't want to overstate the drop. I do think 20W from a panel that would otherwise be at 200W is about what I would expect.

Here are my panels midsummer when the tiny shade of the chimney starts to hit one panel in the southeast array. 187W to 20W (would otherwise have been about 180W) over 10 minutes. There's only a very small amount of shading of the panel to create this near complete cutoff of energy production (it's less shading than what is shown in the picture in the OP).

View attachment 620485 View attachment 620486

My understanding is if you didnt have either micro inverters or optimizers, it would not be just that one panel that would be impacted, it would be the entire string. So the microinverters are still helping you get more power.

Saying that, I would definitely defer to @nwdiver since hes actually in the industry, and I am also well aware of your interest in charging / power consumption so if I have this incorrect, I apologize.

 

[AlanSubie4Life]

Depends on how the shade hits. If only one cell group is in shade which can be up to 33% of the panel you'd only lose ~33%. If you shade 10% of the panel but the shade covers all 3 cell groups you lose >90%. If the panel is in series with unshaded panels you lose 100%. That's why the 'shade tolerance' claims of micros and optimizers annoy me. If one cell group is shaded there's no benefit. If all cell groups are shaded you gain ~20w.... yay?

So maybe the answer to my question is they've optimized the positioning of the panels on this trailer to ensure that only one cell group gets shaded in this scenario, for minor shading situations, anyway?

My understanding is if you didnt have either micro inverters or optimizers, it would not be just that one panel that would be impacted, it would be the entire string.

For sure the microinverters help me. It's just that for the picture in the OP, it seemed like in this (admittedly low sun angle) situation, if it were done improperly, that amount of shading (about 10-15% of the array), even with microinverters, could knock out nearly all of the production from that side of the array (90%). But it sounds like it COULD be as good as just a 33% reduction in output (assuming shading on all of the panels in the bank on that side of the array), based on what @nwdiver says. Sounds like it depends on whether they oriented the panels the "right" way, if I'm understanding correctly!

What I learned when my solar got put in 7-8 years ago was that shading on panels, microinverters or no, must be avoided & minimized if at all possible. Microinverters are not an excuse to put panels close to a chimney - they should be as far as possible away from any sources of shade (even the little vents from bathrooms, etc.) . I did discuss this with the installer, but I was pretty limited with my roof on how far we could push them.

 

[nwdiver]

based on what @nwdiver says. Sounds like it depends on whether they oriented the panels the "right" way, if I'm understanding correctly!

Every panel I've seen the cell groups run the long way. Some of the newer panels have 6 cells groups but they still run the long way.

 

[AlanSubie4Life]

Every panel I've seen the cell groups run the long way. Some of the newer panels have 6 cells groups but they still run the long way.

View attachment 620517

Interesting. So my panels get clobbered even though the shade is coming in on one of the long sides. So maybe mine are different? They're low quality Chinese PhonoSolar panels! Only delaminating slightly...not impacting output...yet.

 

[nwdiver]

Interesting. So my panels get clobbered even though the shade is coming in on one of the long sides. So maybe mine are different? They're low quality Chinese PhonoSolar panels! Only delaminating slightly...not impacting output...yet.

If one cell group is getting shaded but you're losing >33% there might be a problem with the panel. OR... the voltage maybe going outside the MPP band of the micro. The operating range of Enphase 215w micros is 16v - 48v. If you lose 33% of a 30v panel you're at 20v but if you lose a second cell group you'd be out of the band.

I've seen failed bypass diodes but they usually fail as a short.

 

[AlanSubie4Life]

there might be a problem with the panel.

It's been like this since day 1 on all the panels that are so affected by shading, so I don't think it's a panel problem. Anyway, thanks for the information. I guess if I dig around I could probably find the circuit diagram for the panels.

Is it possible they just have a single bypass diode and a single group, or is the reverse-bias breakdown too low on the diodes to make that possible?