Off Grid solar charging station is up and running.. weather permitting!

[The Weatherman]

Just wanted to give an update on this project in case anyone out there is considering such an endeavor. We were never able to get the Emporia charger to work with the solar inverter. The charging watts would fluctuate wildly, and eventually the charger would shut down with an overcurrent error. Signature Solar finally concluded that the EG4 - 6000 inverter would just never work for this application and recommended that we buy a different inverter and charge controller that would have cost us another more than 5K. But, knowing that charging directly off of solar was working with Teslas, I decided as a last resort to buy a TeslaTap and borrowed a friends mobile Tesla charger to test it. Voila, it actually worked and we were able to charge without any shutdowns. The charging amps were much more consistent, only fluctuating in the 100’s column. Emporia processed a return on their charger, and we bought a Tesla wall charger. We are still having some issues with settings on the EG4-6000 inverter related to the battery and low voltage cutoff, but the latest firmware update may have solved that problem. So, we are able to charge continously at 24Amps now, without the charger shutting down. I’m feeling much relieved that this was actually not the stupidest idea I ever had and the system is pretty much working as planned.

Nice! Congrats!

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[Avocadodude]

Thanks for the update. I’ve been thinking about repurposing my dual 6500s and getting the EG4 6k just for charging. I guess I’ll keep my setup as is.

 

[ridgebackpilot]

Just wanted to give an update on this project in case anyone out there is considering such an endeavor. We were never able to get the Emporia charger to work with the solar inverter. The charging watts would fluctuate wildly, and eventually the charger would shut down with an overcurrent error.

I just purchased an Emporia Level 2 EVSE for my system, which includes 36 rooftop panels and 3 Tesla Powerwalls. I've been using a Tesla wall charger left over from when we had a Tesla Model 3. That has been working fine, except that it's not a smart EVSE and will only charge at 40 amps continuous (derated to comply with code).

I'm replacing the old Tesla wall charger with an Emporia EVSE because I want to be able to use all my excess solar production to charge my EVs. I'm hoping that in our system, the Emporia will work well. When paired with an Emporia energy monitor, the EVSE can automatically vary the charge rate to use only the available solar surplus. Since our Tesla Gateway manages the solar production, charging the Powerwalls, and supplying the house, I don't think I'll have the same problem you experienced with the Emporia EVSE. But time will tell!

 

[swngdncr]

I just purchased an Emporia Level 2 EVSE for my system, which includes 36 rooftop panels and 3 Tesla Powerwalls. I've been using a Tesla wall charger left over from when we had a Tesla Model 3. That has been working fine, except that it's not a smart EVSE and will only charge at 40 amps continuous (derated to comply with code).

I'm replacing the old Tesla wall charger with an Emporia EVSE because I want to be able to use all my excess solar production to charge my EVs. I'm hoping that in our system, the Emporia will work well. When paired with an Emporia energy monitor, the EVSE can automatically vary the charge rate to use only the available solar surplus. Since our Tesla Gateway manages the solar production, charging the Powerwalls, and supplying the house, I don't think I'll have the same problem you experienced with the Emporia EVSE. But time will tell!

Please report back, I'll be very interested to know how things work. Your Tesla wall charger must be Gen 1? Gen 2 has a web interface app where you can adjust the charge rate. The problems we were having were something to do with the inverter. It would work fine so long as the solar input was turned off. It would charge and had nice flat charging rate. But, once you turned on the solar input, even if it was pitch black outside, not a drop of solar, the charging rate would fluctuate wildly. Our guess is that it was periodically throwing a spike outside of the set charging range that would trigger an overcurrent fault and charger shut down. If you have decent inverter, you may not have any problems. Signature Solar's ultimate recommendation after months of back and forth was for us to spend another 5K on a different inverter and charge controller. That would have added another 2-3 years to the return on the investment, and we probably would not have gone down this road had those costs been figured in up front. The Tesla Wall charger and TeslaTap was a much cheaper solution, and Emporia took back the charger.

 

[ridgebackpilot]

Please report back, I'll be very interested to know how things work. Your Tesla wall charger must be Gen 1? Gen 2 has a web interface app where you can adjust the charge rate.

Yes, my Tesla Wall Charger must be a Gen1. It definitely doesn't have a WiFi interface, so it's not a "Smart Charger". Using a TeslaTap Mini adapter, it's been working well for almost three years. But all adjustments to the rate and timing of charging have to be done manually or via the EV itself.

Although the newer Gen3 allows you to manually vary the charging amps via the app, it won't monitor solar production and automatically match the rate of charge to any surplus. The Emporia will do that if coupled to one of their energy monitors. That's why I've ordered one. I'll report back how it works!

 

[SmoothJ]

Nice and simple setup. I currently have 46 panels on my roof, and through a set price PPA. Unfortunately mine is considered inefficient since the panels are not facing south, but I still manage to get a more than decent amount of power regardless.

I want to do what you are doing, but that would mean I need to change out the inverters, and that would be a "violation" of the PPA contract. So I would need to find a way to funnel the electricity from the solar production to a battery, and just feed off the battery for the EVSE. However since its all tied together, there would really be no way of me breaking things up.

 

[SpaceEVDriver]

Wouldn't it be great to have it DC (DC/DC converter version required) via a low power home CCS EVSE with CCS directing MPPT power delivered to the vehicle?

https://enteligent.com/dc-coupled-dc-evses

 

[SpaceEVDriver]

We don't actually know, we won't have peak conditions for quite a while. The panels are BlueSun 460W Half-Cell Bifacial Solar Panel (Silver) | Up to 575W with Bifacial Gain.
We will be putting white rock down below the panels to maximize the Bifacial production, but until we have the rock down and a full sun day, we don't actually know. And that would just be a winter sunny day, the summer, who knows. With 10 panels, In theory, we could get up to 5.7KW

It seems counter-intuitive, but since you have bifacial panels already, orienting them so they're facing directly east-west in a vertical orientation would give you greater total output over more of the year. Just need to space them so they only cast shadows on each other in the early an late parts of daylight. (Assuming the panels would have a good view of the horizons.)

https://cleantechnica.com/2022/07/2...tical-solar-panels-have-improved-performance/

 

[swngdncr]

Nice and simple setup. I currently have 46 panels on my roof, and through a set price PPA. Unfortunately mine is considered inefficient since the panels are not facing south, but I still manage to get a more than decent amount of power regardless.

I want to do what you are doing, but that would mean I need to change out the inverters, and that would be a "violation" of the PPA contract. So I would need to find a way to funnel the electricity from the solar production to a battery, and just feed off the battery for the EVSE. However since its all tied together, there would really be no way of me breaking things up.

46 panels, yikes, you must have a huge roof! We went with this stand alone system because it was half the price of expanding our roof top solar. We didn't have any room left so we would have had to swap out our old 175W panels for higher power panels, new power optimizers, and a new inverter. We got one bid, just to see, and I think it was 30K. The stand alone system insulates us from the endless PG&E hikes. They have been relentless in their efforts to also change the rate plans and to increase the cost of solar. After the tax credits, the system cost about 9K... @ an average of .30/kwh, if we drive 15K miles a year, our payback is about 4- 5 years., and it’s likely that over the time rate hikes are going to cut that payback down.

 

[swngdncr]

It seems counter-intuitive, but since you have bifacial panels already, orienting them so they're facing directly east-west in a vertical orientation would give you greater total output over more of the year. Just need to space them so they only cast shadows on each other in the early an late parts of daylight. (Assuming the panels would have a good view of the horizons.)

https://cleantechnica.com/2022/07/2...tical-solar-panels-have-improved-performance/

Ahhh, too late for us, the ground mount lets us adjust the angle vertically to adjust for summer/winter sun angle.. but can’t change them to east west….

 

[SmoothJ]

46 panels, yikes, you must have a huge roof! We went with this stand alone system because it was half the price of expanding our roof top solar. We didn't have any room left so we would have had to swap out our old 175W panels for higher power panels, new power optimizers, and a new inverter. We got one bid, just to see, and I think it was 30K. The stand alone system insulates us from the endless PG&E hikes. They have been relentless in their efforts to also change the rate plans and to increase the cost of solar. After the tax credits, the system cost about 9K... @ an average of .30/kwh, if we drive 15K miles a year, our payback is about 4- 5 years., and it’s likely that over the time rate hikes are going to cut that payback down.

Our house is of New England Salt Box design, so we have a very large roof. Based on the price at the time, it would have been over 60K to do the panel installation, however it was “free” and we pay a fixed rate per month. This allows us to go over production during the spring and summer but under production during the fall and winter.

 

[adoublee]

https://enteligent.com/dc-coupled-dc-evses

That's what my comment was based on - hoping they get to market with it soon!

 

[Maxx]

This guy has a portable setup:

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