Smart Solar Charging

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ridgebackpilot

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Thank you everyone for the informative info in this thread. Today I installed a Emporia EV Charger and Vue Utility Monitor. I have Tesla Solar with Powerwalls. I don't think I setup the Vue correctly. I will contact support on Tuesday. Can't wait for it work correctly, managing the Ford Connected Charger and the MME with excess solar has been a pain...
John: I should also mention that to get the Emporia charger to use excess solar energy, you need to set your Tesla Gateway Powerwall operational mode to “Time-Based Control” rather than “Self-Powered”.

If it’s set to “Self-Powered”, the charger will drain your Powerwalls to charge the EV, which you don’t want. @markboris can verify or correct this advice as I’m still learning!
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John: I should also mention that to get the Emporia charger to use excess solar energy, you need to set your Tesla Gateway Powerwall operational mode to “Time-Based Control” rather than “Self-Powered”.

If it’s set to “Self-Powered”, the charger will drain your Powerwalls to charge the EV, which you don’t want. @markboris can verify or correct this advice as I’m still learning!
Michael, that is interesting as I have my Powerwall's set to "Self-Powered" and it does not do this. The Emporia EV charger only charges the car with excess solar, nothing comes from the Powerwalls. Maybe our Powerwall system is configured differently?
 
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ridgebackpilot

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Michael, that is interesting as I have my Powerwall's set to "Self-Powered" and it does not do this. The Emporia EV charger is only charging the car with excess solar, nothing coming from the Powerwalls. Maybe our Powerwall system is configured differently?
Interesting! Clearly I need to run some more experiments.

My Emporia system waits to charge until it sees excess solar energy being sent back to the grid, which happens when the Powerwalls charge to 100%. However, if the Powerwalls are set to "Self-Powered", the charger ramps up to full power (in my case, 40 amps) and stays there. I don't think the Emporia system can differentiate between excess solar power and energy coming from the Powerwalls.

To avoid draining the Powerwalls and match charging current to excess solar power, I have to set my Tesla Gateway to "Time-Based Control". But perhaps there's another way to do this that I haven't yet discovered?
 

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Interesting! Clearly I need to run some more experiments.

My Emporia system waits to charge until it sees excess solar energy being sent back to the grid, which happens when the Powerwalls charge to 100%. However, if the Powerwalls are set to "Self-Powered", the charger ramps up to full power (in my case, 40 amps) and stays there. I don't think the Emporia system can differentiate between excess solar power and energy coming from the Powerwalls.

To avoid draining the Powerwalls and match charging current to excess solar power, I have to set my Tesla Gateway to "Time-Based Control". But perhaps there's another way to do this that I haven't yet discovered?
I just took these right now. Emporia charger set to charge on excess solar. My car is plugged in and charging. Solar producing it's max 11.4kW, house is as idle (no large appliances running) charger is running at 10.6kW excess solar.

Ford Mustang Mach-E Smart Solar Charging IMG_6088


Ford Mustang Mach-E Smart Solar Charging IMG_6089


I turned on the dryer and house is using 5.9kW, charger is running at 5.3kW excess solar

Ford Mustang Mach-E Smart Solar Charging IMG_6085



The tesla app shows 5.1kW going back to the grid but it is actually going to the EV charger.

IMG_6087.jpeg
 

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Michael, you said you plugged in the EV charger and it went straight to full charge of 40A? If that is the case, while it is charging, on the Emporia app go the the charger screen and hit the "PAUSE" button. That will stop the manual charging and in 2-3 minutes, the charger will start back up on excess solar. Your Emporia app charging screen should look something like this.

Ford Mustang Mach-E Smart Solar Charging IMG_6081
 


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Does anyone have a cookie cutter Tesla setup with a separate Backup Gateway and Inverter? If so can you send a couple pics on how the Vue connects.

I am having great difficulty getting mine to work. I have tried all sorts of wires to connect to, tried changed Powerall's from self powered to time-based control.

Emporia tech had no idea where the connection should be made and sent a ticket of to principal engineer, which he said would take time to get back with me.

Much appreciated. I will upload pics in a few minutes as well.
 

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Does anyone have a cookie cutter Tesla setup with a separate Backup Gateway and Inverter? If so can you send a couple pics on how the Vue connects.

I am having great difficulty getting mine to work. I have tried all sorts of wires to connect to, tried changed Powerall's from self powered to time-based control.

Emporia tech had no idea where the connection should be made and sent a ticket of to principal engineer, which he said would take time to get back with me.

Much appreciated. I will upload pics in a few minutes as well.
John, I do have a Tesla setup with separate backup gateway and solar inverter however I left out of town this morning for 2-3 weeks so won't be able to take photos however, I think your issue is more how the Emporia app is configured than how your sensors are installed. I'm surprised Emporia support was not able to help you configure it. They've always been great to work with.

If you want, we can go over each others systems to make sure your sensors are set up like mine and your app is configured properly. I know how and where I have my sensors and on which breakers. I also can send you screen shots of the app and the devices set up on it.
 

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Having just expanded my rooftop solar array and added a third Tesla Powerwall battery to my house, I'm trying to figure out the optimal charging plan for my three EVs (Two Mustang Mach-Es and a Lightning).

Previously, with 20 solar panels producing 6 kW maximum, I wasn't able to charge my EVs solely by sun power. So I usually charged at night to take advantage of off-peak electric rates from the grid. But now that I have 36 panels making over 11 kW maximum, I'm able to power my Level 2 charger solely by the solar array during midday.

Obviously, I save money by charging my EVs with solar power as opposed to charging them from the grid. However, the nuances are important in this calculation: It costs me $0.076/kWH for power from the grid during off-peak hours in winter. But when I send solar power back to the grid, I'm only paid $0.047/kWH no matter the time of day.

By my calculation, I'm nearly 3 cents/kWH better off charging my cars with solar power than sending that surplus solar energy back to the grid.

These days, my daily regime is: The Powerwalls are set to "Self-Powered" so that they provide power for my home at night or anytime the solar array isn't producing enough. When the sun comes up each morning, I wait until the solar array charges my Powerwalls to 100 percent. As soon as that happens, I plug in an EV and allow it to charge using solar power. By 3 pm when the sun starts to go down and peak grid rates begin, I program my EVs to cease charging. When the sun sets, the Powerwalls take over and power my home.

With 36 solar panels, I'm essentially off-grid for the summer months, including charging my EVs. During winter when the solar array produces only about one-fourth of the power it does in the summer, I'll obviously have to rely more on the grid for charging during off-peak hours.

For those of you with rooftop solar arrays, I'm curious how my experience compares to yours. What is your daily routine? And what tricks and practices do you use to maximize the interplay between your solar array, battery storage, grid power, and EV charging?
We have an 11kw tesla solar roof with 3 powerwalls. I charge my Mache during the day so as to avoid putting any energy back on the grid ( as it does NOT make sense to do so based on the compensation rates which are only about 25% of the value). The only time we allow electricity to go back on the grid is during "events" during the summer. The events basically pay for all our year round electricity (to make up for the winter months living in a northern city).
 
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We have an 11kw tesla solar roof with 3 powerwalls. I charge my Mache during the day so as to avoid putting any energy back on the grid ( as it does NOT make sense to do so based on the compensation rates which are only about 25% of the value). The only time we allow electricity to go back on the grid is during "events" during the summer. The events basically pay for all our year round electricity (to make up for the winter months living in a northern city).
I couldn’t have said it better. That’s exactly what I do.

In the summer months, I can charge all three EVs with solar power and have enough to run the house and charge the Powerwalls for nighttime use. I reckon I'm mostly off the grid for about half the year.
 

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Hi Mark - Sure if get the time send me some screen shots. Have a great trip! Thanks!
Hey John, In what panel is your Emporia Vue Energy Monitor in? What panel are the EV charger breakers in?
 

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To add to previous post(#81):
We have an AC coupled, bimodal PV system(10.695)
we have a 29kWh+ (AGM)battery back up
our main is a 200A panel (which I deemed essential since we are 100% electric) and we have a critical load panel (L1 supply, heat pump, refrigerators, etc.)*
we have a speed wire for solar panel monitoring
we have two Schneider (XW+6848s) inverters w/ a power distribution panel and Combox for monitoring electron flow

do not understand the panel above w/ all of the white wires? Must be some elaborate and detailed monitoring?

We are a CARB state, but in name only (the utility company controls the legislature instead of vice versa). However, we are now permitted to have 200% of our yearly usage in solar panels. And there are no longer any battery restrictions. (when we initially installed, it was only 110%, limited battery, over 10kW meant 10-50kWh "permit" and was another huge battle, letters detailing future electrical use [we were not 100% electric at the start of our journey], etc.).
We could double our current solar array. Which would mean another inverter. And ideally quadruple the battery$$$$ capacity (for winter electron supply). Perhaps too costly (unless I was in my 40s/50s or win the lottery). And then of course there is bi-directional to consider.

We provide much more electricity (one of two EVs plugged in, L1, most daylight hours) most of the year than we consume. We therefor think it prudent to donate it to the grid (at 4mils/kWh, it is a donation)

*We could run our L2 through the critical load panel, but it would only work well for about four hours/day and only about seven months/year and would not be worth the hassle (might be different if we were putting on a couple hundred miles/day). We just plug in L1 for ten hours plus/day and that works fine.

Do not be too harsh on me. I am a biologist and only have taken a few college physics courses, so my design and planning took some work and may not meet your standards, but it works.
 

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Hi Mark - The Vue is in the main panel. EV Charger is top left breaker in the main panel
I think we established earlier that your two 200A sensors are attached to the mains coming into the main panel and they are oriented correctly. When you set up the main panel on the Vue, you chose "solar production" so I am assuming when you do have solar production, you can see what you are producing in the Vue app (Net Production in green).

I believe what you are trying to do is use excess solar to charge your car with the Emporia charger.

Only the 200A sensors connected to the mains going into the Vue are used for to monitor for excess solar.

Let's talk about how your app is configured. If your EV charger breaker is in the main panel, they should be showing up in the main panel page in the app. Are they?

Like this:

Ford Mustang Mach-E Smart Solar Charging Screenshot 2023-06-05 at 7.37.30 AM
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