Bidirectional Charging / V2H / Solar when grid is down.

[millim]

Expect charge rate of no more than 9.6kW to the truck when isolated from the grid if that matters to you.

So my dense question is as follows. I have about 10kW between two systems - a roughly 6kW (AC) Sunpower system installed in 2011 (Sunny Boy inverter) , and a roughly 4kW system using LG panels and SolarEdge microinverters installed in 2018.

Even if I could tie both of them to the Ford/Sunrun system, if I'm barely outputting more than 10kW between both panels, would I really be losing anything with that 9.6kW limitation?

For a customary 1-system install, if the system on an AC basis is less than 9.6kw then is there any downside?

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[adoublee]

So my dense question is as follows. I have about 10kW between two systems - a roughly 6kW (AC) Sunpower system installed in 2011 (Sunny Boy inverter) , and a roughly 4kW system using LG panels and SolarEdge microinverters installed in 2018.

Even if I could tie both of them to the Ford/Sunrun system, if I'm barely outputting more than 10kW between both panels, would I really be losing anything with that 9.6kW limitation?

For a customary 1-system install, if the system on an AC basis is less than 9.6kw then is there any downside?

Doesn't sound like a downside for you. That is probably typical of many residential rooftop installations, which is what "fits" on roof but may be small when supporting home plus electric transportation. Probably acreage-level systems that might get to that 15-25kW size that might need to curtail when isolated from the grid.

 

[bryan995]

You don't have to send all power to the truck. You send all power to the house. The truck is part of the house/charging. As long as you are producing enough excess energy to power your house, you can charge the truck too.

The Powerwall has a 13.5kWh battery - the F150 has 98kWh or 131kWh.

This video isn't perfect, has a few inaccuracies, but is in line with the general ideas:

No, that’s not the way it works. As much as I would love for this to be possible, I really don’t think there is a path to a f150 lighting simply being 10x better than a powerwall.

If it were that easy, you should consider why Tesla has not already enabled this for all of their vehicles.

 

[Mr. Flibble]

No, that’s not the way it works. As much as I would love for this to be possible, I really don’t think there is a path to a f150 lighting simply being 10x better than a powerwall.

If it were that easy, you should consider why Tesla has not already enabled this for all of their vehicles.

Why not? It comes down to the total power of the battery, and what can be delivered. I have gas cans in storage. They hold gas. Otherwise they just sit there in my storage unless we have a power outage. Thats what a Tesla wall is. An ICE vehicle like the Ford Powerboost is the same analogy to this.

Tesla is a company that wants to make money, so they sell things above what it costs. As it is, it is cheaper to use a Lightning for this. Chevy will be coming out with the same with the Silverado, and Hyundai can already do this with the Ioniq 5; though not automatically (so far) like the Lightning.

Tesla could do this. They chose to sell a second product instead of doing this. Maybe they will change - but probably not for a while as it will eat into their powerwall sales.

At the end of the day, for backup power you care about what the battery can do. In the case of the Lightning, it is also a truck.

 

[bryan995]

Why not? It comes down to the total power of the battery, and what can be delivered. I have gas cans in storage. They hold gas. Otherwise they just sit there in my storage unless we have a power outage. Thats what a Tesla wall is. An ICE vehicle like the Ford Powerboost is the same analogy to this.

Tesla is a company that wants to make money, so they sell things above what it costs. As it is, it is cheaper to use a Lightning for this. Chevy will be coming out with the same with the Silverado, and Hyundai can already do this with the Ioniq 5; though not automatically (so far) like the Lightning.

Tesla could do this. They chose to sell a second product instead of doing this. Maybe they will change - but probably not for a while as it will eat into their powerwall sales.

At the end of the day, for backup power you care about what the battery can do. In the case of the Lightning, it is also a truck.

Check this video out. Discussed 16:00-17:30.

 

[Mr. Flibble]

Check this video out. Discussed 16:00-17:30.

Some solar systems can do this. Sunrun is not one of them.

 

[Ken]

i think that video was in another thread where the answer was that you can't charge the vehicle and power the house at the same time. It's unfortunate that they didn't set up the wiring to support this option.

 

[adoublee]

Based on the diagrams of the HIS bidirectional inverter, it is probably much easier to have solar operate to power home and charge Lightning with excess power if the solar connects into the DC inputs of the HIS inverter (DC coupled solar). It is more difficult to make the same to work with an existing solar array that AC couples through the home wiring system, because the HIS has to be able to control the existing inverter by having it back off production if the home can't use the power and the battery is full. There is a theoretical control mechanism for this that uses the AC power system wiring itself called frequency shifting, but equipment on both ends has to be set up for the function and operability between different vendors can be suspect. Also, vehicle charging needs to take place through the DCine during this period so it can be continuously adjusted, versus through AC EVSE that operates at a fixed charging power (even if adjustable).

 

[Texas Dan]

Based on the diagrams of the HIS bidirectional inverter,

What diagrams? The diagrams I've seen on the HIS are hardly more than cartoons. Please provide a link to the diagrams you are talking about.

 

[adoublee]

What diagrams? The diagrams I've seen on the HIS are hardly more than cartoons. Please provide a link to the diagrams you are talking about.

https://www.aeeexpress.com/crsdocro...ts/large/e4b8ae6e467c726e10dc614933665f7d.pdf

Reference the block diagram not the cartoon sketch. EVSE port is indicated as bidirectional, with dedicated DC/DC converter and RS485 comms. PV feeds a common DC bus through its own 4 MPPT and DC/DC converter. In theory the inverter can know the Lightning state of charge, and can directly limit PV production if Lightning is full and load of home is low. Inverter should also be able to fluctuate DC charging rate or pull from truck battery in real time.

 

[Texas Dan]

https://www.aeeexpress.com/crsdocro...ts/large/e4b8ae6e467c726e10dc614933665f7d.pdf

Thank you, best information on the HIS I have seen so far.



But I have to say that the information brings on some disturbing concerns. The biggest concern has to be that there is no mention of an 80 amp, 19 kW AC circuit for the EV charger. So you will still have to have another 80 amp circuit going directly to the EV charger from the main electrical panel if you want to charge at 19 kW that Ford promotes on the F150L website.



Another concern is I expected the transfer switch to be installed inside of the HIS but the transfer switch is identified outside the HIS as the MID panel. The MID panel does not appear to be a normal backup power transfer switch as it appears capable of feed power back to the grid. Unless a F150L owner is planning on installing solar panels and feeding power back to the grid, I don’t see this configuration as being very practical for a F150L owner that just wants to provide backup power to his house, especially since the HIS can only provide 9.6 kW of power whereas the truck on its’ own without the HIS can provide 7.2 kW of power.

 

[adoublee]

Thank you, best information on the HIS I have seen so far.



But I have to say that the information brings on some disturbing concerns. The biggest concern has to be that there is no mention of an 80 amp, 19 kW AC circuit for the EV charger. So you will still have to have another 80 amp circuit going directly to the EV charger from the main electrical panel if you want to charge at 19 kW that Ford promotes on the F150L website.



Another concern is I expected the transfer switch to be installed inside of the HIS but the transfer switch is identified outside the HIS as the MID panel. The MID panel does not appear to be a normal backup power transfer switch as it appears capable of feed power back to the grid. Unless a F150L owner is planning on installing solar panels and feeding power back to the grid, I don’t see this configuration as being very practical for a F150L owner that just wants to provide backup power to his house, especially since the HIS can only provide 9.6 kW of power whereas the truck on its’ own without the HIS can provide 7.2 kW of power.

Agree that the plan appears to be a totally seperate circuit for 80A EVSE than connection to this. Ideally the EVSE would have a fuse or breaker protected output to feed over to this, with inverter intended to be located adjacent to EVSE. I don't think they have done that though. Potential reason might be NEC limits on size of source breaker in panel for grid-intrractive power production, which the inverter can provide from solar or theoretically from stored battery energy as well. Personally I am hoping the inverter EVSE DC port can somehow be used for daily truck charging, at which point I would consider forgoing the 80A AC circuit and charging at max 9.6kW (DC).

Advatantage of HIS arrangement is more in ability to run solar while grid is down IMO. Not a big deal for a small storm outage. Bigger deal for any potential of week+ events. Also, the MID has an autotransformer built in that will allow phase imbalance of up to 30A. So the HIS 9.6kW will be more usable than the than 7.2kW bed outlet with smaller per phase limits.

The MID is as expected for a whole home back-up. Not meaning everything in the home can run at once, but power is physically available to any wiring of the home. This means no more stupid critical loads panels. With that arrangement and grid-interactive power source(s), you only need to be able to isolate or island from the grid and not transfer between two independent power sources. So transfer switch isn't really the right term for what is needed. Home gas or NG back-up generators NEVER produce in synceonozation/parallel with grid, so they get treated differently.

 

[Bombero1394]

If you already have solar and battery setup and don't particularly need the power from the Lightning for the house, you can always use the 40/32amp charger that comes with the truck and charge it on solar. At that point, the truck doesn’t know where the power is coming from. Im sure you can always tune it down to a lower amp like 20 or so so you don’t pull more than your solar is producing and running the house at the same time. That’s what I currently do at home.

 

[williams]

You don't have to send all power to the truck. You send all power to the house. The truck is part of the house/charging. As long as you are producing enough excess energy to power your house, you can charge the truck too.

The Powerwall has a 13.5kWh battery - the F150 has 98kWh or 131kWh.

This video isn't perfect, has a few inaccuracies, but is in line with the general ideas:

The problem with this is when you leave the house, to say go to work. You leave the house unpowered. All solar systems unless tied to some type of battery can not stand alone power the home, the inverters on the panels need to see power to make power. It takes a lot to explain but there is a reason. So in theory yes the truck has 6x the capacity of a power wall, but once you unplug the truck all the solar parts die. Rebooting solar systems is no fun, as well your house is not happy about power sudden losses and restarts.

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