Backup Power

[Maquis]

it should be noted that the HIS can be installed without solar - you're not required to use the solar string inputs. Is the cost high? Perhaps slightly, but this is early adopter territory. 10kW string inverters typically run low-to-mid $2,000s for cost today (maybe a bit less expensive for the big big guys). Add the other components (battery & grid disconnect switch), profit, and early adopter tax and it seems about right.

Personally, I'd think Enphase has to do more development work than all the other string inverter manufacturers (Delta, SMA, SolarEdge, etc.) because their inverters are all 25-50V, ~250-350W and they'd be designing a new "big" inverter. The existing string inverter manufacturers just have to get the software right to create the microgrid (instead of just shutting down due to UL1741).

Here's what needs to happen to supply backup power from the system when failure is detected. It's more complex than the typical UL1741 grid-tie solar install:

* Something needs to become aware of the grid failure (MID, above)
* Grid must be immediately disconnected (but still monitored for return) (MID)
* Inverter uses its dark-start battery to establish the power baseline for a microgrid, keeping the system alive to continue all the rest of the steps to get the truck's power online (inverter using dark-start battery)
* Truck must be instructed to wake up, turn on the HV contactors, and supply the battery to the CCS DC terminals if no errors (EVSE)
* Inverter then begins using DC power available from the truck to supply loads from the home and adjusts to maintain proper voltage while monitoring for ground faults (truck must immediately disconnect DC terminals if DC ground fault detected, which is why EVSE plays a role here)
* When grid power return is detected, the grid can be reconnected to the system by the MID and the inverter can begin tapering its supply and disconnects the DC when no longer needed
* Truck recharges via EVSE

As you can see, it's not just as simple as a cheap 400 VDC inverter.

All the other solar PV that's connected (whether Enphase microgrid or some other external system) will use UL1741 to integrate and will work to match frequency and regulate voltage based on load.

Great write up. I was tempted to do this, but I didn’t understand a couple details well enough to make sure I wasn’t posting something half-assed.
One question I have is: Does the EVSE actually switch the DC, or does it just tell the truck to open/close the HVB contactor? I would think the latter, but I’m interested in your opinion and reasoning. Thanks!

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[FlasherZ]

Great write up. I was tempted to do this, but I didn’t understand a couple details well enough to make sure I wasn’t posting something half-assed.
One question I have is: Does the EVSE actually switch the DC, or does it just tell the truck to open/close the HVB contactor? I would think the latter, but I’m interested in your opinion and reasoning. Thanks!

Short answer: EVSE doesn't switch DC, it merely instructs the truck to connect the battery to the DC pins in the CCS connector. That's achieved by 1) closing HV battery contactors to allow the HV to reach vehicle systems after validating any HV interlock conditions; and 2) closing the CCS DC contactors to allow the HV to reach the CCS port. The truck software ensures the safety before allowing the DC voltage to be present on the cable.

Let me start by saying I have not looked at, nor tested, Ford's implementation of CCS and ISO 15118, so I won't *guarantee* any of this, but it's the way it's supposed to work.

 

[PiMatrix]

it should be noted that the HIS can be installed without solar - you're not required to use the solar string inputs. Is the cost high? Perhaps slightly, but this is early adopter territory. 10kW string inverters typically run low-to-mid $2,000s for cost today (maybe a bit less expensive for the big big guys). Add the other components (battery & grid disconnect switch), profit, and early adopter tax and it seems about right.

Personally, I'd think Enphase has to do more development work than all the other string inverter manufacturers (Delta, SMA, SolarEdge, etc.) because their inverters are all 25-50V, ~250-350W and they'd be designing a new "big" inverter. The existing string inverter manufacturers just have to get the software right to create the microgrid (instead of just shutting down due to UL1741).

Here's what needs to happen to supply backup power from the system when failure is detected. It's more complex than the typical UL1741 grid-tie solar install:

* Something needs to become aware of the grid failure (MID, above)
* Grid must be immediately disconnected (but still monitored for return) (MID)
* Inverter uses its dark-start battery to establish the power baseline for a microgrid, keeping the system alive to continue all the rest of the steps to get the truck's power online (inverter using dark-start battery)
* Truck must be instructed to wake up, turn on the HV contactors, and supply the battery to the CCS DC terminals if no errors (EVSE)
* Inverter then begins using DC power available from the truck to supply loads from the home and adjusts to maintain proper voltage while monitoring for ground faults (truck must immediately disconnect DC terminals if DC ground fault detected, which is why EVSE plays a role here)
* When grid power return is detected, the grid can be reconnected to the system by the MID and the inverter can begin tapering its supply and disconnects the DC when no longer needed
* Truck recharges via EVSE

As you can see, it's not just as simple as a cheap 400 VDC inverter.

All the other solar PV that's connected (whether Enphase microgrid or some other external system) will use UL1741 to integrate and will work to match frequency and regulate voltage based on load.

Yes, good summary all the steps necessary to integrate a complete system. Just saying the IQ8D microgrid inverter can already take 119v dc, 630 watts and create its own micro grid integrating completely with existing iq8 solar panels or iq battery or generator all running and providing additive power input at same time. Seems not too hard to stretch to create a 400v product using 4 multiple iq8Ds. But this does not exist yet.

The system controller 2 can shut off the grid while all the microgrid component work together for additive power. It’s actually pretty amazing. For example a 12kw generator can be running, charging ac backup batteries, adding power to the solar microgrid for the home all at the same time! Tesla shuts down everything, solar included, if gen transfer switch is turned on.

I am thinking in the short term that is how I will use the f150 backup, use as generator input to enphase and trucks power will add to the solar panel grid or charge up the one enohase iq battery I will have if I need to drive truck to supercharger. When every component is grid aware and can communicate, throttle, or shutdown with every other supply to the grid it really gets exciting on what you can do! You don’t even need a powerwall like battery device to do this, just need to make sure you have enough solar, and truck power, to handle home load. All the devices communicate to throttle power to the load. Of course no one has tried this with lightning yet, so look for smoke from my house

 

[FlasherZ]

From FlasherZ comments and the online documentation it seems that sunrun wants to supply that 9.6KW to a backup panel with critical loads. Clearly the power to the charger does not come from the backup power, it comes from the main panel. Note, neglecting few percent efficiency losses in above.

You don't *have* to use a backup panel with critical loads. In theory, you could leave everything in your existing panel and just pipe the whole home through the MID - but I don't think most homes will want that. First, many homes can overwhelm and overload the 10 kW that the inverter can provide, likely causing shutdown or tripping an OCPD.

In my opinion, it's best practice to make conscious decisions on what needs to operate in a backup scenario and have them in a dedicated panel for that backup.

 

[FlasherZ]

I am thinking in the short term that is how I will use the f150 backup, use as generator input to enphase and trucks power will add to the solar panel grid or charge up the one enohase iq battery I will have if I need to drive truck to supercharger. When every component is grid aware it really gets exciting on what you can do! You don’t even need a powerwall like device to do this, just need to make sure you have enough solar, and truck power, to handle home load. All the devices communicate to throttle power to the load. Of course no one has tried this with lightning yet, so look for smoke from my house

That's an option - a lower-cost one if you already have the capability and don't mind plugging in a second plug.

I have a 25 kW genset already integrated with backup load panels separated already, so I'm probably not going to spring for the HIS unless they want to give me one... I'd have to go through some more re-work to move my solar around and get it on the correct "side" of the devices. And my power distribution in my home already looks like spaghetti hell with 3 service disconnects, 6 subpanels, an ATS, a genset, 2 EV chargers, and 2 outbuildings.

 

[PiMatrix]

ha, yes, and then try adding an Emporia energy monitor if you really want a second serving of spaghetti!

https://www.emporiaenergy.com/how-the-vue-energy-monitor-works

Heard about them from sisters lifetime friend who started the CO company. Got one of these with idea I'd monitor things for a few months to see real usage but time flies and we'll have to make decision without. Installers probably won't appreciate all that extra wiring while they are moving circuits, so I'll wait until they are done. Have a 10% off coupon owner gave me if you are interested - DIYSOLAR

They also have AC plugs that can be put in anywhere that communicate with box so you can more granular pin down phantom usage and plot on the same app. Samples every minute I believe. With the gigantic increase in electricity costs recently it really pays to understand where the waste is.

 

[wighty]

ha, yes, and then try adding an Emporia energy monitor if you really want a second serving of spaghetti!

https://www.emporiaenergy.com/how-the-vue-energy-monitor-works

If anyone is looking at buying one of these, I think they are far more useful than something like the Sense, which in theory sounds great but in practice sounds like it really fails/struggles at identifying the loads. I went with the iotawatt, which looks like it is going to be similar to the monitor mentioned above where you put CTs on each circuit you want to monitor.

 

[cvalue13]

Hoping you’ll tolerate a thread resurrection for a shift in topic, seeing how the folks bantering here seem far more agile in these matters than myself (a low bar):

I’ve written off the HIS for the foreseeable future, so I am left wondering how I might in a power outage still utilize the F150L’s battery in a more rudimentary way.

I’m currently discussing with my electrician, who is not agile with EVs or battery backup, the installation of a 240v plug that backfeeds my panel for use with my portable 7.5kW generator. With the generator, the plan would be in an outage situation to (1) cut power to the house, (2) cut power from my (21kW) solar system, (3) flip off all my individual breakers, (4) power up the generator, (5) connect generator to the 240 backfeeeing my panel, then finally (6) selectively switch on the critical breakers (e.g., refrigerator, certain lights, tankless propane water heater, propane stove, etc.).

By now my follow-up question is probably obvious: will I be able to substitute the portable generator for the F150L’s 240 output (assuming the correct cord is used*)?

If ‘yes’ in theory, is anyone here doing/testing this yet?

My electrician was notionally going install the Pro Charger (downrated to 40amps max), and “above” it in the line install a switch that cuts over to a 240 outlet to be used for back feeding the panel with the generator (and/or F150L). In this ok arrangement, it would add a 7th step to the above, namely of switching off of the feed to the charger and instead towards the 240v outlet for backfeedinthe panel.

appreciate in advance any handholding

 

[Firestop]

Hoping you’ll tolerate a thread resurrection for a shift in topic, seeing how the folks bantering here seem far more agile in these matters than myself (a low bar):

I’ve written off the HIS for the foreseeable future, so I am left wondering how I might in a power outage still utilize the F150L’s battery in a more rudimentary way.

I’m currently discussing with my electrician, who is not agile with EVs or battery backup, the installation of a 240v plug that backfeeds my panel for use with my portable 7.5kW generator. With the generator, the plan would be in an outage situation to (1) cut power to the house, (2) cut power from my (21kW) solar system, (3) flip off all my individual breakers, (4) power up the generator, (5) connect generator to the 240 backfeeeing my panel, then finally (6) selectively switch on the critical breakers (e.g., refrigerator, certain lights, tankless propane water heater, propane stove, etc.).

By now my follow-up question is probably obvious: will I be able to substitute the portable generator for the F150L’s 240 output (assuming the correct cord is used*)?

If ‘yes’ in theory, is anyone here doing/testing this yet?

My electrician was notionally going install the Pro Charger (downrated to 40amps max), and “above” it in the line install a switch that cuts over to a 240 outlet to be used for back feeding the panel with the generator (and/or F150L). In this ok arrangement, it would add a 7th step to the above, namely of switching off of the feed to the charger and instead towards the 240v outlet for backfeedinthe panel.

appreciate in advance any handholding

I have been thinking about doing something similar. I already have a standard sub panel wired with my critical loads fed from my house Main Panel and from a 50A externally mounted generator in-feed plug controlled by a manual interlocking transfer switch.

My two questions, which are in addition to yours:

1. Given the trucks 240V outlet is rated at 30A, am I really only safely able to use 24A max. (20% derate) continuous loads in the panel?
2. Do I need to upgrade the CLP to address the truck’s bonded neutral?

 

[hturnerfamily]

1. 'continuous loads' doesn't apply to this situation, as most any home's average uses, devices, appliance, and air conditioners are not in 'continuous' use 24/7... they use power sporadically and as needed. Using the full 30amps is perfectly fine - the truck is designed for it.
2. the bonded neutral issue for 'direct' runs from the truck to a panel is problematic due to a 'ground loop' that arises - the truck doesn't like that. You can remove the ground from one end of the cord, as many bonded-neutral generator owners do on their generators to get around the same issue, for temporary usage needs. It's doubtful that electrical outages are really that common or that frequent, at least not in the majority of this country. Most outages also don't last that long. Some will get by with this type of generator power supply option, and others will invest in the much more and very expensive 'automatic' equipment.

 

[cvalue13]

the bonded neutral issue for 'direct' runs from the truck to a panel is problematic due to a 'ground loop' that arises - the truck doesn't like that.

Thanks for weighing in.

I remember my electrician talking about fashioning a cord to make this work, and I suspect that had to do with this bonded neutral issue you’re referencing.

Since the truck may not “like” that, I suppose we’ll need some Lightning owners with some electrician chops better than mine to try this out and trouble shoot.

For my novice education, though: is there also this bonded neutral problem with the portable generator being put into the back fed 240, or is there a key difference between the generator and the truck in this “bonded neutral” respect?

 

[Maquis]

Thanks for weighing in.

I remember my electrician talking about fashioning a cord to make this work, and I suspect that had to do with this bonded neutral issue you’re referencing.

Since the truck may not “like” that, I suppose we’ll need some Lightning owners with some electrician chops better than mine to try this out and trouble shoot.

For my novice education, though: is there also this bonded neutral problem with the portable generator being put into the back fed 240, or is there a key difference between the generator and the truck in this “bonded neutral” respect?

Most portable generators have a bonded neutral. Some come with instructions on removing the bond for cases like this. Many do not have GFCI protection on the 240V receptacle, so the average user won’t know the difference.

 

[Firestop]

Most portable generators have a bonded neutral. Some come with instructions on removing the bond for cases like this. Many do not have GFCI protection on the 240V receptacle, so the average user won’t know the difference.

Well, that me….average ….and may explain why my current generator hasn’t been an issue, no integral GFIC on its 240V. So, my understanding is the truck’s GFIC is what may be the hang up….and, begs a follow up questio: Is there a reasonable ans safe solution for a temp supply from the truck without having to install a Generac or other brand manual transfer switch?

https://www.generac.com/generaccorp...all-guidelines-6333_6334.pdf?ext=.pdf#page=11

 

[Maquis]

Well, that me….average ….and may explain why my current generator hasn’t been an issue, no integral GFIC on its 240V. So, my understanding is the truck’s GFIC is what may be the hang up….and, begs a follow up questio: Is there a reasonable ans safe solution for a temp supply from the truck without having to install a Generac or other brand manual transfer switch?

https://www.generac.com/generaccorp...all-guidelines-6333_6334.pdf?ext=.pdf#page=11

Either a transfer switch or breaker interlock kit is required by the NEC to make it physically impossible for you to backfeed the grid.

 

[PiMatrix]

Hoping you’ll tolerate a thread resurrection for a shift in topic, seeing how the folks bantering here seem far more agile in these matters than myself (a low bar):

I’ve written off the HIS for the foreseeable future, so I am left wondering how I might in a power outage still utilize the F150L’s battery in a more rudimentary way.

I’m currently discussing with my electrician, who is not agile with EVs or battery backup, the installation of a 240v plug that backfeeds my panel for use with my portable 7.5kW generator. With the generator, the plan would be in an outage situation to (1) cut power to the house, (2) cut power from my (21kW) solar system, (3) flip off all my individual breakers, (4) power up the generator, (5) connect generator to the 240 backfeeeing my panel, then finally (6) selectively switch on the critical breakers (e.g., refrigerator, certain lights, tankless propane water heater, propane stove, etc.).

By now my follow-up question is probably obvious: will I be able to substitute the portable generator for the F150L’s 240 output (assuming the correct cord is used*)?

If ‘yes’ in theory, is anyone here doing/testing this yet?

My electrician was notionally going install the Pro Charger (downrated to 40amps max), and “above” it in the line install a switch that cuts over to a 240 outlet to be used for back feeding the panel with the generator (and/or F150L). In this ok arrangement, it would add a 7th step to the above, namely of switching off of the feed to the charger and instead towards the 240v outlet for backfeedinthe panel.

appreciate in advance any handholding

Hi, a few weeks ago we discussed this in a thread that maybe makes clear the options and risks - https://www.f150lightningforum.com/...-integration-system-self-install.11022/page-2

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