Planning for home backup power

[data003]

So I’ve currently got 100A service. Obviously that’s going to need upgrading. My options are,

1. Add a second meter, 200A service. This option is easier to install and cheaper. If I go with this option I could use the 7.2k 30A plug in the bed to hook up to a transfer switch on my old panel and get backup power but it wouldn’t be automatic or convenient.

2. Upgrade my existing service to 400A or 320A, this is at least a couple grand more expensive because the meters are much bigger. In theory I could integrate this with the Sunrun equipment though and get all the cool automatic transfer features.

Thoughts? Originally I was leaning toward option 1 but now I’m second guessing myself.

I wish they had some specs out on the Sunrun equipment so I could figure out the technical details and costs.

edit: fixed incorrect bed power kW

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[RickLightning]

As an FYI, I contacted my utility company when we added our Mach-E to understand future capabilities, and learned some things:

1) My neighbor and I share a transformer, and we each have 200 amp service. One of us can upgrade to 400 amp service (i.e. pulling 320 amp) just fine. When the second house goes to upgrade, the transformer will need to be upgraded, and they will bear the cost.

2) Our service from the transformer to the meter box on each house can support 400amp (320amp continuous) just fine.

3) Our meter has a separate set of lugs for an electrician to pull the 2nd 200 amp panel's service from. There is no need for a second meter. Of course installation of a 2nd meter would cost money, plus there is a monthly cost for 2nd meter.

 

[data003]

As an FYI, I contacted my utility company when we added our Mach-E to understand future capabilities, and learned some things:

1) My neighbor and I share a transformer, and we each have 200 amp service. One of us can upgrade to 400 amp service (i.e. pulling 320 amp) just fine. When the second house goes to upgrade, the transformer will need to be upgraded, and they will bear the cost.

2) Our service from the transformer to the meter box on each house can support 400amp (320amp continuous) just fine.

3) Our meter has a separate set of lugs for an electrician to pull the 2nd 200 amp panel's service from. There is no need for a second meter. Of course installation of a 2nd meter would cost money, plus there is a monthly cost for 2nd meter.

Yep, that is a big part of this as well. My electrician and utility company have already determined the transformer is fine thankfully. Though in my case if it needed to be upgraded the utility company would pay for it. I assume they recoup the cost by selling us more power.

 

[RickLightning]

They told me cost would be $187, so that can't be the cost of the transformer, just some formula cost.

 

[Bandit216]

So I’ve currently got 100A service. Obviously that’s going to need upgrading. My options are,

1. Add a second meter, 200A service. This option is easier to install and cheaper. If I go with this option I could use the 9.6kw 30A plug in the bed to hook up to a transfer switch on my old panel and get backup power but it wouldn’t be automatic or convenient.

2. Upgrade my existing service to 400A or 320A, this is at least a couple grand more expensive because the meters are much bigger. In theory I could integrate this with the Sunrun equipment though and get all the cool automatic transfer features.

Thoughts? Originally I was leaning toward option 1 but now I’m second guessing myself.

I wish they had some specs out on the Sunrun equipment so I could figure out the technical details and costs.

Trying to power ALL the circuits of a modern house with the Lightning's smallish output isn't going to work, despite Ford's advertisements. Central Air plus an oven, frig, and microwave running simultaneously will likely trip the circuit.

If you want safe, hassle-free backup power, go with No. 1. Keep your old panel but move your non-critical circuits and high load circuits like oven, central air and clothes dryer, etc. to the new 200A panel. Connect the old panel to the new panel thru the SunRun inverter (or other inverter with a built in transfer switch). The Ford supplied charger is connected to the inverter.

When power goes out, you will lose your non-critical circuits on the new panel, but your critical circuits will be feed by the Lightning thru the inverter to the old panel. If the inverter you buy has a generator input capability, you will also be able to have a generator as a second backup. Sounds complicated but is actually the easier, and better approach. Also makes it easier to add in solar later.

Even with Ford providing the Power Station Pro, I don't think it will be possible for those without an existing backup power capability to add the inverter and the necessary wiring for under $3-4,000.

Cheapest ($100), albeit most inconvenient, workable option is 3 or 4 heavy duty extension cords from the Power on Board outlets to frig, microwave, and a few floor lights.

 

[kny]

As an FYI, I contacted my utility company when we added our Mach-E to understand future capabilities, and learned some things:

1) My neighbor and I share a transformer, and we each have 200 amp service. One of us can upgrade to 400 amp service (i.e. pulling 320 amp) just fine. When the second house goes to upgrade, the transformer will need to be upgraded, and they will bear the cost.

2) Our service from the transformer to the meter box on each house can support 400amp (320amp continuous) just fine.

3) Our meter has a separate set of lugs for an electrician to pull the 2nd 200 amp panel's service from. There is no need for a second meter. Of course installation of a 2nd meter would cost money, plus there is a monthly cost for 2nd meter.

Just having two 200 amp panels will not meet the current 320 amp requirement. The 320 amp requirement is not about the total amperage of main service capacity, rather sufficient busbar capacity to support the secondary power source via a backfed breaker in order to meet the 120% rule. SO, what you need is a panel with a 400amp rated busbar, and having two side-by-side 200 amp panels each with 200 amp busbar rating will not meet this requirement.

fwiw, I think this 320 amp requirement will be lessened or eliminated. It only applies due to potential of dual power sources feeding the busbar - grid and vehicle. However, the backup power only applies when the grid is down. WIth the grid power off a 200 amp busbar is more than fine to service a 100amp backfed breaker from the vehicle. The only need for 400amp rated busbar is if both the grid and the vehicle could potentially be feeding the bus, which is impossible. I suspect this requirement will get reduced, but as it sits now, you would need a single 400 amp panel with 400 amp rated busbar and two 200 amp panels will not suffice.

 

[sotek2345]

Just having two 200 amp panels will not meet the current 320 amp requirement. The 320 amp requirement is not about the total amperage of main service capacity, rather sufficient busbar capacity to support the secondary power source via a backfed breaker in order to meet the 120% rule. SO, what you need is a panel with a 400amp rated busbar, and having two side-by-side 200 amp panels each with 200 amp busbar rating will not meet this requirement.

fwiw, I think this 320 amp requirement will be lessened or eliminated. It only applies due to potential of dual power sources feeding the busbar - grid and vehicle. However, the backup power only applies when the grid is down. WIth the grid power off a 200 amp busbar is more than fine to service a 100amp backfed breaker from the vehicle. The only need for 400amp rated busbar is if both the grid and the vehicle could potentially be feeding the bus, which is impossible. I suspect this requirement will get reduced, but as it sits now, you would need a single 400 amp panel with 400 amp rated busbar and two 200 amp panels will not suffice.

hmmm.... Thinking through this, couldn't you also use a single 200A panel with a 100A main breaker to meet the requirement (assuming your loads are low enough to support that)?

I am also hoping that this requirement is reduced - if it holds very very few people will use the home backup solution and Ford will take a big PR hit.

 

[kny]

hmmm.... Thinking through this, couldn't you also use a single 200A panel with a 100A main breaker to meet the requirement (assuming your loads are low enough to support that)?

I am also hoping that this requirement is reduced - if it holds very very few people will use the home backup solution and Ford will take a big PR hit.

Yes, 200 amp panel with 200 amp rated busbar and 100 or 125 amp main breaker would meet the 120 rule busbar requirement. BusbarRating * 1.2 - MainBreaker = Max Allowable Backfed Breaker. So, 240 - 125 = 115 > 100. So, 125 amp main breaker would suffice. 150 amp would not.

 

[adoublee]

Just having two 200 amp panels will not meet the current 320 amp requirement. The 320 amp requirement is not about the total amperage of main service capacity, rather sufficient busbar capacity to support the secondary power source via a backfed breaker in order to meet the 120% rule. SO, what you need is a panel with a 400amp rated busbar, and having two side-by-side 200 amp panels each with 200 amp busbar rating will not meet this requirement.

fwiw, I think this 320 amp requirement will be lessened or eliminated. It only applies due to potential of dual power sources feeding the busbar - grid and vehicle. However, the backup power only applies when the grid is down. WIth the grid power off a 200 amp busbar is more than fine to service a 100amp backfed breaker from the vehicle. The only need for 400amp rated busbar is if both the grid and the vehicle could potentially be feeding the bus, which is impossible. I suspect this requirement will get reduced, but as it sits now, you would need a single 400 amp panel with 400 amp rated busbar and two 200 amp panels will not suffice.

They might be trying to prepare installations for software unlock of V2G. V2G would be dual power sources at once. It could also have to do with a listing requirement if the EVSE can be a power source without use of their own microgrid interface device that ensures two sources are never connected together, though I think they are going to require use of their MID for the EVSE to operate as a source.

 

[sotek2345]

They might be trying to prepare installations for software unlock of V2G. V2G would be dual power sources at once. It could also have to do with a listing requirement if the EVSE can be a power source without use of their own microgrid interface device that ensures two sources are never connected together, though I think they are going to require use of their MID for the EVSE to operate as a source.

I can understand that, but it makes the home backup solution (pretty heavily marketed by Ford) to be cost prohibitive for the majority of buyers - not a good look. Depending on your situation, installing a 400A service and the wiring / equipment needed for V2H (large cabling, automatic transfer switch, inverter, etc.) could cost more than the truck!

 

[Maquis]

Just having two 200 amp panels will not meet the current 320 amp requirement. The 320 amp requirement is not about the total amperage of main service capacity, rather sufficient busbar capacity to support the secondary power source via a backfed breaker in order to meet the 120% rule. SO, what you need is a panel with a 400amp rated busbar, and having two side-by-side 200 amp panels each with 200 amp busbar rating will not meet this requirement.

fwiw, I think this 320 amp requirement will be lessened or eliminated. It only applies due to potential of dual power sources feeding the busbar - grid and vehicle. However, the backup power only applies when the grid is down. WIth the grid power off a 200 amp busbar is more than fine to service a 100amp backfed breaker from the vehicle. The only need for 400amp rated busbar is if both the grid and the vehicle could potentially be feeding the bus, which is impossible. I suspect this requirement will get reduced, but as it sits now, you would need a single 400 amp panel with 400 amp rated busbar and two 200 amp panels will not suffice.

That’s incorrect. The Lightning system is for backup power, not to feed the grid like solar. It will involve a transfer switch - the panel is either fed from the utility or the Lightning, never both. The 120% rule for a grid-tied system does not apply.

 

[adoublee]

I can understand that, but it makes the home backup solution (pretty heavily marketed by Ford) to be cost prohibitive for the majority of buyers - not a good look. Depending on your situation, installing a 400A service and the wiring / equipment needed for V2H (large cabling, automatic transfer switch, inverter, etc.) could cost more than the truck!

Agree, which is why I think @tommolog is suggesting the 400A service isn't actually going to be an installation requirement in all cases, following his conversation with Ford on the system. Still waiting for him to publish the details of what he learned.

 

[Oneand0]

So I’ve currently got 100A service. Obviously that’s going to need upgrading. My options are,

1. Add a second meter, 200A service. This option is easier to install and cheaper. If I go with this option I could use the 9.6kw 30A plug in the bed to hook up to a transfer switch on my old panel and get backup power but it wouldn’t be automatic or convenient.

I’ve been thinking about this for a while now. I think your number 1. is the right choice for me. It’s for emergencies and easy enough to attach from the bed of the truck to an outside plug in the front of my house that goes to a transfer switch, next to my main circuit. Not as cool as putting all the money into Sunrun setting it up. But it will work. I only have a 100A service and need to upgrade anyway for a 50A to a 14/50 for my EV and for another plug for a new hot tub. My father is ordering a Lightning too and already has his transfer switch setup for his generator outside.

In addition to this, I’ve decided to do a DIY solar later on this year that will not go to the grid, but go to my shed , where the Lightning will be parked. I plan on using it to power my Lightning when it’s parked there for days, since I work at home, or power it when the grid is out. I live in California and we are used to experiencing that. No need to tie up that solar to the grid, I only average 360 Kw a month. My Lightning will take more than that.

 

[pstansel]

I can't imagine a 400 amp (or even 320 amp) is going to be required but I guess I could be wrong. The IBP page doesn't even have it anymore I thought?

 

[jefro]

There are a few issues.
One is how one can get power out. Not easy to connect a subpanel to a house panel with a transfer switch while one has a secondary panel/meter.
Two is the ongoing cost of a secondary meter.
Three is the actual load needed to charge. You may have enough to charge at lower amps and still retain the ability to install the Ford ABT.
Other threads said they removed that silly 320A figure.
It may be that your power supplier has energy chargers that make one way or the other better.

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