Integrating future V2H EV charger into soon to be installed residential solar system

[solardreamer]

Ok, so today I talked with my installer and I have more specifics to share. The PV system for my house will be based on the Solaredge inverter model SE10000H-US + optimizers so there will be plenty of room to grow if needed in the future (the 5.6 kW system is being designed around 14 monocrystalline panels @ 405w). He said that Solaredge is already doing beta testing in California with new firmware for their HD-Wave inverters to allow for bi-directional charging on an EV like the Nissan Leaf.

So I am hopeful that in about a year or so this will become a reality in other states including Texas.

If you don't care about producing solar power during power outages then standard SE grid-tied inverters should be fine. Otherwise, you may want to consider the SE Energy Hub Inverters, assuming you want to stick with SE, to avoid the cost and complexity of adding on a hybrid inverter later on.

[curro]

Ok, so today I talked with my installer and I have more specifics to share. The PV system for my house will be based on the Solaredge inverter model SE10000H-US + optimizers so there will be plenty of room to grow if needed in the future (the 5.6 kW system is being designed around 14 monocrystalline panels @ 405w). He said that Solaredge is already doing beta testing in California with new firmware for their HD-Wave inverters to allow for bi-directional charging on an EV like the Nissan Leaf.

So I am hopeful that in about a year or so this will become a reality in other states including Texas.

[curro]

Does you garage get hot in the summer? If so, I wouldn't recommend installing any large battery system in there.

Yes, Texas hot!. Good point. So back to the Nissan Leaf V2H engineering design ...

[Ampster]

..........However, to Ford's credit, they are working with Sunrun for solar integration for their DC based V2H (an option for high end models) with additional external equipment. Not much detail is available yet but I suspect Sunrun will likely integrate the DC based V2H with a hybrid inverter system that includes its own (smaller?) battery system.

I will be interested to see how that works out. If the hybrid inverter can AC couple with an existing grid tied solar system then that would allow the GT system to charge the batteries of the hybrid and possibly the vehicle as well as supplying house loads. That would give them the same functionality as a Tesla Powerwall. AC coupling a GT inverter would not work well without a dedicated battery. The V2H would be additional icing on the cake.

[solardreamer]

Ford's solution may be just a 240 volt AC inverter which would might interface with an extension cord. Details are few but it could function like a generator.

Yes and no. F150 Lightning supports both AC and DC based V2H. The AC based V2H works much like a generator. However, to Ford's credit, they are working with Sunrun for solar integration for their DC based V2H (an option for high end models) with additional external equipment. Not much detail is available yet but I suspect Sunrun will likely integrate the DC based V2H with a hybrid inverter system that includes its own (smaller?) battery system.

[soby]

The Storedge used to only work with the LG Chem high voltage battery but that battery has been recalled.

Somehow, mine was not part of the recall. I'm hoping it lives a long, fireless life in my cool basement.

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[Ampster]

Sure, Ford has already done it.

Ford's solution may be just a 240 volt AC inverter which would might interface with an extension cord. Details are few but it could function like a generator.

Tesla would rather build out more gigafactories to selll PW's than V2H. They want to build a virtual power plant business around all the PW's they sell which wouldn't work with just V2H. Perhaps more competition will change their thinking but I don't anytime soon.

Yes, Tesla must not see that there is a very big market for V2H. As mentioned earlier, they don't want to cannibilize their Powerwall business. I also see issues with the vehicle battery warranty if the vehicle battery is cycled more. To their credit they did move quickly when they saw a market for home batteries and commercial installs of Powerpacks.

[solardreamer]

By the way I was checking online the price of a new Nissan Leaf battery (30 or 40 kW I am not sure): somewhere in the range of 6 to 7 grands. Not bad for that size. I wonder if it can be hooked up to a Solaredge system or similar. The problem would be the size. We put both our cars in the garage right now and the space is very limited with everything else (four bikes, shelves, etc.).

Does you garage get hot in the summer? If so, I wouldn't recommend installing any large battery system in there.

[Ampster]

I bought a used Nissan Leaf pack in 2016 for $1500. I am guessing it had a capacity at somewhere around 20kWh. That price was $0.75 per kWh. I reconfigured the modules into a nominal 48 volt pack to run an Outback Skybox. That Nissan pack is nominally 350 volts and the Solaredge Storedge runs at about that voltage. The Storedge used to only work with the LG Chem high voltage battery but that battery has been recalled.
A new pack at $7000 for 40kWh is around$175 per kWh. You probably cannot find LFP cells in the States for that price but last year I bought 42kWh of LFP cells from two different Alibaba vendors for $125 per kWh delivered to my door. There are examples of brands like Battleborn which are going for $1000 per kWh. Batteries can be expensive but if you have DIY skills you can save money.

[soby]

Sure, Ford has already done it. Tesla would rather build out more gigafactories to selll PW's than V2H. They want to build a virtual power plant business around all the PW's they sell which wouldn't work with just V2H. Perhaps more competition will change their thinking but I don't anytime soon.

I didn't realize Ford built the F-150 Lightning with this in mind. I'm really impressed: https://www.youtube.com/watch?v=Zxe352yOYyk

Now I want to know more about the home integration to make the V2H backup power a reality.

[solardreamer]

It would provide a viable alternative solution for homeowners that already own solar panels and a Tesla EV. Tesla can't meet the demand for PowerWalls so they are only bundling them with solar. For people that already have solar, Tesla can give them a killer home backup solution by supplying:

1) Transfer Switch - Backup Gateway 2
2) V2H EV Charger - Repackage the electronics from a PowerWall 2 (minus the battery) as an EV charger.

The R&D to make #2 above happen is minimal and those two items shouldn't cost more than $5,000. Add another $1,000 for installation and you'd have a 50-100kWh battery ready to provide backup power to your home whenever it's plugged in in your garage. That would be way WAY cheaper than a dedicated PowerWall solution with that capacity. I'd be all over that and it would make a Tesla EV that much more valuable.

Sure, Ford has already done it. Tesla would rather build out more gigafactories to selll PW's than V2H. They want to build a virtual power plant business around all the PW's they sell which wouldn't work with just V2H. Perhaps more competition will change their thinking but I don't anytime soon.

[curro]

By the way I was checking online the price of a new Nissan Leaf battery (30 or 40 kW I am not sure): somewhere in the range of 6 to 7 grands. Not bad for that size. I wonder if it can be hooked up to a Solaredge system or similar. The problem would be the size. We put both our cars in the garage right now and the space is very limited with everything else (four bikes, shelves, etc.).

[soby]

Tesla has the least incentive to do anything V2H compared to other EV manufacturers as they don't want to hurt their home battery business.

It would provide a viable alternative solution for homeowners that already own solar panels and a Tesla EV. Tesla can't meet the demand for PowerWalls so they are only bundling them with solar. For people that already have solar, Tesla can give them a killer home backup solution by supplying:

1) Transfer Switch - Backup Gateway 2
2) V2H EV Charger - Repackage the electronics from a PowerWall 2 (minus the battery) as an EV charger.

The R&D to make #2 above happen is minimal and those two items shouldn't cost more than $5,000. Add another $1,000 for installation and you'd have a 50-100kWh battery ready to provide backup power to your home whenever it's plugged in in your garage. That would be way WAY cheaper than a dedicated PowerWall solution with that capacity. I'd be all over that and it would make a Tesla EV that much more valuable.

[solardreamer]

dcbel's solar integration appears to be only for on-grid operation so solar won't work during grid outages.

In general, bidirectional chargers will only work in charge or discharge mode at any one time with non-trivial direction switching time partially due to CHADEMO/CCS bidirectional charging protocols. So, unlike traditional AC coupled hybrid inverter systems (e.g. Magnasine) which have separate charger/charge controller and discharger/inverter that run simultaneously, a bidirectional charger by itself is won't likely be able to manage the transient conditions in an island grid with grid-tied solar.

Frankly, the V2H/solar integration issue is conceptually the same as the generator/solar integration issue/wish that many home solar owners have raised for years now. Solar vendors don't seem interested in offering a solution as they just want to push dedicated home battery systems.

[curro]

Thanks all for the replies and reasoning this being a more complex set up. Ok, complex now but it looks like dcbel r16 is trying to figure out and make it all integrated.

soby you make very good detailed points about V2H. I also agree with solardreamer that Tesla might have the capability but not the will to set up a well integrated V2H PV residential system. In this regard I wonder how a Wallbox Quasar would integrate into a PV system with either a Solaredge inverter or a PV system base on micro-inverters. They state here that it supports also V2H:

“Wallbox Quasar was engineered to transform electric vehicles into powerful energy sources. The bidirectional charging technology lets you charge and discharge your EV, allowing you to power your home or the grid with your car battery. With Quasar, your EV battery is not just for driving, it also gives you extra energy to power your life.”