Powering the grid from your car

[miimura]

I like it, except I want / need a parallel solar system that can make this system "perpetual" power.

Also, I see no reason that an autotransfer switch can't separate the grid tied panels from the grid. We just need a simple method that regulates load. We could have one switch per solar panel that we could manipulate based on load.

You can "AC couple" your existing grid-tied inverter, but you have to be very careful about where and how it is connected so that it works normally when the grid is up and when it is down. The two different inverter systems I've looked at with respect to AC coupling both say that the Grid Tie inverter must be rated less than the battery inverter. Outback power says that you should not connect more than 6kW of AC Coupled Solar to the 8kW Radian Inverter (125% rule). It handles the isolation to the grid and cuts out the solar inverter when the batteries are full. Of course, the best way to connect solar to this kind of system is to use solar charge controllers instead of inverters. They do MPPT tracking and don't have to do DC/AC/DC conversion, they just let through the DC current to the battery at the optimum DC voltage for each string of panels. When the batteries are full, they just stop letting through the current. Alternatively, you can configure the inverter to start selling into the grid when the batteries are full and the charge controllers keep running full blast.

 

[miimura]

Just for reference, there is a guy in Norway who disassembled some salvage Leaf packs to make his own solar storage system. Their utility pays relatively little for grid feed-in, so it is economically advantageous to consume your own solar generation. Anyway, he did some nice packaging of the Leaf modules in a server rack. Other notables are a BMS that talks to the SMA Sunny Island by CANbus.

His thread at MyNissanLeaf

 

[dstjohn99]

Actually, a system built with an Outback Radian and about 40kWh of junkyard EV batteries would be a really nice setup for you guys.

This is very nice, but still requires 48V battery strings. I still look forward to being able to plug into an EV battery directly at higher voltage. It would be nice to integrate an EV into the system without disassembly and reconfiguring the batteries.

 

[solarjackpv]

Install Chademo on your car.

Wire a high voltage chademo plug into a 6kw Grid tie inverter that can take up to 500vdc In the same place you would wire in Solar. SMA would be my favorite. You'll have to some how fool the chademo port to open.

The 6kw grid tie inverter will pull the current its rated for, X 1.25, so between 6000-7500 watts coming from the EV.


Wire the 240ac output from the grid tie inverter into and Outback radian 8048. The grid tie inverter will not see the grid down because the outback inverter creates 240v 60 hz. The grid tie inverter hooked up to the electric car via the chademo port will take the power from the car through the GT inverter, through the Outback inverter and either power the loads in the house or spin the meter backwards if you have a net metering agreement from solar previously. (6000w inverters matches the OB 8048 wattage it can export to the grid and why I picked that wattage inverter)

You will need a 48vdc battery bank to turn on the outback inverter. Sealed agm would work fine. Min 200 amp hour bank. (More amp hours is better if planning to be tottally offgrid and planning on adding solar)

If the grid is active the outback radian can export to grid. But also if you want to be stealth and have the power company not know What you're doing. You can set the outback radian inverter to be in zero export mode. This mode is used in Hawaii where you get Can't export kWh to grid. Or set the outback inverter to go total offgrid mode by turning off the main grid breaker feeding your sub panel.

In offgrid or zero export mode,
When the 48v batteries are full and no loads are being used in the house.
The outback radian will turn off the grid tie inverter by frequency shifting or raising the voltage and tripping off the GT inverter. When the house loads turn on and power is needed the outback inverter will allow the GT inverter to turn back on which will take power from the EV once again.

If you want to add solar to this system. Do so by adding it to the Outback radian via charge controllers. Each Outback FM 80 charge controller can handle apx 4500w of PV. And adding two charge controllers to a XW8048 is maxing it out. Make sure you have a large enough 48v battery bank to handle the extra charging capacity.

You could also hook the outback radian to a generator in case it's night, Your ev is drained and can't connect with to the grid.

With your EV, Solar, and generator, you become your own power company.


Keep in mind these are all theory's and don't recommend trying it.

 

[Tadol]

Could I suggest something simple? I'd like a simple break out box that would plug into my car, and I could plug in a few extension chords and run a few basic 110v circuits off of. It would let me have some basic emergency power in a blackout, or in the field (bbq, party, construction site) or while camping - Even limited to a minimal output, it could be amazingly useful. In fact, a very basic circuit in the back of my Rav that would easily let me plug in a battery charger to keep my drills charged, or to run a vacuum or similar would be great -

 

[miimura]

Could I suggest something simple? I'd like a simple break out box that would plug into my car, and I could plug in a few extension chords and run a few basic 110v circuits off of. It would let me have some basic emergency power in a blackout, or in the field (bbq, party, construction site) or while camping - Even limited to a minimal output, it could be amazingly useful. In fact, a very basic circuit in the back of my Rav that would easily let me plug in a battery charger to keep my drills charged, or to run a vacuum or similar would be great -

If you only need 120V AC and less than 1,500 Watts, then you can easily get a 12V inverter to do what you want. You just need to connect into the 12V system where the wires are thick enough to support the load. It's those of us that want 5kW-10kW that would need something larger that would draw directly from the traction battery, likely through the CHAdeMO port. These devices exist, but only in Japan.

Personally, I'm looking forward to the Outback Power Skybox system so I can build a stationary storage system. If it is everything I imagine it will be, I will get an EV pack (or packs) from crashed EVs and set it up so that most of my house is basically on a giant UPS. Add some solar that directly charges the batteries and it will keep going for a long time if the grid goes down. Also, if the new solar is not enough, I can charge the batteries from the grid at off peak hours or in the mornings from my existing Enphase solar system. The key point is that I don't want the battery inverter to flow back to the grid.

 

[TonyWilliams]

Use the 1000 or 1500 watt version so that you don't overload the 100 amp DC to DC:

Use 2 gauge wires to connect this DIRECTLY to the battery. When you use it, just put the car in READY, or you will very quickly kill the 12 volt battery:

http://www.xantrex.com/documents/Power-Inverters/Xantrex-Inverters-Hardwired/DS20100113_XP-Inverter1000-1500-3000-5000.pdf

 

[solarjackpv]

Learn about the new Outback Skybox at a Training my Company is hosting in San Diego 25h-27th and other battery and Solar related topics for installers.

http://aeesolar.com/aee-solar-dealer-conference/

let me know if you need passes.

 

[dstjohn99]

It's here! The SolarEdge StorEdge SE7600A-USS2 is designed to work with the 400 volt DC LG CHEM RESU10H 10kW battery. This site is a good link for the required related hardware in one location:
https://greenenergykits.com/product...erter-se7600a-uss20nnb2?variant=5041283006494 though not the best price, this is a VERY affordable solution compared to Outback products and Tesla Powerwall.

It can't be too difficult to manage a connection between the Rav4 battery (~380 volts?) and the StorEdge inverter(s), probably a jdemo interface??

 

[TonyWilliams]

It's here! The SolarEdge StorEdge SE7600A-USS2 is designed to work with the 400 volt DC LG CHEM RESU10H 10kW battery. This site is a good link for the required related hardware in one location:
https://greenenergykits.com/product...erter-se7600a-uss20nnb2?variant=5041283006494 though not the best price, this is a VERY affordable solution compared to Outback products and Tesla Powerwall.

It can't be too difficult to manage a connection between the Rav4 battery (~380 volts?) and the StorEdge inverter(s), probably a jdemo interface??

Yep. I’d love to look into it.

 

[dstjohn99]

I'm excited to find out more about progress here. I hope to have a V2H solution in place in the next 90 days. Tony, have you had any response from SolarEdge engineering? I have another inquiry with them from 12/19 and I have not heard back yet. What is the best way to keep in touch on this, email via QCP?

 

[Aries]

What is the best way to keep in touch on this, email via QCP?

Maybe by posting here. I, too, have a jDemo and are interested in this topic and result. There may be others interested ...

 

[miimura]

EVTV Motor Verks has a variety of inverters available for sale that can directly take the DC pack voltage from an EV and output pure sine 240V split phase power. They have 50kW, 20kW, 10kW and 5kW units. For emergency power when the grid is down these are ready to go with the exception of the CHAdeMO interface. All you would need is a traditional generator transfer switch to ensure that the grid is cut off from the inverter.

They also have all the parts necessary to turn a full intact Tesla battery pack into an off grid power system. Their inverters have a kind of backwards UPS arrangement. Most of the time the load is powered by the inverter and battery pack. However, if the battery pack drops too low, it will turn off the inverter and connect the grid power to the loads. Maybe I shouldn't say UPS, because I think the load is interrupted during switching. Most of the time you shouldn't need to use that feature because you can put a battery charger on the grid to make sure that the battery never drops too low.

http://store.evtv.me/products.php?cat=22

 

[TonyWilliams]

I’ve been on holiday for the past couple weeks.

I’m planning on meeting with the Solar Edge folks in Jan/Feb in Fremont, California.

 

[dstjohn99]

EVTV Motor Verks has a variety of inverters available for sale that can directly take the DC pack voltage from an EV and output pure sine 240V split phase power. They have 50kW, 20kW, 10kW and 5kW units. For emergency power when the grid is down these are ready to go with the exception of the CHAdeMO interface. All you would need is a traditional generator transfer switch to ensure that the grid is cut off from the inverter.

They also have all the parts necessary to turn a full intact Tesla battery pack into an off grid power system. Their inverters have a kind of backwards UPS arrangement. Most of the time the load is powered by the inverter and battery pack. However, if the battery pack drops too low, it will turn off the inverter and connect the grid power to the loads. Maybe I shouldn't say UPS, because I think the load is interrupted during switching. Most of the time you shouldn't need to use that feature because you can put a battery charger on the grid to make sure that the battery never drops too low.

http://store.evtv.me/products.php?cat=22

An interesting alternative that seems cost effective at first, until you factor in the additional $2,400 module needed to interface with a Tesla battery (or EV?). Also not grid tied, so not really a good option "for the masses."

The Solaredge StorEdge is grid tied, needs few additional modules (a load balancing transformer if you want backup power supply - about $270)and will manage several output modes like peak shifting, battery charge times, partition battery between peak shaving and available backup power, etc. It's also only $2700.

That's why it sparks my interest due to robust capabilities and reasonable cost. Since it's already capable of interfacing with the grid and a Powerwall or similar RESU10H battery, I'm hoping the upsizing to the Rav4 pack is a reasonable task like a Chademo plug and simple interface control. We shall see...

 

[miimura]

EVTV Motor Verks has a variety of inverters available for sale that can directly take the DC pack voltage from an EV and output pure sine 240V split phase power. They have 50kW, 20kW, 10kW and 5kW units. For emergency power when the grid is down these are ready to go with the exception of the CHAdeMO interface. All you would need is a traditional generator transfer switch to ensure that the grid is cut off from the inverter.

They also have all the parts necessary to turn a full intact Tesla battery pack into an off grid power system. Their inverters have a kind of backwards UPS arrangement. Most of the time the load is powered by the inverter and battery pack. However, if the battery pack drops too low, it will turn off the inverter and connect the grid power to the loads. Maybe I shouldn't say UPS, because I think the load is interrupted during switching. Most of the time you shouldn't need to use that feature because you can put a battery charger on the grid to make sure that the battery never drops too low.

http://store.evtv.me/products.php?cat=22

An interesting alternative that seems cost effective at first, until you factor in the additional $2,400 module needed to interface with a Tesla battery (or EV?). Also not grid tied, so not really a good option "for the masses."

The Solaredge StorEdge is grid tied, needs few additional modules (a load balancing transformer if you want backup power supply - about $270)and will manage several output modes like peak shifting, battery charge times, partition battery between peak shaving and available backup power, etc. It's also only $2700.

That's why it sparks my interest due to robust capabilities and reasonable cost. Since it's already capable of interfacing with the grid and a Powerwall or similar RESU10H battery, I'm hoping the upsizing to the Rav4 pack is a reasonable task like a Chademo plug and simple interface control. We shall see...

The inverter that EVTV is selling would be a good backup power source. Actually, if you watch Jack Ricard's videos, he is big on solar first, so he designs the system so that the inverter would power the whole house and the solar charges the batteries directly through a solar charge controller. Only when the battery gets low, do you use a battery charger connected to the grid. That way, the inverter is never connected directly to the grid and it only does a fail-over to the grid if the battery gets too low.

A CHAdeMO controller is a whole lot simpler than what EVTV is selling for the intact Tesla pack interface. EVTV had to reverse engineer the whole BMS, which was clearly a big job. Tony's team likely already knows the CHAdeMO protocol well enough to make the V2H CHAdeMO interface with little new information. Since it's only acting as a battery interface and not a charger, it does not even have to have any current control. It just has to make the car think it is connecting to a valid CHAdeMO system and that the connections are safe.

 

[miimura]

In case I didn't say it, I feel that CHAdeMO connected V2H is only good for backup power. If you want a battery inverter to interact with the grid, you should dedicate a stationary battery to that task. Of course, it could be a salvaged EV battery, but then you don't need the CHAdeMO interface because you're stationary and don't need to disconnect it.

 

[dstjohn99]

In case I didn't say it, I feel that CHAdeMO connected V2H is only good for backup power. If you want a battery inverter to interact with the grid, you should dedicate a stationary battery to that task. Of course, it could be a salvaged EV battery, but then you don't need the CHAdeMO interface because you're stationary and don't need to disconnect it.

Interesting, why do you say that? I think it would be great to get home from work, use my remaining capacity for peak shaving the 4-9pm peak period, then charge from 12am-5am at off peak rates. Repeat daily. I would like to avoid spending another $6k for a dedicated battery that has less capacity than my car. It would cost $24k to get off the shelf batteries with capacity equivalent to my car - cheaper to buy another car (a battery I can drive, if needed!). If I get used Leaf batteries or similar, then there is the infrastructure complexity and expense of making them suitable for long term PV backup.

If I could just connect a Chademo plug and my L2 EVSE on timer, then forget it until next time I need to drive that would be ideal. I'm sure the inverter is not anticipating a vanishing battery pack, but that's where a little engineering can be used to create an interface to resolve any related issues, I hope.

 

[miimura]

In case I didn't say it, I feel that CHAdeMO connected V2H is only good for backup power. If you want a battery inverter to interact with the grid, you should dedicate a stationary battery to that task. Of course, it could be a salvaged EV battery, but then you don't need the CHAdeMO interface because you're stationary and don't need to disconnect it.

Interesting, why do you say that? I think it would be great to get home from work, use my remaining capacity for peak shaving the 4-9pm peak period, then charge from 12am-5am at off peak rates. Repeat daily. I would like to avoid spending another $6k for a dedicated battery that has less capacity than my car. It would cost $24k to get off the shelf batteries with capacity equivalent to my car - cheaper to buy another car (a battery I can drive, if needed!). If I get used Leaf batteries or similar, then there is the infrastructure complexity and expense of making them suitable for long term PV backup.

If I could just connect a Chademo plug and my L2 EVSE on timer, then forget it until next time I need to drive that would be ideal. I'm sure the inverter is not anticipating a vanishing battery pack, but that's where a little engineering can be used to create an interface to resolve any related issues, I hope.

Superficially, your scheme sounds workable. How effective it would be would depend on the actual usage pattern in your home. If the wife and kids get home before you, then you can't offset that usage because your car is not there.

Since I have solar, I think about these things assuming others do too even though I suppose it's not a requirement to have solar to use a battery to offset your peak usage. However, any grid interactive inverter needs Permission To Operate from the utility. People have been finding that the utilities have not been easy to work with on this and they have occasionally run into strange an nonsensical issues like the utility demanding grid impact studies and infrastructure upgrade costs based on combinations of system outputs that would never happen. This happened to a PG&E customer that had Tesla PowerWalls installed even though the tariffs and PTO process have already been updated to streamline the processing. The easiest residential PTO approval follows a path that ensures that the battery never actually discharges into the grid but instead purely offsets household loads.

This is getting more involved the more I think about it, so to save time I will just drop some other issues below without any further explanation right now.
- NEM 2.0 Non-Bypassable Charges
- Solar self consumption strategies that avoid utility interconnection
- How many kWh do you actually need to offset on a daily basis?
- Additional car battery pack degradation due to extra daily cycles beyond vehicle mileage

 

[davewill]

In case I didn't say it, I feel that CHAdeMO connected V2H is only good for backup power. If you want a battery inverter to interact with the grid, you should dedicate a stationary battery to that task. Of course, it could be a salvaged EV battery, but then you don't need the CHAdeMO interface because you're stationary and don't need to disconnect it.

Interesting, why do you say that? I think it would be great to get home from work, use my remaining capacity for peak shaving the 4-9pm peak period, then charge from 12am-5am at off peak rates. Repeat daily. I would like to avoid spending another $6k for a dedicated battery that has less capacity than my car. It would cost $24k to get off the shelf batteries with capacity equivalent to my car - cheaper to buy another car (a battery I can drive, if needed!). If I get used Leaf batteries or similar, then there is the infrastructure complexity and expense of making them suitable for long term PV backup.

If I could just connect a Chademo plug and my L2 EVSE on timer, then forget it until next time I need to drive that would be ideal. I'm sure the inverter is not anticipating a vanishing battery pack, but that's where a little engineering can be used to create an interface to resolve any related issues, I hope.

I sure wouldn't want to add the extra daily cycling to my car's battery. If a dedicated battery degrades, I just keep using it until I decide it's cost effective to replace it. If my car's battery degrades too much, my car becomes useless. Also, you've created a false equivalency on your pricing scenario. If you're just using the tail end of your car's capacity after your driving day to cover a small peak period, you probably only need a small (10kWh ?) battery to give you that same utility. Besides, how complex is the infrastructure if you buy the solution off the shelf?