Solar Edge Inverter and EV charger

[QuantumSlice]

I had a question today that I think I answered for myself. SolarEdge sells a "smart" EV charger that takes advantage of solar production to boost the car charging. This is crucial for me because I don't want to add6 0 amp breaker to my panel for my new VW ID.4. This car can accept 11? kW charging... but if I did this right from the grid I would be overloading my panel in the evenings. SO... SolarEdge solution seems ideal. How does this work?

I learned that the charging device communicates to the car how much current the car should pull without overloading the type 2 charger. So it is the responsibility of the charger to know this. The SolarEdge setup process allows the installer to enter the breaker size it is attached to. The added ingredient then is a data link between the inverter and the EV charger. Thus the EV charger has enough information to monitor solar production, and also be aware of the breaker size. Simply keep updating the car for how much power it should take and it will work. Clouds? Not a problem hopefully.

Looking forward to experiencing high charging speeds, while maintaining a low impact to the service panel. I wonder if other vendors can do this? I like the SMA equipment, but not sure they can do this trick of managing the car charging process.

Fun afternoon of research.

[Ampster]

What size will your solar be?. That will be one limitation. If you don't put in a 60 Amp breaker, I doubt the charging port would allow the charger to draw 11 kW from the inverter. The inverter itself only comes in one size which is 7.6 kW, but it may be able to pull from the grid to make up the difference. You may have to look at the details to confirm.
As you mentioned, the charger in the car only knows the Amperage it can draw by getting the duty cycle signal from the EVSE which in this case is the Solaredge inverter. If your installer sets it for a breaker smaller than 60 Amps that will be the limit. Incidentally there is a limit for continuous loads of 80 percent of the breaker size so that would be 48 Amp draw on a 60 Amp breaker which is about 11kW. I have two EVs that I charge overnight and even at 20 Amps I can fill up one of them overnight. 7

As far as I know Solaredge is the only inverter that offers this. The big advantage is that there is apparently a setting so that it will only charge from available solar. If clouds reduce the output of solar then the inverter signals the EV to draw less.

[heimdm]

Reading through the Solar Edge EV install guide (https://www.solaredge.com/sites/defa...n-guide-na.pdf). It looks like it has an AC connection to the inverter. In most cases they have you replace the WAGO connection blocks to add space for the connection to the charger. Based on what I am seeing the charger is AC coupled, so it is going to use inverter capacity. I believe they are using the monitoring platform to determine how much voltage it will push to the car if you want to only use "solar." The charger is added to the RS-485 communication network or the ethernet network. From a quick read it sounds likeits more magic than anything. My gut is its an AC charger that is bridged to the AC side of the inverter.

[QuantumSlice]

Yep, read the installation guides. The EV charger installation guide was the most informative. There is a configuration guide as well that describes what you can do after installation. The EV charger is tied to the inverter AC terminals as you describe. Uses RS-485 as you describe.

My physical plan is to have dual 5000 watt inverters. I wanted to do more, but the utility here requires much higher liability coverage when going above 10kW(10kW is a strange choice in my opinion). One of the 5000 watt inverters will be supplying the EV charger. So the breaker panel will get two 30Amp 240V breakers.

I suspect this is will become a popular way to go for people, how many houses have an extra capacity for 48 amps? It takes your 200 amp capacity down to 150 amp essentially. the cars charge for long periods of time.

Still a number of details to work, this will be my first double inverter installation. The car is somewhere in the Atlantic ocean headed to me so I better get a move on. Thanks for the help.

[Ampster]

I did not see where Solaredge offered the EV charging from their 5000 Watt inverters but that may be a new addition. It may be simpler and more cost effective to use a subpanel to add the necessary breaker capacity so you can add two inverters and an EV charging station with the higher charging capacity you desire.
There are complex rules about how much you can backfeed into an electrical panel and that may be what you are referring to by derating your 200 Amp panel to 150 Amps. I am not clear about what your existing panel capacity is?

[heimdm]

The situation level 2 charges potentially pulling 50 amps each, is why part of solar projects is a panel upgrade. If you have to do a panel upgrade anyway, then that would be the time to look at some of the newer options such as span.io. I believe the Span solution adds about 4k to a traditional panel upgrade. The utility is essentially limiting the ac inverter capacity. It is common to have oversubscription on the dc side. Having more DC capacity than AC so, that the inverter runs closer to 10Kw more of the time. Checking your inverter for limits on oversubscription. With DC/optimizer solutions such as Solar Edge the oversubscription is an aggregate at the inverter level. On Micro's it's as the micro/panel level. For example you might have a 400 watts panel attached to a micro that maxes out at 360.

My experience when ever I see this semi-unique products to a standard problem is there are usually caveats and come with a set of limitations that sometimes I regret. If you panel isn't too far from where your cars are going to be, then it might make sense to eat the cost for a panel/service upgrade, and just connect the charger to the ac of the house.

[Ampster]

........., how many houses have an extra capacity for 48 amps? It takes your 200 amp capacity down to 150 amp essentially. the cars charge for long periods of time.
........

Responding to your specific question, the answer may vary. It depends on whether you are talking about capacity for additional breakers or 48 Amps of additional load or backfeed. The answer is in the building code.
EV charging loads are one of the few loads that you can control. You can charge them fast at high Amps or you can charge them overnight at less current.
I put in a 50 Amp circuit so I had the ability to charge fast if needed. I rarely use that capacity. It may depend on how far you intend to drive each day. Even if it is a hundred miles per day that might only require 30 to 35 kWhs per evening based on using about one kWh per mile. 40 Amps is the most you can use from a 50 Amp circuit and that is 9.6 kWs so it would take less than four hours to charge your EV. If you charged at 20 Amps, like I often do, it would still only take eight hours to replace that 100 miles of range. It takes me ten seconds to plug in one of my EVs and the timer is always set to start at 11PM when the rates are lowest.. The car is fully charged by morning, even if I have to add over 100 miles of range. Don't let range anxiety force you into a more expensive solution than is cost effective. Fast charging is definitely needed on road trips but I don't need it every day.

[QuantumSlice]

I am working the permit today, so good timing. First off, I am not using the integrated 7.6 kW with EV charging. I have three separate units. 2 x 5k inverters, and one "Smart EV Charger".
I want this design to support the worst case possible. I doubt the humans in my household can follow rules that protect something. We will have three EV drivers sharing this charger.

Sequence. Replace the inverter bus bar and AC terminal blocks, Connect RS485 between the inverter and smart EV charger, Figure 10 shows how to daisy chain. The Leader connects to the EV Charger, which connects data to a follower inverter. The leader inverter (protected by 30 amp breaker) connects both data and A/C to the Smart EV Charger. The line between inverter and smart EV charger allows 40A maximum AC current. Thus... 30 Amp breaker yields (30*0.8*240=5760 W... this is less than the rated 5000 watts of the inverter). The inverter then adds 5000 watts (5000/240=20.8 amps). So the two added together is 24 from the grid via 30 amp breaker plus... 20.8 amps from the inverter = 44.8 amps available to the EV charger if it wants it.. The EV charger limits to 40 amps. So maximum charge to EV is 40 * 20 = 9,600 Watts AC. The secondary 5K inverter will get its own 30 amp breaker.

Documentation... "Smart EV Charger Installation" Chapter 1: Introduction:
"Additionally, there is an option for connecting the Smart EV Charger to a Single phase inverter with HD-Wave technology at your site, enabling to use PV power as well as grid power for EV charging."

"Before connecting the Smart EV Charger to the Single phase inverter with HD-Wave
technology, replace the bus bar and AC terminal blocks inside the DC Safety Unit as
described in these following procedures, using this extension kit."

[heimdm]

As Ampster discussed, the important thing is to understand the use case that you are solving for. If you need to fully charge in EV in 4 hours, then architecting that solutoin, but if you only need to charge in 8 hours, then that is different. Or, maybe it is better to be able to charge multiple vehicles simulaatenously but over a longer period of time.

I can not verify this works with the charger, but if you have extra ethernet ports you may be able to just connect via ethernet between the inverters and charger. On my 3 SE inverters, I didn't go with RS-485, and just connected each inverter to my router. RS-485 is nice because it is a dedicated network between all devices.

[QuantumSlice]

Overview of the electrical on this property...

200 amp service comes from the street. It is split to a 200 amp box on our 4500 sq ft house. And also goes to our external garage with 1000 sq ft apartment and 100 amp box. The main house currently has a heat pump for a/c and heat. both properties have electric dryers, microwaves, electric ovens, etc. The external building is heated with propane. There is a hot tub also (this may need to go away depending on my load calculations.).

The solar install is going onto the external property roof... 12k of panels.

Both the house and external building boxes are full of breakers, no space available.

The 200 amp service box from the street has empty slots for the solar... So maybe a 100 amp breaker in the 200 amp street box that can protect the solar circuits. 100 amp wires run to the production meter, from there the 100 amp wire goes into a 100 amp box with the two 30 amp breakers. Then each 30 amp breaker services an inverter.

Technically I will need to confirm the service box is good for more than 200 amps since the solar production could end up driving the box up to 260 Amps. But if i place the solar at the bottom, it will separate the source currents on either side of the load circuits. I am good with that, let the inspectors raise an issue if they like.

The EV charger is hooked into the lead inverter AC system and does not run into the added 100 amp service box directly.

[Ampster]

Sounds like you have a plan. The most complicated part of my installation was making sure I had enough bus bar capacity to satisfy several NEC rules on backfeeding capacity. I can't offer any help because my compliance was resolved by replacing my main service panel with a solar ready panel that had a 225 Amp rating and a main breaker of 200 Amps. I had to replace my old dangerous Zinsco 100 Amp panel so that step was already in the works for me.I just wanted to mention the bus bar rule in case your were not aware of it.

[QuantumSlice]

I guess a general comment on my philosophy for charging EVs... I have a Chevy Bolt with 66,000 miles on her. We don't need to reach full charge every night. You learn to relax a bit. If I need electricity and I don't think I can get it at home, I simply stop at a high speed charger and top off the battery the next day. This never really happens in practice. More often I will forget to plug in at night, and find that I must charge on the road the next day. The newer cars make this easy to do. My new ID.4 accepts fast DC charging of 125kW. The battery fills very quickly at that rate. So what is home charging for? Saving money on the majority of my charging needs is basically what I am after. I don't mind spending $10 from time to time on a fast charge.

[SunEagle]

I guess a general comment on my philosophy for charging EVs... I have a Chevy Bolt with 66,000 miles on her. We don't need to reach full charge every night. You learn to relax a bit. If I need electricity and I don't think I can get it at home, I simply stop at a high speed charger and top off the battery the next day. This never really happens in practice. More often I will forget to plug in at night, and find that I must charge on the road the next day. The newer cars make this easy to do. My new ID.4 accepts fast DC charging of 125kW. The battery fills very quickly at that rate. So what is home charging for? Saving money on the majority of my charging needs is basically what I am after. I don't mind spending $10 from time to time on a fast charge.

Sounds like a plan to keep your vehicle charged. I would say just be aware of all of the remote charging stations and their cost if you decide to go on a long trip.

Some day EV's and charging stations will be all over the US but it seems like a very slow and expensive process in most states.

[soby]

I too have an ID.4 with 3 years of free Electrify America charging. I'm trying not to charge at home since there is an EA charger 2 miles from our house and it's free. I plan to install an L2 charger some day and make use of the 14-50 outlet I had installed in my garage on a 50A breaker when my solar panels were installed in 2019.

Recently, I was looking at some Black Friday L2 charger deals but I opted not to spend the money on one quite yet. I am still working from home these days so the ID.4 doesn't get used a lot. The 30-40 minutes I spend in the car charging at EA once a week is perfectly fine for now.

Honestly, I would avoid the integrated SolarEdge charger if you could. I think it's best to keep those systems separate. The inverter should last you 12-25 years but who knows what car chargers will look like in 5 years. You don't want to have to upgrade your inverter to upgrade your car charger and vice versa.

One other thing to consider is the possibility that the ID.4 will get V2G capabilities in the future via software update. It isn't clear yet what 2021 owners should expect but it hasn't been ruled out. At this point, I'm going to wait and see if a bidirectional charger becomes available that provides backup capabilities from the ID.4 in a power outage.

[Ampster]

I have free charging with one Tesla and pay reasonable fees to charge the other Tesla. Tesla has over 10,000 Superchargers and it is nice to see EA charging stations being installed at some Superchargers. In the past five years charging stations have become ubiquitous except for those without EVs. LOL Because many charge at home we will never see charging stations on every corner like we used to see with gas stations.

I charge mostly at home at $0.20 per kWh and when I go to a Supercharger the rate is $0.28 per kWh for the one Tesla without free charging. That is California and I suspect it could be less in most parts of the country where energy costs less. My wife just took a trip from California through Nevada to Utah and she never incurred a charging expense of more than $12. I remember filling up my sister's pickup truck on a trip and it was $60.