I need solar EV charging system advice

[Glongo]

Does anyone have installation experience or design expertise for an off grid EV charging PV system? To be clear, I fully understand grid tied systems, I am researching a specific design constraint. My stumbling point (end of my topic knowledge) is if you are generating AC power after the AC buss,, how do you design to the point of the EV charging unit? In other words how do you solve for the variability of available power from minute to minute. I can do it with battery bank(s) to smooth out the power supply, but wondering if there is a more elegant and simple solution?

Background
- So Cal Edison
- New service to the house is being established, so no Old NEM rate plan therefore no I don’t want to use them as a “battery” considering grid tie costs and requirements
- Large capacity for array - focused on about 7kW max. capacity
- New construction, so I can wire anything anywhere

Thanks!

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[Revelation]

Easiest way is to use OpenEVSE, Solar Assistant and Home Assistant to handle the automation process.

Solar Assistant can communicate with your Inverter / batteries.
Solar Assistant and Home Assistant will talk with each other.
Home Assistant can adjust the "power output" of the OpenEVSE automatically based on communication with Solar Assistant.

 

[Glongo]

Easiest way is to use OpenEVSE, Solar Assistant and Home Assistant to handle the automation process.

Solar Assistant can communicate with your Inverter / batteries.
Solar Assistant and Home Assistant will talk with each other.
Home Assistant can adjust the "power output" of the OpenEVSE automatically based on communication with Solar Assistant.

I am familiar somewhat with Home Assistant. Now it looks like I’m heading down a multi-hour rabbit hole on Solar Assistant.

Thanks for the tip Revelation!

 

[j.w.s]

Easiest way is to use OpenEVSE, Solar Assistant and Home Assistant to handle the automation process.

Solar Assistant can communicate with your Inverter / batteries.
Solar Assistant and Home Assistant will talk with each other.
Home Assistant can adjust the "power output" of the OpenEVSE automatically based on communication with Solar Assistant.

If you aren't able to integrate using open source stuff as above, which definitely works, there are a few vendors who can make it work if you buy their whole system. If you have Enphase solar, for example, you can add an Enphase IQ EVSE and get out of the box integration to do what you want.



I haven't yet deployed this, but I'm Enphase, so it's appealing. But apparently there are some limitiations, so I hope the software side gets better over time:

 

[Glongo]

If you aren't able to integrate using open source stuff as above, which definitely works, there are a few vendors who can make it work if you buy their whole system. If you have Enphase solar, for example, you can add an Enphase IQ EVSE and get out of the box integration to do what you want.

I hadn’t purchased the components yet. In design phase right now. But enphase is one of our preferred components suppliers for micro inverters, batteries, etc. , for our construction company.

 

[Blueassassin]

Couldn't you use something like this?
https://us.ecoflow.com/products/delta-max-dual-fuel-generator?variant=40138329096265

 

[Glongo]

Couldn't you use something like this?
https://us.ecoflow.com/products/delta-max-dual-fuel-generator?variant=40138329096265

Thanks but trying to avoid batteries or other storage/supply components.

 

[Blueassassin]

Thanks but trying to avoid batteries or other storage/supply components.

I think you would need at least some battery for a buffer to go with it or just a small cloud going over could stop and start the charger and give issues right?

 

[connoisseurr]

Few options exist for this:

Enphase Energy Systems offer this with the latest generation of IQ Gateway products. This system can give you the option of having grid-tied solar, with the option of having grid-down energy storage and EV charging. This is definitely the most intuitive solution, but is a closed architecture. You cannot bring any non-enphase products into the fold. Enphase will also be offering a bi-directional EVSE that can be integrated with existing Gen3+ systems; Enphase also has traditional L2 EVSEs that can integrate with any generation of energy system.

Tesla Energy Systems can also operate the same as Enphase does, and can also be integrated with SPAN energy systems, should you wish to have a more granular view on your home's energy consumption.

SolarEdge does offer solar-only charging, but does require specific central inverters, where the EVSE directly connects, rather than connecting through a breaker panel or ATS.

I will also mention there are many new providers coming to market with cutting-edge technology, such as FranklinWH, that offers fantastic whole home energy and solar integration solutions, but currently do not offer additional EVSE integration.

As a certified Enphase installer, I do like the product, and trust it fully; even more so now that the latest generation of products use a CAN system for communication, versus the shitty wireless comms that existed on 1st and 2nd gen. I installed my own system and integrated a SPAN panel and SPAN drive into my home, but will probably end up replacing with an Enphase EV charger, since every time I plug in to charge, I have to change my battery discharge profile from self-consumption to full-backup (won't need to do this with an Enphase EV charger).

 

[Polar]

Have you looked into Dcbel yet?

If you’re building a net new system - they will keep DC into the vehicle so you don’t have any conversion losses from Dc to Ac and then back via the OBC of the car.

Problem is their system is a single unit and I don’t bselieve a large inverter either. And honestly - not sure it’s even to market fully yet.

@connoisseurr - any word on the Enphase installer front as to the BiDi EVSE hitting the market?

 

[Glongo]

Few options exist for this:

Enphase Energy Systems offer this with the latest generation of IQ Gateway products. This system can give you the option of having grid-tied solar, with the option of having grid-down energy storage and EV charging. This is definitely the most intuitive solution, but is a closed architecture. You cannot bring any non-enphase products into the fold. Enphase will also be offering a bi-directional EVSE that can be integrated with existing Gen3+ systems; Enphase also has traditional L2 EVSEs that can integrate with any generation of energy system.

Tesla Energy Systems can also operate the same as Enphase does, and can also be integrated with SPAN energy systems, should you wish to have a more granular view on your home's energy consumption.

SolarEdge does offer solar-only charging, but does require specific central inverters, where the EVSE directly connects, rather than connecting through a breaker panel or ATS.

I will also mention there are many new providers coming to market with cutting-edge technology, such as FranklinWH, that offers fantastic whole home energy and solar integration solutions, but currently do not offer additional EVSE integration.

As a certified Enphase installer, I do like the product, and trust it fully; even more so now that the latest generation of products use a CAN system for communication, versus the shitty wireless comms that existed on 1st and 2nd gen. I installed my own system and integrated a SPAN panel and SPAN drive into my home, but will probably end up replacing with an Enphase EV charger, since every time I plug in to charge, I have to change my battery discharge profile from self-consumption to full-backup (won't need to do this with an Enphase EV charger).

thanks for the response. I am reading the Enphase system descriptions but can’t tell if it can handle rapid swings in delivery without storage. Like Blueassasin suggested a cloud of some other sudden change would be difficult for a system to handle I imagine. If the charger stops the draw or the solar delivery spikes, how would the controller dispose of the excess wattage? Perhaps I am resolved to some level of batter capacity.

 

[Glongo]

Have you looked into Dcbel yet?

If you’re building a net new system - they will keep DC into the vehicle so you don’t have any conversion losses from Dc to Ac and then back via the OBC of the car.

Problem is their system is a single unit and I don’t bselieve a large inverter either. And honestly - not sure it’s even to market fully yet.

@connoisseurr - any word on the Enphase installer front as to the BiDi EVSE hitting the market?

I would prefer to keep it DC but I don't see an available product that fits the constraints. I do see a few product launches that may be a solution when available??

 

[Mark_AZR1T]

I use the Tesla Energy System with the SPAN breaker/control panel assembly, but for my application we buffer using three Powerwalls and 20kW of grid tied solar. We're hedging against power delivery issues, cost of energy, along with the ultimate goal of creating a gas-station for our two Rivian's. Flawless thus far.....

 

[Glongo]

I use the Tesla Energy System with the SPAN breaker/control panel assembly, but for my application we buffer using three Powerwalls and 20kW of grid tied solar. We're hedging against power delivery issues, cost of energy, along with the ultimate goal of creating a gas-station for our two Rivian's. Flawless thus far.....

20 kW - that’s practically a sub-station!

 

[Revelation]

20 kW - that’s practically a sub-station!

Just keep in mind, you will often find that you will not pull the full-rated power of the panels. For instance if you setup 20kW for 11.5kW EV charging is a good bet on most days.

Whereas if you setup 12kW for 11.5kW EV charging you will often come in lower due to various factors. I know your original question was about having the system dynamically adjust the power delivered, but don't "shoot yourself in the foot" when panels are the cheapest part of a solar system.

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