EV charging

[KevinW]

@willprowse My kids come over and plug their Tesla's into my outlet to charge them. I would like to build a solar charging system that they can plug into when they are here for the weekends. Can you point me to one of your videos that may address this? I'm not sure if I could do it with two solar panels or 4 solar panels with a charge controller, inverter, and battery storage. Having said that, I should also define/outline how to expand it should I purchase my own EV.

Thanks. I love your channel.

 

[time2roll]

Vehicle battery is fairly large at 60+ kWh
Charging rate is about 1 kW minimum with 7 to 10 kW preferred.

I think the system would need to be close to 10x what the vision is.

 

[billvon]

@willprowse My kids come over and plug their Tesla's into my outlet to charge them. I would like to build a solar charging system that they can plug into when they are here for the weekends. Can you point me to one of your videos that may address this? I'm not sure if I could do it with two solar panels or 4 solar panels with a charge controller, inverter, and battery storage. Having said that, I should also define/outline how to expand it should I purchase my own EV.

Thanks. I love your channel.

So Teslas can charge at 10kw. You can limit them to 1.4kw by using a Level 1 adapter.

Best approach will be to get a ~5kw solar power system that feeds the grid. When they are over, it will easily supply the 1.4kW they need and offset your bill as well.

 

[Hedges]

On grid or offgrid?

Where are you located?
Is net metering available?

Best way to go may be grid tie net metering, and charge from grid.

With California's NEM 3.0 (Solar Billing Plan), many people are going to be interested in an EV charger controlled by CT around wires from utility meter, so it seeks zero export by charging from surplus.

 

[dewhite04]

So Teslas can charge at 10kw. You can limit them to 1.4kw by using a Level 1 adapter.

Best approach will be to get a ~5kw solar power system that feeds the grid. When they are over, it will easily supply the 1.4kW they need and offset your bill as well.

FYI - charge can be limited to as low as 5a @ 120v = 600w from app or in the vehicle display menus.

Found out because I needed to share a single receptacle with my nephew at a beach house over a long weekend...

 

[Hedges]

How readily can you ramp it up and down between 600W and 10kW?

A monitor reading power meter with CT at service entrance, commanding charge up and down to achieve zero export, is desirable to avoid exporting for wholesale credits under NEM 3.0

 

[dewhite04]

How readily can you ramp it up and down between 600W and 10kW?

A monitor reading power meter with CT at service entrance, commanding charge up and down to achieve zero export, is desirable to avoid exporting for wholesale credits under NEM 3.0

Probably not that fast. I think the Tesla API checks in every 60 seconds. Pushed commands can probably be sent in 5 or 10 seconds, but I think there are also concerns about rate limiting for constantly spamming commands.

I don't know that much about it, but the guy who runs teslafi.com could probably give you meaningful answers...

 

[Hedges]

Doesn't have to be fast in this case because we're not prohibited from exporting.
Just needs to be fast enough to use locally rather than exporting (or importing) 95% to 99% of the time.

Thinking in terms of HVAC, pumps, laundry cycling. Could be dryer and oven cycle on relatively often, so 10 seconds preferable to a minute. Except ...


... Whatever window of import/export is blended together by the tariff comes in to play.


This is going to be a big deal for all new PV installations in California. And matters to those fewer of us who installed 20 years ago. "Batteries" is the plan of record, but anyone with EV to charge should be able to minimize additional battery purchase (if parked at home during sunlight hours.) So it won't help the average commuter.

 

[dewhite04]

My retail electric provider in Houston, Texas cut 30% off my electric rate in exchange for control of when my Tesla charges. I mostly just let it do its thing, but when I occasionally look at the "charging plan" for that day, it has a incremental blocks of time as small as 5 minutes. That tells me that resolution is no problem for the API. I would guess finer details control is reliably possible. I think the limiting factor would be Tesla's TOS to use the API...

 

[alan.com]

@willprowse My kids come over and plug their Tesla's into my outlet to charge them. I would like to build a solar charging system that they can plug into when they are here for the weekends. Can you point me to one of your videos that may address this? I'm not sure if I could do it with two solar panels or 4 solar panels with a charge controller, inverter, and battery storage. Having said that, I should also define/outline how to expand it should I purchase my own EV.

Thanks. I love your channel.

Sounds like your kids are coming round every week to charge their Tesla's for free.
Limit the charging infrastructure to 1kw and see if they will still visit every week