Time to Charge the X (with 8kW solar panels above)

[Ferrett]

So, I've had solar panels (8kW) installed for 4+ years now and will be getting delivery of the X next week (I pray so). I've learnt that it has windows where it lets you charge at cheap rates. With solar panels above,
is it still a good idea to charge at night ONLY? Anyone has the same predicament?

- Michael Soo

 

[pvogel]

Are you on net metering? You are in San Jose, so I assume you have PG&E? How much of your current usage does your 8kW system cover on an average day?

In my case, my costs are the same regardless of time of day, so I just leave Merlin plugged in all the time when he's at the house (a connected Tesla is a happy Tesla) with my charge limit set to 90% per Tesla recommendations. If you charge during the day you are charging with sun power unless you really have 6.4kW (derating your panels to 80% efficiency) load at your house without the Tesla. My HPWC is limited to 32A so it charges at 21 miles per hour, so I'm pulling 7kW for Merlin but only for 1-3 hours on a weekend day and almost nothing the rest of the time when Merlin hasn't left the house.

 

[Ferrett]

Looks like I can change my rate... Which ones are you using? I assume the Electric Vehicle Rate plan is a good option?

 

[pvogel]

Looks like I can change my rate... Which ones are you using? I assume the Electric Vehicle Rate plan is a good option?

I'm in Santa Clara, Silicon Valley Power, not PG&E so I just pay (and sell my solar) at the flat 11.x cents per kWh.

 

[MarchX]

I'm in Santa Clara, Silicon Valley Power, not PG&E so I just pay (and sell my solar) at the flat 11.x cents per kWh.

You're lucky....
I'm on PG&E and just lot my great E7 rate, now will probably switch to their EV rate as its only 11 cents per kWh off peak. So my yet as unnamed X will charge after 10 pm. I'll sell my 4kw solar power back at peak rates.

 

[ohmman]

EV-A is a good rate if you've got a solid solar installation, as OP does. I have a 9.5kW system, sell at ~40c/kWh during the day and buy back at ~11c/kWh at night. I shifted much of my usage to night as well, splitting my pool pump and running it at high speed at night for some hours and low speed during the day.

While I used a few GWh of electricity last year, I wound up with a hefty monetary credit (which you forfeit if you don't generate surplus energy). I could use quite a bit more electricity and still net to 0 annually. That said, we're installing more solar so we net out our usage, which for us is more important.

Anyway, OP should definitely move to EV-A and schedule charging for 2-3am, such that the car is finished charging right before it's time to head out in the morning.

 

[Falkirk]

I have a new (one month old!) 9.945kWh system installed and love it. Ordered the Model 3 so I'm really looking forward to going electric. We also have a great micro-fit program in place (Ontario) so I just sell everything I make at 38.4c/kWh and buy at 4.9c/kWh for 80% of the day!