Power Wall charging question

[Zer0t]

I was looking at the Generac Powercell battery as an alternative to power walls. The big feature they are pushing is off grid charging from your solar in case of a grid outage. Do Power walls not have the ability to charge when solar is available during the day and the grid is out? Sorry for the Bush league question but I just assumed if I lost power any excess solar would charge the power wall during the day. Perhaps I am mistaken?

 

[getakey]

PWs can charge from Solar when grid is off. Also, if they get to 100% and the house cannot take all of the solar production, they will turn off solar until PW state of charge is lowered a bit and then turn solar back on.

 

[BGbreeder]

Powerwalls will charge from your solar when the grid is out. The only potential gotcha is having enough Powerwall capacity to accept all of your solar output, or the Powerwall system will turn the solar off. Microinverters respond gracefully to Powerwall charging limits, and turn down their output. (Charge limit is 5kW/Powerwall)

All the best,

BG

 

[Zer0t]

I’m doing a 12.24kw solar and 3 PW. The solar isn’t enough to cover me 100% However if it makes sense I’d gladly buy a 4th power wall.

 

[getakey]

I’m doing a 12.24kw solar and 3 PW. The solar isn’t enough to cover me 100% However if it makes sense I’d gladly buy a 4th power wall.

What do you mean solar won't cover you 100%? 100% on an annual basis? Are you on Net MEtering?

 

[Laketime]

In short as mentioned- yes the PWs will charge off solar. If they said they won't that would be a big red flag. What has also been mentioned is how much output can be handled by your batteries. If you are producing say 10kW of electricity and your Powerwalls are full but your demands are 4kW then the system will shut off the solar output (the energy has to go somewhere!). You will then start running off of the walls until they deplete enough for the solar to turn on and recharge them. Sometimes when power is down it makes sense to crank up your demands while deep in production to take care of later loads such as doing laundry, dishes, cranking the AC etc.

 

[aesculus]

I was looking at the Generac Powercell battery as an alternative to power walls. The big feature they are pushing is off grid charging from your solar in case of a grid outage. Do Power walls not have the ability to charge when solar is available during the day and the grid is out? Sorry for the Bush league question but I just assumed if I lost power any excess solar would charge the power wall during the day. Perhaps I am mistaken?

This was some FUD that Generac was pushing recently:

Power Wall question about charging on solar

Hello all, I have searched but cant find the answer to this question .. I am getting ready to pull trigger on solar system+ battery . My choice is between Tesla with 3 PWs or Local installer using 2 18kw Generac Power Cells. Im all leaning towards Tesla and then the local installer points out...

teslamotorsclub.com

 

[jjrandorin]

This was some FUD that Generac was pushing recently:

Power Wall question about charging on solar

Hello all, I have searched but cant find the answer to this question .. I am getting ready to pull trigger on solar system+ battery . My choice is between Tesla with 3 PWs or Local installer using 2 18kw Generac Power Cells. Im all leaning towards Tesla and then the local installer points out...

teslamotorsclub.com

I think I said in the thread you linked, that it felt like the Generac salesperson was reading from an "overcoming objections" sales playbook. I am guessing what the salesperson was telling @Zer0t was in the same vein as that thread, just worded differently / poorly (the "black start" argument that it seems they have settled on for "overcoming tesla powerwall sales".

 

[Zer0t]

What do you mean solar won't cover you 100%? 100% on an annual basis? Are you on Net MEtering?

Yes but I know at any instant it can be more than my needs. Sorry should’ve been more clear. Yes I’ll be net metering.