I'm going to be putting in an order for a Model Y and a 17kw solar system with 3 powerwalls come monday. Regarding charging the Y, I have a 120 mile total commute each day (3 days a week). Living in northern Utah, what expectation for overnight charging should I have? Regarding the charging plug, what's the best charging outlet I can install to get the maximum rate?
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Charging from Powerwall
- Thread starter ScubaBri
- Start date
ChrisMPK
Member
Install an HPWC with a 60A breaker. Put this in front of your powerwalls as you don't need / want to power your vehicle from your your home batteries. You will quickly drain your reserve power and loose 15% additional efficiency. Charge overnight via scheduled departure and let the batteries power the rest of your home. There are quite a few threads about this in the Tesla Energy section of the forums.
ChrisMPK
Member
Sure, at some point with a software update that may be possible, but that's not really the issue. The issue is that you are trying to charge a battery the size of 5 power walls off of 3. You are going to drain the capacity of the powerwalls and have nothing left to power your house or offset your peak demand. Also, you are loosing and additional ~15% efficiency (on top of the minimum ~15%) by doing a second DC->AC->DC conversion to charge one battery from another with AC inverters and a power supply in between.
If you put your HPWC in front of the gateway, you are still using excess solar to charge if you have production, but more likely you are going to program the vehicle to charge at night off of very cheap and abundant base load generation that is otherwise wasted. The solar and powerwalls are meanwhile powering your house and reducing your daytime and peak demand to near zero. The only thing your power company sees is the low-cost demand at night when your vehicle is charging. If you really want to cover yourself for driving to the grocery store during the zombie apocalypse, install chargers both before and after the gateway and have both options. Or maybe some kind of Dr. Frankenstein looking giant knife switch that changes the source breaker for the HPWC from your main panel to the CL panel.
If you put your HPWC in front of the gateway, you are still using excess solar to charge if you have production, but more likely you are going to program the vehicle to charge at night off of very cheap and abundant base load generation that is otherwise wasted. The solar and powerwalls are meanwhile powering your house and reducing your daytime and peak demand to near zero. The only thing your power company sees is the low-cost demand at night when your vehicle is charging. If you really want to cover yourself for driving to the grocery store during the zombie apocalypse, install chargers both before and after the gateway and have both options. Or maybe some kind of Dr. Frankenstein looking giant knife switch that changes the source breaker for the HPWC from your main panel to the CL panel.
Oooh, good thinking! I'll be the envy of all the kids. Seriously, I'm going to get 4 powerwalls instead of three. And I like the idea of putting the outlet ahead of as well as after the pw.
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