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What hours should I run my Powerwalls

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For me - EV2 plan (PG&E). I use the cost savings setting and set the schedule strictly according to the rate plan. The only thing I vary is the reserve setting (since my primary motivation for batteries was protection from grid failure). From April thru October, I use a 25% reserve and in the remaining winter months, I use a 50% reserve. I get annual checks from the utility based on the automatic arbitrage offered in those settings.
Everyone has a unique situation and needs - this works for me.
 
My billing has peak rates from 4-9 at $0.41 and off peak at $0.17. So I set mine to Balanced with peak from 4-9 during the winter. I run off the battery during peak and impermanently during the night until it reaches my reserved settings.

During the summer I set my peak to 7-9 and shoulder from 4-7. This way I still use much of the solar during the 4-7 hours with the battery providing the balance that solar may not provide
On my wish list for features would be the ability to put the actual prices in the peak, off peak, and shoulder.
And to handle Winter vs Summer rates.
 
Because I need to send as much power back to PGE for credit so it can be used during winter. For folks who have gas heat, one never has to worry about it. But for folks like me that have electric heat, it actually takes more than AC. So, without NEM2, and 99% electric, solar would not make any sense from an ROI.
You harp on gas heat a lot, but it's really not a thing... do you complain about the person who lives in an area that doesn't require AC in the Summer? Or someone who doesn't need heating in the winter (like AZ)? How about people who don't have pools?

I'd say my situation is WORSE than yours for net metering because when I have a surplus of PV (non AC season) the credits I'm earning are at lower prices than if you have a surplus in Summer (especially on EV2-A).

I'm considering replacing my very old inefficient AC / NG HVAC units with Heat Pumps when the time is right.
I think I'll use significantly less energy in the Summer which will more than offset swap from NG to electric heat in the winter. I might even opt into EV2-A without a EV because the price differentials are so much better.

If that goes well I'll probably switch from NG to Hybrid / Electric or tankless water heater. If I had known better I probably wouldn't have purchased a NG dryer; but I don't think I'll ever move off gas oven / range.

Setting aside all resiliency factors, we size PV based on desired usage offset, and ESS only helps if you can price arbitrage.
There are tons of variables that make up your unique usage curve, some we can control and some we can't...
 
One thing to look out for with Cost Based is that the algorithm used is not well known nor may it be a perfect fit for other than lowest cost. Plus of course if weather changes the whole algorithm can be worthless.

Case in point: Yesterday way before my peak at 2pm and before my battery was fully charged, it diverted power to the house and utility. It had correctly calculated that I would not need the power fully charged to make it to the end of peak based on my normal consumption and that the next day was going to be off peak for much of the day, so it decided to make more cash on Friday than it would on Saturday. Completely logical and true.

But had I changed my consumption or had the solar been less on Saturday because of weather, well then it could have left me under charged.

So my point is that Cost Based is a bit more complicated than setting a utility cost plan. It does it's best to work the rate plan in your favor, at the expense of storage.
 
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Hi all,

I've got a recent solar installation with a single PW2. I'm in the Bay Area, on PGE's ETOU-D plan. So far I had set it up in Advanced mode - so that the battery only provided power in the evening during the peak rate window, which is 5pm-8pm on weekdays only. This seems suboptimal - My battery goes down to about 70-75% in these 3 hours.

The 'simple' question I have is: If I use 1 kWh from the grid, and return 1 kWh to the grid, is it a net zero $ game.

OR

Is PGE doing the math has 20cents (1 Kwh from the grid) minus 3c (1 kWh back to the grid) - so I'm 17cents in the hole? (Rates may not be real - just for example's sake)

Depending on clarity on the above question (Is it $0 or -$0.17?) - I will need to tweak my plan to MAXIMIZE being self-powered.

Note also - that off late, the energy production for me has been huge. and I'm giving back unto 35-40kwh back to the grid, daily. Also, if it matters, I expect to run my central AC, intermittently during the mid-Jun thru end-August - that will change my consumption profile for sure.

Any tips / pointers? My primary objective is to MAXIMIZE $ savings, or ideally, the PGE refund at the end of the year.

Thanks in advance!
-G
 
Hi all,

I've got a recent solar installation with a single PW2. I'm in the Bay Area, on PGE's ETOU-D plan. So far I had set it up in Advanced mode - so that the battery only provided power in the evening during the peak rate window, which is 5pm-8pm on weekdays only. This seems suboptimal - My battery goes down to about 70-75% in these 3 hours.

The 'simple' question I have is: If I use 1 kWh from the grid, and return 1 kWh to the grid, is it a net zero $ game.

OR

Is PGE doing the math has 20cents (1 Kwh from the grid) minus 3c (1 kWh back to the grid) - so I'm 17cents in the hole? (Rates may not be real - just for example's sake)

Depending on clarity on the above question (Is it $0 or -$0.17?) - I will need to tweak my plan to MAXIMIZE being self-powered.

Note also - that off late, the energy production for me has been huge. and I'm giving back unto 35-40kwh back to the grid, daily. Also, if it matters, I expect to run my central AC, intermittently during the mid-Jun thru end-August - that will change my consumption profile for sure.

Any tips / pointers? My primary objective is to MAXIMIZE $ savings, or ideally, the PGE refund at the end of the year.

Thanks in advance!
-G
On just one PW, good luck.
 
Hi all,

I've got a recent solar installation with a single PW2. I'm in the Bay Area, on PGE's ETOU-D plan. So far I had set it up in Advanced mode - so that the battery only provided power in the evening during the peak rate window, which is 5pm-8pm on weekdays only. This seems suboptimal - My battery goes down to about 70-75% in these 3 hours.

The 'simple' question I have is: If I use 1 kWh from the grid, and return 1 kWh to the grid, is it a net zero $ game.

OR

Is PGE doing the math has 20cents (1 Kwh from the grid) minus 3c (1 kWh back to the grid) - so I'm 17cents in the hole? (Rates may not be real - just for example's sake)

Depending on clarity on the above question (Is it $0 or -$0.17?) - I will need to tweak my plan to MAXIMIZE being self-powered.

Note also - that off late, the energy production for me has been huge. and I'm giving back unto 35-40kwh back to the grid, daily. Also, if it matters, I expect to run my central AC, intermittently during the mid-Jun thru end-August - that will change my consumption profile for sure.

Any tips / pointers? My primary objective is to MAXIMIZE $ savings, or ideally, the PGE refund at the end of the year.

Thanks in advance!
-G
Depending on how "recent" your install is, the algorithm might not have learned your usage profile well enough to do the projections.

Advanced mode has two options: Balanced and Cost Savings.

According to Tesla's descriptions of the two modes, Balanced will give you the higher self powered rating.
That is what I use. I would recommend leaving it on Balanced for at least two weeks and then reporting back to us.
 
The main thing I don't like about Balanced is it will draw power from the Powerwalls during off-peak hours in the morning. Having backup power was my main objective of getting the Powerwalls and I want them to have as much reserve as practical during off-peak hours.
Cost savings mode prioritizes recharging from solar in the mornings and then diverts power to the house/grid once the batteries are charged.
 
The 'simple' question I have is: If I use 1 kWh from the grid, and return 1 kWh to the grid, is it a net zero $ game.
No. There are two different measurements going on. One is measuring the value of energy when you give it to the grid in $. The other is the total amount of kWh that you produce vs use during your yearly (prior to true up) period. This is where NBCs and other factors are considered.

So you not only have to consider the time value of the energy you use and provide, but you need to be aware of how your total energy usage affects how much you pay too.

And it can get even more complicated if you are on a rate plan that is tiered but I have little understanding of how those work with solar and they are going away anyway. And you are on the TOU plan.
 
The main thing I don't like about Balanced is it will draw power from the Powerwalls during off-peak hours in the morning. Having backup power was my main objective of getting the Powerwalls and I want them to have as much reserve as practical during off-peak hours.
Cost savings mode prioritizes recharging from solar in the mornings and then diverts power to the house/grid once the batteries are charged.
I LOVE that basically my PW's are powering my house like 23 hours a day. I have ZERO concern about backup power in the summer, once the sun comes up, the PW's get recharged fast
 
The main thing I don't like about Balanced is it will draw power from the Powerwalls during off-peak hours in the morning. Having backup power was my main objective of getting the Powerwalls and I want them to have as much reserve as practical during off-peak hours.
Cost savings mode prioritizes recharging from solar in the mornings and then diverts power to the house/grid once the batteries are charged.
Completely agree with you. It is bizarre. Cost Savings should power the house load through the peak and when solar kicks on in the morning it should go to the house load first and then to recharging the Powerwalls before sending anything to the grid. This maximizes export credits and minimizes imports.

I switch to Balanced when I get up at 6:30am and back to Cost Saving at lunch everyday.
 
Completely agree with you. It is bizarre. Cost Savings should power the house load through the peak and when solar kicks on in the morning it should go to the house load first and then to recharging the Powerwalls before sending anything to the grid. This maximizes export credits and minimizes imports.

I switch to Balanced when I get up at 6:30am and back to Cost Saving at lunch everyday.
Why? My batteries are charged 100% by noon, so solar is used by the house, and the left over gets send back to the grid. Batteries are in standby until 3pm when they do 100% of the house load and 100% of solar goes back to PGE
 
Why? My batteries are charged 100% by noon, so solar is used by the house, and the left over gets send back to the grid. Batteries are in standby until 3pm when they do 100% of the house load and 100% of solar goes back to PGE
I have frequent power outages where I live, I've had 2 this month. They were short but one never knows. Any power taken from the powerwalls needs to be replaced later on so the net cost is the same as long as they get recharged to 100% before the peak rate change. The difference is the earlier they are recharged, the better prepared I am for a power outage.
 
Completely agree with you. It is bizarre. Cost Savings should power the house load through the peak and when solar kicks on in the morning it should go to the house load first and then to recharging the Powerwalls before sending anything to the grid. This maximizes export credits and minimizes imports.

I switch to Balanced when I get up at 6:30am and back to Cost Saving at lunch everyday.
It sounds like were looking for the opposite. I want my powerwalls recharged ASAP which Cost Savings does but Balanced doesn't. The net cost is about the same for me since I expect a credit at True-Up but the earlier the powerwalls are recharged the more prepared I am for an outage.
 
I have frequent power outages where I live, I've had 2 this month. They were short but one never knows. Any power taken from the powerwalls needs to be replaced later on so the net cost is the same as long as they get recharged to 100% before the peak rate change. The difference is the earlier they are recharged, the better prepared I am for a power outage.
Mine pretty much do this but as I note up thread there are exceptions. If the algorithm does not think I am going to need the PW storage that day it will fill up to a certain point (not 100%) and then start using it for the house and spilling the remainder to the grid. This is the model for Cost Savings.
 
Mine pretty much do this but as I note up thread there are exceptions. If the algorithm does not think I am going to need the PW storage that day it will fill up to a certain point (not 100%) and then start using it for the house and spilling the remainder to the grid. This is the model for Cost Savings.
I've been using Cost Savings Mode every since I've had my Powerwalls installed except for a brief experiment with Balanced mode. My Powerwalls always prioritize recharging to 100% before peak rates if the solar power is available.