I’ve got two powerwalls and have tried the balanced and cost savings mode. I kinda hate that during expensive times it sends solar power to the grid as opposed to charging my power wall. I have to switch it to self powered to overcome that. I would rather it do almost a combo - cost savings but always keeping as much solar power I generate as possible rather than trying to offset usage. Am I crazy? I’m in CA and just feel as little of the grid as I can use, the better.
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Question on powerwall mode
- Thread starter Ngenn
- Start date
Saw this in another post and it looks like I should just change my costing to be defined as shoulder to do what I want? Anyone else tried this?
—copied from another post —
Cost Savings-Charging Priority: 1. Any solar (Off-peak) 2. Any solar (Shoulder)
Cost Savings-Discharging Priority: 1. Any usage (Peak) 2. Any usage (Shoulder)
I look at the charging and discharging as kind of a net cloud effect. Even though it says the battery will discharge for any usage in Shoulder, it appears that since the battery will also charge with any solar in Shoulder, the net effect (at least for me) is that the battery will really only discharge for net usage in Shoulder.
From my experience, it appears to me that in Shoulder periods, the net result is that solar will first be used for net usage, then sent the battery, and any remainder will be sent to the grid. Discharging only occurs in Shoulder if solar cannot cover net usage.
—copied from another post —
Cost Savings-Charging Priority: 1. Any solar (Off-peak) 2. Any solar (Shoulder)
Cost Savings-Discharging Priority: 1. Any usage (Peak) 2. Any usage (Shoulder)
I look at the charging and discharging as kind of a net cloud effect. Even though it says the battery will discharge for any usage in Shoulder, it appears that since the battery will also charge with any solar in Shoulder, the net effect (at least for me) is that the battery will really only discharge for net usage in Shoulder.
From my experience, it appears to me that in Shoulder periods, the net result is that solar will first be used for net usage, then sent the battery, and any remainder will be sent to the grid. Discharging only occurs in Shoulder if solar cannot cover net usage.
People on TOU rates normally want to send solar to grid during peak to both get maximum credit for their solar from the utility for net metering, and power the home from the powerwall so you dont pull from the grid during peak.
People who want to lower their reliance on grid can use self powered mode which does what you want. Is there some reason you are not using self powered, since it seems it does what you want (use solar to offset home usage first, then charge powerwall till full, THEN any excess to grid.... when home usage > solar production, pull from powerwall to make up the difference. Only use grid when powerwall hits reserve, or usage can not be covered by solar + powerwalls).
People who want to lower their reliance on grid can use self powered mode which does what you want. Is there some reason you are not using self powered, since it seems it does what you want (use solar to offset home usage first, then charge powerwall till full, THEN any excess to grid.... when home usage > solar production, pull from powerwall to make up the difference. Only use grid when powerwall hits reserve, or usage can not be covered by solar + powerwalls).
Thanks this is helpful. I was using self-powered but was hoping that I could get the best of both worlds.
I wanted the system to predict how much I needed to get past peak and charge the battery to make that happen. What I was seeing is that during peak it was sending solar power to the grid and using up the powerwall but it seemed unlikely that I was going to get all the way through peak before running out. To be fair I was boosting my reserve at the same time since I live in San Mateo County and am not that far from the fires.
I was hoping I didn’t have to manually swap it back and forth.
I wanted the system to predict how much I needed to get past peak and charge the battery to make that happen. What I was seeing is that during peak it was sending solar power to the grid and using up the powerwall but it seemed unlikely that I was going to get all the way through peak before running out. To be fair I was boosting my reserve at the same time since I live in San Mateo County and am not that far from the fires.
I was hoping I didn’t have to manually swap it back and forth.
Granted my usage has been really crazily lately with the heat causing A/C to be on a lot during the day and then the smoke and heat forcing me to keep it on all night. I used to be able to get the two walls charged by noon and then survive until 3am. Now it’s cloudy/smoky and A/C on even in the morning so they are taking way longer to fill up if they even do and are discharged before midnight. That’s doubly annoying since I just switched rates to be on high rate from 4-9pm and shoulder from 3-4pm and 9-12pm.
My simple brain says keep off the grid 3pm-midnight and don’t try to arbitrage it since PG&E always finds a way to mess you up.
My simple brain says keep off the grid 3pm-midnight and don’t try to arbitrage it since PG&E always finds a way to mess you up.
Sounds like you're on EV2-A. You're still better off sending solar to the grid 4-9pm even if you run out before midnight. The extra Peak credit will pay for more kWh than if you had kept that solar in the battery. Even if you're paying NBCs, you're still better off the way TBC works compared to Self-Powered. This is just talking about net metering and billable costs. If you wanted to keep that energy to have a larger buffer in case of outage, that may be a different story.
Great to know and yes I am on EV2-A. Do you prefer that option or time of day 4-9pm? Pge tells me EV2 is more expensive but I’m assuming it’s because I didn’t have a powerwall before. I would have thought Tesla needed to know the price differential between the tiers to know if the arbitrage was worth it.
Up until this heat wave which I think is a big outlier, I keep the reserve at 5% since the power has only gone out twice for 30 seconds. If we are going to have another wildfire outage I’m assuming storm watch will give me enough notice as well.
Up until this heat wave which I think is a big outlier, I keep the reserve at 5% since the power has only gone out twice for 30 seconds. If we are going to have another wildfire outage I’m assuming storm watch will give me enough notice as well.
With PowerWalls, you're almost certainly better off on EV2-A unless you're a surplus generator. In other words, if you owe money at the end of the year and charge cars Off-Peak, you will pay less on EV2-A than TOU-C (Peak 4-9pm). The main reason is that you are paying double ($0.35/kWh vs. $0.166/kWh) for Off-Peak vehicle charging.
eml2
Member
I am on Balanced mode. Excess solar goes to charge battery, even on peak. It only exports when battery is full.
Peak: 11a - 7p
Shoulder: 7a - 11a and 7p - 11p
Off-peak: 11p - 7a
The reason I don't want to export during peak is because I don't have 1:1 netmetering. Only got paid for export at wholesale price.
Peak: 11a - 7p
Shoulder: 7a - 11a and 7p - 11p
Off-peak: 11p - 7a
The reason I don't want to export during peak is because I don't have 1:1 netmetering. Only got paid for export at wholesale price.
Hi jjrandorin,
This is exactly what I want, but somehow, my PowerWalls aren't behaving this way for me.
Would you know what I need to do, to make it behave the way you described?
I have a 11 kW Solar panel system, with 4x PowerWalls installed.
I'm on TOU rates in Nevada (NV Energy) where the summer peak price is $0.435 (with +$0.407 credit for net-metering), and off-peak rates are just $0.053 (with +$0.045 credit for net-metering). This means that for every 1 kW I send to the grid via net metering during my peak hours (from 1 pm to 7 pm), I can get credit from NV Energy, and it's worth like 7.6 kW of electricity off-peak.
I'm already on TBC + Cost Saving mode. I've set the Peak times properly in the app.
During Peak times (from 1 pm to 7 pm), I get this behavior with my PowerWalls (which is NOT what I want...):
- When Solar output is HIGHER than the Household load (Early Afternoon), only the Excess Solar goes to the grid, and PowerWall doesn't contribute at all. This means that there's valuable Solar that is NOT going back to the grid for net-metering credits, whereas my 100% charged-up PW is sitting idle. Bummer!
- When Solar output is LOWER than the Household load (Late Afternoon), then the PW kicks in to supply only the DIFFERENCE of what the Household load requires from what the Solar produces. There is no pull from the grid (which is good), but unfortunately, the full Solar still is NOT sent to the grid for net-metering credits (which would be awesome). Given the high net metering credits, I would GLADLY prefer to use PW to power the house during the WHOLE Peak period, and to send ALL the Solar (100%) to the grid for the high-rate of net metering credits.
Is it an issue with my PW system? Or is this behavior not supported by PowerWalls?
(Anecdotal evidence from forum members seem to suggest that my desired behavior IS INDEED supported, but somehow my PW doesn't do it...)
thanks,
Bobby
I use self powered, so I cant help you with that, sorry. I know many others here use the advanced modes. In general, the advice I have seen on here is to eliminate putting shoulder in the app, and only use peak and off peak.
Maybe look into the difference between balanced mode and cost saving? Like I said I am not sure.. I use self powered as I am not on a TOU plan.
Maybe look into the difference between balanced mode and cost saving? Like I said I am not sure.. I use self powered as I am not on a TOU plan.
I see. Thanks.
So would you happen to know which TMC forum members are in my predicament, where they want to export as much Solar to the Grid (during Peak) to get the most Net Metering Credits?
thanks,
Bobby
Post a intraday chart like this one. It will show what the system is doing. I suspect you want something like what my system does In TBC-Balanced Mode below. In my case, I have a shoulder period for one hour before Peak and 3 hours after Peak.
My chart looks like this in TBC-Balanced Model. But unlike the @bobbyclee it only will get me offsets for usage and $0.03 for any excess at true-up. I am on PG&E TOU-2 with peak M-F 4PM-9PM. No shoulder, just peak and off-peak.
My last true-up with Powerwalls had a net usage over 10,000 kWh. I really need to double my solar to cover my EV charging and future A/C install. No worry about poor excess compensation here.
Not sure I am totally followng, but your PW cannot send back to grid. They can only power the house. That said, during peak, the PWs should power the house and all solar go back to the grid unless the house is needing more than PWs can provide.
I think Cost Saving does this. I have off peak, shoulder and peak. I noticed when I first started to use this, the Powerwall would only charge during off peak. All solar would be sent to the grid during shoulder and peak. Either a software update or learned behavior has changed such that sometimes the Powerwall will charge during shoulder, but all solar is still sent to the grid during peak.
Here's my chart. As you can see, the issue is that even during Peak, Solar is partially used to power the house (and not 100% sent to the grid). Again, all I would like is that during Peak, for 100% of solar to go back to the grid, and let PowerWalls power the house during that whole time.
I have mine set on TBC-Cost Savings mode.
Is there a way to reset or reboot the system, for it to start fresh?
