We had a powerwall installed three weeks ago and I had all sorts of software issues for the first couple of weeks. One thing I didn't realize was that it takes an hour or two for a setting entered into the app to make it to the powerwall. I didn't figure this out until I used a computer to directly connect to the powerwall gateway via wifi and look at the settings using the web-based powerwall UI. I also had a situation where things would seem to work after Tesla would visit and tinker with the powerwall. But then I would play with the app and the powerwall would start to misbehave and show obviously incorrect data in the app (solar energy was correct, but home consumption was shown as exactly matching solar and grid energy was shown as zero which didn't match the electric meter or common sense). I could also get things to behave again by hitting the reset button on the gateway and then re-entering the wifi info and other stuff through the web-based powerwall UI. I was able to get self-consumption mode to work as long as I didn't try to change the reserve setting in the app. I also turned off storm watch just in case that was messing things up. Eventually I gave the Advanced time-based control a try (with the cost saving option) and much to my surprise it worked perfectly! I haven't changed the settings in the app since then and the powerwall now does exactly what I want it to given our time-of-use plan.
In the morning before peak prices start, all the solar is being used to charge the battery and the power to run the house is coming from the grid. When the battery fills up then the excess solar is sold to the grid. Once we hit 2 pm when peak prices start, the powerwall switches to using the battery to run the house and sells ALL the solar to the grid. Once the sun goes down, the house is powered exclusively by the battery until 9 pm when the peak prices end. Then the house switches back to the grid.
In order to qualify for the federal tax credit and/or to make our local utility happy it seems like the powerwall is only able to charge from solar and can only use this stored energy to power the house rather than selling it back to the grid. Under these constraints, the powerwall seems to be behaving optimally.
I can't be completely sure if rebooting the gateway + leaving the setting on the app alone is what fixed the problem. I also sent lots of emails to Tesla technician who installed the system and he escalated things to his manager so it's possible Tesla did something remotely to fix things.
The TL;DR version is to try rebooting the powerwall gateway, connecting directly through wifi to the gateway, and leaving the settings on the app alone as tempting as it is to tinker with things.
Hi all,
I'm new to this Tesla Motor Club forum... but I'm a huge Tesla fan, and eager to participate.
This is a Solar + PowerWall + TOU Rates + Net Metering + SAVE MONEY topic.
My PowerWalls are not behaving as expected (as I want them to behave.) I've been searching the forum and trying to see if anyone out there is encountering my use case with Time-of-Use rates and Net-metering:
I recently had a 4x PowerWall system installed (I think it's PW2), adding to my existing Tesla solar panel system of 11 kW. I got Permission To Operate on August 16, and turned on the PowerWalls then.
I'm in Las Vegas, Nevada, and my utility is NV Energy. I'm on TOU rates, 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).
As you'll notice from the rates I've posted, the net-metering credits during the summer (at +$0.407) are huge multiples from the evening off-peak prices ($0.053), at almost 8x. 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.
Using my PowerWalls, I'm simply trying to arbitrage the rate differences using net metering:
1) Mornings during off-peak (until 1 pm):
a) Use solar to charge up the PW battery (the morning solar is enough
to fully charge the PW)
b) Send excess solar to grid for +$0.045 / kW.
2) Afternoons/Evenings during peak (from 1 pm to 7 pm):
a) Use 100% of PW to power 100% of house (My fully charged PW battery has enough
to power the house)
b) Send 100% of solar to the grid, to earn the net-metering credits at +$0.407 / kW.
3) Evenings off-peak starting at 7 pm:
a) STOP discharging
PW, and save the remaining battery level for next day
b) Use the Grid for 100% of load for the whole off-peak duration
Is this possible? I ASSUME the answer is YES, as it's so simple! (the post quote above seem to show evidence that this DOES indeed work for some people
out there...)
The Time Based Controls + Cost Savings mode should do it.... but the reason I'm posting this is because my PW system is NOT doing it for me.
Here's what happens on my system, referencing the 3 points I listed above:
1) Yes, (a) and (b) both happen.
2) No. Here is what happens during peak period:
- When Solar output is higher than the Household load, 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 charged up PW is sitting idle.
- When Solar output is lower than the Household load, then the PW kicks in to supply the difference of what the Solar produces, from what the Household load requires. Yes, there is no pull from the grid (which is good), but unfortunately, the Solar still is NOT sent to the grid for net-metering credits (which would be awesome), as I would GLADLY prefer to use PW to power the house during the whole Peak period, and sending ALL 100% Solar to the grid for the high-rate of net metering credits.
3) Nope... the PW will sometimes continue to discharge at night, which is mind-boggling, because we all know that charge-discharge of PW results in at least 10% penalty due to inefficiency.
Why is my system not behaving the way I like? Any clues?
I'm already on TBC and Cost Saving mode. I've set the Peak times properly in the app.
Do I need to reboot the Gateway or are there better ways to fine-tune what the PowerWalls do?
thanks,
Bobby