Sinse the (Darwin) App stopped working, do you know of any plans for Darwin to resolve the auth problem or, is it (support) permanently gone?
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Strategies for Powerwalls and Utility Demand Plans
- Thread starter DanAman
- Start date
First 2 weeks with 2 PW on existing 12Kw system.
Turn on was Self Powered. Didn't used a single watt from the grid for 3 days. Pretty cool. Then came the options...
Got Advanced and started using Time Based Balanced - However, I wasn't expecting it to behave the way it did because of the way I thought of solar.
We'd never planned to use the PWs for AirCon. We have a Whole House fan and can generally get by without hitting the AC most evenings until late into summer.
Balanced...does what it says. It's balanced. Takes some from solar and grid and battery. It's not the way I'd have done it.
It was taking shoulder power in the morning and the evening and "attempting" to return more power to the grid. That slowed renewing the PW charge quite a bit.
I actually seem to be fairing better using self generated, then I manually switch to time based after sun goes down and that makes sure I charge at Super Off Peak and return to Self Generated in the morning.
That gives me full batteries without much grid draw and keeps a better reserve while running everything in the house except for AC and Charging.
However, I do have enough peak in the day to charge somewhat and enough in the evening to run an AC vs selling to grid.
I'll keep experimenting, but so far self-powered and switching on nights that I charge appears to be working better for me.
Turn on was Self Powered. Didn't used a single watt from the grid for 3 days. Pretty cool. Then came the options...
Got Advanced and started using Time Based Balanced - However, I wasn't expecting it to behave the way it did because of the way I thought of solar.
We'd never planned to use the PWs for AirCon. We have a Whole House fan and can generally get by without hitting the AC most evenings until late into summer.
Balanced...does what it says. It's balanced. Takes some from solar and grid and battery. It's not the way I'd have done it.
It was taking shoulder power in the morning and the evening and "attempting" to return more power to the grid. That slowed renewing the PW charge quite a bit.
I actually seem to be fairing better using self generated, then I manually switch to time based after sun goes down and that makes sure I charge at Super Off Peak and return to Self Generated in the morning.
That gives me full batteries without much grid draw and keeps a better reserve while running everything in the house except for AC and Charging.
However, I do have enough peak in the day to charge somewhat and enough in the evening to run an AC vs selling to grid.
I'll keep experimenting, but so far self-powered and switching on nights that I charge appears to be working better for me.
Thought I’d add some of my experience with managing my single PW2 / 6.6kw PV system under SRP’s (Arizona) TOU plan. The plan has relatively cheap per kw costs but extreme demand charges based on 30 min of utilization during peak periods.
The attached shows yesterday production and utilization curve under Advanced - TOU / cost savings with a 30% reserve and 2pm-8pm peak period. As you can see battery is charged prior to 2pm (but unfortunately seems to be used to run AC through am which seems a little inefficient) and then solar is sent to grid initially (creating some cost arbitrage) and then solar / battery provides sufficient power through 8pm. Excess over reserve is then discharged the next am.
To make this work I need to do some demand management:
- do laundry in morning
- pre cool home 30 min before 2pm peak
- ensure only one AC on at once (set each one a separate schedule)
So far have managed to limit peak demand to 0.1kw… will see how it managed when we’re in the 110’s (only hit 100 yesterday) and have about 45% left in reserve
In my opinion the algorithm seems to work well but can be disrupted by lower production days (eg cloudy day) or higher demand than average (e.g. increased AC needs as temps initially climb)
The attached shows yesterday production and utilization curve under Advanced - TOU / cost savings with a 30% reserve and 2pm-8pm peak period. As you can see battery is charged prior to 2pm (but unfortunately seems to be used to run AC through am which seems a little inefficient) and then solar is sent to grid initially (creating some cost arbitrage) and then solar / battery provides sufficient power through 8pm. Excess over reserve is then discharged the next am.
To make this work I need to do some demand management:
- do laundry in morning
- pre cool home 30 min before 2pm peak
- ensure only one AC on at once (set each one a separate schedule)
So far have managed to limit peak demand to 0.1kw… will see how it managed when we’re in the 110’s (only hit 100 yesterday) and have about 45% left in reserve
In my opinion the algorithm seems to work well but can be disrupted by lower production days (eg cloudy day) or higher demand than average (e.g. increased AC needs as temps initially climb)
Attachments
Are you on the average demand SRP Solar Generation TOU plan? I waited way to long to switch to that plan. Probably you already know this, but while the 30 minute demand peak $ rates are a bit higher (which is why I didn't select it originally) than the non-average TOU plan it doesn't really matter if we're generally zero'ing out our peak usage most days.
The reason being without averaging, one bad 30 minute period on one day sets your demand charge for the whole month. However, that same one bad/surprise 30 minute peak of usage, say it was 3k of usage, when averaged over 20 or so other non-weekend days of zero peak demand usage, means that 3k peak demand gets averaged down (if all other days are zero demand usage) to 0.15 peak charge (3/20 = 0.15) - so even at a higher demand rate because of our PowerWalls that eliminate peak demand usage altogether most days, the charge for 0.15 will probably be lower even at a higher rate than a 3k charge at the slightly lower non-averag plan demand rate.
Anyway, it tends to save me $5-20 vs the non-demand-averaging plan when there a minor blips where I accidentally have usage during peak times - usually because I was fiddling with app settings and left something in a state I didn't intend, or if I run out of PW juice earlier than expected during a peak window, etc. It only happens once or twice a month usually, and occasionally not at all - but the averaging plan makes those hiccups only cost me usually a $1-2 or less.
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I'm on the "standard" Customer Generation TOU Plan but I did look at the average demand plan the other day and would agree with you that it would seem to be a good plan to help that one bad day which is probably my biggest worry. Glad to hear you benefitted so likely the route I'll go!
Glad to say we have fixed the code, to solve captcha problem.
We now use a service called 2captcha , if you do use our solution please create a referral account with 2captcha, if you don't want to do that we can share my account, I am paying for.
Appreciate a donation if you can.
* pip install svglib
* get 2Captcha account, replace API key
Enjoy
https://github.com/fkhera/powerwallCloud
We now use a service called 2captcha , if you do use our solution please create a referral account with 2captcha, if you don't want to do that we can share my account, I am paying for.
Appreciate a donation if you can.
* pip install svglib
* get 2Captcha account, replace API key
Enjoy
https://github.com/fkhera/powerwallCloud
destructure00
Active Member
Hey Farooq, your original script that I've been using (without the Captcha fix you just did) started working again yesterday. Looking at the logs, was working fine up to 5/27, then was not able to authenticate on 5/28. The script does not run on the weekends or holidays, so I am not sure about 5/29, 5/30, or 5/31. But it started working again successfully yesterday 6/1 and just worked fine now on 6/2 to change my self-powered reserve to 0%. Maybe Tesla changed something again? Anyway, just wanted to give you a heads up that it's working again. I'll update if something changes.
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destructure00
Active Member
Did Tesla change something with the API again? Scripts ran successfully for me at 3pm and failed at 8pm.
destructure00
Active Member
I'm on 21.20.2 right now. Haven't been tracking to see if that's different than before.
It appears they activated captcha again. Just set to 'True' in latest code here and enter captcha api key:
powerwallCloud/captchasolver.py at master · fkhera/powerwallCloud
Contribute to fkhera/powerwallCloud development by creating an account on GitHub.
github.com
HI Darwin:
I am also in Phoenix with SRP and getting Powerwall and solar, probably around September/October 2022. How has the demand management worked in the summer for you?
Have you verified Tesla will sell to your address? I’m in SRP territory in Mesa and had Tesla install Solar 2 years ago. They no longer offer installation in my area per their Solar website. I even reached out to ask them about upsizing my system and the answer was no because they no longer get service my address. I assume it’s because of SRP.
I'm having a contractor provide my system and they are including the powerwalls so I am not dealing directly with Tesla.
I'm in Queen Creek (phx metro area) with SRP and the demand management in the Tesla app has worked fine and is a relief to finally be able to just configure it there instead of using third part apps to try and make it all work. It does seem like Tesla is still tweaking how things work unfortunately, so at least once I've had to change how the buy/sell $s are configured to keep it working as expected but have totally been able to configure it so it doesn't draw the PW when I don't want it too. I.e. charge PW with zero draw down during off-peak, and use Solar first during peaks, and only use Powerwall if Solar isn't producing enough to cover my usage during peaks, and then turn off after peak.
Very cool. That is the exact behavior I am looking for. Out of curiosity are you in the E27 or E15 plan? I am leaning towards the E15 plan in case I have some screwup in the configuration in the first few months, but would like to understand your experience a little more.
We're on E-15 with the averaging. I actually started on the E27 because in theory the cheaper demand charges. However, since we have PWs I'm effectively zeroing out all demand during all peak periods so it really doesn't matter which plan/rates I use since the off-peak rates are all the same and that's the only grid I use is off-peak. An average peak demand, when usage is zero kWHrs used, is zero. And, 0 usage multiplied by any rate is still zero.
To your point though, if there ever is a big mix up or problem with the settings or function of the system, then the averaging will come in more handy because that's likely to only occur once in a month, and even then only during a rare month based on my experience. I think I changed my system to 100% reserve once or twice over the last few years and forgot to change it back until Monday night after most of the peak period - so the averaging worked in my favor to a small degree on those couple of occasions.
One little tip I use....
I have my home pre-cool through the morning's coolest period (cheapest rate period 3.7-4.7 cents depending on season), and then again for the 1-2 hours before peak starts in the summer. meaning it runs almost non stop for that 1-2 hour period before peak, but it costs me almost nothing. Then throughout the peak period of each day I use HomeKit to schedule my ecobee thermostats to only run for 20 minutes "spread" across two 30 minute SRP demand billing periods/windows during each peak hour. So the ac runs exactly six predictable times during the 2-8 summer peak period.
I.e. each hour the AC only runs (full blast by setting the temp very low, like 70 degrees but only for 20 minutes) from like 2:20-2:40, then I bump it to 80 degrees until at 3:20-3:40 it runs again for a solid 20 minutes by bumping back to 70, and so on. We have what I think of as a large house (3 ac units), and this way even though the AC runs for a solid 20 minutes each hour, the AC specific usage actually only counts as 10 minutes of high AC usage during any 30 minute demand window. SRP's "demand" windows are exactly two each hour, first thirty minutes, then second thirty minutes of each hour. For our house, the common rooms/offices AC that I run during peak uses about 4.5kWhr more than the normal 750 watts the house uses otherwise 24/7 just for fridges, computers, house fans, clocks, NAS drive, wifi, routers, fountains, yard lighting, etc. So by only running the AC for 10 minutes during any 30 minute demand window that mostly limits my additional possible "accidental" demand in the summer to an extra 1.5kWhrs of AC related "demand" (4.5/3=1.5 i.e. 10 minutes is 1/3rd of the 30 minute demand period).
So even in the case where I forgot and left the PW at 100% reserve, so the PWs didn't power my house at all during peak from the PWs like they normally do - my max peak demand was only like 2.3KW (750 watts + 1.5) even though for a while each hour the instantaneous usage while AC was running was more like 5.3kWhrs (750 watts + 4.5). Hopefully that all makes sense. Plus, then that peak was averaged across like 21 or 22 days in the month which worked out to like 0.1-0.2 of peak "demand" usage for the month because of the E-15 demand averaging plan (2.3 one day peak demand usage / 22 days). So I think just a few times in many years I've had $1-$4 of billed demand charges on either E-27 or E-15 after I changed to E-15. I've actually had more in $ credits than demand charges where my solar goes back to the grid for a few hours at peak rates (using the sale$ value) for a few hours after peak starts at 2pm which is the only time I allow the "extra" solar kWs (beyond what the home is pulling) to go back to the grid vs into the PWs.
As it gets cooler, but still warm I may reduce that 20 minute AC window each hour to 16 minutes (8 minutes each demand window), and during the 115+ degree days I may bump up some of the hours to 24 or 26 minutes (12/14 minutes each peak demand window). So the strategy can be modified depending on the time of year, the type of home, and who is at home during the peak period. We both work from home so I need it cooled during the entire peak period but it's highly controlled as described here. This is all done very easily via my home automation app once a month or so at most, and does not require using Tesla settings which I never have to change anymore.
Also this AC strategy minimizes the PW usage, which leaves me more backup for summer monsoons and such even after the peak is over.
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