Pulling from grid on cue at 11 PM. This is good. Hopefully it goes back to battery at 5AM.
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Powerwall Time-Based with 2 peak periods
- Thread starter Dan123
- Start date
Pulling from grid on cue at 11 PM. This is good. Hopefully it goes back to battery at 5AM.
The irony of all this is that I kept saying "I can't wait for solar so I can forget about what time I can do laundry or having to pre-cool the home."
So now I'm counting watts and trying to micromanage everything - it's even worse, lol (at first only I hope). I just naturally want to get efficient and this stuff all has a lot of knobs to adjust.
So now I'm counting watts and trying to micromanage everything - it's even worse, lol (at first only I hope). I just naturally want to get efficient and this stuff all has a lot of knobs to adjust.
Chancellor32
Member
I have the same demand manager installed by Sun Valley Solar solutions (who also did my SunPower panels and PWs). The demand manager has always worked well with the PWs since install early this year.
I have had a couple instances of it not updating on the schedule. Not sure if it’s the gateway or SmartThing or what. Both times I woke up to find it never changed the PW setting for the morning peak period. Otherwise working quite well.
My impressions from others that have nearly directly west facing panels, winter can be pretty rough for production, like close to half or 1/3 of summer peak, and being a few degrees north of west you'll probably be at the lower end of that range - but in late spring and summer when you really need the production in AZ you should be in a nearly perfect orientation for summer utility peak windows.
I use Darwins app similar to @dhskiracer71, but actually use TBC Cost Savings mode, but do similar things with the reserve. Great App.
My settings, and results in the screen shots. I have redundant schedules setup to attempt twice to lower the reserve before the evening peak. For what ever reason, on a couple occasions the evening change has not gone into effect, so I setup redundant schedules 5 minutes apart.
By using TBC-Cost Savings instead of Self-Consumption, I can use take advantage of the Peak Window to force no evening PW discharge after 9pm and before 5am regardless of reserve, and also not having to depend on the 3 way communication between SmartThings, Tesla, and my local gateway when not required. It also frees up not having to use up two scheduling slots at the end/begin of day in Darwins app since the defined TBC controls that overnight period, if I want to do my nuanced tweaking of the % during the day. Technically I don't need those first & last schedules adjustments to % because of the TBC window, but I had those setup while I was testing different ways to control all this. Schedule 5 got cutoff, but it basically makes sure the reserve is at 5% or less overnight, since TBC is preventing PW discharge.
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I'm hopeful. I'm still pulling from the grid a bit at night w/o car charging but I think it can go to zero. Heck, I'm still trying to get the batteries full. A lot of trial and error. I'm probably screwing up it's learning by running advanced cost savings then hitting 100% button to start hoarding sunlight 100% for the batteries while still pulling a bit from the grid. After a few days, I'll look at solar in vs home usage to see if I'm neutral in winter and can cut the cord for max savings.
I assume these batteries are like the cars in that they prefer to be around 50% charge on average? Or are they designed for the high average stored so there's always a nice reserve? Ya, what do I need for reserve right? Whole other question. Right now my setting is 40% so I can get the charge higher on up. Maybe that's too much?
I've read from some on these forums, that these are maybe a different chemistry, and should be okay sitting at a full SOC. However, for folks that have actually done some capacity testing after holding at 100%, for maybe a year or more, their total capacity after a year or so seems to be going down at the same rate as the research indicates for most all lithium chemistries when fully cycled to 0-100, and or when stored at 100. Some research indicated holding lithiums at 100% reduces capacity at roughly the same rate as cycling between 25 and 100% - which either way is still guaranteed to be 70% after 10 years if following the rules of the warranty in regard to discharge cycles general speaking. So still really good. I'm just shooting for longer and less capacity loss if possible, and configured and did my cost/pay-off analysis with that in mind.
That kind of leads me to believe like all other lithium chemistries, these will last longer if not cycled or stored at a high SOC when not otherwise needed, they can sit at 40-50% for longest life - but that's really only possible if we're willing to install more more PW than we need. In my case I was forced to do that because of my peak summer time needs. I installed what I needed in peak summer which is pretty extreme and only for a few weeks, so while the install happened at the very end of September, I did have it running for a couple weeks of 100 degree weather, and I seemed to be cycling between 40% and 90% to cover peaks (with four PWs), so I'm guessing during our very hottest weeks, I'll cycle between 20% and close to 100%, but that should only be for several of the hottest weeks.
For the coolest 5-8 months of the year I think I'll be cycling between 30-60% at most, with it sitting overnight usually around 50% - so I figure that will work out to some life extension. But then I don't use the PWs during off peaks at all because the rates are so cheap, and the PWs are expensive. I'd rather just store them overnight at about 50% charge and not use them, except during the day when solar production fills the PW above my set peak level, the with TBC-Cost savings, then the settings will let the house pull it back down to the reserve during the day-time off-peak if needed.
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I'd like to go for 15+ years, we'll see.
Funny thing just happened. I was trying to muscle in more power to the battery (100% first time, then maybe again in a month or so). But I happened to get to 100% early today and saw it going to utility (for pennies). So I plugged in the car and now getting 10 mi/hr to top that off (also at 80%). I'm ready for a storm now
Our air handler uses a lot of power (gas heat, but elect fan). 1-2kW for extended periods, I'd be better off getting a space heater for the bedroom (hopeful again) for an even smaller footprint. As I compare the past 3 days of data, I should be able to maintain off grid minus the car, but it's close with our setup.
This whole thing is a big science experiment between the car and home (and the stock)! Time of my life...
Funny thing just happened. I was trying to muscle in more power to the battery (100% first time, then maybe again in a month or so). But I happened to get to 100% early today and saw it going to utility (for pennies). So I plugged in the car and now getting 10 mi/hr to top that off (also at 80%). I'm ready for a storm now
Our air handler uses a lot of power (gas heat, but elect fan). 1-2kW for extended periods, I'd be better off getting a space heater for the bedroom (hopeful again) for an even smaller footprint. As I compare the past 3 days of data, I should be able to maintain off grid minus the car, but it's close with our setup.
This whole thing is a big science experiment between the car and home (and the stock)! Time of my life...
Ok, I set up my smart hub using and tested it last night. Worked wonderfully, I had 82% left when I woke up this morning at 4:45am to check on the program. I did notice my projected SRP bill went up $5, but it might have been a coincidence...I really like my $65 electric bills.
I only set up 3 schedules
4:30am switch back to time based/cost savings
4:50am switch back to time based/cost savings (I added a redundant step just in case)
9:01pm switch to backup 100%
I can get away with my batteries (2) and my solar (8kw) powering my house all day using 1 long peak period. I might change this in the future, but for now it seems ok.
I think I figured out why Tesla won’t do a 2 peak period setup because people wouldn’t need additional batteries. I was seriously thinking about getting a 3rd battery to avoid starring at the Tesla app wondering if I will make it through the morning. I believe with this program (thank you Darwin) it solved my problem/concerns.
I probably will hook back up my Demand Manager just to see how it performs, but I feel its probably overkill.
I only set up 3 schedules
4:30am switch back to time based/cost savings
4:50am switch back to time based/cost savings (I added a redundant step just in case)
9:01pm switch to backup 100%
I can get away with my batteries (2) and my solar (8kw) powering my house all day using 1 long peak period. I might change this in the future, but for now it seems ok.
I think I figured out why Tesla won’t do a 2 peak period setup because people wouldn’t need additional batteries. I was seriously thinking about getting a 3rd battery to avoid starring at the Tesla app wondering if I will make it through the morning. I believe with this program (thank you Darwin) it solved my problem/concerns.
I probably will hook back up my Demand Manager just to see how it performs, but I feel its probably overkill.
My install got activated on 12/31, and I've been playing with the settings and getting familiar. Is anyone aware of a recommended minimum for the "Reserve for Power Outages"? Since I can't find any information on this, is it purely what you personally need or should it default to 20% for the good of the battery, etc? If I recall, it looked like it was already set to 16%. Mine seems to never go below 15/16, even if I have it set to 10. Follow-up question, I have two powerwalls but they show as combined, essentially one large battery. So if it keeps going down to 16 then switching to grid, is that actually taking both down to 8?
Lastly, I've noticed my max solar input seems to cap at exactly 5.2kW with an 8.19kW + old smaller solar dovetailed in. Tesla on east roof, older/smaller solar on west roof. Should I be seeing higher at optimal angle for Tesla on a clear day, or is this a winter thing? Is there a calculator for this type of thing anywhere?
EDIT: Nevermind I just hit 5.7, so the I'll keep analyzing the data.
Lastly, I've noticed my max solar input seems to cap at exactly 5.2kW with an 8.19kW + old smaller solar dovetailed in. Tesla on east roof, older/smaller solar on west roof. Should I be seeing higher at optimal angle for Tesla on a clear day, or is this a winter thing? Is there a calculator for this type of thing anywhere?
EDIT: Nevermind I just hit 5.7, so the I'll keep analyzing the data.
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@oldpueblo You just set it based on your home needs. I have my reserve setup to 65% which covers me to about midnight due to the heater. I had it set to 20% and covered 3:30pm to 8am which was great but during this winter months I could not fully charge during the day which meant full grid usage during day and then running short over night causing more usage. I have a 4.41 kWh setup with 1 pw2 and I average a non occupied hourly draw of .2kwh an hour and an occupied usage of .6kwh and with furnace .9-1.2kwh draw then again my home is not energy efficient with old blown in insulation no wall insulation and single pane windows. And I’m in SoCal. I should also add all my panels are west facing so I do not get a good charge until 9:30-10:30 and I began losing light around 2:45. And u get less generation due to winter months regarding your 2 pw I do not have an answer
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Do you think srp will ask us to give back the battery incentive money back if we use the Darwind app since they also their software to monitor our usage for their study?
Wouldnt you just need to make sure you make the minimum amount of monthly powerwall discharge?
Chancellor32
Member
New
Thanks Chancellor, another question do you think with a 4.2 kw system (cover 42% of my usage) will be enough to charge 2 pw to 100% from 6am to 1pm and then cover me from demand charge at the 2pm to 8pm peak period? I estimate i will be using about 28 kw from 2pm to 8pm.
Chancellor32
Member
That’s exactly the same system I have. Depends on your usage. We use 17,000kw’s a year or so and our PW is fully charged everyday by 2pm.
Okay, i have ordered 8.16kw system and 2 pws. I am thinking of changing it to 4.02kw and 1 pw as my usage is only 15,500. Do you think it would be enough to get by with 1 pw?
