Time-Based Control?

[AnthonyB]

I've seen an interesting change in behaviour that I hope persists...

As a reminder, I'm on Tesla T.B.C - Cost Saving and have a ToU tariff with a Shoulder period that is only marginally higher than my off-peak. My off-peak is 10pm-7am.

What I had previously been observing is that as soon as I got to 10pm (start of off-peak) my battery would immediately start charging from grid, and charge to some arbitrary amount based on, I assume, what it felt I needed to sustain through the following day's Peak period and allowing for Solar top-up. What I found odd was that it would stop charging from the grid and start discharging in the early hours of the morning, still in the Off-peak period (see first 3 red circled peaks - discharge starts between 3-6am).

Last night, it actually maintained full charge all the way up to 7am when my off-peak ends and shoulder period starts (right-most circled peak). This is the behaviour I would prefer (i.e. don't discharge during off-peak!). To be honest, I'd also prefer it to not discharge during Shoulder, but one step at a time..

Note: ignore 26th and 27th April - that was when I was messing around with removing my Shoulder period from the T.B.C. config to try and force a more desired behaviour.. and failed

 

[Neil_dsb]

Great thread, have had my PW2 in the UK since August 2017, received TBC ~4 weeks back, yesterday had my dual rate meter fitted (EoN Economy 7) set the app to 'Cost saving', but the PW2 did not charge during my off peak period of 01:30 - 08:30....? have raised a ticket with the Tesla support, hoping the forum team can help me quicker... PW2 on 1.15.1 Android app 3.3.5, thanks Neil

 

[AnthonyB]

Odd that there is now 3 different firmware versions in play; 1.15.1, 1.15.3, and 1.15.5, and it doesn't seem to relate to time-based control given there are people on 1.15.1 with T.B.C. and 1.15.5 without T.B.C.

 

[AnthonyB]

Hmmmm.. looks like Tesla have also standardized on the Powerwall Modes of Operation with Solar. definitions.

Back on this post from 2 weeks was what used to be on the Australian Tesla site - Time-Based Control?

But now what is listed on the AUS and US sites are the same:

- AUS - Powerwall Modes of Operation with Solar

- US - Powerwall Modes of Operation with Solar

I wonder if the differences previously was a mistake or whether they have made a change and standardized?

 

[Neil_dsb]

Hmmmm.. looks like Tesla have also standardized on the Powerwall Modes of Operation with Solar. definitions.

Back on this post from 2 weeks was what used to be on the Australian Tesla site - Time-Based Control?

But now what is listed on the AUS and US sites are the same:

- AUS - Powerwall Modes of Operation with Solar

- US - Powerwall Modes of Operation with Solar

I wonder if the differences previously was a mistake or whether they have made a change and standardized?

UK site
Tesla Powerwall
Supported Applications
Solar self-consumption
Time-Based control
Backup and off grid require additional hardware that is not currently available in the United Kingdom.

email received - 27/03/2018 7:25 AM
Your Powerwall recently received a software update, including a new feature called Time‑Based Control. This feature maximises the value of your solar system by monitoring how your home consumes energy. As a result, you can avoid paying variable prices for electricity during the day.

You can access this feature in the Tesla app. Just select “Customise” then “Advanced – Time‑Based Control”. Note: Your app will need to be updated with the latest software for this feature to function correctly.

Visit our configuration guide to learn how you can choose your energy settings and edit your price schedule. If you need additional assistance, you can also contact us by phone at +44 8000988064.

 

[Neil_dsb]

Time-Based Control

 

[dotbombjoe]

View media item 118282
I've been waiting a long time to see this...beautiful!

I just noticed the new TBC settings and other than not being able to set the shoulder out to midnight, it seems great...hopefully it works, but that pic is a good start.

 

[AnthonyB]

Time-Based Control

Right. So the UK site still reflects the same Modes of Operation with Solar table as what the AUS site used to. it will be interesting to see if this also changes.

 

[Ulmo]

My first two days on Time Based Control have been disappointing for me. Tonight, it hit the reserve during the Peak TOU period because it had not charged itself enough during the Part-Peak period, instead letting the solar during that time go to export. I had to manually lower the Reserve in order for it to power the house through the last two hours of the Peak period. See graphs below.

View attachment 291926 View attachment 291927

If you look at yesterday, I turned on TBC and it took effect at 9:30am. Prior to that it was taking all the solar to charge the batteries. At 9:30 it started exporting the surplus solar, but it did do a little charging too. It started powering the house from battery when the Peak period started at 2pm and stops discharging at 9pm. Perfect. The problem is that it did not take the opportunity to charge to full before 2pm, so it ended at ~56% IIRC, when I had the Reserve set to 50%. Then today, starting from a low SOC, it still didn't take all the energy it could before the Peak period started. Also, what's with the profile of the charging that it is doing around noon? What kind of algorithm is that?

I can't make heads or tails of those graphs. I looked at them for 10 minutes and couldn't understand them. I'm so used to looking at my own graphs ( Ulmo.Solar ), that looking at someone else's format can be extremely difficult.

 

[Ulmo]

Monday Peak hours just ended and TBC Cost Saving mode failed me again. It started the day with a very generous 84% SOC and exported all the surplus solar until the Peak period started at 2pm. Then it supplied the house loads from the Powerwalls and exported 100% of the solar. The Powerwalls hit the 50% Reserve at 8:40pm, short of the end of the Peak period at 9pm.

It makes no sense to me that the algorithm doesn't know that there is no Off-Peak solar available on weekdays. It's fine on the weekend when there is Off-Peak solar available, but it should charge with Surplus Solar during Part-Peak because it's the only way to store up energy for the Peak period during the week. I would be much more impressed if it calculated the charging rate required to hit a certain SOC, say 90%, by the start of the Peak period and exported the surplus above that. However, with Net Metering it doesn't really matter the charge rate, if there is enough solar production the batteries will eventually be full and the rest exported.

Am I expecting too much? Should I just give up on Cost Saving and fall back to Balanced to see what that does?

Most of solar is available during Part-Peak, not in Peak nor in Off Peak, in your and my rate plan (the same).

 

[Ulmo]

I think the assumptions in every post of this thread need to be stated. The variables that can literally change everything:

• How much solar array (note that not every solar array behaves the same; tracked vs not tracked, which way it's pointed, type of cell, etc.).
  
• How much insolation that day (includes clouds, angle of sun, shade)
  
• Time of use periods (all of them), and the prices
  
• How much battery
• How much use
• Regulatory and benefit program restrictions (such as SGIP, etc.)
• How much home use and when

My answers are for a solar system (5.8kWp) insufficient for all household needs except about a third of the year, and two PW2 batteries also insufficient for much of the year, EV-A tarrif with weekday 11pm-7am off peak, 7am-2pm partial peak, then 2pm-7pm peak, then partial peak at 7pm-11pm. Peak is about 50c/kWh, partial is about 35c/kWh, and off peak is about 15c/kWh. Weekends there's no partial peak, with peak at 3pm-7pm, at around 40c/kWh, and off peak around 15c/kWh.

We have shading most of the year that stops most solar input in the afternoon after around 5PM. Here's a rare sunny day that shows the maximum pattern:

http://ulmo.solar/powerflow/2018/04/17.png

Most of our solar comes in before that. Around half my solar comes in before peak rate starts. None of it comes in during off peak, except for weekends, when most of it comes in in off peak.

Clouds are common.

http://ulmo.solar/powerflow/2018/04/18.png
http://ulmo.solar/powerflow/2018/04/24.png

What do you want it to do during partial peak?

 

[Shygar]

When you say insufficient except for about 1/3 of the year, how are you measuring whether it's sufficient or not? Generally speaking, your solar production should be looked at over a 12 month period to see whether it's sufficient or not. Unless you are looking at your solar on a daily basis. If you build it to cover your costs in January, you will be making way more than you will ever use in July (again, generally speaking). That's the problem with trying to cover your usage on a daily basis, vs over a 12 month period.

 

[Neil_dsb]

It just started working....

 

[Neil_dsb]

It just started working....

Maybe I posted too soon, yes the PW charged in the off peak, but it's not charging from exesse solar, its now exporting? (~40% left to charge) and it not discharging from the battery.....

 

[Dborn]

Well, today my system went totally off the wall. It charged the battery from off peak up to 100% presumably because yesterday was a cloudy day, and today failed to discharge at all!! No peak discharge, nada!!
This after randomly starting to discharge between 4.30 and 7am which has been my issue, same as Anthony B. I have changed nothing. So, what the heck?

 

[RTB01]

Well, today my system went totally off the wall. It charged the battery from off peak up to 100% presumably because yesterday was a cloudy day, and today failed to discharge at all!! No peak discharge, nada!!
This after randomly starting to discharge between 4.30 and 7am which has been my issue, same as Anthony B. I have changed nothing. So, what the heck?

Well, today my system went totally off the wall. It charged the battery from off peak up to 100% presumably because yesterday was a cloudy day, and today failed to discharge at all!! No peak discharge, nada!!
This after randomly starting to discharge between 4.30 and 7am which has been my issue, same as Anthony B. I have changed nothing. So, what the heck?

 

[RTB01]

Got the same problem here. Battery charged to 100% overnight then not using it during the day when on peak rate. Also the Tesla app is indicating that all of the solar generated is going straight to the grid whilst the home is drawing from the grid
Spoke with Tesla and they said they have had many call from owners in the UK with the same problem- apparently they will get back to us either tomorrow or the day after.
Here’s hoping!

 

[Neil_dsb]

Yes same response from the support team, told to revert to consume mode then change back after 12hrs

 

[Tim_btt]

Yes same response from the support team, told to revert to consume mode then change back after 12hrs

I've also got the same problem here in the UK. Charged to 100% overnight and now all the sunshine is being exported. Nothing I do makes the powerwall start providing power to the house.

 

[Neil_dsb]

I've also got the same problem here in the UK. Charged to 100% overnight and now all the sunshine is being exported. Nothing I do makes the powerwall start providing power to the house.

Hi Tim, changing to 'Self-powered' mode works for me....back to normal solar charge and discharge...will try/revert 'advanced TBC' around 10pm BST