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Multiple Peak/Off-Peak time slots

Multiple Peak/Off-Peak time slots

The Powerwall app only allows one time slot for Peak and one time slot for Off-Peak. This means that if you have multiple time slots then you are out of luck. Tesla could allow multiple time slots for both Peak and Off-Peak, mostly using the same interface, by allowing the user to set Peak time slots by tapping above a horizontal bar and Non-Peak time slots by tapping below the same horizontal bar. This would use the same interface currently used to adjust the single permitted slots.
The existing Peak/Off-Peak buttons would display the total Peak/Off-Peak hours and allow all Peak/Off-Peak time slots to be disabled.
When the user taps above/below the horizontal bar a new time slot would be created at the corresponding time. The time slot start/finish can be moved to adjust the time and duration. A duration of 0 would remove the time slot.

gregbrew | June 4, 2020

There's actually three Time-of-Use periods within the Tesla app. Peak, Off-Peak and Shoulder. After setting Peak and Off-Peak, the remaining is Shoulder.

mem10123 | June 4, 2020

For my utility (SRP in Arizona), the 3 choices available don’t let me accurately depict the rate changes in the winter. We have 2 peaks (5a-9a, 5p-9p). Everything else is the same low off peak rate. There is no means to set this in the app with just a single peak, shoulder, and off peak.
I’d second Tesla adding better control here. Also, I think they should add a tie in with vehicle charging to change the charge rate of the car to match “excess” solar, even during peak, if it would be sold back to the utility at a cheap export rate. I’d rather have the option to dump into the car

TeslaTap.com | June 5, 2020

I've changed my charging strategy to start charging at 1 pm, near the peak solar. I set the car to charge at a low rate of 16 amps. With the lockdown, I'm not driving as much and I'm home at that time as well. Several hours at this low rate is usually enough to get the charge needed.

I wrote this article last month on how you may shift what you do to optimize solar/Powerwall/Grid and reduce wear on the Powerwalls here: https://teslatap.com/articles/solar-powerwall-system-optimizations/

ArizonaJon | June 5, 2020

Like mem10123 with TEP (Arizona) we also have two peak times during the winter - 6 am to 9 am and 6 pm to 9 pm. So I need two peak periods. Now, during the summer we only have one peak period.
As gregbrew said there are 3 options. Because I have an BEV I have three rates - peak, off-peak, and super off-peak. I use the shoulder for the off peak and reserve the off peak for the super off-peak. I think this will work the way I want it to, but since I just got my solar meter set yesterday, it will take a while for the system to learn my usage pattern, and for me to observe is this is a good solution.

gregbrew | June 5, 2020

I don't understand how your system can "...learn my usage pattern...". To the best of my knowledge, neither the TEG, nor the PWs have adaptive algorithms that would allow them to "learn"...anything.

bb0tin | June 5, 2020

Unfortunately the 'learning' of the PowerWall is pretty useless.
For example, while in Advanced mode, my PowerWall ran flat overnight and then started charging from the grid this morning, even though the entire weekend is off-peak. I am in NZ so it is Saturday. What it should have done is left the solar to charge the battery. i.e. The PowerWall actively did the opposite of what is best.

mem10123 | June 5, 2020

I thought I read that the Tesla gateway does look at usage, and tomorrow’s forecast weather to predict solar production, when determining whether to pull out of the battery or pull from the grid for house usage. Don’t remember where I read it though. But it sounded cool! Will be a bit of a disappointment if untrue...

gregbrew | June 6, 2020

When I look at real-time behavior and history in the app, I can see zero evidence that there's any adaptive algorithm at work.

ArizonaJon | June 6, 2020

I concur with mem10123 re learning. The following is from the Tesla website https://www.tesla.com/support/energy/powerwall/learn/how-powerwall-works
"The Backup Gateway learns and adapts to your energy use over time, receives over-the-air updates just like the rest of Tesla's products and is capable of managing up to ten Powerwalls."
It also checks for "stormwatch alerts". I don't know if it checks for weather forecasts. Not sure that would be very useful as weather forecasters and stock brokers are the two professions where you get paid for often being wrong.

bb0tin | June 6, 2020

In the example I gave for charging on a Saturday morning from the grid, when the entire weekend is Off-Peak, there is no good reason to charge the battery from the grid, regardless of any "learning". The only time the battery should charge from the grid is from Sunday night onwards. I have even seen the PowerWall charge from the grid at Peak times with is ludicrous. Tesla's management of the Powerwall in Advanced mode is useless and often worse than useless. They can easily fix this by allowing the user to specify the times to charge from the grid and the times to export to the grid. Tesla choose not do this.

adam.lippiatt | June 7, 2020

I have the same issue with my legacy TOU tariff with two peak periods during the winter week day. Because my consumption is low enough (and the Powerwall can charge from the grid during off-peak when it sees a low-insolation day coming up at low SOC - there are some smarts for sure, although how much is the company I bought it off (which company actively monitors and manages the Powerwall, so they say) and how much is the Powerwall / Gateway I don't know) I just set the whole week day as peak. I have kindly asked Tesla in a feedback form if they could give us multiple peak period optionality in the app, it would be a good change particularly as we might potentially move towards more tariff complexity / opportunity in the near future.

There is at least one company offering up exposure to the real-time market in Australia, and given we have forward pricing, ultimately it would be good to have the Powerwall supporting opportunities to arbitrage price (and renewables) against behind the meter production (which many of us have). This is an untapped opportunity for battery ownership at present.

tom.dillon | June 28, 2020

I live in Sacramento Municipal Utility District (SMUD) and they provide an off-peak discount for charging your EV. The discount is daily from midnight to 6:00am. It’s only $0.0150 kWh discount, but it is cheaper. I only have 4kWh solar and it takes 5-6 hours to recharge my two Powerwalls back to 100% to handle the peak time and into the evening hours. I would like to have the Powerwalls recharge during the EV charging time slot and use my solar production to run the house during the day and the Powerwalls to run the house from Peak until Midnight.

TeslaTap.com | June 29, 2020

@tom.dillon - In most parts (all?) of the USA, that's not allowed by the utilities. It seems stupid, but you can only charge the Powerwalls via solar or from the grid during a storm watch. Tesla is just following the rules. Some countries like Australia and the UK do allow off-peak charging.

bb0tin | June 29, 2020

@TeslaTap Tesla does not allow the homeowner to schedule to charge the PowerWall when the want , or to send excess solar production to the grid when they want, even when the utility and power authorities do not prevent it.
It is not a matter of Tesla following the rules, except their own rules, which are bad for the homeowner, bad for the grid and bad for emissions.

adam.lippiatt | June 29, 2020

@teslatap and @tom.dillon Correct for Western Australia. The Powerwall will charge from the grid during off-peak times to have enough stored electricity it predicts you will use during peak times (taking into account solar production). Why utilities don't allow charging during off-peak is a mystery to me. These are times when they get little value from generation - wouldn't they want to increase demand?

I am not sure I agree with @bb0tin.You put storage in to save your solar because it is worth more to you than what you get for sending it to the grid. If you set the off-peak time in the app, then the Powerwall does charge when you want it to, that is, when electricity is the cheapest (and as wind and solar is the cheapest electricity, then more and more the cleanest).

I would just like a bit more flexibility as we have split peak periods in winter here and the Powerwall takes a bit more electricity from the network than is required because I have to force it to assume the peak period is not split (and thus a much longer period).

bb0tin | June 29, 2020

In New Zealand I have tried using both Advanced Modes and it does not charge the PowerWall at off-peak times. Sometimes the PowerWall will drain to empty while in Off-Peak and then charge during Peak. The PowerWall is supposed to 'learn' what to do but it doesn't do it well. I, and others, do not want it to 'learn' and decide for itself what to do. We want it to do exactly what we want, when we schedule it to do so, and allow multiple Off-peak and Peak times. This is how the PowerWall should work.