Tesla: we need more control over our PowerWalls

[mspohr]

Looking beyond charging and storage, I think the PowerWall needs to have robust load management features.

It needs to have the ability to manage larger loads to ration stored power.

Here's an example of a Dutch company developing a product for the Tesla HPWC to match the load to the grid. After much hacking, Tesla finally gave them the specs to build it. Ultimately they would like this to be a software only product. It would be ideal if it was incorporated into the PowarWall.
Maxem Allows For EV Charging On Europe's Constrained Grid Connections | CleanTechnica

 

[miimura]

Ultimately, Tesla needs to work with utilities to do car charging load management and Powerwall virtual power plant completely through software. The Maxem solution is primarily addressing the limitations of small household grid connections in Europe. That problem requires an on-site solution that responds immediately to variable loads in the house. Tesla can provide larger aggregated benefits to the grid through their back end systems and existing vehicle and Powerwall Gateway connectivity.

 

[mspohr]

Ultimately, Tesla needs to work with utilities to do car charging load management and Powerwall virtual power plant completely through software. The Maxem solution is primarily addressing the limitations of small household grid connections in Europe. That problem requires an on-site solution that responds immediately to variable loads in the house. Tesla can provide larger aggregated benefits to the grid through their back end systems and existing vehicle and Powerwall Gateway connectivity.

I'm sure the utilities would like to be able to control load and battery feed-in and that should be a priority. (See Green Mountain Power which has been very progressive in building these systems with Tesla PowerWalls.) Whoa! Heatwave Savings for All GMP Customers Could Reach $500,000 Thanks to Innovation and Storage - Green Mountain Power

I think it's also crucial to have the PowerWall control local loads. During routine use, the power company could control loads such as electric water heater, A/C, heat pumps, etc. to manage loads and peaks and valleys. During a power failure, I would like the ability to prioritize loads to ration battery power. (i.e. shut off the hot tub, manage the heat pump and water heaters, etc.) A single PowerWall with 5 kW and 14 kWh storage can meet all of my needs indefinitely (as it is topped up daily by solar) if it will manage loads... especially in Winter.

 

[miimura]

I'm sure the utilities would like to be able to control load and battery feed-in and that should be a priority. (See Green Mountain Power which has been very progressive in building these systems with Tesla PowerWalls.) Whoa! Heatwave Savings for All GMP Customers Could Reach $500,000 Thanks to Innovation and Storage - Green Mountain Power

I think it's also crucial to have the PowerWall control local loads. During routine use, the power company could control loads such as electric water heater, A/C, heat pumps, etc. to manage loads and peaks and valleys. During a power failure, I would like the ability to prioritize loads to ration battery power. (i.e. shut off the hot tub, manage the heat pump and water heaters, etc.) A single PowerWall with 5 kW and 14 kWh storage can meet all of my needs indefinitely (as it is topped up daily by solar) if it will manage loads... especially in Winter.

As we get more and more internet connected loads, it will be easier to do local load management. However, today, it is not practical to install remote controlled breakers or other controllable disconnects on high current loads. For example, communicating with a smart thermostat or putting in a low power relay in the Y wire between the thermostat and A/C is much easier than wiring in a device to cut off the power to an A/C compressor.

 

[mspohr]

The major circuit breaker manufacturers are starting to introduce remote controlled circuit breakers. These would be ideal for PowerWall control.
http://www.eaton.com/Eaton/Products...ers/RemoteControlledCircuitBreakers/index.htm
Pow-R-Command lighting control
https://www.amazon.com/Schneider-El...r=8-4&keywords=Remote+Control+Circuit+Breaker
https://www.amazon.com/CNZJSC-Wifi-...42308358&sr=8-4&keywords=wifi+Circuit+Breaker
https://www.amazon.com/Square-EHB14...=2025&creative=165953&creativeASIN=B0075AOR3Y

 

[mspohr]

This company built an AI platform to meet the needs of commercial companies. It understands rate schedules, customer use, etc. to minimize electricity cost.

Stem Is Moving Beyond Energy Storage Into Solar+Storage Solutions | CleanTechnica

I think the Powerwall needs something similar.

 

[cwied]

This company built an AI platform to meet the needs of commercial companies. It understands rate schedules, customer use, etc. to minimize electricity cost.

Stem Is Moving Beyond Energy Storage Into Solar+Storage Solutions | CleanTechnica

I think the Powerwall needs something similar.

I think that this kind of system doesn't make sense with consumer rate plans. I think the main application of AI to the problem would be to predict rate fluctuations. Since consumer rate plans are relatively static, this would be unecessary in a Powerall.

 

[mspohr]

I think that this kind of system doesn't make sense with consumer rate plans. I think the main application of AI to the problem would be to predict rate fluctuations. Since consumer rate plans are relatively static, this would be unecessary in a Powerall.

Rate plans are more predictable for consumers but the current Powerwalls don't seem to take these properly into account.
Also, load demand, solar generation, weather and outages are complex in the consumer arena and these would benefit from a smarter Powerwall.

 

[cwied]

Rate plans are more predictable for consumers but the current Powerwalls don't seem to take these properly into account.
Also, load demand, solar generation, weather and outages are complex in the consumer arena and these would benefit from a smarter Powerwall.

I agree that a smarter Powerwall is necessary, but I think the biggest variable is load demand and AI would have a hard time predicting that. I think more configurability is a higher priority than adding AI. I think one of the biggest problems with the current software is that it's trying too hard to be smart rather than providing predictable behavior so users can tune the settings to their needs.

 

[JohnRatsey]

I agree that a smarter Powerwall is necessary, but I think the biggest variable is load demand and AI would have a hard time predicting that. I think more configurability is a higher priority than adding AI.

For me, the solar output is the biggest variable with today producing only 1/10th of yesterday (and that's without snow which can turn the output to zero). I think the domestic load probably varies between no more than 50% to 150% of average in the extreme which is a factor of three. Probably 90% of the time the domestic load is varying no more than 25% from the average. Tesla could tap into a solar forecasting system (eg Solcast) for the solar output but it's difficult to use anything more precise than a moving average for the household consumption (with the possible exception of consistent weekday and weekend differences).

 

[MorrisonHiker]

Today my Powerwalls only got to around 48% before all of my solar production started going back to the grid about 90 minutes before peak started. Of course it's going to be snowing all day tomorrow but not enough to trigger Storm Watch...so my Powerwalls will go down to 25% tonight and may be charged back up on Sunday if I'm lucky. If only we had a manual way of activating Storm Watch or a quicker way of changing the priority to charge the Powerwalls instead of pushing everything back to the grid...

 

[cwied]

If only we had a manual way of activating Storm Watch or a quicker way of changing the priority to charge the Powerwalls instead of pushing everything back to the grid...

I may have missed where you mentioned it, but are you aware that changes made through the setup wizard take effect immediately, without the lag you get when you go through the app?

 

[electracity]

I agree that a smarter Powerwall is necessary, but I think the biggest variable is load demand and AI would have a hard time predicting that. I think more configurability is a higher priority than adding AI. I think one of the biggest problems with the current software is that it's trying too hard to be smart rather than providing predictable behavior so users can tune the settings to their needs.

In my area, ComEd has day ahead pricing forecast. Combine that with a solar forecast and a few rules. The price occasionally goes negative overnight due to all the old nuclear.

Predicted Prices | ComEd's Hourly Pricing Program

 

[MorrisonHiker]

I may have missed where you mentioned it, but are you aware that changes made through the setup wizard take effect immediately, without the lag you get when you go through the app?

Yeah. Unfortunately, I wasn't home so I couldn't change it via the setup wizard. We only had one really solid hour of sunshine today so I wasn't able to charge the Powerwalls in time.

Hmm. I just remembered that I do have a stick PC that I could've connected to remotely. From that, I could've connected to the gateway directly. Guess I'll try that next time!

 

[PBBear]

I think it's also crucial to have the PowerWall control local loads. During routine use, the power company could control loads such as electric water heater, A/C, heat pumps, etc. to manage loads and peaks and valleys. During a power failure, I would like the ability to prioritize loads to ration battery power. (i.e. shut off the hot tub, manage the heat pump and water heaters, etc.) A single PowerWall with 5 kW and 14 kWh storage can meet all of my needs indefinitely (as it is topped up daily by solar) if it will manage loads... especially in Winter.

While I think there are benefits to having this sort of local control, I'm not convinced this should be performed by the PowerWall, or the power company. I don't want the power company deciding which loads of mine I should have off or on - that should be my decision to make, not theirs.
Similarly, I'd prefer 'prioritising loads to ration battery power' in the event of a grid failure, or (thinking the other way - working out what else to turn on when the sun is powerful, the battery is full, and the energy is just being exported to the grid)*, to be a separate home automation system that takes the battery charge state, remainder-of-day forecast and 3-day forecast into account. But not necessarily the Powerwall system, let it do its job without overloading a pile of extra complexity into it.

(*quite often we notice when the battery fills and the app switches over to pumping out to grid, and think 'how can I better use this 'free' energy - green ironing? green dishwasher? green coffee? green jacuzzi?) - much more often than "what to switch off when the grid has failed")

 

[PBBear]

Today my Powerwalls only got to around 48% before all of my solar production started going back to the grid about 90 minutes before peak started.

That seems too weird to export to grid in that state - what settings are you using in the 'customise' screen, and what 'reserve for power outages' do you have set?

 

[mspohr]

While I think there are benefits to having this sort of local control, I'm not convinced this should be performed by the PowerWall, or the power company. I don't want the power company deciding which loads of mine I should have off or on - that should be my decision to make, not theirs.
Similarly, I'd prefer 'prioritising loads to ration battery power' in the event of a grid failure, or (thinking the other way - working out what else to turn on when the sun is powerful, the battery is full, and the energy is just being exported to the grid)*, to be a separate home automation system that takes the battery charge state, remainder-of-day forecast and 3-day forecast into account. But not necessarily the Powerwall system, let it do its job without overloading a pile of extra complexity into it.

(*quite often we notice when the battery fills and the app switches over to pumping out to grid, and think 'how can I better use this 'free' energy - green ironing? green dishwasher? green coffee? green jacuzzi?) - much more often than "what to switch off when the grid has failed")

I did say that I would like to prioritize loads based on battery power. It's not that difficult to program but the Powerwall does need to have an interface to "smart" circuit breakers. Doing this manually running around switching breakers would be tedious and I don't want to have to hard wire my house for "priority loads". Just give me an interface to my smart breakers and I don't even need to be home to monitor and control things.

 

[JCUK]

I think the powerwall 2 is amazing, it can predict energy generation (a Tesla engineer told me it uses local weather forecasts), and somehow knows when I am going out for the day or longer, or when I return from holiday and have a lot of laundry to do on a wet day.
Unfortunately my Powerwall hates me and often does the exact opposite of what I want it to do. On the worst day of the year with severe weather warnings (for the UK) it put 0.5KWh into the powerwall from the grid during off-peak, when the powerwall was already empty, and then released 0.2KWh during the same period. Why? It is like planning a long journey (for the UK) in your electric car, and in the morning when you get into it, it informs you that you can travel 5 miles, and if you want to travel further please use more expensive more polluting forms of transport.
For about seven months of the year I am self sufficient and use the self-powered mode, but for the rest of the year I use the cost saving mode. In my financial calculations before buying the powerwall it was essential that I use off-peak energy instead of peak energy to make it financially viable. However cost saving mode is frequently unpredictable, sometimes it is OK but often it does the exact opposite of what I would have done. It is annoying when it makes these mistakes, I would prefer to make my own mistakes. Why should the powerwall tell me what I can do. Yesterday evening it went down to 2%, and this morning during off-peak it put in 1.3KWh but during the same off-peak period released 1.3KWh, (according to the app) on a day that was predicted to be very cloudy; I am now using peak energy from the grid; why?

I have complained to powerwall that we need to be able to control off-peak charging and discharging, but nothing has been done. The backup system appears to have some controls already so I do not understand why the system suggested by "JohnRatsey" cannot be implemented in the near future. This lack of control is costing me money, and them as well as a number of people have asked me what it is like, and I can only recommend that it is not suitable for their requirements. When I purchased the powerwall in early 2016, one of its advertising features was the ability to charge during off-peak, no mention was made that you had no control over this process, and I have been considering sueing them for compensation.

Sorry about this rant but I am very frustrated with this companies level of service.

 

[JohnRatsey]

I think the powerwall 2 is amazing, it can predict energy generation (a Tesla engineer told me it uses local weather forecasts), and somehow knows when I am going out for the day or longer, or when I return from holiday and have a lot of laundry to do on a wet day.
Unfortunately my Powerwall hates me and often does the exact opposite of what I want it to do. On the worst day of the year with severe weather warnings (for the UK) it put 0.5KWh into the powerwall from the grid during off-peak, when the powerwall was already empty, and then released 0.2KWh during the same period.

It has became evident to me that my PW2's off-peak charging in "Cost Saving" mode reacts (and usually over-corrects) based on what happened on the preceding few days. There is no hint of any forecasting of solar generation. Today being a good example: Following a couple of days of particularly poor solar generation the battery charged overnight so it was almost full (12.4kWh of electricity used) with the consequence that by 10:30 the battery was fully and energy flowing back to the grid (which earns me no extra money). Given that yesterday the battery charged to 73% and then dropped to 23% before today's recharging there's no obvious reason to massivle increase the charge level at the end of the off-peak period. An additional problem is that switching the PW back to balanced mode (the sensible thng to do if a sunny days is expected) seems to cause it to forget the history and it then has to re-learn the "cost saving" behaviour from the beginning.

 

[miimura]

It has became evident to me that my PW2's off-peak charging in "Cost Saving" mode reacts (and usually over-corrects) based on what happened on the preceding few days. There is no hint of any forecasting of solar generation. Today being a good example: Following a couple of days of particularly poor solar generation the battery charged overnight so it was almost full (12.4kWh of electricity used) with the consequence that by 10:30 the battery was fully and energy flowing back to the grid (which earns me no extra money). Given that yesterday the battery charged to 73% and then dropped to 23% before today's recharging there's no obvious reason to massivle increase the charge level at the end of the off-peak period. An additional problem is that switching the PW back to balanced mode (the sensible thng to do if a sunny days is expected) seems to cause it to forget the history and it then has to re-learn the "cost saving" behaviour from the beginning.

As far as I can tell, the Time Based Control modes Balanced and Cost Saving assume that you have net metering. Therefore, it seems to me that you would be best off using Self Powered if you don't get anything (or a pittance) for your grid feed-in. An additional switch to block discharge during certain Off-Peak hours would be useful to preserve battery power for daytime use when solar production is low or you want to charge your car directly from the grid during Off-Peak.