Forums

Powerwall energy flow control

Powerwall energy flow control

It seems like there are currently only two customizable modes for the Powerwalls (Backup and Self-Powered). Will more modes be available soon?
Self-Powered seems to only let you reserve a minimum charge for the batteries. Is that basically what it does?
Is there any way to control when the power walls charge or discharge. If so what is the mode, is it something one can setup to happen automatic or must it be done manually.

Thanks in advance for your help.

zubinanary | 2017年10月1日

What you're looking for is called "Time of Use Load Shifting" and it should be coming by end of year in a PowerwallOS update. Right now, without Solar, you have to set it up as Whole Home Backup, and manually do your own Time of Use Load Shifting, which allows me to charge between 11pm and 6am at the cheapest rate, and then consume the battery from 6am to 11pm.

Not perfect, but it works until the software comes out with that capability.

dmturner1718 | 2017年10月1日

Thanks for your comment. I do have solar panels. Does this mean the Whole Home backup will not work for my configuration. I look forward to the Time of Use Load Shifting.

harrye | 2017年10月1日

The "Backup-Only" setting reserves all battery power for a grid outage and functions like an Uninterruptible Power Supply (UPS) with or without Solar (Without Solar, the battery would have to charge from the Grid anyway).

When using "Self-Powered" the Reserved percentage is used for grid outage like a UPS and the battery is charged from Solar when there is excess Solar power available. If the battery is at 100% then excess Solar is exported to the grid.

If the battery is above the Reserved and the Solar output drops below the Home/Site Load, the extra (or needed power) is first taken from the battery then replenished from Solar if/when excess is again available. This maximises Solar generation/use for self consumption.

If the battery charge falls below the Reserved percent (ie: during a grid failure) the grid is used to get it back to the Reserved percent (if available).

I have found so far the Reserved percent can not be changed via the mobile App but I believe it is supposed to be dynamic so one can do this. Example, if you know bad weather is coming, you can raise the reserve value to cover yourself for a possible extended outage.

If one was to set the reserved value to 100% then this (in theory) should be the same as setting ""Backup-Only" mode.

If the Energy Gateway had a RESTful interface then one could adjust these setting via programmatic methods (Which I am looking and hoping for sooner then later :-)).

With the introduction of "Time-Shifting" facilities in the Gateways Operating System we should be able to program the Gateway as to when to provide battery power and/or control charging sources/time windows directly.

Cheers,

Harry E.
===

Bigtanuki | 2017年10月1日

I think you'll find that the reserve percentage can be changed but it only updates periodically. My I haven't verified whether it will update every 30 minutes but I am certain it will every 60. Mine updates about 45 minutes after the hour. I routinely change the percentage to limit how much I drain when charging the MS. After charging I change the reserve to what I anticipate needing for the night. With 2 PW2 units my night time reserve is 30%.
The only hitch to this scheme is if the car is plugged in, charging, and we have an outage the MS would quickly drain the reserve.
I'm hoping Tesla gives us cross compatibility to prevent the car from charging off the battery in a loss of grid situation. I can only hope.