Netzero App

[C DM]

Thank you for the app, @offandonagain.

One small visual thing that was randomly noticed: when looking at the Gateway information section in the System Info tab of the Diagnostics screen there's an item called "Installation datez:" where it looks like there's an unexpected 'z' being included at the end.

 

[Mark Purcell]

Does anyone have any insight into some of the decisions the Powerwall makes?

I run an open source energy management package called EMHASS which uses a mathematic linear programming model to create an optional schedule for battery operations based on forecasts for future solar production, household loads as well as buy and sell prices.

Intro / Quick start — emhass 0.8.6 documentation

Powerwall optimisation is a bit of a black box and I haven't seen anything published, but I can tune EMHASS to deliver the same outcome as Tesla Time Based Control, which leads me to speculate Tesla are also running a linear programming optimisation.

In the below chart you can see the EMHASS forecast at the top and what TBC actually did in the bottom.

 

[OCJeff]

@offandonagain - Quick question about automations and reserve settings.

It appears that currently when NetZero modifies the reserve setting, it is also affecting the VPP reserve setting. Can that be disabled, or made a separate option?

 

[offandonagain]

One small visual thing that was randomly noticed: when looking at the Gateway information section in the System Info tab of the Diagnostics screen there's an item called "Installation datez:" where it looks like there's an unexpected 'z' being included at the end.

Thanks, fixed in the next release.

It appears that currently when NetZero modifies the reserve setting, it is also affecting the VPP reserve setting. Can that be disabled, or made a separate option?

I couldn't reproduce this. Did you ever change the VPP reserve setting independent of the backup reserve in the Tesla app? I wonder if the VPP configuration tracks the backup reserve, until you manually change it.

 

[OCJeff]

I couldn't reproduce this. Did you ever change the VPP reserve setting independent of the backup reserve in the Tesla app? I wonder if the VPP configuration tracks the backup reserve, until you manually change it.

I did. However I've changed it back to 10% and will report back tomorrow after automations to see if they are affected again.

 

[OCJeff]

I did. However I've changed it back to 10% and will report back tomorrow after automations to see if they are affected again.

So far reserve setting for VPP has not been modified by the automations. I'll report back if I see this happen again, but it may have been just tracking to the set reserve until the VPP reserve was set independently.

 

[OCJeff]

This is not a huge issue, but I thought I would mention it. I have an automation to set the reserve level to 100% once the charge level reached 100%. I’m not sure why, but it looks like it ran twice today. I suspect that maybe the PW hit 100% then dipped to 99.99% and then went back to 100%. Maybe there is a way to buffer it or something.

I have that rule set so that once my PW is fully charged I can start to charge my car and ensure it will not draw from the PW.

 

[offandonagain]

This is not a huge issue, but I thought I would mention it. I have an automation to set the reserve level to 100% once the charge level reached 100%. I’m not sure why, but it looks like it ran twice today.

Thanks for the report! It's unlikely that the same automation ran twice a few seconds apart, both because of a cool off period and how frequently automations are evaluated. Are you sure you don't have a separate automation that might have triggered the same action? The release that's coming out today will show the event that triggered an automation. If you use the web app, it already has that change.

 

[miimura]

My Powerwalls frequently charge to 100% then the SOC drops without discharging and charges some more. I assume the batteries are balancing, then charging some more.

 

[gsdubs]

Hi @offandonagain, one minor issue I see with solar estimates: the monthly estimates are inconsistent with the summed daily estimates. My April 2024 summed daily estimates come to 1128.1 kWh but the monthly display shows 1034.5 kWh. Or perhaps they are pulling from two different PVWatts calculations and are not meant to match exactly?

 

[joekieffer]

Not sure where to ask this. I have 2 solar inverters without powerwalls feeding into 1 of my 2 100 amp panels on located on the opposite side of the house. I would like to use emporia for monitoring home use and the neurio for solar production. Can you set up netzero to work with 2 vue version 3's and tesla at the same time. I cant seem to find in app. I thought it was there at one time? Any help would be appreciated.

 

[offandonagain]

Not sure where to ask this. I have 2 solar inverters without powerwalls feeding into 1 of my 2 100 amp panels on located on the opposite side of the house. I would like to use emporia for monitoring home use and the neurio for solar production. Can you set up netzero to work with 2 vue version 3's and tesla at the same time. I cant seem to find in app. I thought it was there at one time? Any help would be appreciated.

Emporia is no longer available in the app, details in this post:

Netzero App

What is the long term support mechanism for NetZero? How do you plan to keep this going from a cost perspective? Costs are low right now. If that changes in the future (e.g. Tesla starts charging for the API), I'll re-evaluate. It now says the test was successful but the message says it is...

teslamotorsclub.com

 

[offandonagain]

Hi @offandonagain, one minor issue I see with solar estimates: the monthly estimates are inconsistent with the summed daily estimates. My April 2024 summed daily estimates come to 1128.1 kWh but the monthly display shows 1034.5 kWh. Or perhaps they are pulling from two different PVWatts calculations and are not meant to match exactly?

Short answer: you should not sum the daily numbers manually, use the monthly sum from the app. Netzero does some smoothing at the daily level to account for historical weather variation, which skews the sum.

Long answer: PVWatts uses hourly typical meteorological year (TMY) data, which is one year's worth of data over decades of collected weather data for a specific location. For every month it picks the most typical weather year for that month, and uses that month's data in the model. So let's say for the month of April the most typical weather year was 2010. Daily data will depend on what the weather was that year; but if April 15 2010 happened to a cloudy day, and April 15 2024 is clear, it gets a bit confusing. So Netzero does some more smoothing at the daily level, substituting April 15 with a typical day between ~April 10 and April 20. This will exclude outliers, but the sum across days is no longer accurate.

A better solution here would be to use actual insolation and solar forecast data, but unfortunately I haven't found a reasonably priced API for that yet.

 

[gsdubs]

Short answer: you should not sum the daily numbers manually, use the monthly sum from the app. Netzero does some smoothing at the daily level to account for historical weather variation, which skews the sum.

Long answer: PVWatts uses hourly typical meteorological year (TMY) data, which is one year's worth of data over decades of collected weather data for a specific location. For every month it picks the most typical weather year for that month, and uses that month's data in the model. So let's say for the month of April the most typical weather year was 2010. Daily data will depend on what the weather was that year; but if April 15 2010 happened to a cloudy day, and April 15 2024 is clear, it gets a bit confusing. So Netzero does some more smoothing at the daily level, substituting April 15 with a typical day between ~April 10 and April 20. This will exclude outliers, but the sum across days is no longer accurate.

A better solution here would be to use actual insolation and solar forecast data, but unfortunately I haven't found a reasonably priced API for that yet.

Thanks very much for the detailed response! Understood.

 

[matchosan]

You can now create automations based on Powerwall state of charge, e.g. turn Export Everything on/off when SoC crosses predefined thresholds. Would that allow you to make use of the incentive program?

Thanks for your reply

The program I'm enrolled in is amount-based. I promised to supply 10kWh in a daily two-hour time slot, and the power company will only credit me for the ten but will penalize me for giving them less unless there are certain weather or outage conditions.

Sometimes my battery is in use, or not at 100% when that period begins and I'll end up supplying too much, or not enough, So I was wondering if we could be able to control the amount of stored energy sent to the grid by kWh and not by a percentage that does fluctuate daily.

 

[offandonagain]

The program I'm enrolled in is amount-based. I promised to supply 10kWh in a daily two-hour time slot, and the power company will only credit me for the ten but will penalize me for giving them less unless there are certain weather or outage conditions.

Sometimes my battery is in use, or not at 100% when that period begins and I'll end up supplying too much, or not enough, So I was wondering if we could be able to control the amount of stored energy sent to the grid by kWh and not by a percentage that does fluctuate daily.

Interesting, is this the HECO Battery Bonus program? Looks like the program allows one to use or export the battery, so it seems that it should be enough to track the state of charge of the battery (as opposed to tracking grid export). You basically need to make sure the battery discharges ~75% (~10kWh) during that time slot, either by powering your home or exporting to the grid. I assume the utility doesn't provide any support for that, i.e. they're not using the VPP API to control your battery.

It doesn't seem like there's a whole lot of wiggle room there, unless your backup reserve is set at 0% and you're worried you would discharge it below 25% during the time slot? Similarly, you would need to make sure it's at 100% at the start of the time slot, so avoid any discharge before the time slot.

So the configuration that would make sense is:

• 25% backup reserve.
• Time-Based Control with a peak window during your time slot, off peak for everything else. Hopefully this aligns with your actual utility plan.
• Export Everything, to maximize battery discharge during the time slot. It's probably more beneficial to use the battery for your own use, but you might not be able to sustain 5kW for 2h.
• I'm not sure if grid charging is necessary, but it would allow you to keep a higher backup reserve at night. If you do turn this on, I would keep track of aggregate discharge, since you might run into the warranty limits.

So I'm not sure if Netzero is needed here, but I might be missing something.

 

[BreatheSafe]

Just wanted to say thanks for this app. It really fills a gap for automation of the battery.
Currently using it to keep my PW2 from depleting overnight thus avoiding peak period grid charges of the mid morning. I have it set to grab a little top up charge early am when rates are relatively inexpensive (OVO EV plan in Aus) until I hit the free 3 hour window and blast it full again.
As we head into winter in the Southern hemisphere with reduced solar output it is proving it's usefulness.
Keep up the great work!

 

[OCJeff]

It was a pretty rough day here in Southern CA. 5/15. A good day would have been 44kwH with my 6.6kw system.

For my system the trend line is pretty accurate for reference.

 

[bmah]

Thanks for the app @offandonagain !

I'm using an automation to turn off grid charging at the start of our partial peak time (15:00), that way I can manually enable grid charging at any time before that on low solar production days and know that I'll only be using off-peak energy to charge the batteries. Simple use case but it fills my needs. I also like being able to see all of the graphs on a single screen.

Here's a idea for a feature motivated by this thread (there are others like it):

System down - production compensation

So my inverter went down in January. I didn't know until March or so when I randomly went into my app. I noticed no solar production. Made an appointment - ealiest was 6 weeks away. They diagnosed and determined I needed a new SolarEdge gateway. Fast forward to today when it was finally...

teslamotorsclub.com

What about some kind of optional alarm/notification if people have solar but there's zero solar production in a day? That might alert people who don't obsessively monitor their power systems in case of an inverter/gateway failure. (I'm sure there's a bajillion edge cases that I didn't take into account.)

Thanks!

Bruce.

 

[offandonagain]

What about some kind of optional alarm/notification if people have solar but there's zero solar production in a day? That might alert people who don't obsessively monitor their power systems in case of an inverter/gateway failure. (I'm sure there's a bajillion edge cases that I didn't take into account.)

Thanks for the suggestion! This is actually the next major feature on the roadmap. A lot of the work done so far--solar production estimates, string diagnostics, Powerwall degradation--have been building blocks for what I've wanted to build from the start: a system that alerts immediately when there's an issue, to reduce the time to diagnose and resolve the issue -- thus saving money and reducing stress. Tesla does not seem to be very proactive about these issues, all too often people find out about them when the next month's utility bill is higher (or even worse at the annual true-up).

Complete loss of production is easy to spot, but issues like a single string failure in a winter month might be hard to spot even if you look at the charts daily. An automated system with access to diagnostics will do much better here. Of course, it will take some time to tune the alerting system for precision and recall.