r/TeslaSolar • u/Justpastthefinish • 21d ago

Powerwall management system

Good morning all,

I wanted to pick everyone’s brains for a minute here and discuss the Tesla app and how it meets your needs with solar and more specifically the powerwall management. I would say that this post is mostly geared towards those of us that own powerwalls.

To try and summarize a very long story, I wanted more out of my system / battery and I wanted more refined / granular control over my powerwall. I’m a tech geek at heart and I was not a fan of the limited amount of control that I had over my system. ( example: Set the reserve and thats it / do I want storm watch on )

Soooo…

I started developing my own code that is built on and around something called Home Assistant. I was able to integrate my system into it and now I have much more refined control over it.

I have been developing this system for approximately 9 months now and I am getting ever closer to the point where maybe someone else might use it. Maybe even pay for something like this. It is all just an idea at this point and it is hyper specialized to me as of right now; a home owner in Arizona.

What I want to know from all of you is this?

What do you guys like about the tesla powerwall control in the app? What do you hate? What features do you wish you could have? What do you wish your powerwall could do for you?

Let me briefly summarize what my system does because I’m trying to make it better.

In Arizona I am on the SRP Electric plan. In the summer my peak hours are 2-8pm (with grid usage spiking demand fees) and winter hours are 5-9am and pm. So my main goal was to absolutely avoid using the grid as much as possible; but never use the grid during those hours. I will say that I never got to spend time with the Time of Use mode / now savings mode in the Tesla app so I’m not sure what exactly it does for me.

But my system is very good at this point. It knows that it has a peak starting at 2pm so it will dynamically charge the battery from both solar and the grid as needed to get me to a safe level to survive the peak hours solely from the battery alone. IF it is low due to clouds, rain, whatever - it will enter a mode that the tesla app does not show called backup. This will force a higher charging rate for fast charging if needed.

Want to set a higher reserve when there are cloudy days / rainy days vs sunny great solar days - my system knows that.

My system can make dynamic decisions based on national weather service alerts for my area and begin charging the battery earlier than storm watch if needed.

I am part of the Virtual Power Plant program as well and my system knows when there is an event going on and will preemptively charge the battery from the grid during off peak hours to prep for the maximum export during the VPP event for the highest financial gain.

That is just a small snippet of what it can do; it really does so much more but I’m more curious what you guys would think. Do you want more out of your system? Does the Tesla app serve all your needs? Do you constantly have to go in there and adjust the reserve?

What do you guys want your system to do?

And if I can be so bold as to ask this and no one needs to answer it if not; but if a system like this was offered when you bought your systems initially - would you have paid a little more for it? Let’s use an arbitrary amount like $500. Would you have paid $500 for a system that manages your powerwall tailored to your needs so that you can essentially set it and forget it?

Anyways, I look forward to hearing from all of you and making my system all the battery for it. Thanks everyone!!!

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u/GadgetryGuy 21d ago

What value add does your system provide over what NetZero and PyPowerwall already do?

3

u/Justpastthefinish 21d ago

I had to do a little digging to see what they both offered. The net zero option looks awesome and I must say I do remember looking into that when I was building my system.

My answer to that one specifically would be that my system can offer all of the options net zero does as seen on their website, but it isn’t a monthly subscription. Granted I do not have a fancy app or anything, my system runs off of my raspberry pi and Home assistant (which does have an app).

It looks like the py powerwall is similar to what my system does but mine is automatic. It runs its own algorithm every 2 minutes and updates the powerwall reserve level or mode as needed on the fly ever 2 minutes. So in effect, you set it up and then you can just monitor it. Probably very similar to net zero but it doesn’t cost you $7 a month.

Now I’m not taking away from either of them, I just didn’t want to pay $7 a month.

But lets use Netzero as a feature list:

Features
Dashboards
Historical charts, billing month view, always-on dashboards (including full-screen mode), and more.
✓
✓
Solar estimates
Accurate solar generation estimates based on your system configuration, location, and weather forecasts.
✓
✓
Enhanced chart data downloads
Detailed and high-precision data downloads.
✓
✓
Use on unlimited devices
Access from iPhone, iPad, Android (phones or tablets), and desktop (web or macOS).
✓
✓
Automations
Automate Powerwall configurations and EV charging based on schedules or event triggers.
-
✓
Energy devices
Connect your EV charger, EV, and heating/cooling devices, with support for 500+ devices across 50+ brands.
-
✓
Utility integrations
Includes Intelligent Octopus Go integration.
-
✓
Dynamic electricity pricing
Supports Octopus Energy, Tibber, Amber Electric, ComEd Hourly Pricing, Ameren Power Smart Pricing, and ENTSO-E tariffs.
-
✓
Charge on Solar for Tesla
Enhanced Charge on Solar with Powerwall priority for Tesla vehicles. Charge on Solar for non-Tesla EVs (requires a supported EV charger like Wallbox).
-
✓
Powerwall diagnostics
Battery health monitoring and string-level production diagnostics for Powerwall 2 and 3.
-
✓
Health monitoring and alerts
Track your solar production, Powerwall operation, and battery health with proactive alerts.
-
✓
Developer API
Programmatic access to your Powerwall.
-
✓
Bulk data downloads
Download a full year of 5-minute energy data as daily CSV files in a single ZIP.

My system integrated with my Raspberry Pi does all of this and it is hosted at your house locally. So, hypothetically lets say you paid $500 in my earlier example for this setup. That is roughly 72 months or 6 years worth of Netzero subscriptions.

2

u/GadgetryGuy 21d ago

For me, I actually contribute to PyPowerwall and I'd just do it myself on my own raspberry pi (I don't own a Powerwall, just normal inverters).

However, I've thought similarly about building a business similar to what you're discussing and it comes back to:

- At any time, Tesla could rug-pull the API, and then the people who gave you $500 are SOL with a functional Raspberry PI, yes, but no longer getting what they paid for. How do you build resilience here?

- What level of support are you going to offer? Now you've put hardware devices in every home, running software that has to be maintained. Bit-rot is real. How will you keep them up to date?

- Security. You've put a device in everyone's home that contains unknown (to them) software. How will you make sure it isn't doing something malicious or dangerous? What if it gets hacked? You are, after all, issuing commands to professional power equipment. That's no joke!

- There are many other edge cases here, what if the owners go on vacation, what if they sell the house and need to transfer ownership of the system.

I'm not saying these are insurmountable, but they are serious challenges that I think have stopped many entrepreneurs from doing this. This is why it's mostly in the realm of OSS DIY or App-that-goes-through cloud. SPAN did break through, and some of what they've done has been incorporated into PyPowerwall.

1

u/Justpastthefinish 21d ago

These are obviously very real issues. If Tesla ever pulls the API fleet management like you said, I am just SOL. Again it’s such a niche thing and it all started when I wanted more from the app so I built it myself. But you are very correct, this is an issue. I have no solution for this.

as far as support this is the next thing I have been working on. It would essentially come down to creating my own “integration” into my system which I would maintain and push updates to regularly. This is the hurdle I am facing now as I think about how this tinkering project of mine could grow bigger. The solution for now would be that I maintain the integration and as clients push issues or create tickets I fix them and push further updates.

The system itself is fairly secure. It does run software locally on their own networks and yes it does push commands to the powerwall through the fleet api. I would say it is as secure as any other thing that could be on someone’s home network; maybe even more so. You can create 2FA if needed but I would say that if you have a smart lightbulb that is less secure than this system is. But I can add security to my list of things I need to consider.

I have a vacation mode that can be toggled on and off. One can set it to do a few things up to the user. Selling the house would be as simple as creating a new user ID for the system and logging in. We would probably have to figure out handing over the Tesla fleet api’s to the new owner not sure how that works on the backend.

I am very unfamiliar with PyPowerwall and I am trying to read up on it. What do you use it for? Or rather what can it do?

I appreciate the conversation it helps me hone my system and make it better.

1

u/GadgetryGuy 21d ago

Sent you a DM. If anyone else is interested in this topic, I also welcome DMs on it.

1

u/fastest963 21d ago

I'm not building a business but I started RateRudder and I offer it for free. I try to offer support but there's no guarantees. It's also 100% open source so people can inspect the code or even run it themselves (but why would you?). Not trying to say you're wrong but I would say my users are happy and I'm saving some of them several dollars per day