Solar Assistant vs. Home Assistant

[cmack]

I finally made the switch to Solar Assistant from the default logger (PV pro) for my Sol-Ark. Now that I have it running, I wanted to share my experience and pose a question.

Good things:

• Easy setup
• I have control over my data
• I do not rely on an internet connection to log data
• Logging frequency is much higher (10 seconds instead of 5 minutes)

Bad things:

• 10 seconds is still not fast enough. Their website clearly states "Per second metric accuracy". I purchased assuming I would get 1 second historical data
  • I understand the dashboard values update every second, but that's mostly useless to me if I can't view the data points
• I can't setup notifications (PV pro would alert me if the grid went down, for example)
• Dashboard values do not update in sync
  • Load and Grid values update together, then a second later the Battery and PV values update
    • Ex. Furnace turns on, 2KW "Load" value updates, but battery is unchanged
    • 1 second later, the battery shows the load from 1 or 2 seconds ago
• The UI has limitations
  • Charts are not interactive on mobile (an issue that appears in high demand for their charting system called Grafana)
  • Navigating the Charts page is a mess, not easy to find or customize the views, just a ton of charts slapped on a page
  • I can't customize the dashboard
  • No dark theme

Question:

I hear many people use Solar Assistant in combination with Home Assistant. Why have Solar Assistant in the middle if the data can be sent straight to Home Assistant with a much more customizable experience?

My best guess is the ease of setup, support for many inverters / BMS, and remote inverter configuration. $80 is easily worth it if I am saving many hours of reading and configuring. Very curious to hear what other people have to say about this. Thanks!

 

[Quattrohead]

Yep ease of setup, solar assistant is all in one and does that specific thing well whereas home assistant is all over the place with its integrations.

 

[wattmatters]

Dashboard values do not update in sync

It can only update based on the data it receives. First look at the source data before assuming SA itself is at fault.

Not sure why you'd want 1-second data logging. That's a LOT of data across all data channels. It's a Raspberry Pi, it needs to work efficiently within its limitations. Database interrogations and charting is resource intensive.

The whole point of SA is to do the important things simply, efficiently, reliably and to enable that across a wide range of inverters and battery systems.

If you wish to do more than the available defaults, customise displays, design your own automation controls etc, that's why they provide the MQTT interface - so you can poll that data in your own system (be it Home Assistant, Node Red or something else) and knock yourself out with whatever customisations you like to control the inverter.

My automations use a range of parameter inputs not available to SA, e.g. what my grid-tied PV system is doing, solar PV forecasts, weather data, load monitoring and management.

 

[MajicDiver]

Bad things:

I agree with everything you point out and more BUT he has produced a reasonably good product at a reasonable price and you can see improvements in the beta versions that are slowly coming out. The primary thing I find fault with is the documentation ( the help file) does a very poor job of indicating what is actually implemented for each type of inverter - thus you don’t really know what you are getting until you buy it.

It’s a good product considering it’s a part time effort for folks that appear to have day jobs earning a living working on something else. I know a number of guys that could quickly build a application that would run circles around Solar Assistant but they are not hungry and would expect to make a lot more $ than almost nobody buying Solar Assistant would be willing to pay.

 

[Mr.Hyde]

My system will be installed this spring and I will attempt to go from the Sol-Ark straight to HA using RS485.
I'll definitely post how it goes.

 

[Watts Happening]

I use both and see them as different “uses”. I also had a couple Pi’s laying around so factor that in. I’m Sol-Ark based as well.

I use Home Assistant running on a Synology NAS for many things, it has become the backbone of our smart home and in general serves to provide me a single pane of glass into my most commonly used functions. Basic solar info, HVAC, weather, lights, door locks, garage door etc. Probably 98% of the time it’s enough information, and I could certainly add more or even another dashboard to have more granular control/information if I wanted it

However, if I’m needing more information than what I’ve chosen to display in home assistant, I’ll simply open up solar assistant and now I have “everything” I may need.

I enjoy the full level of control, monitoring and graphing provided by solar assistant, however once your system is up and running reliably you’ll generally find yourself only checking to see a few things like battery level, daily production total, current production and current output from the inverter. All of which I get quickly from home assistant.

Both great tools nonetheless!

 

[cmack]

It can only update based on the data it receives. First look at the source data before assuming SA itself is at fault.

My inverter shows all values update at once, and I would assume it's sending those same values to the logger, just looks like an implementation issue. The dashboard does not update all values at the same time, making them appear to be incorrect.

Not sure why you'd want 1-second data logging. That's a LOT of data across all data channels.

Why would you want 10 second logging? Why not stick with 5 minutes? Or 30 minutes? Faster logging = greater accuracy = easier to identify problems. What if an inrush current from your AC is causing a disconnect or bogging down the inverter? You would never see that consistently at 10 second intervals. Bottom line - SA falsely advertises 1 second data metrics.

Database interrogations and charting is resource intensive.

Charting doesn't happen on the Pi, that's handled by the client (whatever device you're loading the dashboard on). The Pi is already receiving and processing data at 1 second intervals, just needs to write to disk. I don't need 10 years of data to fit on a 16 GB card, I'd be much happier with a higher resolution and if I need 10 years of data stored, I'll use a bigger SD card.

If you wish to do more than the available defaults, customise displays, design your own automation controls etc, that's why they provide the MQTT interface - so you can poll that data in your own system (be it Home Assistant, Node Red or something else) and knock yourself out with whatever customisations you like to control the inverter.

I am comparing to the free solutions that are included with most inverters. I have used 2 different ones, and they offer notifications and simple customizations so I can see data I care about without digging. It's not hard to do, and this is a paid product.

It’s a good product considering it’s a part time effort for folks that appear to have day jobs earning a living working on something else. I know a number of guys that could quickly build a application that would run circles around Solar Assistant but they are not hungry and would expect to make a lot more $ than almost nobody buying Solar Assistant would be willing to pay.

Fair points. I didn't know it was a small team / hobby project. The solutions to the problems I have described are pretty simple:

• Allow the user to choose logging interval. A Pi 4 can easily handle 1 second, I should be able to select that if I want
• Use a better charting library - Tons of open source options that have much better interactions and mobile support
• Add support for notifications - They use browser apps which already support push notifications - just need to let the user define what conditions should trigger a notification (ie. grid goes down, batteries full, etc)

once your system is up and running reliably you’ll generally find yourself only checking to see a few things like battery level, daily production total, current production and current output from the inverter. All of which I get quickly from home assistant.

This I agree with, although it took me quite some time (several months) to get my system running reliably, largely due to lack of data at 5 minute intervals. If I had 1 second logging from the beginning, I would have identified and solved problems much sooner.

 

[MajicDiver]

Why would you want 10 second logging?

I have seen no information to indicate wether Solar Assistant is “logging “ data or “archiving” data. High end “historian” products do not actually write every single data point to disk. In summary, for each data point type (such as watts or frequency or voltage) you set a sample frequency and a resolution. The sample frequency should be obvious in meaning. The resolution (in simple implementations) is the amount of change in the points value at which you want the data point archived. For example, archive a point if it’s value has changed by 5 watts from what it was the last time a point was archived. There are many complex algorithms for accomplishing this which off course require a complex interface for the user to be able to set it up (and of course a much higher level of knowledge the user must have)

I’d be surprised if Solar Assistant does anything but simply write every single point it reads from a device to disk, which I would call pure data logging. If that’s the case, logging every second would probably cause lots of problems and could make the system very prone to freezing and such. There are many more implications also.

 

[cmack]

I’d be surprised if Solar Assistant does anything but simply write every single point it reads from a device to disk, which I would call pure data logging. If that’s the case, logging every second would probably cause lots of problems and could make the system very prone to freezing and such. There are many more implications also.

The dashboard values are updated every 1-2 seconds, so SA is definitely receiving this data. This includes AC load, battery load, PV, and SOC. The charts for these values only offer data points every 10 seconds. No mystery here!

 

[Tulex]

SA does update per second, it just doesn't update charting per second.

 

[robby]

One second graphing would be nice but it's not really practical given all of the constraints.
I asked Sol-Ark that question and they said that the CPU system would get bogged down if it was being polled every second for all of the data.
Also the PI is going to have the same issue.

I keep saying it, but minus your one second issue it is best to stick to Solar Assistant for realtime data and use PowerViews Website for graphing data. Powerview is the only thing that can access the 64 different data sets in the Inverter.

 

[robby]

SA does update per second, it just doesn't update charting per second.

I don't know about that. My display does not update in one second but it's not as long as ten seconds.
It seems to vary but the average is about 3 seconds.

 

[Tulex]

On a side note, a tech at Sol-Ark told me that the Mysolark app now isn't scheduled until last quarter of this year at earliest.

 

[cmack]

SA does update per second, it just doesn't update charting per second.

The historical data provides the real insight into your system. Unless you're staring at the dashboard all day, the charts hold the real value.

From their website, very misleading:

One second graphing would be nice but it's not really practical given all of the constraints.
I asked Sol-Ark that question and they said that the CPU system would get bogged down if it was being polled every second for all of the data.
Also the PI is going to have the same issue.

It is already being polled every second by the logger. The issue is that SA is not writing those values to the disk on the Pi. Or if it is, they are not available in the charts.

 

[MajicDiver]

The dashboard values are updated every 1-2 seconds, so SA is definitely receiving this data.

What must be understood is that just because the dashboard is updating fast does not mean that data is being written to disk which is necessary for it to be trended on the historical trends. Looking at some of the replies I’m not sure all understand that.

 

[Tulex]

As pointed out by Robby, turning the data into presentable data would take a lot of CPU. It has to do a tenth of the record keeping to store every ten seconds as it does every second. It's using the data it records every second to come up with the presented data.

 

[cmack]

On a side note, a tech at Sol-Ark told me that the Mysolark app now isn't scheduled until last quarter of this year at earliest.

With solar assistant I see no need for the app. What benefit would it provide?

just because the dashboard is updating fast does not mean that data is being written to disk

Yes, exactly.

As pointed out by Robby, turning the data into presentable data would take a lot of CPU

Again, this is not the job of the Pi. This is handled on the client - your computer, phone, tablet, whatever.

 

[Tulex]

I don't know about that. My display does not update in one second but it's not as long as ten seconds.
It seems to vary but the average is about 3 seconds.

I think it updates as data changes. Not all values change at once every time, but sometimes I see various values change one after another in rapid succession.

 

[Tulex]

With solar assistant I see no need for the app. What benefit would it provide?

Considering that we don't know what the final product looks like, I can't say.

One benefit is that it's supposed to move data out of China if I understand correctly and give techs better control of the data.

 

[cmack]

give techs better control of the data

This is a good point. Without this, you would need to give techs access to your SA dashboard, and they may not want to use a different interface to help diagnose problems. They would, however, have access to higher resolution data. Last I heard, they are targeting 30 second data points (big improvement over 5 minutes, but still nowhere close to live)