If you’ve got a Powerwall2, Tesla lets you keep an eye on it via their iOS or Android App, which means it’s only visible on compatible phones/tablets (or a PC if you want to put up with running an Android emulator), and it only provides today, yesterday, last week, and last month snapshots.
If you want to see more detailed usage and keep historical data, a webpage that you can leave running on a spare screen would provide another simple way to do this. For our usage, PVOutput.org, which has been running as a solar tracking site for some years now, has been recently upgraded to deal with PW2 data.
In the graph above, you can see the home power use as a red line, battery discharging and charging as blue, solar-system output as yellow, and the battery charge level as the green line. The real-time graphs are available here. Read on to see how to set your PW2 up on PVOutput.
A PW2 with wifi enabled
A wifi router that the PW2 can connect to
Admin access to your router to find out the IP of your PW2
An always-on Windows PC with internet access on the same network as the PW2
Get connected to the PW2
Your PW2 has a wifi AP in it that can connect to your network. It may be enabled and connected to your network already – go to your router’s DHCP Connected Clients page and look for an entry like “TEG-xxxx” (where xxx is your PW2’s serial number). If you see one like this, copy it’s IP address and paste it in to a browser tab, and you should get a current-status display from the PW2 as follows – if you do, skip to the next bolded subheading:
If your PW2 is not connected to your wifi, you need to associate it to your Wifi router, using the wizard from the PW2 page above – the login details are the installer email and the serial number of the PW2.
Confirm the PW2 is outputting raw data
Enter the following address : http://x.x.x.x/api/meters/aggregates in a browser window (replacing x.x.x.x with your PW2’s IP), and you should see the instant data like this:
The text may be unformatted if you are using an older browser, but the data itself will be read by a separate tool provided by PVOutput, so you just need to confirm you are getting this data at that IP.
Entering http://x.x.x.x/api/system_status/soe in a browser should return you the charge-state percentage as follows:
If you got these pages successfully, move on to making an account at PVOutput.org.
Configuring the graphing options at PVOutput.org
Create an account at PVOutput here: https://pvoutput.org/register.jsp – it’s free for simple solar system uploading, but PW2 needs to use Extended Data values that are part of the Donation Features, so donate some Paypal to unlock these, at least $15. Fill in your details and visit the settings page : https://pvoutput.org/account.jsp
Towards the bottom, enable API access and generate a new key – this is what the software on your PC will use to identify you when it uploads data. Under “Registered Systems”, click “Add System”, fill in what details you know and save.
You should now have a new system on the bottom of the settings page – edit the system, and fill in your Energy Tariff Times and costs if you are on TOU.
Now go to the Extended Data section, and fill in the details as per the screen below – these are the labels for the graphs for the values that the PW2 will be exporting.
For the Battery Flow, Home Load and Solar Generation, click the cog on the right, and set the modifier to “Divide by 1000” to scale the data correctly. Click the Area / Line to change it’s state to suit your needs, and click the colour blob if you want to pick an alternative colour for any of the graphs.
Save, and from the bottom of the settings page, bookmark the link with your system’s name (that’s what you’ll click on to see the graphs), and keep this page open as you’ll need to copy the API key and System ID in the next step.
Grabbing the data from the PW2 and uploading it to PVOutput.org
On the always-on Windows PC, visit the link below to download the free PVPOutput Integration software: https://bitbucket.org/pvoutput/pvoutput-integration-service/downloads/org.pvoutput.integration.v1.5.2.zip
and unzip it to a folder in your root directory. There’s discussion about the PW2 at their forums, where new versions are posted: https://forum.pvoutput.org/t/powerwall-extended-parameters/298/34
Follow the install instructions first step to install the service.
Edit the conf/pvoutput.ini text file, and paste in the API Key from the bottom of https://pvoutput.org/account.jsp. Paste the System ID to SID=xxxxx from that page also, save and close pvoutput.ini.
Open the conf/powerwall.ini and paste the following to replace all the text there, substituting x.x.x.x with your PW2’s IP:
url=http://x.x.x.x/api/meters/aggregates poll=30 direction=in voltage=instant_average_voltage v7=battery.instant_power v8=load.instant_power v12=solar.instant_power soc-url=http://x.x.x.x/api/system_status/soe soc-parameter=v11
In the above text, the v-parameters are the available data sets that PVOutput will accept, but you can vary the content by changing the part after the “=”. Have a look in the original copy of the powerwall.ini file if you want to know the kinds of params each power type can export.
Save and go to the BIN folder, and run “start-service.bat” as an Administrator. Now, give it 10 minutes or so and you should start to see graph data appearing at the page you previously bookmarked at PVoutput.org. Note that you need to click the right-most blob under the graph / above the date to expose the extended values graph.