Powershell script to download Zappi status data from myenergi servers and upload it to PVOutput.org
Following previous investigations by twonk and others, I was keen to understand what data from my myenergi zappi 2.0 EV charger (and available via calls to the myenergi web services) could be used for. As a proof-of-concept, I have written the Zappi2PVOutput.ps1 powershell script to gather power consumption data and some other bits and pieces, and to upload this to the PVOutput.org website.
myenergi is an award-winning British designer and manufacturer of renewable energy products that increase the self-consumption of green energy. I've had one of their zappi EV charging units installed since September 2019. The zappi integrates brilliantly with my existing solar PV system, so I can choose to charge the EV only when the sun is shining!
myenergi provide a neat (Android or iOS) app for monitoring consumption & generation data relating to your system. This requires a myenergi hub device which sits between the Zappi charger and the myenergi servers that host the data. You must register your hub in the app and set up credentials to authenticate with the myenergi servers.
PVOutput.org is a free service for sharing, comparing and monitoring live solar photovoltaic (PV) and energy consumption data. I've been collating my PV generation data on their site since it was installed in 2011. The zappi2pvoutput.ps1 script is complementary to another script I use to upload the PV generation data to that site.
While it is possible to use PVOutput.org to record only consumption data, this script is primarily aimed at those who already have a PV system registered and are currently uploading generation data but not consumption data.
The script makes use of undocumented and unsupported calls direct to web services on the myenergi servers. Myenergi may change these APIs at any time without warning. Just because the script works today does not mean it will work tomorrow!
The script is provided 'as is' without any warranty of any kind.
The script will send web service requests to the myenergi server to query the latest status information from the Zappi charger. This information includes details of the power being generated, the power being imported from the grid and the power being diverted to charge a currently connected EV. It also includes information such as the supply voltage.
This information is collated and power consumption figures are derived. Optionally, temperature information is obtained before the status data is then uploaded to PVOutput.org.
The script Zappi2PVOutput.org should be downloaded and run from a local device on your Windows system. Internet access is required, but the volume of data transferred is relatively small.
The script has been tested with Powershell 7.2, and some arguments passed to the invoke-webrequest cmdlet require a minimum of Powershell 7.
By default, the Windows PowerShell execution policy is set to Restricted which means scripts cannot be run! To check your execution policy, run the Get-ExecutionPolicy cmdlet from a Windows PowerShell prompt.
To weaken the Windows Powershell execution policy to allow scripts you have written yourself to run, along with downloaded scripts that have been signed by a trusted publisher, open a Windows PowerShell prompt as an Administrator and run Set-ExecutionPolicy RemoteSigned. However you should first run Get-Help About_Signing to determine whether this execution policy meets your security requirements.
Because the Zappi2PVOutput.ps1 script has not been signed by a trusted publisher, if the execution policy is set to RemoteSigned you will then need to run the cmdlet unblock_file with the full path to the Zappi2PVOutput.ps1 script as a parameter to allow the script to be invoked.
There are no parameters that can be passed to the script, but at the top of the script are a number of variables which must be modified to suit your individual environment.
You will first need to register with PVOutput.org and create a system which will have a unique ID. You will also need to enable API access in the account settings page and generate your API key.
Depending on how frequently you wish to upload status information to PVOutput.org, you may wish to reconfigure the Status Interval for your system.
For more details refer to http://www.pvoutput.org/help.html
Your myenergi app username is the serial number of your hub device and is typically a string of 8 digits. The password will have been set when you first registered it in the myenergi app.
This is typically a string of 8 digits and is available from the menus on your zappi charger.
This should be a writable location on your device. The script sends diagnostic information, by default, to a file called Zappi2PVOutput.log located in this directory. In addition to providing diagnostic information, the log also serves as a journal to ensure that the same statuses are not repeatedly posted to PVOutput.
The log file Zappi2PVOutput.log can be manually pruned or deleted periodically to save disk space.
A number of other log files are generated to report the responses to different web requests.
The script can optionally download weather data for the local area from openweathermap.org. This is then used to estimate the current temperature and provide this information in the status update to PVOutput.org.
If this functionality is required, register on the openweathermap.org site and obtain an API key (for free!) Follow the instructions on the site to obtain the ID of the location closest to you.
The script is intended to be run periodically at a frequency determined by the status interval configured for the system on PVOutput.org - eg every 5 minutes. Scheduling functionality is not part of the script. As an example, the Windows Task Scheduler provides a very capable method for providing this. In this case, the scheduled action would look something like:
pwsh.exe -command "& \"C:\Users\Bob\Downloads\Zappi2PVOutput.ps1\""