NEPViewer supplement for desktop/laptop computers
Before 2025 (?), nepviewer.com didn't show most of the data it had received from NEP micro inverters (including those re-branded by Anker or NuaSol, e.g.) registered with the site. This led me to creating my own set of tools to access and display my micro inverter's data stored with NEP.
Since then, the site (and the Android app) have improved, so that they probably fulfill most users' needs. When NEP changed the API I had used in my tool set until April 2025, I abandoned my tools and restricted myself to using NEP's official offering (NEPViewer web site and app).1
...but then I wanted some changes/additions:
- correct figures for monthly production (in already completed months, NEP omits the last day)
- more informative overviews of my PV system's overall performance (see examples below)
This is why I created...
This Python script reads each day's energy production (kWh) from the NEP server, stores it in a local CSV file (to avoid having to re-fetch already known data with each run), and displays some informative (at least to me) plots of the data.
Sadly, NEP doesn't provide older data with its current API, but in case
you had been using NEPgetCR.py and NEPjson2csvCR.py from
v2_obsolete before the April 2025 NEP API change,
NEPviewerCR++.py will initially load the
resulting *.csv before asking the NEP server for newer data.
To use NEPviewerCR++.py, you must provide it with your credentials for
nepviewer.com in environment variables, e.g.
NEP_ACCOUNT=me@home.de NEP_PASSWORD=secret NEPviewerCR++.py
Footnotes
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...especially after realizing that NEP now fakes Watt readings in their "minute" plots: Instead of showing when it received what power reading from the micro inverters (which could be up to every five minutes, or not at all for longer periods of time), they pretend to receive a new value every fifteen minutes, with the power value being somehow interpolated. The "last update" values (timestamp and power) readable from the NEP server are still okay, though. ↩