ValueError: Excel file format cannot be determined, you must specify an engine manually.

[Constable1819]

I have been struggling with this error for weeks now. Please help.

ValueError: Excel file format cannot be determined, you must specify an engine manually.

[ekatef]

Hello @Constable1819 and many thanks for the report.

I assume you get the error in build_powerplants, correct? If that is the case the problem are caused by some troubles with an assess to one of the powerplants databases. Currently, the problem is fixed in powerplantsmatching but this fix has not yet been included into release which means that some additional tricks are needed to make it work.

@swaechchha has tested the following procedure for that:

1. comment out powerplantmatching>=0.5.7 line from environment.yaml specification
2. add the following line to install powerplantmatching from master branch of its github repo

- pip:
  - git+https://github.com/pypsa/powerplantmatching@master

3. remove cache ~/.local/share/powerplantmatching/
4. build a new environment (best to use a modified environment name to keep a previous version of the environment).

As a quick fix, you can comment out in configs/powerplantmatching_config.yaml the datasets of Global Energy Monitoring, namely
GBPT, GGPT, GCPT, GGTPT, GNPT, GSPT, GWPT, GHPT. However, that will likely lead to a significant data loss and may be recommended only as a temporally solution.

[Constable1819]

Hi... This worked, thank you

[FabianHofmann]

The problem comes from GEM and their urls being more restrictive (happened last week THU). We will release a new powerplantmaching version today which will resolve this