https://ibb.co/7xhkDk5Z
What's the point of technology if it doesn't give anything? Or am I doing something wrong? Improving the charging station doesn't give anything either.

All the EM upgrade technologies effects are handled by script—their effects can be observed looking at the EM train panel in the top left, the EM train entity tooltip when "charged" (invisible fuel item is added by charger), others by watching the power usage of chargers.

https://ibb.co/wFJYj5m6

The mod is useless and unprofitable, it consumes a lot of energy, the technologies do not give anything...

Useless and unprofitable? lol!

Can't tell anything from those pictures.

This shows my results loading up a test world just now and researching the upgrade technologies..

If there are issues on that end provide a save file for analysis.

I've upgraded all the technologies.

Until you provide a save file for analysis that claim is unsubstantiated hearsay.

https://drive.google.com/file/d/1JkfcavkdW4QRBaMewM3ZefFSXhW6bjhf/view?usp=sharing

Loading in to that save things appeared correct but researching technologies doesn't cause it to update.

Will look into it.

That's very strange then.

Is it possible to add a mechanic for adjusting the charging coverage, like the beacons in the Pyanodon mod?

Issue is fixed in 1.2.50.

Adjustable ranges would be something to do down the line when eventually rewriting EM charger checks to account for more than one surface.