There is no consensus on this as the site relation never considered the vast areas covered by hydro plants and its tunnels and reservoirs.

I have reverted old mapping using site for hydro plants due to this and only used site for wind farms.

As long as there is no defined center point for a site relation on hydro plants, using relation will cause a big mess and a very ugly map.
The site relation has also never been through a proposal for power or voting process.

Please don't use site relation for hydro plants. This is more for wind farms. There is no defined main point in the current system so looking up hydro plants using this can cause the center point to be off my many kilometers. Some hydro plants have tunnels and reservoirs in a 100 square km area or more.

Simply tag the building, or turbine hall if under ground, with the appropriate tags.

How did you find all the solar panels?

I've also noticed that you've misplaced a lot of them because you've completely ignored image perspective. You can't just add the panel on tall buildings right at the the spot in the image if the photo is taken at an angle.

Removed a 166km long duplicate 400kV line north of Karlstad causing the large changeset area.

Apparently you can hold Alt when clicking to place node when in way more to avoid connecting to existing elements.
osm.wiki/ID/Shortcuts

Just don't place a node at the point the line goes over/under unrelated data. You risk linking them together.
I am not very familiar with the iD editor as I went to JOSM early on. In JOSM I can use Ctrl when placing nodes creating a way to keep it from accidentally connecting to nearby ways.

Please be more careful when editing things. You managed to change a power=line to higway=path and connected it to several tracks and paths that go under it.

We don't tag all roads that are part of a national highway or E roads as trunk. If its a resting area or bus terminal with limited access it will get the service tag.

Please stop breaking landuse relations. If you don't know how to map with relations, then read up on it and use JOSM that can is much better at dealing with them.

Please don't use garden for residential areas. This is better used for public gardens. It is also conflicting with residential landuse.

https://josm.openstreetmap.de/ticket/21566

Nice find!

Could probably make a ticket for JOSM asking to add this to validator. It is very much needed.
Taginfo shows 2378 uses so far as well, so its not that rare.

I fully agree we should have a tag for these to help with validation. I'm not that good with formulating things and don't have enough wiki knowledge to add a proposal.

Was thinking I would start counting, but if I include 22kV distribution lines then there are probably thousands of taps around the country.
Some examples on openinframap:
4 taps on this one for the 132kV lines: https://openinframap.org/#17.9/59.276012/9.543613
3 taps here: https://openinframap.org/#17.9/59.727655/9.819084
2 here: https://openinframap.org/#17.57/59.132268/9.474693

There are many many more :)

Mid air taps are quite common in those types of junctions actually. The tower on the through line is an anchor termination tower with no connection of the line, so it has to go via the two branch ones to the nearby substation.

Hard to find visual examples of this, but here is one close to a streetview: https://goo.gl/maps/cXHLkhVzvFfwpy4V8

Lines can have a mid air tap where one crosses over the other. there is no connection like you did. Problem is it is impossible to know for the validator if there should be a tower at a node or not, so you can't remove it.

Also keep in mind we might have used plan drawings to add a road that is not yet in the official Kartverket road database. These are often found on road project websites.
If you don't find a match, ask the previous editor first.

The Norway Orthophoto layer should never be older than around 5 years, but it varies. The low res images(0.25m) are normally rotated every 5 years and is funded by Kartverket. For more central locations the municipality may request higher res images as often as once a year. This typically the cities that have a bigger budget for these things.

What is showing in iD is normally the most recent one even if its the low res image.

The "kartverket road network" overlay is the best one to use. Its a bit spotty with iD as the sever don't like to many requests at once.

The N50 layer is actually currently showing way to much. It's supposed to be 1:50000 max. The resolution it's currently showing we are not legally allowed to use. Keep that in mind.

Make sure to check with all sources before moving roads. Aerials might not be up to date. The segment of highway 13 between the bridge and tunnel was perfect, but you moved it for some reason.
If you could revert that part it would be nice.
way/822323407

Nice import work for Vik btw!