A real tour of a nuclear plant would be awesome (i.e. getting to hear / see the reactor), but tours of wind farms / turbines / dams etc. would also be great. Preferably in English.
It looks like this (photo I took when I was there earlier in the year) https://www.instagram.com/p/BD1Ao-1IaXi/
Details: https://en.wikipedia.org/wiki/Islay_LIMPET
It's not a "tour" (it's unmanned) but it's fascinating. While you're on Islay, you can also enjoy whisky, wildlife and being in one of the most beautiful places on the planet.
Additionally, many universities have research reactors - they often have tours or a tour can be easily arranged.
Pish posh, it's absolutely possible to visit active nuclear plants, usually for free, though you may need a small group (half a dozen or more) depending on the operator.
For pumped storage there is Dinorwig[1] (North Wales) and Cruachan (West Scotland). If you arrive by public transport you can get a free tour of the Cruachan pumped storage hydro plant.
[0]: https://www.edfenergy.com/energy/education/visitor-centres
[1]: http://www.electricmountain.co.uk/
[2]: http://www.visitcruachan.co.uk/
Edit:
There's a photo at the bottom of this blog post from my visit to Cruachan last summer: https://unop.uk/mobile-gb-rail-live-departure-boards
If you're in the French Alps then you could visit Grand'Maison on a bad weather day: http://www.musee-edf-hydrelec.com/
Temelin, nuclear power plan [1]. Pretty nice information center in a historical building with models, plant simulator and a small cinema. Although the most exciting part is visiting the actual power plant site - generators, accompanying infrastructure, going through radiation check point. Not sure if the site visit is publicly available.
Lipno, hydro plant [2]. Not as interesting information center as in Temelin, but the underground facility with turbines, generators and outlet tunnels makes you realize the huge mass of water in the dam and the amount of power the plant is able to generate.
The next item on my bucket list is pumped-storage in Dlouhe Strane [3], which looks like a hill with the peak cut off, having there a large pond instead.
Sources: [1] https://www.cez.cz/en/power-plants-and-environment/nuclear-p... [2] https://www.cez.cz/en/contacts/information-centers/lipno-inf... [3] https://www.cez.cz/en/contacts/information-centers/dlouhe-st...
Web info unfortunately only in Finnish, but guides can handle English of course: http://www.tvo.fi/vierailukeskus
Also the other Finnish nuclear plant in Loviisa (with Soviet-designed PWR reactors) may take visitors but does not organize it on daily basis.
0. https://www.tripadvisor.com/Attraction_Review-g274951-d18864...
Or at least you could 10 years ago.
They showed us the nuclear waste disposal facility on the grounds of the power plant, it's temporary while Sweden builds a huge disposal facility for all of the country's nuclear waste (and it looks like a scenario for Half-Life, it was very cool).
Apart from the nuclear disposal facility our tour also went to the reactor control room simulator where the technicians practice and get certified (we could even try the SCRAM procedure and all) and also showed the grounds around the facility, where the water that cools the reactor comes and goes to, etc.
Would completely recommend doing it if you are ever in Sweden and can manage to go there.
I work for Vandebron in the Netherlands. Some of our smaller producers are happy to show visitors around. It helps if you are one of the households they are supplying of course ;)
They've all been decommissioned. #3 was the last one to shut down in 2000.
On a related note, this Youtube user [0] has videos from what appear to be tours inside units 2, 3 and 4 (the one which suffered the meltdown in '86). The one from the reactor hall in unit 2 [1] is particularly interesting.
[0] https://www.youtube.com/user/Thallium208/videos [1] https://www.youtube.com/watch?v=Oe_zzTQFV3o
The whole complex is in the process of being decommissioned.
[0] https://en.wikipedia.org/wiki/Chernobyl_Nuclear_Power_Plant#...