I have always thought, mistakenly perhaps, that the UK had vast reserves of potential power in the form of harnessing wave and tide forces around our shores.
It seems that we have one of the largest "heights" between low and high tides in the world.
It was only a matter of harnessing this obvious, continuous source of energy,which could be safely left to our engineering boffins, in order to generate all the electricity we need in all weather conditions.
You only have to swim a few yards from a beach and be hit by a wave to experience the huge amount of force which sends you tumbling underwater.
Apparently, the tides flow up the North Sea and the Irish sea every day and then out again.
But it hasn't happened.
Why?
There's been talk of barriages such as the Severn barrage for years but it hasn't progressed possibly because of the impact on migrating fish and bird life.
There are some small schemes in Scotland and underwater turbines at Strangford Lough in Northern Ireland, but these seem to be reseach-orientated rather than significant producers of energy.
Are there fundamental technical issues or is the concept flawed?

Siemens gave up on it and sold it’s tidal power unit. That suggests it’s about as viable as most green tech.

The tech seems to be considered "still in the development phase".

Interestingly 3 tidal stream projects did just win the government's "CfD" auction, the first time tidal tech has.
https://www.scottishrene...ontracts-for-first-time

But as the prices there show (onshore wind and solar ~£45/MWh, offshore wind £37/MWh, tidal... £179/MWh!!!), at this point it's basically throwing money at a charity case in the hope of it getting cheaper and future "diversity of supply" benefits.

Thanks I didn't know that tidal generation had won a contract. The price is pretty irrelevant I think in the overall energy market place. We had exactly the same thing during the period where wind and solar power first became active on the grid. It's a very welcome development I think.

The vulnerable bit of offshore power generation is the HVDC cables connecting them to the shore. Don't know about the Norks but Russia is thought to have been developing specialist subsea-cable cutting submarines and submersibles. Most of the reporting on them focuses on the threat to the global data cable network - perhaps because journos are horrified by the thought of life without Twitter - but if I was Russia I think subsea power cables might be similarly attractive targets, both the "interconnect" ones connecting the UK and Ireland to continental Europe and the ones bringing power from large offshore wind farms ashore.