Why not harness tidal energy?

[Amari]

Given the current power crisis and lack of strong winds, Shirley we should harness tidal energy?
1.The UK has one of the highest tidal ranges (ie. height/nadir) in the world.
2. We have a long coastline cf land area with lots of indentations.
3. Despite King Canute’s efforts the tides never stop
4. Tidal flow is amongst the strongest in the world - think Pentland Firth, Gulf of Corryvreckan.
5. I seem to remember that the cost of the proposed Swansea Bay project was less than HS2.

It seems a no-brainier to me.

 

[jenkinsbrynmair]

The government refused to back the Swansea bay project so it was shelved - not enough money in it for their sponsors.
There was a proposal to incorporate tidal generators in the causeway of Llewelyn's bridge (the second Severn crossing)
but that was also dismissed for the same reasons

 

[Wilco]

I'm sure there was someone on here who knows something about tidal power... But I may be confusing who I've spoken to and where. Apparently there is a big issue with wear although I think some sort of tidal system has just been launched somewhere in Scotland so hopefully it's been sorted.

 

[madasafish]

Tidal energy relies on water flows. There is minimal water flow at high and low tide. So output is intermittent. There are two high tides and two low tides a day.
So every 3 hours you have an energy peak and then an energy low. Try running that into the National Grid: it means you need alternative supplies to balance out the troughs. Which means either a non green gas plant powering up or battery storage (in its infancy).

So it is neither easy nor simple.

And of course the moon creates higher highs and lower lows at times.

 

[jenkinsbrynmair]

Tidal energy relies on water flows. There is minimal water flow at high and low tide. So output is intermittent. There are two high tides and two low tides a day.
So every 3 hours you have an energy peak and then an energy low. Try running that into the National Grid: it means you need alternative supplies to balance out the troughs. Which means either a non green gas plant powering up or battery storage (in its infancy).

Which is why the Swansea bay scheme and the two scrapped on the Severn estuary were planned on the lagoon system

 

[Buzby]

Tidal energy relies on water flows. There is minimal water flow at high and low tide. So output is intermittent. There are two high tides and two low tides a day.
So every 3 hours you have an energy peak and then an energy low. Try running that into the National Grid: it means you need alternative supplies to balance out the troughs. Which means either a non green gas plant powering up or battery storage (in its infancy).

So it is neither easy nor simple.

And of course the moon creates higher highs and lower lows at times.

As opposed to the hundreds of heavily subsidised wind powered turbines that haven't turned for quite a few days this year.

 

[Wilco]

Although tide times do vary throughout the UK and whilst there is a period of slack water at each high or low, there is still a flow for the majority of each tide. As a result, a series of plants around the UK could result in a slightly more consistent supply to the grid than @madasafish suggests.

 

[Wilco]

Which is why the Swansea bay scheme and the two scrapped on the Severn estuary were planned on the lagoon system

Although weren't there some environmental concerns with those lagoon schemes?

 

[Murox]

With very little imagination a Tide Mill, a simple water mill driven by tidal rise and fall and common in the Middle Ages, could supply a significant amount of power albeit on a local basis – the tide comes in and fills a storage “pond”, when the tide is low the stored water is released to turn a water wheel. (Same principle as hydro really).

 

[Apiarisnt]

There is a long history of tidal power inthe UK - in fact going back to Roman times when they used the tides in the Thames estuary to power mills. The first real functioning tidal electricity scheme in Europe was in France at the River Rance ( and I am so old I can remember seeing it being built - it opened in 1966).

I have seens many, many proposals for tidal and wave (Salters' ducks was an early one) generation schemes through my professional life. The wave ones have all been a disaster, the tidal ones have yet to be shown to be economical ( and the Swansea scheme was created in fantasy land)

The common theme for failure could be one that JBM may attest to. I have spent only a few years at sea, in my oil and gas days, but JBM may confirm that the sea is a formidable, unforgiving force - which may be good for power generation, but can be disastrous for any equipment out at sea. The bits of offshore wind turbines that are in the sea are fixed. The bits of wave and tidal generators that are in the sea are meant to move and turn. Building something that will resist the onslaught of the sea can be very, very expensive and that will entirely screw up the economics.

 

[Apiarisnt]

As opposed to the hundreds of heavily subsidised wind powered turbines that haven't turned for quite a few days this year.

Modern wind turbine generators no longer require subsidies, not even the expensive offshore ones. Offshore wind competitiveness in mature markets without subsidy - Nature Energy

 

[Murox]

Modern wind turbine generators no longer require subsidies, not even the expensive offshore ones. Offshore wind competitiveness in mature markets without subsidy - Nature Energy

Maybe thats one reason why the local manufacturer of the wind tower sections has gone out of business, but they had no orders and the government left them high and dry. So thats another green job opportunity wasted.

 

[Poly Hive]

The European tidal test centre is at Scapa Flow where some of the fiercest tides flow. Scale test sites : EMEC: European Marine Energy Centre

Some years ago Robert Gordons Engineering students built a testtidal rig and put it in the Pentland Firth. Bear in mind this faculty was the go to place for offshore engineering so they knew it would be tough conditions. It didn't last 12 hours......

PH

 

[Boston Bees]

Still a technology in its infancy, definitely

Orbital O2: The world's most powerful tidal turbine - YouTube

 

[nerak99]

There was a successful one in the Bay of Fundy but it caused too much fish death and was closed down. There is a new one just launched I think that is designed to have fewer environmental issues.
I am not a tide power fanboy but I like the fact that people are always trying new stuff and do not feel the need to be dismissive of other peoples efforts just for the sake of it.

 

[Gilberdyke John]

Modern wind turbine generators no longer require subsidies, not even the expensive offshore ones. Offshore wind competitiveness in mature markets without subsidy - Nature Energy

I'm still waiting to see the price of electricity to the consumer to go back to pre Ed Moribund CCA days.

 

[madasafish]

There is a modern one being built with battery storage

"

The European Marine Energy Centre (EMEC), Orkney, Scotland will deploy an Invinity Energy Systems (AIM:IES) 1.8 MWh flow battery at EMEC’s tidal energy test site on the island of Eday.

This unique combination of tidal power and flow batteries will be used to power EMEC’s hydrogen production plant, demonstrating continuous hydrogen production from variable renewable generation.

The commercialisation of green hydrogen is an essential step toward a 100% renewable future. Green hydrogen is created and consumed without carbon emissions and can replace fossil fuels in the energy mix, supporting the decarbonisation of heavy industry and transport sectors. The Offshore Renewable Energy Catapult estimate that developing a green hydrogen industry could create 120,000 jobs and deliver £320 bn to the UK economy by 2050."

https://www.emec.org.uk/flow-batteries-combine-with-tidal-power-to-produce-green-hydrogen/

 

[Apiarisnt]

There is a modern one being built with battery storage


The European Marine Energy Centre (EMEC), Orkney, Scotland will deploy an Invinity Energy Systems (AIM:IES) 1.8 MWh flow battery at EMEC’s tidal energy test site on the island of Eday.

If you are really interested that I could provide you with a long list of all the flow battery projects around the world that have failed and the billions that have been lost in the process. A UK example was Regenesys, owned by National Power / RWE. After more than £200m invested they pulled the plug. I unfortunately have some knowledge of the Plurion (Ce Zn couple) project. The Scottish government lost as few millon when that went bankrupt.