STW: font of all knowledge: Tidal power

On the current them of power generation….

Tidal power about a decade ago was being toted as ‘the answer’ to reliable, predictable power. And that West or North coast of Scotland had some ideal locations. I read a figure that Scotland and NI tides had enough energy to power way more than the UK needs.

I was reading on holiday earlier this year about the West Islay scheme which was granted all sorts of money and permissions as far back as 2011, with work ‘starting in 2019’ promises in 2017. Like £millions. And a local speaking about the fact they now had turbines that could have a 2-year undersea between service life, and designs for shallower water that were nearly as easy to access and maintain as a wind turbine. The local seemed convinced it was workable and would happen.

I know at some point in that last decade the tax breaks and funding support was removed by Westminster Government.

And here we are in 2022 with none….?

So where are we now with tidal power?
Is it viable and cost effective?
What is the downside? (marine life I assume)
Is the technology there and working?
With current high price of energy, is now the time to see it happen?

What is the downside? (marine life I assume)

…you only get power twice a day!

…and it’s at different times every day – pesky moon!

🙂

…you only get power twice a day!

Not if you have arrays around the coast – and you can predict the ‘twice a day’ for centuries in advance.

What is the downside? 

Kills the Forever Wave at Falls of Lora?

Not that I ever managed to get on the damn thing….

Kills the Forever Wave at Falls of Lora?

It would make a missed roll even spicier than it currently is….

The installation and maintenance costs are apparently quite staggering, especially when considered in respect of the power generated and the potential ecological effects of both their installation and use.

Only get power twice a day? Why? Other than slack tide every 6 hours(as a very general rule) it’s moving, some places there isn’t really slack too.

Blue Mull sound in Shetland has some tidal generation going on for local use, and I know there’s been lots of methods investigated around Orkney and the Pentland Firth.

Tidal energy: it’s clean, it’s predictable and it’s invisible

you only get power twice a day!

Surely if the tide is even just partially held back the turbines never need to stop turning?

I am sure there.must be some very good reasons why tidal power hasn’t been exploited, but it has long been a mystery to me as to what they might be.

Negatives would be large installation and maintenance cost (currently), general lack of investment of public money, marine biology and ecology impacts so doesn’t have the favour of environmental groups etc.

But personally I’d have thought oil and gas company lobbying is prob most to blame for lack of investment across many areas of alternative energy sources.

you only get power twice a day!

IT WAS A JOKE!!! 🤦‍♂️

But personally I’d have thought oil and gas company lobbying is prob most to blame for lack of investment across many areas of alternative energy sources.

I don’t think this is a valid conspiracy tbh. The O&G companies are ideally placed to become energy companies and be the ones rolling this stuff out. Why wouldn’t they?

Not any money in it for the Tories mates so starved of investment and the tories do not want Scotland to have surplus to export. Its pure politics. Holyrood cannot invest more than tiny amounts due to not being able to raise money on international markets.

If we had invested in tidal all the money wasted on nuclear we would have no need for nuclear. Tidal has had minuscule investment.

There is also the totally rigged fake market which means ridiculously high cost to access the grid if you generate electricity in Scotland

Pentland firth and sound of islay are 4 hours apart on tides. A decent array in both would provide great smooth baseload.

The tech is there. The interconnects are there. Its blocked by the tories.

Salt water is a horrible environment for moving machinery. I imagine the technical challenges (and costs) are considerable.

There used to be someone on here worked in Tidal, rode with him probably 10+ years ago and from what he said I’ve been expecting to see it any time…. But nothing.

Salt water is a horrible environment for moving machinery. I imagine the technical challenges (and costs) are considerable.

They manage dragging $$billions of oil and gas out of the sea.

I don’t think this is a valid conspiracy tbh. The O&G companies are ideally placed to become energy companies and be the ones rolling this stuff out. Why wouldn’t they?

Ill follow this with this quote.

Not any money in it for the Tories mates so starved of investment and the tories do not want Scotland to have surplus to export. Its pure politics.

Although it’s not just Scotland, wasn’t there a plan / gov feasibility study for a tidal generator across the river Severn at some point in the 90’s?

The tech is there, it’s seems a damn sight simpler to me than oil and gas extraction. The problem is the infrastructure needs development & the political and commercial systems we have in place are too comfortable with more traditional energy investments which are making vast sums of money.

^ the Severn barrage is very different from open channel/flow of the sea proposals for much of Scotland I think.

I also know there was a European research hub for all this on one of the northern isles.

It may be as TJ is saying, a lack of political will, as much as any cost and technical challenges.

They manage dragging $$billions of oil and gas out of the sea.

Different challenge – the moving parts of oil platforms are out of the water aren’t they?

Although it’s not just Scotland, wasn’t there a plan / gov feasibility study for a tidal generator across the river Severn at some point in the 90’s?

Severn barrage and Swansea Bay barrage have been talked about for years but they are potentially hugely environmentally destructive, removing some internationally important sites for migrating birds.

I don’t think they have much in the way of moving parts underwater though do they Jimmy?

I’ve just read an article which pointed out noise pollution from turbines and its possible affect on marine mammals – I’m out. I recall reading once how whales used to be able to communicate with each other across oceans but no longer can due to noise pollution from ships.

Surely the source of reliable renewable energy must now be down to geothermal energy? We might not have the technology yet but I can’t imagine that in the future it won’t be relatively easy to drill however many miles necessary to make geothermal available wherever necessary. I know that Southampton has access to geothermal energy but much deeper boreholes throughout the UK must surely one day be possible?

Tidal barrages are much more problematic ecologically and infrastructure wise. There was also the cardiff bay barrage that was killed off.

Tidal flow we have two perfect sites. Pentland firth and sound of islay. We could be generating significant baseload in much shorter times scales than for new nuclear at much lower financial and environmental cost.

Its purely political and anti Scottish pitical at that.

The tories intend Scotland to be dependent on english electricity. Thats why Scotland has not been allowed to have any investment nor now has no blackstart capacity

the pilot in Strangford lough was pretty successful in generating electricity, then it was decommissioned. possibly that was the intention all along but no sign of a replacement

You can use lagoons to smooth out/control the power cycle. See David Mackay’s book.

There are some places (around Shetland?) with really strong powerful flows that could be used. No I don’t really know why there’s so little apparent progress. But it all costs money and may have significant environmental impact. Maybe wind is cheaper and easier? And solar has a really high energy density compared to most other renewables, plus no moving parts.

don’t think they have much in the way of moving parts underwater though do they Jimmy?

The best looking prototype imo is the turbine in a barrel. Its all underwater including the generator.

I’m not so sure the conspiracies and political blame game are the reason, in most cases we are looking at pre current gov. Any investment will have to wash its own face and if the sums don’t add up it won’t happen. Goodness I did an A level coursework piece on the Severn Barrage, that was a while ago!
I just dont think the generation yield is anything like what it needs to be for the capital outlay.
It’s a shame, I’ve been in Plockton all week and you can see and feel the energy but without a barrage it’s going to be tricky to harness enough. Not so sure a barrage anywhere would get past the first local engagement meeting!😂

I remember visiting La Rance when I was about ten, but unless you are prepared to barrage estuaries like the french commercial tidal is a long way off. maybe never. bit like wave power, lots of prototypes about but very few can get the funding to bridge from demonstrator to commercial.

offshore wind is where the money seems to be at right now.

Seems the bedt sites for tidal power don’t balance each other out so there are large spikes in generation twice a day along periods of zero generation.

Swansea Bay Tidal Lagoon and Baseload Tidal Generation in the UK

Tidal looked to be more expensive than a combination of wind and nuclear.

https://www.google.com/url?q=https://www.theguardian.com/business/2018/jun/25/government-rejects-plan-for-tidal-lagoon-in-swansea&sa=U&ved=2ahUKEwiC_pSRuvb5AhXAS0EAHR6QCgUQFnoECAwQAg&usg=AOvVaw1W3Mp9QgWKnV4mAdwWuHEI

the severn barrage will never happen. for a start, they’d spend most of their time emptying mud out of it. I’ve been out on the port of bristol dredger and the mud there is amazing.

there is no seabed as such, the mud just gets thicker and thicker. they define a nautical horizon instead which is the density of mud a ship can drive through. ~250kg/m3 from memory.

Had involvment with the Pelamis Wave Generator Pelamis which won loads of awards and ultimately went bankrupt

Same guy from Pelamis is now in Orbital Marine Power hich ive had involvement in Orbital for a new tidal generator.

Been involved in a few concept studies for others which never got to sea trials.
They attract funding, get to sea trials, then run out of funding from my experience.

Tidal looked to be more expensive than a combination of wind and nuclear.

A barrage is very different to a turbine in open channel.

Tidal flow we have two perfect sites. Pentland firth and sound of islay.

They are perfect in that they have some of the fastest tidal currents in the World.

However, the challenges of operating offshore construction vessels in these areas are massive, so the installation and maintenance is extremely difficult, almost impossible on a large scale. This also makes it extremely expensive.

Will they ever overcome the challenges? Possibly, look at the difference in early offshore oil and gas and what they can do now. However, there has been achieved with massive investment and encouraged by massive profits.

encouraged by massive profits.

With the current energy prices, are we not there yet?

Also – I was in northern Spain at a wave power station. It wasn’t huge, but seemed to be making a good chunk of the energy the small town needed.

Lots of bold claims about this new form of tidal/wave generation but certainly looks promising:

https://www.independent.co.uk/tech/wave-magnet-renewable-energy-swel-b2156572.html

Matt. I think that might have been pelarmis? Commercial scale trial. Scottish company thats gone under because of lack of investment. One of the oil companies took a stake then pulled the plug once oil prices rose. Uk government refused to invest anything. Holyrood did what it could and i think a small R& D group is left.

20 years development gone on the whim of an oil co

It was this place:

https://en.m.wikipedia.org/wiki/Mutriku_Breakwater_Wave_Plant

We have the tech ready to go. Its nothing new or revolutionary. It just needs investment. There are numerous designs all working at trial scale

I don’t think this is a valid conspiracy tbh. The O&G companies are ideally placed to become energy companies and be the ones rolling this stuff out. Why wouldn’t they?

An oil co. killed pelarmis.

Not gone, is it though they learnt that it wasn’t viable or profitable at that point, didn’t they!
Maybe it is profitable now, it may see a resurgence.

Its bssically dead pelarmis. Could be reinstated i guess.

I read a figure that Scotland and NI tides had enough energy to power way more than the UK needs.

David MacKay reckons we could get ~ 10% of our power needs from tide – http://www.withouthotair.com/c14/page_81.shtml.