So the UK government agree with my assessment on the Swansea

[Suff]

Tidal power project.

But Business Secretary Greg Clark said however "novel and appealing" the project did not meet the requirements for value for money.

He said the electricity generated by the lagoon programme by 2050 could cost up to £20bn more to produce compared to generating that same electricity through a mix of offshore wind and nuclear.

That would cost the average British household consumer up to an additional £700 between 2031 and 2050, he said.

Hardly the "value" that renewable energy hold themselves up to. It was never going to fly, it was always a fairy story.

[Workingman]

It was never on, except in the minds of dreamers.

The theory is sound: hold back the incoming tide then charge the lagoon and get electricity as it fills. When the tide goes out do the reverse. Controllable electricity over long periods twice a day like clockwork.

The problem is making a lagoon big enough to do the job economically and with as little environmental impact as possible.

Good decision to cancel.

[TheOstrich]

Fair enough. Cost / return the over-riding criteria.

So now cancel Heathrow 4 and HS 2 ……..

[Suff]

The problem is making a lagoon big enough to do the job economically and with as little environmental impact as possible.

I don't necessarily disagree that we want to use tidal power for the UK. I do think it is a good thing. But what was being put forward here was a white elephant of gargantuan proportions which would have damaged the cause for renewable energy in the UK for decades to come.

Not really something I would like to see as I believe renewables are important to the UK energy security. Regardless of what I think about how they are going about it.

[cruiser2]

When I was working went to a site in North Wales. The owner had been generating electricity for the works and his house using a water turbine.
He said he had never had a failure. Has had the generator and other parts serviced. It may still be working.

[Workingman]

Cruiser, some of us have been banging on about small scale water generation for decades. They are extremely cheap to install, have minimal environmental impact, and are very simple to maintain.

There are tens of thousands of suitable sites in the UK. It is true that their individual output is in the hundreds of kilowatts, but collectively they could produce gigawatts. Also, if 100 go down there are still 9,900 producing electricity day and night all year round.

The trouble is that they are not 'big ticket' items so no headlines and therefore of no use to politicians.

[cromwell]

Sites such as Gayle Mill in Hawes, North Yorkshire. Sited on Gayle Beck it had a double vortex water driven turbine that powered woodcutting machinery and at one time provided electricity to the village.
https://en.wikipedia.org/wiki/Gayle_Mil ... _Yorkshire

I think it's closed for repairs atm but it's well worth a visit. And like WM says there must be thousands of sites like this that could be used. Hardraw Force waterfall just down the road from Hawes being another.

[Kaz]

Cruiser, some of us have been banging on about small scale water generation for decades. They are extremely cheap to install, have minimal environmental impact, and are very simple to maintain.

There are tens of thousands of suitable sites in the UK. It is true that their individual output is in the hundreds of kilowatts, but collectively they could produce gigawatts. Also, if 100 go down there are still 9,900 producing electricity day and night all year round.

The trouble is that they are not 'big ticket' items so no headlines and therefore of no use to politicians.

This!!

[Suff]

I think it's closed for repairs atm but it's well worth a visit. And like WM says there must be thousands of sites like this that could be used. Hardraw Force waterfall just down the road from Hawes being another.

I did a real deep dive into this today. The key problem with renewables is a two word phrase "Capacity Factor".

Essentially the capacity factor of standard power stations is around 90%. The station is rated to the max capacity, it runs 24x7 and delivers almost exactly that capacity. The capacities for renewables are significantly lower. Large dams are around 23%, solar is between 10% and 30% depending on how close to the equator you are. Small river wier based systems are nearer 50%, tidal river flow is near 50% and wind is around 48% for offshore but drops to 15%-30% on land.

Nuclear is 90%, waste and geothermal are both around 65% and biomas is just under 50%.

So you can see why the government is investing in offshore wind, biomas and nuclear. Wind is cheap and easy, not wonderful but a quick win. Biomas is also cheap and easy and, whilst not so quick, is more consistent than wind.

I missed the part about tidal lagoons. The capacity factor of a tidal lagoon is normally 10%. Swansea would not be expected to be any more. The figures given out by the project were designed to confuse. They gave the nameplate (Absolute max) and the load factor but they did not give the all important capacity factor. If you do a bit of digging, you see what the capacity factor of a tidal lagoon is.

However, if you replace the tidal lagoon with 128 instances of the Kirkthorpe hydro plant, you still wind up with a shortfall.

I messed about with the figures and if you take the status quo and use 128 instances of Kirkthorpe, you still wind up topping up the strike price of electricity to £90 per MWh for the next 40 years.

That is, if you keep things are they are. Wholesale electricity is £42 per MWh. But we buy it at £150 per MWh. The only way to make any of these things make sense is for the government to become a power utility. To do the builds itself and operated them for the next decade or so. The government can then sell the plants for 3/4 of the cost price of producing them (they have almost repaid themselves), and take that money to do it all over again.

Don't, however, expect any of the governments to think of that one. Labour is "Nationalise and to hell with it", the Tories are "No public utilities and to hell with hit" and the Lib Dems don't count, although they would be the most likely to follow that idea.

What are we left with?

Wind and Nuclear with a bit of Biomas going on in the middle.

Geothermal?? What's that!

Of course there is always the brand new NASA "kilopower". A hybrid of nuclear heat and sterling heat engines. 10 years, no maintenance and just take the power.

[Workingman]

Many have forgotten, or never even knew, the important thing indicated in Cromwell's link is that water was the initial driving force of the Industrial Revolution. Armley Mill (1707) in Leeds, was once the world's largest woollen mill and was driven by two waterwheels. Many, if not all, of the North's wool and cotton mills from the 18th century were powered by water.

The Thomson double-vortex turbine used in Gayle Mill, despite being inefficient by today's standards, produced 7.5kW. A modest modern installation, where efficiency is up to 90% could easily treble the Thomson with the same head and flow. A "run-of-river" system with multiple power plants could easily deliver 500kW to 1MW without the need to dam or change the flow of water.

The power to be converted to energy is there, all it needs is the will to use it.