wirral forums

Tidal Turbines

Posted By: diggingdeeper

Tidal Turbines - 21st Mar 2016 3:23am

At last after years of money being thrown away on wind power it looks like Tidal Turbines are making progress with a few planned to come online in the next few years.

Tidal Turbines have loads of advantages over wind farms including the most important one - they are cost effective.

Hopefully the government will see sense and promote this technology and dump their idiotic plans for nuclear and wind power altogether.

Liquid Air Energy storage is also making great progress, power storage is an essential part of any non-continuous power source such as wind, tidal or solars.

Posted By: Greenwood

Re: Tidal Turbines - 21st Mar 2016 8:48am

I'm amazed that we are not further forward in this - as our islands are surrounded by the sea, and the tides - unlike wind or sun - are utterly reliable, it's a no-brainer for power generation for the future. There have been several small-scale trial projects, my favourite being the Pelamis which minimises the risk of mincing marine wildlife, as the rocking motion of the waves acting on the hinged units creates the movement that drives the turbines. The units are sealed, unlike tidal barrage systems through which the water has to pass. Bring it on, I say! The sea has protected and sustained us for so long - this is another way it can help us.
Edit: I just checked on Pelamis and it seems the developing company went into administratin as of end 2014. Argh! That is a real shame. We need someone very rich to take up the baton on this, I think. Won't be me... *sigh*
Posted By: Excoriator

Re: Tidal Turbines - 22nd Mar 2016 12:13am

The Pelarmis was for wave energy rather than tidal energy.

I don't think there is any chance of tidal turbines mincing anything, by the way. They rotate quite slowly and are much smaller than windmills so the tip speed is lower and it is easy for any fish to avoid with ease. The fact that you cannot fish anywhere near them means that they could actually provide breeding sanctuaries for fish, something which we need if overfishing doesn't scoop up the lot!

Land based windmills, by the way, produce power at more than competitive cost. A 3MW machine these days costs about 2 million. It will produce - on average - about 1MW or 24,000 kWh a day. That's about 220 million kWhs over a working life of 25 years, so the cost is under a penny a unit. Maintenance costs are negligible. That's cheaper than fossil or nuclear, even if you ignore the cost of pollution or care of nuclear waste.

There is another benefit of wind energy which is rarely mentioned. And that is the short time it takes before they start generating a cash flow. A windmill can be installed in weeks. Hinkley will take a decade or two before a single joule is produced, during which a massive cost is incurred.

The UK's first floating offshore wind farm is now being designed and built in Scotland. It is possible these will reduce the cost of offshore wind to something comparable to onshore wind power, but that remains to be seen. I notice that the developers are proposing a Li-ion battery in order to save unwanted output from the windmills so it is a most interesting project altogether.

Posted By: diggingdeeper

Re: Tidal Turbines - 22nd Mar 2016 5:27am

I don't know who dreamt up offshore wind generation, total madness.

Onshore wind has very few suitable sites to achieve the 30% capacity figures. Excessive turbulence, excessive windspeed, omni-directionality, space requirements and aesthetics all play a part in reducing the viability of sites but as it will become the cheapest source of electricity the pressure will be on to have more.

I will admit that I would prefer to have wind turbines everywhere than even one nuclear fission site. Why we are still looking at fission instead of fusion I have no idea, I'm sure the technology would be there if the money was - if we can produce the Large Hadron Collider, surely we must be able to produce a viable fusion reactor.
Posted By: Excoriator

Re: Tidal Turbines - 22nd Mar 2016 11:45am

I doubt floating turbines are any more expensive to install than onshore ones. The necessary flotation tanks are pretty simple to construct and are probably comparable to the cost of excavation and building a concrete base and roads.

Floating turbines can be produced entirely on land and simply floated out and moored.

Fusion seems to be a dead duck. We are still thirty years off getting a working one, and have been ever since the 1950s. Nobody has managed to make a sustainable one yet, let alone solving the engineering needed to extract the heat from a few micrograms of gas at 100 million degrees into steam at a few hundred degrees. Fortunately, we don't need to. We are bathed in a constant flux of plentiful energy from the fusion reactor 93 million miles away. All we have to do is go and collect it!

Making onshore turbines much bigger would not only reduce the cost of the electricity they produce, it would also greatly increase the number of suitable sites. Unfortunately onshore turbines in the UK are limited by law to what is now a lot smaller than the 7 and 8MW monsters you can build at sea.
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