GoatBoater

Tidal currents in a country like the UK, with a very high tidal range and a (for use of a better word) crinkly coast, are usually formed by a difference in tide heights around a peninsular or area of coast line - or when flow is constricted through narrows in marine topography. The tidal flow then runs to re-equilibriate that imbalance. So yes, in this country they can often be parallel to shore, or at least very close to it. But tidal streams also appear for other reasons, salinity gradients in the mid-Pacific for instance. The 'underwater windmill' is still the basic tenent of the tidal stream world (w.marineturbines.com or w.swanturbines.co.uk), simple and effective. But the power of the tide is not to be underestimated. There has been more than one prototype that has been deployed and effortlessly decimated by the next tide. Great power to be harnessed, but greater almost needed in the harnessing. GB

High tidal differences power tidal barrage devices - there has been quite a lot of work on this. We need to look into these technologies as well as tidal stream and wave energy. GB

AI has faced huge issues in its years of ascendance; after all when advanced computing began the main problem was making anything work at all! However there have been points in its history where AI has taken a huge step backwards. I say backwards because often we arrive at a point, realise our path is not ideal and take a turn for the better often involving going back to where we started and thinking again. One important such point was where AI began to think Qualitatively rather than quantitatively. This step is essential in moving towards programs that 'think' as we do, because humans do not process data quantitatively at all. This paradigm shift led to a whole new branch of AI springing up almost over night known as 'Qualitative Reasoning'. I, amoungst others, wait to see when we will be blessed with our next great leap backwards. GB

Afternoon All, I know this thread has been a bit quiet of late but please allow me to stir it up a little bit. What we appear to be talking about are Wave Energy Converters (WEC's) and Tidal flow generators (the other technology usually confused with these is Tidal barage - which is basically a tidal driven Hydro Dam and involves storing water). WEC and Tidal flow use the naturally occuring energies of the ocean to generate power. WECs and Tidal devices are very different though. A Tidal device uses a flow of water, somekind of tidal rip current, to drive turbines. Useful tidal zones are not common but where they exist they are incredibly predictable (a tide table and a simple calculator and you can plan 1000 years ahead quite simply - apparently). WECs are different because they use Ocean Waves. These are less predictable than tides but considerably more prevalent. Almost without exception WEC utilize unbroken longwave length waves, i.e. green waves and most take energy from the verticle movement of the wave. Ocean waves are used because shore waves have already lost a huge amount of energy thought friction with the sea bed, and broken waves are more destuctive. Current working technologies (my research is basically european so please forgive any units I might miss from elsewhere - I would of course be more than happy to here about them). Tidal Marine Current Turbines (marineturbines.com) is the only turbine company I know of with a demonstrator in the water. It is a 300 kW unit the UK Coast at Lynmouth. They are currently installing a 1MW unit in a tidal loch in Northern Ireland. WEC Shore-based Pico - OWC on PICO in the Azores Islay - OWC on Islay in the Shetland Isles, Scotland (wavegen.co.uk/what_we_offer_limpet_islay.htm) Floating WaveBob (breakingnews.iol.ie/news/story.asp?j=176113818&p=y76yy45z4) Has recently been flaoted. Wave Dragon (wavedragon.co.uk / wavedragon.net) has had a unit in the water since 2003. So far as I can see these are the only two Ocean Wave devices that are actually out there at the moment. Wave Dragon is currently trying to install a 7MW unit of the coast of Pembrokshire and have announced a 50MW wave farm off portugal. Pelamis (oceanpd.com) have a very successful unit that has been extensively tested in Scotland and they are just about to install Europes first wave energy farm off the Coast of Portugal. Three of their 750 kW units will be hooked up to the grid which will also mark the first ocaassion that anyone has tested / used WEC arrays ever. I hope that any body who drifts across this will see that this is a very interesting time to be in Wave or Tidal energy. GB

I found it somewhere but have not seen it since, must try harder. Only just seem to have been given permission to say so. Thanks GB

Hi All, I'm the GoatBoater. I found your forum on Wave and Tidal Energy and just had to add my two pence worth (well cents I suppose in hono(u)r of our hosts). It haas been quiet in there for a while but I hope there are still people willing to chat about this. GB