Tide power has been an idea that’s been bounced around for decades. Aside from the environmental impacts (which are massive as you increase in scale), it’s very difficult engineering in practise as I understand it. Very vulnerable to weather and corrosion, as well as getting jammed up by floating junk. Our resident guru on all things marine engineering @megahertz may be able to shed more light.
Gut feeling - it’s maybe more viable in places like Britain. Here in Aust we have so much scope for solar, which is already robust and proven technology, that investing in speculative and experimental tidal generation seems a bit like buying Betamax.
OK @Humble_Minion, you have dragged me into the ongoing cage fight that is the climate change thread.
There are two options for tidal power:
Marine barrage. Basically take an inlet or estuary with a large tidal range, and build a wall across it. As the tide changes, it creates a height difference across the wall, and you can use that to power hydroelectric turbines. Fairly reliable, proven technology that, because you are blocking off the inlet, causes a whole lot of environmental damage comparable to building hydroelectric dams. It is probably feasible in what are already heavily human impacted estuaries such as the Severn in the UK, but do we really want to do that somewhere like Broome?
Tidal current turbines. These are like a wind turbine that is put somewhere where there is a high current, and they extract kinetic energy from the current. They don’t block the flow, but they put a big whirly fish chopper in the ocean. (I attended a conference in the US, they were talking about the acceptable level of laceration to salmon moving upstream past these types of turbines.) Places that have fast currents that are good for these types of turbines also tend to be gaps that ships need for navigation (think, the Port Phillip Heads, or under the San Remo bridge in Westernport), and these turbines can create a hazard to navigation. There are also places off Flinders Island and Cape Barron island that are good for this, and Cook Strait in NZ. In the latter, the current also has a tendency to roll several tonne boulders along the seafloor, which is a bit of an issue for the turbine too.
The other issue is that these are fairly capital intensive - the barrage especially. Land based wind and solar are so much cheaper per kilowatt, and we have lots of space, so they are the economically preferred solution for now. The next step will be offshore wind turbines - there are leases being issued for Otways, Gippsland, Illawarra and Hunter regions at the moment. These cost a whole lot more than onshore turbines, but they can be a whole lot bigger than onshore turbines (10 MW to 20 MW, compared to up to only 6-7 MW maximum onshore, and research is underway for 25 MW offshore turbines) and the wind is much more reliable offshore. So despite the higher capital expense, these are being actively pursued for installation in the next 5-10 years. In Australia, these will mostly be floating offshore wind turbines as most of the sea areas are too deep for fixed turbines (Gippsland has some shallow areas suitable for fixed turbines.)
Wave energy also exists, but is miles off commercial viability as the cost per watt is significantly more than wind. And I say that despite working for a company that has demonstrated technical feasibility of a floating wave energy converter - which we did in the UK despite being an Australian company, because we lack the infrastructure to support the test programs here. (Also, despite a number of high profile companies in Australia, basically all of them have sucked up funding and have even less to show for it than we managed on our shoestring budget - and had done it before we were in the market and so destroyed any remaining appetite to fund wave energy…)
It’s possible in fact desirable to be inquisitive without being a “denier” Problem is that it’s impossible to ask genuine questions in this thread without being hounded. Sure there are some genuine deniers here but it’s not worth sticking around for a discussion when you get yelled at.
There are many discussions that could be had re the pros and cons of various energy solutions. I’m all for that but not if it means being subjected to abuse.
I think you’ll find the people that are actually genuine in their genuine question asking will find an open and honest discussion with most people in here
It’s the people that ask questions without wanting to know the answers that most have no time for
