It might be interesting in this age to look at this argument in terms of 'rationalism'. A fusion generator preceded our planet. In fact, it is responsible for all life on this planet. Currently, we utilise less than 4% of all energy sent from that generator to this planet.
As good economic rationalists, should we not maximise our efficiency in exploiting existing resources, before moving on to new sources?

Philo,

The highest variation in tides in Australia is about 10.3m, in the Derby area, NW Australia:

http://www.abc.net.au/science/scribblygum/kingtide/default.htm

Tidal power is the dark horse in the race. Although there thousands of kilometres of Australia's southern coastline that are almost constantly exposed to reasonably strong wind, and therefore suitable for wind power generation, there is the huge expense of instructure to transport the power. And of course many people consider it to be an eyesore. Tidal power turbines can be placed near human settlement much more easily. Also tides and currents are more predictable and realiable.

A growing number of great tidal power turbine systems are being developed, but it is not something that people are used to, unlike wind power which has been used for thousands of years, starting with grinding grain for example. And of course the machine age has been built on coal power systems, still very much the staple, and still with a very powerful influence on our political systems. Also it is more difficult to construct lasting structures in marine environments, but a lot of progress has been made with corrosion resistant and strong building materials/alloys/coatings, etc.

Long after nuclear fission has run it's course, uranium reserves depleted, and when our grandkids' grandkids are still cursing the present generation's decision to leave them with impossible-to-store-for-a-long-time radioactive waste, technologies that utilise the power of the sea will be widespread.

Here are some excellent examples:

Marine Current Turbines Ltd.
http://www.marineturbines.com/technical.htm

Blue Energy Canada Inc.
http://www.bluenergy.com/index.html

Hammerfest Electricity (Norway)
http://www.e-tidevannsenergi.com/

I wish anyone who wishes to develop or invest in these technologies the most sincere best wishes.

'I wish anyone who wishes to develop or invest in these technologies the most sincere best wishes.' - this shocking sentence was the result of fatigue, as were the other couple of spelling errors in the post above! Apologies..

I've found another excellent example of marine turbine design, in addition to the ones listed in the above post:

Turbines by Tidal Stream, UK
http://www.teleos.co.uk/Turbines.htm

Tidal power is interesting. Does there exist somewhere in the world a tidal generator with a significant output? Given that most demand is in cities where coastal land is at a premium, where could they be constructed? How are visual pollution, environmental degradation and the threat of storm damage dealt with? Perhaps this is a power source of last resort.

I notice that the critics of nuclear power talk about its long term legacy, and that is certainly a major problem. What about the long-term legacy of fossil fuel. Some scientists say that even if fossil fuel burning was ceased abruptly, the damage already done would take decades to reverse.

Excellent posts Ludwig & Ev.

I find the whole proposal of nuclear energy as an 'alternative' totally ironic given that it is yet another NON renewable resource.

Our efforts must be focused on both discovering and developing true alternatives.

Paul.
If the federal government has come to the conclusion that global warming (heating) is real then I missed any evidence of this in the recent budget.
Where are any tax incentives provided to use less power?
Where there any provisions for a pollution tax?
Where are the tax incentives to encourage the R&D in the renewable energy sector?