Kept in the dark on alternative power

Central Western Daily
Saturday 5/5/2007 Page: 16

IT concerns me that, while most people are aware of solar and wind, the potential and uses of many other low emission and renewable technologies seem to pass them by. For instance, no-one appears to challenge John Howard when he states categorically that none of the alternatives are able to carry the base load of our power, ie: the 24 hour, all day, all night demand.

The wind, he points out, blows only sometimes, while solar energy is produced only during the day. These things are true, but they both need to be understood; wind farms are placed in varying locations, that frequently have patterns of strong winds at different times, while solar energy is collectable during peak periods, ie: during the day, when the demand for power is at its highest - it's peak. This makes it an ideal complement for a relatively low, continuous 24 hour flow. The continuous ramping up and decreasing of output increases substantially the wear and tear on the mechanisms of the coal fired power stations.

But are coal and nuclear the only ways to produce a 24 hour flow of power, as John Howard continuously declares? Indeed, no. Both geothermal power, eg: the hot dry rocks at Innamincka, or wave power will give us this 24 hour supply, if we care to use them.

Not only is there an Australian made wave machine, 'Energetec', now known as Oceanlinx, already in operation at Port Kembla, but a completely different form of wave power technology, the Polamis, has just been launched in Scotland, as the world's largest wave farm in Orkney. (Max Carcas, business development director, Ocean Power Delivery, Edinburgh Scotland http://www.oceanpd.com/default.htm)

The approach there has been to develop a machine that harvests the maximum day to day power of the waves, while avoiding destruction by the occasional wild storms that occur. This explains its shape: it looks like a thin set of windowless train carriages. They are designed to always point into the predominant swell.

This means that the waves pass in sequence down the length of the machine and it never presents a wide cross sectional area to their force. The hinged joints of the carriages move up and down and side to side in response to the movement of the waves. That movement is resisted by hydraulic rams, which pump high pressure hydraulic fluid through hydraulic motors which turn generators.

The ocean is active day and night, so that this is yet another way that base-load, 234 hour power can be available for use. Calculations indicate that less than 0.1 per cent of the power that can be harvested from the oceans would supply the planet's entire energy needs. So why doesn't somebody tell the prime minister?

Much of this information was presented in the Science Show, ABC RN 28/04/07.