Saturday, April 30, 2016

Australia's wind resources

As a rule, solar resources are strong close to the equator and wind is stronger closer to the poles, where the angle of the sun is low, but the Coriolis force is strong.  It's more complicated than that because at the equator there are clouds, whereas in the mid-latitudes there is desert.  And wind can be stronger outside the roaring forties on the western edge of continents, where the SE trade winds blow.

The first map below (source) shows wind speed at 80 metres for Australia.  Orange/yellow means strong, blue means slight.  Tasmania has high wind speeds from the "roaring forties", but SA, Victoria and WA benefit from both the westerlies and the southerlies/south-easterlies.  On the other hand, coastal NSW has lower wind speeds on average, about half those of coastal SA or WA.  So although you could build wind turbines there, the electricity they generate would in principle have an LCOE twice that of turbines in SA, western Vic or WA.  The trade-off between putting wind farms in SA/WA far from the demand in the east then comes down to the costs of moving the electricity back east.  HVDC lines lose 3% of their transmitted electricity every 1000 kms, but there are also conversion losses when transforming from AC to DC and back again.Plus of course the capital and maintenance costs of the lines.  But from SA and western Victoria to the eastern seaboard is only 1000 kms, more or less.  Feasible.  There are also some areas of relatively strong winds in eastern Victoria and in NSW.









The second map (source) shows Australia's solar resources.  As you move away from the coasts, where there is more rainfall/clouds, irradiance rises, and as you go north closer to the equator, ditto.   Given that there are areas of high irradiance and reasonable wind resources which overlap, logic would suggest that we use both solar and wind to provide our electricity.  As I discuss here, a mixture of  1/3 each of wind, solar and concentrated solar would cost less than coal while providing us with zero-emission electricity 24/7.  Why aren't we moving aggressively towards this?



No comments:

Post a Comment