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?



Friday, April 29, 2016

2016 will be a scorcher

Based on the first 3 months of this year, 2016 is likely to be the hottest year on record.

Hat tip



Sunday, April 24, 2016

China means business

A common rant in the deniosphere (among those who even admit that global warming is happening) is that there's no point in us doing anything to reduce emissions if China and India are not.  That's why I found this tweet about Q1 GDP in China most interesting.




Xinhua News Agency is the government's official news agency.  And the tweet shows real GDP, year on year CPI inflation, job creation and so on.  All well and good.  All quite normal for any government spruiking its achievements.  But look at the last line of that list.  "Reduction in energy consumption per unit of GDP".  The implication is that this is now one of the key policy objectives of the Chinese government.  And that's incredibly good news.  They really mean to do something about climate change.  I admit, I've been sceptical, arguing that their efforts to green their energy supply are mostly about air pollution.  This convinces me that they do in fact see global warming as a serious problem, and one that deserves their attention.  All countries should do this.  Along with GDP and unemployment data, they should be publishing monthly, easily accessible data about the greening of electricity generation and the sales of electric cars and the year-on-year declines in energy intensity.

The only fly in the ointment is this.  A decline in energy intensity of 5.3% per annum is simply not enough.  Let's assume world growth averages 3% per annum for the next 25 years.  If all countries managed to reduce their energy intensity by 5.3% per annum, following the Chinese lead, it would mean that in absolute terms, emissions would be falling by 2.3% per annum. This means global CO2 emissions  would fall by just 44% over 25 years.  This isn't fast enough, given how much temperatures have jumped over the last year.  We need to cut emissions faster than that.  To get a 80% cut in total global emissions over the next 25 years we need to cut absolute emissions by 6.5% per annum, or to cut energy intensity by 9.5% per annum.

China's commitment to cutting energy intensity of GDP is a big step in the right direction.  But we (the rest of the world) need to take more steps.  China's doing a lot to slash its emissions.  But she needs to do more.  And so do we.