When the wind doesn't blow

The state of South Australia has a wind sector of 1595 MW installed. Yesterday, at 3.15 pm, the output of that sector was zero. South Australia’s PV sector was delivering supply on this sunny day, but as we nudge toward winter, that supply tapers of strongly and disappears at about 5 pm.

South Australia is connected to Australia’s National Electricity Market (NEM), the largest (geographically speaking) grid in the world. NEM-wide, the installed wind capacity is 3875 MW.

Yesterday at 3.15 pm, the entire NEM output of wind was 98 MW, or approximately 2.5% of the installed capacity.

Sometimes, even over a huge area, wind provides virtually or actually nothing

Sometimes, even over a huge area, wind provides virtually or actually nothing

It is not anti-renewable energy to point out that this is a major challenge. It is times like this that drive system-costs; unusual periods.

South Australia has the largest share of installed wind generating capacity. The second largest share is in Victoria. The two states have 75% of the total installed capacity (1595 MW and 1294 MW respectively).

They are also neighbours, and the wind resource is known to be well-correlated. When wind is low in South Australia, it is also likely to be low in Victoria. This is also true (to a lesser extent) between South Australia and NSW. At 3.15 pm yesterday, the Victorian wind sector delivered 1 MW. If another 1000 MW were split between South Australia and Victoria, then yesterday at 3.15 pm they would have delivered an additional 0.4 MW of supply.

It is not until we get to Queensland that there really might be some reliable geographic smoothing of the wind output. What is the installed wind sector in Queensland? Twelve megawatts. Count them. Twelve.

Wind supply can be correlated even over large geographical spaces. Patters running from bottom-left to top-right indicated correlation of wind supply. Image from Integrating Large Scale Wind Generation in the NEW by AEMO (2012)

Wind supply can be correlated even over large geographical spaces. Patters running from bottom-left to top-right indicated correlation of wind supply. Image from Integrating Large Scale Wind Generation in the NEW by AEMO (2012)

It is not anti-renewable energy to say that this geographically imbalanced build of variable renewable energy is unhelpful. In provide incentives for renewable energy in Australia there has been no consideration of this geographical reality, either directly or by some technical proxy (e.g. addition of firm capacity to the existing system). In modelling work we are currently undertaking we see a profound impact on the prospects of a larger reliable supply from wind by geographically spreading installed capacity. It is arguably hurting the prospects of renewable energy to keep building in South Australia and Victoria. In seeking to expand the renewable sector in Australia many remedies might be considered. One valid remedy is “no further developments in these regions at this time. Incentivise developments in other regions”.

Australia's wind sector is concentrated in South Australia and Victoria which, with their correlated supply, means we are not taking advantage of our geography with adequate planning and intelligent policy.

Australia's wind sector is concentrated in South Australia and Victoria which, with their correlated supply, means we are not taking advantage of our geography with adequate planning and intelligent policy.

But we don’t hear this. That’s probably because it involves a concession that many renewable energy advocates appear unable to make: that variability and correlated supply from wind is both undesirable and a real challenge. It seems anathema to do or say anything that doesn’t blame the critics, the market, the regulator…anything but the variability of the wind itself.

This is shortsighted, ideologically driven advocacy, particularly since a more moderate view may support the successful development of a much larger renewable sector in due course. Here at Bright New World, we do not subscribe to that model of thinking. We want optimal solutions to urgent challenges, and that means being honest about both the advantages and disadvantages of different technologies.

For more information, read these peer-reviewed papers:

Beyond wind: Furthering development of clean energy in South Australia

Burden of proof: A comprehensive review of the feasibility of 100% renewable-electricity systems

Ben Heard