Wind Integration Inertia: AEMO Special Report

Hi there, I’m Jervis Whitley. Today’s Friday, 21st of June, and you’re listening to WindFront, the weekly roundup of the wind industry from Australia and around the world. Today, I’ll cover the top three in wind. Who’s been earning the most and wind this week? And wind and inertia, and look at AEMO’s latest wind integration report.

First, let’s start with the top 3 in wind. Now top 3 wind farms, were Waubra, Macarthur, and Portland, with Waubra pulling in over half a $1,000,000 this week. However, overall this has been down on last week’s results. We saw last week’s $6.5 million earned throughout the wind. That’s down this week. We’re up to $3.5 million total collected from wind farms in Australia.

So let’s have a look at the wind and inertia. AEMO has been releasing a series of wind integration studies. The 1st one a little while ago, which is the one we talk about now, which is sort of understanding the impact that increased wind will have on the Australian power system. AEMO found that there will be almost 9 gigawatts of additional wind generation by 2020, which is 4.5 times what we have today, which is a huge amount of wind to integrate into our power system. But they say there might be a hard time connecting those wind farms. So this study is all about how developing the technical model that wind farms will need for long-term power system forecasting. Without those technical models and the understanding of how wind farms will change in the future, they won’t be in a very good position to do the forecasting. So it’s great that they’re doing this work now.

So some of the findings in this 1st round have found that when turbines will continue to grow in size, when they 1st came out, I mean, turbines may have been less than a megawatt, but they’ve steadily increased and now we’re seeing 3 megawatt turbines come online. They have better and faster controls and provide better local power system voltage support. But interesting, they found that none will contribute to inertia or frequency control.

So for those who aren’t familiar with the term inertia, it’s sort of, the power system can be thought of as a large spinning wheel. And as energy is drawn out of the power system, that wheel, which has an inertia in it which is spinning, can slow down a little. But because of the weight of the wheel, it doesn’t slow down very much. Now, the weight of the wheel is contributed by all the power generators on the system. So these huge coal plants and gas plants and hydro plants, they all contribute to the weight of this spinning wheel. Whereas a wind farm typically hasn’t in the past. And the concern is that as more coal power stations go offline, and gas turbines aren’t running, that wind will make up the difference, but it’s not contributing to inertia. So we have a very lightweight wheel spinning instead of a heavy one.

So the question is, why don’t wind turbine owners provide inertia? So AEMO found that there is no requirement for wind farm operators right now to provide any response. And they are free to take part in a frequency control market, but most choose not to. So only sees that this probably won’t change in the future.

But can wind provide inertia? Well, it has, and I found that, yes, they can, in certain circumstances, they can provide some inertia, either by the actual technical capabilities of the turbine itself. Certain turbines, the way the setup can draw some inertia from those 2 bones. I do provide a small amount. Or something called like a synthetic inertia, which is where the wind turbine doesn’t run at full rated capacity. So, say the wind’s blowing very strongly, they won’t take advantage of the entire wind. In fact, they’ll back themselves off a little bit, and that way, if something was to happen on the power system, such that they were required to supply some inosia, then they could dip their blades into the wind and draw up a little bit more power. And provide that as an inertial response, like a synthetic and no short response. And of course, that requires that a wind farm operator run less than their rate of capacity and miss out on some revenue because of that.

And the rest of the world, I had a look at how they are sort of treating the problem of providing inertia. There are some loose requirements, but there really isn’t anything set in stone right now. The Nordic grid has a requirement that it’d be possible for a turbine to control active power, to control power system frequency, and Quebec has a requirement for them to contribute to large frequency disturbance is greater than a 0.5 hertz, for about 10 seconds of, so over the short time frame there. There aren’t any hard tangible requirements on wind farm operators yet across the world. And AEMO hasn’t suggested that they’ll bring that in either. Just in this 1st report, all they’ve done is had a look at how turbines have grown and how they will grow until 2020, and how inertia sort of fits into that. Is it possible for a wind farm to provide inertia, under what circumstances will it provide that measure?

So that’s it. The next report’s coming out at the end of July, and so we’ll look forward to seeing that one as the next step in their studies into wind integration in Australia, getting ready for the large amount that should be installed by 2020. So if you have any thoughts on wind daybones, providing nature, I’d love you to sort of left a comment on the block and I’ll go through maybe the next week’s podcast. Until then, keep buying those green electrons.