Wind capture and storage

Hi there, I’m Jervis Whitley. Today is Friday, August 16th, and you’re listening to WindFront. The weekly roundup of the wind industry from Australia and around the world. Today I’m going to talk about a science fact. Wind capture and storage is here. And our roundup, the weekly top 3 earners in wind.

First, I’ll talk about the Notrees wind farm storage unit. Now built into the remote Notrees wind farm site in Winkler County, West Texas, is a quiet revolution in wind. But no, it isn’t the wind farm itself that is breaking new ground. The Department of Energy and Duke Energy teamed up to pay equal parts, $22 million to Xtreme Power, to build a 36 megawatt battery storage installation. The battery, which is huge, has a storage capacity of 24 megawatt hours, or 40 minutes at full wind. And the project purpose was to serve as a model for other entities to adapt and replicate. And the tech is a lead acid battery, and it went into service in January of this year. In the report, Duke Energy listed the benefits as being congestion reduction, energy dispatch optimisation, lower energy costs, grid reliability improvements, carbon emissions lower, and furthering the knowledge of wind energy.

Now, ERCOT, who is the ISO in that region, has reported that there were some challenges fitting this new technology type into the existing market. And the dual nature of the generation and load caused problems with their systems for settlement and market operation processes. But in an interesting twist, the batteries aren’t being used to store power at all. At least not in the capacity that I would have imagined. You see, when I hear wind battery tech, my mind immediately considers energy arbitrage between low and high priced periods, of which there are plenty in Texas, but in a press release, the Department of Energy states that since February, the battery has been providing fast responding regulation service to the grid. Dispatch dispatches power in one minute intervals up to a burst of 3 minutes in a row. Now, originally ERCOT envisaged only using 25 to 30% of the power before requiring a recharge. But in practice, it’s actually pulled up to 90% of the power at times, which shows they have a great confidence in the technology.

Now with the success of this plant, there are more storage devices planned for Texas, including some as large as 290 megawatts. Although those use a more lossy compressed air energy storage, or CAES, technology with a round-trip efficiency of below 30%, and essentially what they do is they pump compressed air down into some caves underneath the ground, losing some of the heat from the air in the process, because as you compress air, the temperature will rise. But if you lose that heat, when you go to draw the compressed air back out of those caves, it will need to be reheated again before it could be passed through the turbines to generate electricity. That act of reheating costs energy, lowering the overall efficiency.

Now, I looked at the power output for the battery technology. ERCOT has a system where prior output is released for 60 days prior, later than 60 days, I should say. So I was able to look at 2 months ago’s output for about a month’s worth of time, which is the amount they have perfectly available. I couldn’t see it regularly being used. In fact, I couldn’t really see it being used at all. So it really does look like they aren’t using it for energy arbitrage, and they are keeping it on standby for that fast responding regulation service to the grid.

Now let’s move on to the top wind farms of this week. Macarthur up at $1.6 million, Lake Bonney II, and Waubra behind again.

So that’s it for this week. Before I go, I’ll leave you with one final question. With Texas, they do have a large amount of wind, sometimes up to 9 or even over 9 gigawatts of wind produced at times. They’ve invested quite a lot in the network, moving from a zonal to a more nodal dispatch network, which is actually increase the efficiency of the way they’re running. They are significantly investing in this battery technology right across the state. Would we see similar benefits here if we were to install battery technology?

And two, I’ll see you next time. Keep buying those green electrons.