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Improving Wind Farm Efficiency

Optimizing wind turbine efficiency can save millions and reduce reliance on fossil fuels. University of Illinois doctoral student, Lucas Buccafusca, is helping make it happen.

FALL 2020

“On a gusty October day, I found myself staring at my wind turbine simulation results. I take a sip of coffee and smile. The results validate a promising hypothesis.”

This quote out of an article by Lucas Buccafusca caught our eye and we wanted to learn more. What was he so pleased about? What was he working on? The following conversation is an excerpt from our podcast interview on Illinois Innovators.

 

Describe your background and how it led you to Grainger Engineering?

LUCAS – I completed my undergraduate degree at the University of Colorado in Boulder in electrical and computer engineering and I proceeded to look for graduate opportunities. Illinois had a spot open so I came here to do my Master’s in electrical engineering. I then transitioned from to my doctoral work in industrial and systems engineering.

Elaborate on how your field of study fits into ISE in Grainger Engineering?

LUCAS – Industrial engineers often get a reputation that their goal is to optimize everything. They try and find every possible situation that they can improve. I like to say that industrial engineers make good things great and great things perfect. Now, my background was in electrical and computer engineering so I was able to come in to the department with a slightly different education. I have a controls framework ideology so when I switched into industrial engineering, I was able to use a different lens to look through problems with this optimization framework.

It turns out that wind turbines and wind energy straddle the line where you can move between the two realizations and find improvements looking at the problem in two different ways. It’s kind of an odd thing to think about at first but it naturally fits into the sort of problems that industrial engineers like to want to solve.

Were you focused on something different before you physically saw the turbulence or was that more of an “ah-ha” moment for you?

LUCAS – For those that are not familiar with my article, my work was initiated when I drove up to Chicago to meet with my now fiancé. My GPS led me astray off the major highways and had me drive through a wind farm on a foggy day. I was able to visualize and actually see turbulence patterns as the wind was going through the wind turbines. I just started my early research into turbines and optimization so was still understanding the fundamental problems and the possible solutions.

When I actually saw the real-world visualization of how this turbulence field was generated, it was my “eureka” moment. I knew I could see the behavior and knew I could improve it. No one is thinking about this or if they are, they are throwing very complex algorithms that are not remotely solvable in real time. That moment definitely turned the light on for me.

How did you decide on your faculty advisor and how does that impact your work?

LUCAS – My advisor is Professor Carolyn Beck, in the Industrial & Systems Engineering Department. When I first started graduate school, my goal was to find an advisor both whose research area (distributed systems and control) and personality meshed well with my own. Another professor introduced me to her early in my Master’s program and we have been working together since. To say that Prof. Beck is fantastic, both in guiding research and mentoring throughout the Master’s/PhD process is an understatement.

My work with her is continuing by exploring research on wind turbine control in a couple of brand new areas. First, we have developed a multiobjective predictive control optimization model in which we can take into account possible future wind speeds and directions and balance that with power demands and wake loads. Second, I am in the process of writing a paper on a distributed storage method for turbines. Instead of one large battery that all turbines feed into, it would have a subset of smaller batteries, each at the local turbine level.

Explain why it is important to increase wind farm efficiency without modifying turbine design?

LUCAS – One of the big advantages is if you’re able to optimize a wind turbine without having to change the 50-meter-long blades, you can implement these algorithms, these techniques on existing systems. So you can program through a computer to tell the underlying architecture to have the turbines spin at a different operating torc and thus you can implement these techniques, these ideas without having to pay the thousands or low millions amount that it would take. The infrastructure is already there, let’s make the most out of it.

By increasing the efficiency, have you found if it can be done quickly and at a cost that’s reasonable?

LUCAS – So surprisingly or not surprisingly enough, private industries already do these techniques. They’re already starting to implement the sort of underlying ideology because it turns out that a single wind farm in the middle of an open field, this is very easy to implement. You set it up, you point it at the wind, if it’s windy, great you have energy. Once you start having multiple turbines, these tend to interact with each other. Quite quickly they realized in the private industry, in addition to academia, that, “Hey, you can do somewhere between four and six percent better just by taking this into account.” So, if you’re talking four to six percent of a multimillion dollar industry, they’re throwing money at the problem to solve it. These techniques are already being implemented.

Elaborate more on how the turbines affecting the output of each other.

LUCAS – The tragedy of the commons is a socioeconomic phenomenon. Let’s say you and I are both farmers here in Illinois, right? If we equally shared the land or some grazing land, we’d be able to each benefit from this additional resource. But suppose I, being a self-interested farmer, says, “Well, I’m going to graze beyond my allocation.” What will end up happening is you’ll still graze your allocation but the underlying resource will eventually be destroyed. That’s the same sort of behavior that’s going on with wind turbines in which as wind passes through the front-most turbine, it creates this turbulence field. This turbulence field leads to a lower average wind velocity which is directly correlated with the amount of power a turbine can extract. The front-most turbine, acting completely in its own self-interest, will actually lessen the available power for the entire rest of the farm.

My goal is to get these wind turbines to work together as a collective under the knowledge that the turbines in front do affect those downstream so let’s have them spin a little bit slower. They themselves will lose a little bit but the entire farm as a whole gets the reward.

Can the speed be changed in real time then according to what’s happening?

LUCAS – Right now there are two main techniques. There’s a lot of wind estimation so you can sample what the wind is going to be like at any given possible location of a wind farm over a period of a year or longer. This has already been done in a variety of locations.

You know the general direction that the wind if going to come from with high probability. You already know the baseline of what’s going to happen. Yes, there will be some changes in the wind and how you take that into account is where you can get these additional small percentages.

Can your efficiency model be implemented in current wind farms?

LUCAS – Yes. The theoretical maximum that exists for wind turbines is if you imagine just a big disc. As if wind went through the disc, the change in velocity is how much energy you pulled out, it’s the kinetic energy of the wind. It’s all about getting as close to that theoretical maximum as possible. You lose energy due to friction, due to noise, due to just the underlying system and so it turns out that you can’t actually control those challenges without new turbines. Other than that, your goal is to maximize the incoming wind velocity for the system as a whole. That can be done just by implementing smarter techniques. Right now, new wind farms are being designed with this in mind.

How can increasing the efficiency of wind energy positively affect the climate crisis we are in?

LUCAS – Wind energy as a whole is very cost effective and clean. We don’t get carbon emissions from wind energy. The thing is once you set up a wind turbine, the wind is there. You can make the most out of it and so the more energy you are able to get per square acre or per acre you can start to make it more and more cost efficient. It becomes more and more integral into our society without having to worry too much about cost, which was the guiding factor for a while.

Now that factor is being reduced?

LUCAS – We have companies that are blossoming all across the United States, China, and Europe that are all rapidly expanding their wind energy output. Some people say that wind energy could satisfy as much as a third of the U.S. electricity needs by 2050. That’s how big the field is. So every little improvement you can make, it can be worth millions of dollars.

With every pro comes a con. Do windmills adversely affect people?

LUCAS – There is this underlying stigma about life with wind turbines. I’m sure you know of the placebo effect where you go to a doctor and you’re doing a test study, they’ll give you a drug, a sugar pill that does nothing, and yet you’ll feel your symptoms get better. That belief that something is helpful causes it to be helpful–just that belief.

The nocebo effect is the other side of the coin where a harmless thing causes harm because you believe it is harmful. So, one of the big things that hovers on the horizon of wind turbines is something called the wind farm syndrome where people believe that wind farms get them sick and then they get sick. The nocebo effect is unusual because the symptoms are all real. You believe you will get sick and you will get sick. And so often, what this is caused by is someone feels ill and a local news story advertises it on the news. People see that story and believe it since it’s on the news and then they will get sick. The propagation of information leads to people getting sick.

“My work is mostly to try and identify what could be underlying things to improve in the real world.”

However, all blind studies and all analysis of wind turbines say they’re not caused by the turbines themselves. It’s just the belief that people will get sick leads to people getting sick. One of my favorite quotes that I’ve come across in my research is from a 2009 study from Canada that said, ”Annoyance in wind turbines is not a disease.”

his is not to say that wind turbines don’t have downsides. As you said, for every pro there is a con. Older turbines are actually noisy and can get irritating. Newer turbines have rapidly improved this because noise is a direct correlation to energy loss, therefore, that needed improved. However, the negative effects are more with the underlying environment. They do lead to, specifically for birds and bats, some level of difficulty. Bats in particular like to build their nests around the tallest object in the area and these wind turbines are 100 meters tall, they’re huge. You can stretch your arms across the base and not even go across it. These things are enormous and bats find themselves flying to close and unfortunately the change in pressure from the wind turbines tends to harm them. It’s a noticeable effect but it is not extreme.

What does the future look like in this field?

LUCAS – China is already throwing billions and billions of dollars into their clean energy program. It’s fundamentally going to be one of the pillars to transition us into a green world. If anywhere between 20 and 35 percent of the world transitioned to wind energy, we’d be self-sustaining in this century.

What other innovations to wind energy do you think would be helpful?

LUCAS – One of the things I’ve found fascinating across my research is how diverse the research is on wind turbine design. There exists the traditional large white windmills in a field. There are also these vertical blade turbines that spin and look like enlarged childrens’ toys. And the most fascinating innovation I’ve ever seen was in Taiwan where they built five- to six-foot-tall versions of these and put them between the highways. Cars driving past spin these turbines and the process of cars going by leads to energy coming out.

How does your work in turbine optimization fit in with the larger wind energy community?

LUCAS – The field is rich with people and with connections. My work is mostly to try and identify what could be underlying things to improve in the real world. Often times, there are problems you don’t see coming so one aspect of my research that I personally don’t spend a lot of time on is actual turbine placement. The reason for this is, it turns out under the presence of no external factors, the best way to configure turbines is to put them in a big grid. You know roughly where the wind is coming from and you put it in a grid. What often ends up happening is that other factors play a role.

For example, a company I spoke to was putting in a turbine farm. However, there was a little river that ran through a little corner of the proposed area. There was an endangered species of newt there and so they had to completely scrap that entire design and come up with a new one. There exists pretty straight forward algorithms to optimize placement but there’s all these little things that tend to come up. I work on the theoretical side to help build a baseline for those actions that work in the industry.

Are there policy changes that can help increase wind energy efficiency and energy sustainability?

LUCAS – The private sector already knows what’s up. They see, much like with self-driving cars or with solar energy, that there’s a lot of money to be made. They’re investing money to make these things more efficient. In terms of policy changes, it’s more of generating a social change than it is a political change. The wind turbines can look big and thick and scary. Some people say that they’re tacky and ruin the natural environment but it’s all about getting us to a point socially where you can see the advantages of it. There are some things that need to be done in terms of modernizing the power grid, of being able to incorporate it.

Ultimately, the big, scary demon on the horizon is getting off of fossil fuels. Being able to handle that on the political side is not something I’m going to touch on here, but it’s definitely something that is key to maximizing at least the available energy that wind energy can provide.

What can other engineers do to help this field?

LUCAS – he most important thing is to take five minutes out of your day and actively go out and pursue information. There’s a lot out there and you should go out and do your own research from accredited sources. You can see how beneficial the energy can be and you can learn about the pros and cons yourself and build a rational informed decision. From there, if you’re interested in it, the best way is just to find someone in the industry and talk to them. You’ll find that people are fascinated and excited about the options and choices and everything going on regarding sustainable wind energy.

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