Success is up in the air
Many people are somewhat "in the dark" about how wind can be converted into something that can power the electrical appliances in your home or office. Basin Electric's Jeremy Woeste answers questions.
Basin Electric Power Cooperative
- April 11, 2010
Originally published by the Minot Daily News
Reported by Dave Caldwell
The current push for "green" sources of energy has elevated wind power to the status of darling among those espousing renewable assets.
With the recent completion of a new, 77-tower, 115-megawatt wind farm just south of Minot, Basin Electric has moved well past 300 megawatts of power from renewable energy sources, with designs on nearly doubling that in the near future.
Wind energy has been around for well in excess of 2,000 years, with some sources tracing windmills back to China circa 200 B.C. Sailors were using wind energy to propel boats as early history was beginning to be recorded.
Even so, many people are somewhat "in the dark" about just how a breeze can be converted into something that can power the electrical appliances in your home or office.
In an effort to spread the word on the benefits of green energy technologies, Jeremy Woeste, alternative technologies coordinator at Basin Electric in Bismarck, spoke to Kiwanis Club members March 9 in Minot.
Basin Electric has 135 members in a nine-state territory, serving 2.8 million consumers. Locally, Verendrye Electric is a member-owner of Basin Electric.
Woeste started off with the basics.
"Why did we get involved in wind? Because all nine of the states that we service fall within the top 12 in wind energy potential," Woeste said. "We have a definite strong wind resource in this region."
While wind promises to be a resource that will never go away, the actual science of distributing the energy it creates is still being developed.
Form and function
"All the wind really does for us today is reduce the amount of fossil fuels that we need to use when we're producing power from wind," Woeste said. "We still have other costs that remain in place. (The cost of) over half the power supplied to your homes and businesses is from the wires, not from the fuel sources at all.
"Basin Electric's current green portfolio consists of 352 megawatts of wind as well as 44 megawatts from waste heat. (The source of the wasted heat is) a gas pipeline that runs from Canada into the Chicago area.
"There are stations along that line that emit about 900 degrees worth of exhaust. We capture that exhaust and power turbines with that to save 5.5 megawatts of power from each facility. In the end, about 200 degrees of that exhaust goes into the atmosphere, versus the 900 that we started with."
Projects aplenty
Woeste said that Basin's green projects are certainly not limited to Minot, rather they are spread out across a wide area.
"We have some additional projects being built in South Dakota and in Iowa, and now we have a new wind project we're building in South Dakota as well," he said. "All told, it will bring us to over 650 megawatts worth of large-scale, renewable energy.
"Basin also has power, of course, from coal and natural gas and other resources like that," he added.
"But what's driving us to move further and further into the wind area? Evolving public policies, carbon dioxide restraints, federal legislation, state legislation. (They) are limiting the amount of carbon dioxide that can be emitted by a power facility.
"Also renewable portfolio standards, or renewable energy standards, (are factors). Those basically are standards that state by a certain year, a certain amount of all your power generated or consumed has to come from green, or clean, resources."
Woeste referred to a map projected on a screen showing the various standards that states have enacted. North Dakota and South Dakota have set renewable "goals" of 10 percent by the year 2015, while Montana and Minnesota have officially enacted standards. Minnesota's legislated standard is 25 percent by 2025, while Montana strives for 15 percent by 2015.
"The most common thing you'll hear is that 20 percent needs to come from renewable energy by 2020, or 25 percent by 2025," Woeste said to summarize the overall, nationwide picture.
Wind at the fore
Woeste said wind trails only natural gas in the number of new projects added to the power grid in recent years. The main advantage of natural gas, he said, is that it can be relied on as a constant source, whereas wind energy is dependent upon - obviously - wind.
"Wind made up over 40 percent of all new energy resources brought online in this country in 2009," Woeste said. "It was second to natural gas in both years, largely because natural gas can help offset the ups and downs from wind."
Woeste said there is a pecking order involved in utilizing these new sources of energy, a line to join the transmission grid referred to as a queue. That line is growing increasingly longer as new sources are brought on-line. In order to have a new facility ready to begin paying for itself once complete, the building company needs to have its ducks in a row well in advance.
"There are over 300,000 megawatts of potential projects in the U.S. transmission queue," he said. "The queues that are out there, basically you have to get in line for access to transmission, to get your power to market.
"Those queues can take anywhere from two years to maybe seven or eight years to get your name from the bottom of that list to the top of the list to actually build a project. So you need to be in line basically four or five years before you plan to actually build your project to actually have any chance of building it when you're ready."
Woeste said that although wind power installation has grown steadily through the past decade, there was hardly any power whatsoever put into service in 2000 and 2004, due to the production tax credit being allowed to expire in those years by the federal government.
Climbing investments
Woeste told the audience that like most everything, wind power installation costs are rising, having more than doubled in the past decade. Being in a more isolated area such as Minot, away from major interstate highway conduits, makes costs even higher, he said.
"The project costs continue to rise, maybe a little more leveling in 2010 due to the state of the country," he said. "In 2001 when we built the Minot project we were around $1 million to less than $1 million per megawatt.
"Today, per megawatt, we're at about $2.3 million. So you can see a 100-megawatt facility went from $100 million to $230 million over the course of six years. That's largely due to the lack of value in the dollar and the increase in construction costs as well.
"The interesting thing is, on our new project in South Dakota, that project is 30 turbines more than the project south of Minot, but it's going to cost us less to build from a construction standpoint. So competition has gotten a lot greater because there are less projects out there to actually be built.
"Our 700 resources, you can see on the map there, 352 megawatts to our service territory.
How much power?
Woeste explained just how much electricity is generated by Basin's wind project.
"How much power is that? If (the turbines) were all producing at 100 percent, basically 26 mph and above, that would be enough power for 305,000 homes," he said. "However, they produce on average about 39 percent in this region. So we have the average over the course of the year for about 120,000 different homes.
"Of course if there is no wind blowing, we don't have any power. Like I said, at 26 mph we reach 100 percent production."
The basics on PrairieWinds 1
Woeste showed a graphic explaining the various parts of a wind turbine while explaining basic operation to the audience.
"You have the blades in the front of course, connecting into the hub, which is the rotor," he said. "The main shaft (then) goes into a gearbox. The gearbox controls the speed at which the shaft turns from the gearbox into the actual generator. So it either ramps up the speed of that or decreases the speed."
"The project just south of Minot here consists of 77 turbines, known as Prairie Winds 1, the largest cooperative-owned wind project in the country," Woeste said. "We also added three turbines to the existing Minot 2 turbines that were there, which gave us Minot 2. So a total of 80 new turbines (were installed), all 1.5 megawatt machines built by General Electric Co."
"The first thing (in) actual construction is you have to have somewhat of a (ground) base before you put down your actual turbine base," he said. "It's basically a simple mud mat, basically just to give us a dry, level area to start working on.
"Then we have rebar. Each of these towers has 2,400 feet of rebar, and they have 142 bolts that you see standing up here that will actually hold the turbine. They're about 7 O feet in length for each bolt."
Preparation continues with the tying together of all the rebar, before a boom truck actually pours the concrete.
"There is 318 cubic yards of concrete in each one of those, and what does that mean? It means 25 cement trucks worth of concrete for each one of those turbine bases."
Woeste explained different options for the bases, including a spread plate, which branches out like a tree root system, and a Patrick and Henderson, which is a straight-down boring system up to around 40 feet.
"This (spread plate) is about 10 feet deep when it's backfilled. So it's a really big difference in how you actually put the towers up."
Total height of the turbine is 262 feet to the center of the hub, he said.
Big tools, lots of wire
Woeste explained that due to the sheer size of a turbine, special machinery must be used in construction.
"Most of the cranes that come in cannot just be driven in, so they have to be shipped in on rail and trucks and things like that, then they have to be put together on site over two days," he said. "This crane is the largest mobile crane in the world. I believe there are five in the U.S., and we had two of them on-site during this project. They're used to top out each of the sections on each of the actual towers.
"We had a lot of weather issues. It was really wet at the start, so we had cranes that ended up getting stuck. You lose two or three days if you happen to get a crane stuck, and it happened twice.
"The blades are approximately 120 feet long. Each blade weighs about 14,000 pounds, and they do have curve to them."
In addition, extensive amounts of wires must be used to transport the electricity, composing an underground collector system. Woeste said 60 miles of wire were trenched at PrairieWinds 1, marked by red tape to warn anyone who might be digging in the area.
"So if you're out there digging and you hit that red, it would be a good idea to stop," he said with a chuckle. "It's not going to be a good day otherwise."
A transformer lies at the base of each turbine, which is essential for power to get into the main transmission system, he said, passing through an interconnect transformer substation.
"That actually converts the power into that grid," Woeste said. "This thing alone ships at almost 200,000 pounds, and after you put the oil in it it's about 212,000 pounds, so it's a pretty significant item.
"The base pad for it has a basin around it, in case for some reason that transformer would become damaged and leak out the oil, we prevent any kind of environmental issues by capturing all our oil beneath that."
"The collector substation, this is where all the underground (wiring) from each turbine comes together, collects into this substation and then moves up into the main transmission grid, which was also on this project in the same site. We didn't have any distance to cover to get to the main transmission system.
"The first power base was put into place on Oct. 1 and the last section was completed on Dec. 30," Woeste said. "It took three months from the time we started putting in power bases in to get the project done.
Technological "guts"
Like most other things these days, Woeste said, the wind turbines are controlled by computers.
"In the middle, you have the computer components that actually control the turbines. Every turbine is self-controlled," he said. "They control the pitch of the blades, the direction where that turbine goes - everything is done self-sufficiently within the turbine."
Photographs of the huge tower parts being raised into place were shown.
"That first section is 126,000 pounds, so it might pinch a little bit (if your fingers get caught)," he laughed. "(A total of) 276,000 pounds is the entire tower, top to bottom. Just the tower section is about 14 feet wide at the base, and tapers to about eight feet wide at the top.
"(The blades are) all put together on the ground and lifted as one unit. People on the ground use ropes to help keep (the blades) from moving around, so of course obviously if it's a windy day, we don't lift anything.
"Basically, any days over 15 mph, we didn't have any sort of lifts like this going on."
An extra benefit
Basin is adding an extra perk to its towers, designed to aid its workforce in more ways than one.
"We're also putting service lifts in our towers, which is something that's different than what most of the industry has done," Woeste said. "(The trend is) starting to go that way, but in May, June and July of this year, the towers will have service lifts put in.
"They cost a fair amount of money, but the way that we've started to look at it is, it's going to allow us to keep our techs a lot longer, because when people are in their 30s and 40s, they kind of don't like climbing anymore," he said. "It's easy to find a 25-year-old that doesn't mind it. But we'll be able to keep our techs a lot longer, as well as basically stealing techs from other projects that don't have service lifts.
"At the end of the day, as well, if you've climbed four or five times and a turbine goes down, do you want to climb again? Probably not, but if you have a service lift, you might go up there and take care of it again at 5 o'clock."
The air up there
Woeste showed a picture taken from the top of an assembled turbine.
"I just want to point out those safety rails, those are for latching onto when you go and work on the hub of the turbine," he said. "People actually do slide over the front and go into the hub.
"The blades on these turbines actually pitch, so they'll actually turn basically flat to catch as much wind as possible, but they also turn out of the wind as well, they kind of reduce how much wind they catch. So of course there's motors in each of those areas (to rotate the blades), and they have to be serviced."
Building a wind farm isn't as simple as finding an open area and throwing turbines up, Woeste said.
"Some of the issues that we've dealt with in siting our projects (are) landowner concerns," he said. "(Issues like) making sure they can still use their property, not interfering with their business, landowners that might not be interested, and balancing the economics of our projects.
"We have a lot of things that we have to kind of watch out for. Stay 1,400 feet from residences, 400 feet from roads and section lines, and avoiding other utilities that are out there.
"Then there are shadow flicker issues as well. Shadow flicker is (caused by) anything that crosses the path of the sun creating a bit of a shadow as it goes by. (It's possible to) have those blades crossing through the path of the sun coming in through your front picture window.
"We deal with issues like that up front so they don't happen, or if we find out they will happen a couple hours per year, we'll deal with that landowner and help find a solution for that.
"We have other environmental issues, of course, cultural issues, Native American issues, things of that nature. We start out with a project, apply those exclusions, and we end up with a (much smaller) site."
Precision in placement
The exact location of each turbine is an important step in a project.
"It can get quite difficult to find a place to put 77 turbines in that area," Woeste said. "And then it's important to get them in the right area because for every small increase in wind speed, we get a large increase in production from our turbines.
"They start producing power at about 8 mph. At 13 mph they get about 250 kilowatts of energy."
At 26 mph, however, the output rockets to 1,475 kilowatts.
"We double the wind speed and we get six times the amount of power," Woeste said. "Projects in this region will probably average around the 15, 17, 18 mph range over the course of the year. So if you can take the project from 17 over to 18 mph, you get a significant jump in production from your project. We're talking about many millions of dollars over the course of the project. So getting them in the right spot is very critical.
Like they're not even there
Basin strives to leave minimal impact on the landowner, Woeste said.
"Roads are built pretty much flat for turbine access, so landowners can farm over the top of them, without having to lift implements and go around the actual turbines," he said. "(There is) only a 35-foot gravel base around each turbine as well."
Woeste stressed that although wind energy is a great source of renewable power, diversity is still very important.
"The reason I want to talk about this is some people have said, 'Well, you put in enough wind turbines throughout the country, we'll be able to get all of our power from wind, because if it's blowing here and not blowing somewhere else, that will just balance out,'" he said. "We did a study on this throughout our service territory, we added more projects to this, and what we've basically found is that at least throughout our region, that is not true.
"Basically if the wind is blowing in one of the states, it's blowing in the other states, and if not, it's not blowing in other states either."
Monsters with flaws
Towering more than 250 feet above the prairie, it's sometimes hard to think of wind turbines as being fragile. But they can be, Woeste said.
"Turbines shut down at 20 to 25 degrees below zero," he said. "That's to protect the internal workings of the turbine. They don't have any kind of heat in them, so it's just to protect them from damage.
"And then also at 104 degrees above zero, they'll shut down for the same purposes, to stop overheating issues as well.
"The issue that this causes for us is, on cold and hot days are the days when we need the most possible power for heating and cooling.
"Well, there's two things that are happening. If it's too hot or too cold they're shut down. At the same time, even if it's 100 degrees and they're not shut down, generally when it's hot and cold, there isn't wind either.
"So on the largest (demand days) of the year, we don't have any power from wind, or very little power.
"Lightning strikes are also very common but not an issue. They get hit on a fairly frequent basis. It might trip a breaker or something like that, but damage from (lightning) strikes is very rare."
At the wind's mercy
"Wind is a non-dispatchable fuel, meaning that we cannot call on it anytime that we want it, we're simply at the mercy of Mother Nature," Woeste said. "When the wind blows, we get power, and when it doesn't blow, we don't.
"So its value, as I said earlier, is based on fuel displacement. We can reduce the amount of fossil fuels that we use today by using wind. Wind will displace the system's highest-cost fuel.
"You're going to back down whatever facility costs the most to run when you get more power with the wind. The best facility to do that with is gas facilities, and like I mentioned, that's part of why gas is so popular now.
"Prices are fair to produce power from it, but also you can ramp up a gas facility and ramp it down, meaning you can get more power from it quickly or you can cut back how much power is coming out of it quite quickly.
"With a coal facility, you can't do that. It can take hours to actually reduce the amount of power coming from a facility, because once that turbine gets spinning, it's going to keep spinning for a while. Then to bring the heat level down, it's pretty difficult to do."
Woeste then presented a video of the last day of construction on the project, before taking questions from the audience.
Q & A
Woeste was asked about the life expectancy for a wind tower.
"It's not 100 percent known for sure because the projects just haven't been around long enough to have proof of this, but basically 20 years to 25 years," he said. "It's expected 25 years, but most of them are just kind of assumed that at the 25-year level, we'll probably have to go in and change out a lot of the components, and maybe take towers down completely because technology might have changed so much.
"Switching them out might be a matter of putting in a new foundation, or replacing heads and things like that. We don't know for sure.
"One of the largest major (current) issues with turbines is the actual gearboxes. In these turbines there are approximately 400 sensors, and every one of those sensors is looking for a reason to shut the turbine down, in order to protect what's in there.
"So they do, many times, shut down for false readings. It might be a faulty sensor, things like that. Most of that stuff is fixed very quickly, probably a half-hour to an hour.
"But one thing you have to remember as well with a wind project, let's say a 100-some megawatt wind project like we have south of town, is that if we take one natural gas facility we have one power-piece of equipment. Here, we basically have 80 power plants. So you're doing maintenance on 80 different facilities versus one with the same amount of power, so you're going to have more issues."
How many years is estimated for payoff?
"It really varies on your accelerated depreciation, and the tax credits and the amount of production that you can get from a facility, but probably somewhere in the seven- to 10- to 12-year range," he said. "It's pretty much assumed that within 10 years, you can probably get your money back.
"I think for this project, I think it will be shorter than that, because the production for this facility should exceed what we had planned for. Throughout most of the country, they see about a 25- to 28-percent production level from their wind. In this region, we planned at 39 percent, but we're expecting to see well past 40 percent.
One audience member told Woeste he had recently driven to Bismarck, and along the way he noticed a lot of the wind towers were not spinning.
"There's a lot of things, especially now, there are still little bugs that are being worked out," Woeste said. "There are still cabling issues that are being dealt with. I think there was a day last week, I don't know what day it was, but there was a day where something happened with the grid that actually knocked off part of the facility.
"But anytime you have a new project, you're going to have issues that you are going to have to work on.
"Another thing to keep in mind, too, is sometimes it's as simple as one part of the project is getting wind and the other part isn't. It's possible to have two turbines side-by-side, about 400 yards apart, one operating and one not, simply because of wind.
"You'll see that off and on with one of these kind of projects.
"Another thing is what's called the yaw in a turbine. The turbine head actually follows the wind. And as it spins, of course you have cabling that's connected. If it keeps spinning too long, you're going to snap off cables and have things twisted up. So it will spin a certain distance - I forget how far - but when it reaches the end of its yaw and it pulls the warning chain, the turbine will actually shut down on the spot, and the head will come back around to a safer area and start to follow the wind again.
"That probably takes about 20 minutes to a half-hour for a turbine to do that."
Do you always have a market for the power that's going out?
"Today we do," Woeste said. "Throughout this country as a whole, there's always a place for the power to go."
However, he said, it is not yet possible to store that power for usage at a later time.
"No, there's no way to store power today - not on a large scale."
So if you had them all running at once, would you have too much?
"You're going to back down on other facilities," he said. "Depending on what kind of transmission you have.
"If you have what's called firm transmission, then you can push power into the grid anytime you want, and you don't have really much of any issue. It will probably get sold somewhere.
"If you don't have firm transmission, the facilities that do have firm transmission get to fill up the actual grid first. If you don't have it, you might have to back down from the grid if it's actually full, or actually shut off."
How do landowners get paid?
"In general, most landowners are paid a lease based on the number of turbines on their property," Woeste said. "Generally some will be paid between $4,000 and $6,000 per year with an escalator in that, so it actually goes up through the years.
"There's two different ways that it can happen. One is it can be tied to the actual generation, which is a huge risk to the landowner because if there's no generation, there's no payment. The payoff might be if the facility does better than thought, you might get more money as well.
"But in most cases, it's a flat fee, it's a flat yearly payment regardless of what the project does."
What's the cost of generation from wind?
"The cost of generation from wind in general, without tax credits, is between 6 and 8 cents per kilowatt hour," Woeste said. "That's just for the generation, that's not for the wires and things like that. And then after we apply tax credits, and the sales of green tags and carbon offsets, things of that nature, we can get the price down to the 4 cent range, which is a lot closer to what current fossil fuels are.
"Those are still higher than what the older fossil fuel facilities were, being around 2 cents for the older facilities, but getting a little bit more competitive."
Do they shut down if the wind is too strong?
"Yes, they start generating at about 8 mph, at 26 mph or 27 mph they reach their rated capacity," Woeste said. "So they'll be at full production until about 56 mph, at which time they'll turn so they're not taking the wind and they'll actually stop producing.
"The reason for that is, the wind starts to be a lot more turbulent once you get up over those levels, so you're bringing a lot more risk of damage to the turbines, so they'll shut down to protect themselves."
Headquarters
1717 East Interstate Avenue
Bismarck, ND 58503-0564 USA
Phone: 701.223.0441
Basin Electric Power Cooperative will provide cost-effective wholesale energy along with products and services that support and unite rural America.
