All-of-the-above generation approach is the right choice for reliable, affordable power
Let’s travel back in time to the multiple choice quizzes we were all so fond of in school. Don’t worry, you won’t be graded.
When it comes to weather in Basin Electric’s service area, which of the following are common:
a. Bone-chilling temperatures
b. Hair-destroying winds
c. Sweltering summer days
d. All of the above
If you chose d, all of the above, you get a gold star. Now, what does this answer have in common with Basin Electric’s energy portfolio? The answer is that it, too, includes all-of-the above resources.
The power Basin Electric uses to serve its member load obligations comes from many different sources, including coal, renewables, natural gas, water (hydroelectricity), oil, and recovered energy. Basin Electric also purchases power from the market. Because this resource portfolio is so diverse, the co-op’s power supply is very reliable – if one source isn’t producing, there are other options available to fill in the gaps.
This winter was a prime example of why an all-of-the-above energy strategy is so important. In late January, a “polar vortex” brought high winds and sustained periods of sub-zero weather to much of the Midwest. During a time when Basin Electric and many of its members were experiencing an all-time high member demand, wind turbines were being shut off because extreme cold compromises the integrity of the wind towers.
“It comes down to the brittleness of the towers,” says John Jacobs, Basin Electric’s senior vice president of Operations. “A good analogy would be to compare the tower to a rubber hose. If it gets too hot, it’ll melt, and if it gets too cold, it’ll snap. Just like a hose, if it gets too cold (between -22 to -24 degrees Farenheit, depending on the manufacturer) the integrity of the tower is compromised, so the turbines have to be shut off. They also have to be shut off when winds are too high for the same reason.”
Each wind tower has its own separate weather station for accuracy, which measures the temperature at that exact spot – not a mile or more away at the local airport. “That’s why sometimes you’ll see one turbine running and the one right next to it isn’t,” Jacobs says.
During situations like this winter when it was too cold for the wind turbines to run, coal-based generation, natural gas, and purchased power make up the difference. See graphic on page 17 to see how Basin Electric’s member load was served during the polar vortex. “We had to really keep our eye on the ball for the entire months of January and February to make sure we had enough power to supply our members,” says Dave Raatz, senior vice president of Basin Electric’s Asset Management, Resource Planning, and Rates department. “People don’t realize what it takes to economically balance supply and demand during extreme events like this.”
Last winter was another example of the importance of a diverse energy portfolio. During an extreme cold snap in December 2017 and January 2018, the Northern Border Pipeline issued critical notices of a forced majeure, or unforeseen circumstances, as the result of equipment failure at the Glen Ullin and St. Anthony, North Dakota, compression stations. As a result, Basin Electric’s peaking stations to the south, Deer Creek Station and Groton Generation Station, were impacted with limited availability. During this event, purchased power and coal-based generation were again very important in maintaining the increased member load that is inevitable during exceptionally cold weather.
Winter isn’t the only time when diverse generation resources are important. In the spring and fall when wind is the most prevalent and member loads are typically lower, Basin Electric’s operations team takes this opportunity to perform scheduled maintenance outages on its coal-based facilities, which often worked hard during the winter months. While not all the coal-based facilities are down at the same time, if demand increases and additional power is needed, Basin Electric’s marketing team can either purchase power from the market or start up the gas peaking plants, which are able to come online in 10-15 minutes.
Next to winter, summer sees the highest use of electricity, because temperatures are high and members turn on their air conditioners to stay comfortable and their irrigation systems to support crop growth. For that reason, outages at Basin Electric’s coal plants are scheduled to be completed by the summer months, and again, coal provides 24/7 generation. Wind also provides energy, and gas and purchased power make up the difference.
In addition to the diverse mix of generation resources, the location of these resources is another important aspect of an all-of-the-above energy strategy. “Our coal-based facilities are built near mines, and they always have a coal pile next to the plants so supply is never interrupted. And, our gas plants are built either on the Northern Border Pipeline or in the Bakken, so the supply of natural gas is right there, as well,” says Tom Christensen, senior vice president of Basin Electric’s Transmission, Engineering, and Construction department. “Urban areas typically require significant amounts of natural gas for residential and commercial use in addition to power generation, which sometimes is an issue when weather gets really cold, so having gas plants built right on top of the supply is a good thing.”
Transmission is an essential piece of the puzzle
Being a member of regional transmission organizations Southwest Power Pool (SPP) and MISO also allows Basin Electric to purchase power from other members in different regions. The 2,500 miles of extensive transmission infrastructure that has been built over the years makes this possible. “You can have all the generation in the world, but without the transmission to get it from point A to point B, it’s not going to get from the plant to the member at the end of the line where it is needed,” Christensen says. “We have strategically placed Transmission System Maintenance shops with the staff and equipment necessary to react to transmission issues as soon as they arise.”
Power from the market
Another benefit of membership in SPP and MISO is that there are times when power is cheaper on the market than what it costs to dispatch our coal and gas units. “However, it’s important to remember that the market is very volatile, and while it may be cheaper to purchase power off the market now, that won’t always be the case,” Raatz says. “The best way for us to keep our rates as low as possible is to rely on both our owned resources, which are the backbone of our system, and power from the market. Stability comes with our resource base.”
Load management connects the dots
With the numerous generation facilities, the different weather and maintenance scenarios, and different needs during different seasons, how does Basin Electric know what to produce, when to produce, and what to buy?
“Load management is an essential tool that supports our all-of-the-above strategy,” Raatz says. “The generation resources can’t just produce the same amount of energy flat across the clock. We have to match what is needed with what we produce and purchase.”
Basin Electric’s load forecasts are planned well in advance of when the needs actually happen. The resource planning team plans for normal weather conditions for each season, while taking into consideration plant outages and other factors, then works with Basin Electric’s marketing team to help fill in the gaps, whether that means dispatching the co-op’s gas plants, buying power from the market, or selling excess power it is not using on the market.
Most people don’t realize what it takes to maintain reliability on the power grid. They just want the lights to come on when they flip the switch, or their cell phone to charge when they plug it in. “Most people take electricity for granted, which really is a good thing, because it means we’re doing our job,” Raatz says. “An all-of-the above approach provides the redundancies necessary to make sure our members have the reliability they need at the lowest possible cost.”