A Refined Approach to Onsite Power Generation

The Pine Bend refinery in Minnesota added a 45-MW solar power array to support the facility’s supply of electricity, reaping the benefits of reduced costs, lower emissions, and more.

Owners of commercial and industrial facilities are always looking for ways to improve competitiveness. For many companies, that means installing technology to make their sites more energy-efficient.

The Pine Bend refinery in Rosemount, Minnesota, owned and operated by Kansas-based Flint Hills Resources (FHR), is considered among the most energy-efficient refineries in the U.S., thanks to innovation and modernization that supports the facility’s production of transportation fuels that are delivered throughout the Midwest. Pine Bend is partly energized by a 45-MW solar power plant, the largest of its kind at a U.S. refinery.

The solar photovoltaic (PV) plant has 120,000 panels covering about 200 acres of a 350-acre site adjacent to the refinery, which is located 17 miles southeast of Minneapolis. DEPCOM Power, headquartered in Scottsdale, Arizona, designed, procured, and built the $75 million PV plant in 2023, connecting the system directly to the refinery to lower energy costs, improve energy efficiency, and reduce emissions. The solar array has an estimated annual production capacity of about 92,000 MWh.

Officials say the project, which was commissioned in November of last year, is likely the largest “direct use of solar power” in the U.S., as it provides “roughly 30% of the refinery’s 135-MW power needs during optimal conditions.” The solar complex provides power during the day when energy costs are typically the most expensive.

“This is an extraordinary project and exciting opportunity to demonstrate how solar can be seamlessly integrated into a large industrial facility with a high, consistent power demand, reliably and at a lower cost than conventional, retail power,” said Justin Bloch, DEPCOM Power’s president of Solar. “You don’t often see utility-scale projects for a single facility and while this may be the first project of its kind at this scale, it won’t be the last. Distributed solar generation is proving to be a competitive and reliable source of power for many energy-intensive industries.”

The Flint Hills Resources Pine Bend refinery produces transportation fuels, including most of Minnesota’s gasoline, diesel fuel, and jet fuel, as well as other products such as propane and asphalt. The facility has a refining capacity of 375,000 barrels per day.

Pine Bend is a model example of an industrial facility innovating to improve its competitiveness while also improving its environmental performance, which is among the reasons it’s been chosen by POWER to receive its 2024 Commercial & Industrial Generation Award.

Solar and CHP Providing Power

Officials with Flint Hills and DEPCOM said the new solar installation (Figure 1) now serves as FHR Pine Bend’s second source of onsite power generation, after completion of the site’s combined heat and power (CHP) system in 2019. The CHP plant supplies the refinery with about 50 MW of electricity, or roughly 40% of the 135-MW load required to power daily operations. The solar and CHP systems combined meet about 70% of Flint Hills Resources’ power needs, “making the Pine Bend refinery one of America’s most energy-efficient fuel producers,” according to those familiar with the project.

1. The 45-MW solar power array at Flint Hills Resources’ Pine Bend site in Rosemount, Minnesota, covers about 200 acres of a 350-acre site adjacent to the refinery. The $75 million project features 120,000 solar panels. The solar plant provides about 30% of the refinery’s power needs during optimal conditions. Courtesy: Flint Hills Resources

“This is DEPCOM’s first significant ‘behind-the-meter’ project where we designed and built a large solar complex to power a single facility, in this case an oil refinery. And not just any oil refinery, but a refinery that is responsible for producing the vast majority of the fuels the people of Minnesota depend on every day, a place where reliability really matters,” said Darrell Birck, DEPCOM’s senior vice president of Operations. “We are seeing more of these types of projects being proposed across the U.S., but it’s thrilling to be able to say we were among the first to do anything like this at this scale. We are proving that solar is a reliable, cost-competitive, emission-free source of power.”

The CHP and solar power systems have helped Pine Bend improve its energy efficiency by 10% over the past five years, putting it into the top quartile of all U.S. refineries. The refinery has earned the U.S. Environmental Protection Agency’s ENERGY STAR certification for the past five years.

Construction of the project began in November 2022. The modules for the solar array were supplied by HT-SAAE, whose modules are known for their high power and high reliability. Inverters for the project came from Ingeteam, a Spanish group that works in 15 countries and has more than 80 years of experience in the electric power sector.

GameChange Solar, headquartered in Norwalk, Connecticut, provided the racking for the system. The company has sold more than 30 GW of its fixed-tilt racking and tracker equipment, and earlier this year announced an expansion of its U.S. manufacturing. The company has a network of more than 30 manufacturing locations across 16 states.

Reducing Emissions

“Pine Bend is already one of the most efficient refineries in the country, but we are always looking for ways to continuously transform our business,” said Jake Reint, Flint Hills’ vice president of public affairs. “As one of the largest-of-its-kind solar installations, this project is a bold and exciting opportunity to lower energy costs, improve our energy efficiency, and reduce emissions.”

The refinery since 2010 also has reduced its traditional criteria emissions by about 70%, and has reduced greenhouse gases about 10% relative to production. Other recent enhancements at the site include the addition of two modernized cooling towers, which reduce energy consumption, and leveraging ammonium thiosulfate technology, which creates fertilizer while producing ultra-low-sulfur gasoline to reduce vehicle emissions.

Pine Bend, with about 1,000 full-time workers, is one of the largest employers in Dakota County. Officials said the refinery directly and indirectly supports 3,400 jobs in Minnesota.

Habitat Management

“Continuous improvement is foundational to who we are as a company,” said Reint. “This project is a great example of how we constantly evolve and find better ways to produce fuels and other products people need and use every day.”

The Pine Bend PV system is considered the largest such installation for a single user in the U.S. Along with providing power for the refinery’s operations, it also supports the strategy of collocating generation at a large energy-consuming site. This helps avoid line loss, or electricity that would be lost as it is being delivered along the transmission system serving the complex.

“This largest-of-its kind solar installation is helping us improve our competitiveness by lowering our energy costs and improving our energy efficiency, making us one of the most energy-efficient refineries in the nation,” said Geoff Glasrud, vice president and manufacturing manager for Flint Hills Resources. “Solar also helps us further reduce emissions associated with producing the fuels and other essential products we make that people across the state and the Upper Midwest rely on every day. We’re proud to be the first refinery and largest manufacturing facility to utilize solar at this scale.”

“With this project we are improving our ability to provide the fuel people need in a way that will allow us to be more competitive today and well into the future,” said Jeff Ramsey, president and CEO of Flint Hills Resources. “Our refinery operations are among the best in the world, and we continue to innovate and find new and better ways to produce and deliver the fuel and other petroleum-derived products that remain essential to the economy and modern life.”

—Darrell Proctor is senior editor for POWER (@POWERmagazine).