Pairing Solar with Linear Generators Yields a Revolutionary Energy Solution

A Novel Generation Technology

Cold storage warehousing is highly energy intensive, and for Lineage Logistics—the world’s largest temperature-controlled real-estate investment trust (REIT) and logistics solution provider—finding new and innovative technologies that could reshape its energy profile had long been an ambition. “We own and operate over 400 locations throughout the world,” Chris Thurston, director of Energy and Sustainability at Lineage, told POWER.

But while Lineage’s facilities are integral end-to-end logistical solutions, they represent a combined 2 billion cubic feet of capacity. Their consumption of power is a “big cost for us,” Thurston said, noting that most of the company’s facilities pull power from the grid. Meanwhile, Lineage has long been conscious of its carbon footprint. While the company in 2015 set out to reduce its energy intensity by 25% over 10 years, it met that target in just two years. In November 2021, the Novi, Michigan–headquartered company became a signatory to the corporate community–driven Climate Pledge, committing to achieve net-zero carbon emissions across its business operations by 2040. “And so, we had been on a journey to develop a self-sustaining warehouse where we could generate 100% of our power needs through clean technology,” Thurston said.

The company chose its Agua Mansa facility in Colton, California’s Inland Empire for the first-of-the-kind installation effort. According to Thurston, the site presented an ideal study. The warehouse, which serves as a cross-docking facility, is utilized to consolidate and redistribute shipments for a large grocery firm. It had the ideal square footage of roof space, and uniquely, “it doesn’t operate at our normal freezing temperatures,” he noted. “It’s closer to being a cooler at 30F, so using less energy per square foot overall. It was the perfect combination where we could solve for the 100% self-generation with a generator backup unit,” he said.

A Novel Generation Technology

Lineage tapped PowerFlex, a long-time distributed generation commercial solar partner, to install a 3.3-MW rooftop solar array on the warehouse comprising 8,426 individual solar panels (Figure 1). “Lineage and PowerFlex have formed a strong partnership over the past eight years, successfully developing more than 25 onsite solar PV projects across the U.S.,” PowerFlex Director Danny Ptak told POWER. However, Lineage also chose to pair the rooftop solar arrays with linear generators, a breakthrough new power generation technology launched in March 2021 by Mainspring Energy. Lineage estimated that while the 3.3-MW rooftop array could provide up to 73% of the facility’s needs, if two 230-kW Mainspring Energy Linear Generators were integrated onsite, they could firm the solar arrays for the additional 27% of the load, Thurston said.

While novel (see sidebar), linear generation technology was recommended by Lineage’s research team based in San Francisco. “We loved the technology because the emissions were just so low from natural gas generation, it was a unique unit, and it was already built out to support clean fuels in the future,” Thurston said. Linear generators were also “the only technology able to provide both dispatchability and fuel-flexibility for grid parallel operation and protection against long-duration grid outages,” he said. “I like to think of it as a better version of a battery.”


Here is how a linear generator works:


Closely held

20 watts