Sibanye-Stillwater Smelter Installs Montana's First Behind-the-Meter Industrial Scale Solar Array

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As of December 20, 2017, the Sibanye-Stillwater metallurgical complex in Columbus can now boast the first “behind-the-meter” industrial scale solar installation project in the state.

The 100 kW solar array was installed by OnSite Energy, based out of Bozeman. The project was completed in a short time-frame to accommodate the end of the fiscal year, and the OnSite crew of four pushed through an icy December to complete the installation process.

Many commercial and residential solar installations in Montana are net-metered, meaning when the panels are producing more energy than is being consumed on site, that excess energy is exported back to the electric grid for other customers to use. There is currently a 50 kW cap on net-metered systems for NorthWestern Energy customers. The Sibanye-Stillwater project is unique in that it is a “behind the meter” installation. This means the array was designed such that it will not export electricity back to the grid. Because of this, there is no need for a net metering agreement with the utility company, and the system capacity was able to be increased to better meet the financial investment goals of the project owner.

The energy requirements of the metallurgy equipment and offices of the Stillwater complex will be partially offset by the new solar installation, providing greater energy independence for the US and South African based company. An estimated 143,380 kWh will be produced by the solar array each year. According to the company, this is about the amount of energy needed to offset the usage of their main office building over the same time period. The project was paid for in part by a Universal Systems Benefit grant, which allots funds for entities to increase energy efficiency or install new renewable energy projects.

Installing solar panels at the Sibanye-Stillwater Smelter
Installing solar panels at the Sibanye-Stillwater Smelter

Orion Thornton of OnSite Energy says that this project will not be the last behind the meter project his team will be tasked with. Already OnSite has been contracted to install a similar single-meter, non-exporting, 216 kW solar array system for Montana State Universities’ new Norm Asbjornson Hall, which will house parts of the campuses’ engineering department, which will go online this summer. “Behind the meter systems, like the Sibanye Stillwater project, represent an emerging market within the solar industry,” Thornton says. “When combined with advanced energy storage technologies, industrial facilities will not only be able to offset a significant percentage of their energy usage with solar electricity, outside of any net metering limitations, they will also be able to reduce their peak demand from the utility grid, furthering the already favorable economic return of solar energy while adding value to the overall infrastructure of the electrical grid.”

With innovative designs like this, the solar industry is demonstrating why it is one of the fastest growing sectors in the country. “Solar energy is an unstoppable force,” says Thornton. “In 2016, solar represented 39% of all new electricity generating capacity development in the US. One way or another, solar energy has and will continue to play a major role in our energy future.”

Quick Stats

  • Capacity (kW): 100.8
  • Owner: Sibanye-Stillwater Mining Group
  • Location: Columbus, MT
  • Incentives: Universal Systems Benefits Grant
  • Installer: OnSite Energy
  • Equipment Used: 320 Canadian Solar 315 watt panels; 2 SMA 50 kW Core1 inverters; RBI Solar Ballasted Ground Mount