At the utility scale, Montana's legacy hydroelectric dams and wind farms form the foundation of the state's renewable energy generating mix. With ample natural resources, Montana is well-suited for utility scale renewable energy projects that can meet both in-state and export market demands. Most recently, utility scale solar development has arrived in Montana. In 2017 alone, Montana added 17 MW of utility scale solar through six different utility-scale solar projects.
Utility scale generation has several key differences from distributed generation (e.g. rooftop solar). The most obvious is size. The low-end of the utility scale generation scale is typically considered anywhere from 1-2 MW (1,000- 2,000 kW) up to 10 MW. For reference, a typical residential rooftop solar installation in Montana is about 5 kW. One of the largest wind farms in Montana is the Glacier Wind Project, which is made up of 140 individual turbines and has a total installed capacity of 210 MW. Another is the Judith Gap Wind Farm, which came online in 2016. It has a total installed capacity of 135 MW and was one of the first utility scale wind projects in Montana!
Renewable Portfolio Standards
The Office of Energy Efficiency and Renewable Energy (EERE) has resources on utility scale policies and programs. One key policy consideration for utility scale generation is the Renewable Portfolio Standard. According to EERE, "A renewable portfolio standard (RPS) is a regulatory method mandating utility companies operating within a certain jurisdiction to increase production of energy from renewable sources, such as wind, solar, biomass, and other alternatives to fossil and nuclear electric generation. This is also known as a renewable electricity standard."
Montana's RPS was signed into law in April of 2005, and required public utilities to obtain 15% of their retail electricity sales from eligible renewable energy resources by 2015, and maintain that 15% level for every year thereafter. Eligible resources include solar, wind, geothermal, certain projects biomass, certain hydro projects, certain hydrogen fuel cell projects, and certain battery storage projects. The NC Clean Energy Center has a good description of Montana's RPS.