Utility-Scale Renewable Energy

NorthWestern Energy (NWE) is Bozeman’s electricity and natural gas provider. NWE owns and operates our electric and natural gas transmission systems, and provides energy through a combination of utility-owned generation and energy purchased on the open market. The Bozeman Community Climate Action Plan estimates that the energy needs of commercial and residential buildings make up 72 percent of our greenhouse gas emissions, as of 2008.  These emissions were 57 percent from electricity and 43 percent from natural gas.  Energy provided by NWE comprises most of Bozeman’s CO₂e emissions. Bozeman’s largest individual consumer, Montana State University, has an aggressive Climate Action Plan of its own and has developed a plan to incorporate more renewable energy into their energy portfolio.

Natural gas is the primary heat source for most Bozeman residents and businesses.  Northwestern Energy purchases this energy in the form of a portfolio of fixed term contracts negotiated on the open market.  Natural gas is readily available, and prices are relatively low, so it is likely that natural gas will remain the number one source of space heating, water heating and cooking fuel in the near future.  Alternative forms of energy are more attractive to those without access to natural gas.  Natural gas is also an increasing source of electricity in Montana. Conservation is the best way to reduce household consumption of natural gas.

Power Lines in Montana

Power travels long distances from source to user on transmission lines.

Most of Bozeman’s building-related energy consumption and CO₂ emissions result from electricity for lighting, cooling, heating, and a myriad of electrical devices.  Where does this electricity come from? NorthWestern Energy owns 10 dams in Montana with a net nameplate capacity of 439 MW. These hydro assets make up 38% of their supply. NorthWestern Energy owns a 40 MW wind farm, Spion Kop, which contributes 2% of their supply. In addition, NorthWestern Energy owns a share of the Colstrip #4 coal fired power plant, which provides base load. The rest of the supply comes from a portfolio of contracts including wind, hydro, natural gas, thermal, and coal.

Electricity in Bozeman

If you are a NorthWestern Energy customer, the electricity powering your home or business is supplied from variety of sources:

  • Hydro – 39%
  • Wind  – 12%
  • Coal – approximately 36%
  • Thermal resources – approximately 12%
  • Natural gas – 1%
  • State-wide, Montana is an electric energy exporter, using only 58% of the energy produced in-state (2007).
  • Wind and natural gas are growing sources of electricity nationally and here in Montana.

Sources: NW Energy, DEQ & DOE Montana

Wind-Renewable Energy

Wind turbines at Judith Gap have a 135 Megawatt capacity. Photo: Northern Plains Resource Council

The Montana Public Service Commission has a Renewable Energy Portfolio Standard that requires NorthWestern Energy to provide 15 percent of our electric supply from renewable sources. Most of this energy comes from wind sources, which are not included in NorthWestern Energy’s base load capacity due to their intermittent supply.  Small-scale hydro-electric generation also comprises a small portion of the renewable portfolio.  This renewable energy supply also includes “Renewable Energy Credits” purchased by NorthWestern Energy.

NorthWestern Energy is actively pursuing conservation as a part of their long-term energy picture, as conserved energy is less expensive than construction of new sources. Think about it: building a new power plant is one expensive endeavor! This economic fact has the added benefit of reducing CO₂ emissions.


E+ Energy Efficiency Programs

Home Energy Audit: If you are a NorthWestern Energy customer, your home is eligible for a free energy audit. This audit includes an insulation evaluation, a blower door test to detect areas of air leakage, water heater temperature check, refrigerator temperature check, gas equipment safety check and energy usage survey. You may be eligible for free water  heater tank wrap, hot water pipe insulation, low-flow faucet aerators and showerheads, CFL bulbs, and air sealing materials, depending on the results of your audit. After the audit, you will receive a customized report on your home’s energy usage, recommendations for energy savings, and further information on rebates for installation of energy-efficient measures. The program is limited to houses five years and older, with no E+ Audit history. To see whether your house has already had an audit or to schedule one, call (800) 823-5995. E+Rebates: NorthWestern Energy offer rebates for installing a wide-variety of energy-efficiency measures for the home. The rebates cover everything from efficient furnaces to light bulbs, dehumidifiers to televisions, and boiler tune-up to new insulation for natural gas customers. For details, see the E+Energy website

Approaches to purchasing green power come in five main categories: renewable energy credits (RECs), on-site generation systems, third-party purchase agreements, and community renewable energy development, and community choice aggregation. The first two are active options in Bozeman. Renewable Energy Credits: NorthWestern Energy customers are able to purchase Renewable Energy Credits through the utility’s “E+ Green” program, which are tracked and sold separately from electricity. The funds generated are used in three ways: some money goes to the owner of the renewable energy project (e.g. a wind farm), another portion is invested in new renewable projects in the region, and the rest is used in outreach and education to build awareness and support for new renewable resources. NorthWestern buys RECs from the Bonneville Environmental Foundation. On-Site Generation Systems: Many Bozemanites and businesses have opted for distributed generation with on-site energy generation. In Bozeman, this often means solar photovoltaic panels. The City has several highly visible systems. If you’re considering a solar PV system, read these many success stories of citizens and businesses from throughout the state. See the ‘Small-Scale Renewable Energy’ section of this website for more relevant information on installing your own small-scale renewable system. Solar Power Purchase Agreements: Solar Power Purchase Agreements can be a solution to the high start-up costs associated with installing solar photovoltaic (PV) systems. Businesses or organizations with a large roof and favorable solar access might pursue a contract with a third-party developer who owns, operates, and maintains the PV system. Under this arrangement, host customers agree to site the system on their roof or property and purchase the system’s electric output from the solar developer. Host customers enjoy the benefit of receiving clean energy at a set rate, while the solar developer receives income generated from the sale of electricity to the host customer and potentially receives tax credits. Community Renewable Energy Development: Community Renewable Energy Development gives residents an opportunity to directly purchase a share of the production capacity from a local renewable energy project. Community solar is active in other states, notably Colorado and California, where community-owned solar farms are flourishing.  When considering how to shrink the carbon footprint of our growing community, directly purchasing alternative energy offers the unique promise of shrinking our carbon footprint while growing and creating local jobs in local installation and maintenance. Community Choice Aggregation: Community Choice Aggregation is a larger group power purchasing system which operates on the municipal scale and gives communities agency in choosing the mix of its power supply, while still relying on the utility company’s transmission and distribution system.  Typically the energy purchased is generated off-site and involves negotiating a community-wide purchasing contract.  Such purchasing systems are growing rapidly in California, Massachusetts, and Illinois. Community Choice Aggregation must be enabled by state legislation.


To educate yourself further on these topics, check out the following resources: