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 which it purchases primarily on the open market, through a portfolio of contracts with energy producers.

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 at historic lows in 2012, 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?

NWE owns a share of the Colstrip #4 coal fired power plant (operated by PPL Montana, Montana’s largest electricity producer), which provides 26 percent of NWE’s base supply.  The rest of the supply comes from a portfolio of contracts which varies from year to year.  PPL, which also produces power in other states, gets most of its renewable power from 11 hydro-electric dam facilities in Montana, with the remainder of their supply resources from coal.

Electricity in Bozeman

If you are a NorthWestern Energy customer, the energy powering your home comes from a variety of sources:

  • Coal provided roughly 78% of NorthWestern’s electric supply in Montana (50% nationally) and natural gas contributed 2.4% of our electric supply in 2011.
  • Hydro-power provided 6 to 9% of our electricity in 2011 (6% nationally). In 1960, 97% of Montana’s electricity was from hydro sources.
  • Wind contributed 10 to 13% in 2011, with another 60 MW ready to come online by 2013.
  • 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 there is huge potential for wind energy development.

Sources: NW Energy Portfolio Report 2011, 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 by 2015.  The supply was 10 percent renewable in 2011.  Most of this energy comes from wind sources, which are not included in the NWE base 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 NWE.


NWE 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.

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 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; the last three hold interesting potential.

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. A REC costs $2 per 100 kWh. 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; in 2011, the RECs for NorthWestern came from Condon Wind in Oregon, a 49.8 MW project located on private land also used for wheat and barley farming and cattle grazing. Bozeman does not currently have a method of directly purchasing renewable energy supplies from our utility, just the option of these credits.

On-Site Generation Systems:
Many Bozemanites and businesses have opted to become their own mini-power plants with on-site energy generation. In Bozeman, this almost always means solar photovoltaic panels. The City has several highly visible systems. If you’re considering a solar PV system, make sure to view the live monitoring displays for the City of Bozeman’s two solar photovoltaics systems at the Bozeman Public Library and Bozeman City Hall, and 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, but there is potential for such a program to exist in Montana.


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