Generation and Loads

Renewable Portfolio Standards

Avista maintains a diversified portfolio of generation. The company must comply with renewable portfolio standards detailed in Washington’s Energy Independence Act and must use eligible renewable resources, renewable energy credits (RECs) or a combination of both to meet the following annual targets: 3 percent of energy used to meet customer demand by Jan. 1, 2012, 9 percent by Jan. 1, 2016, and 15 percent by Jan. 1, 2020.

To meet the 2012 targets, Avista has added qualifying renewable generation capacity with upgrades at its hydroelectric projects and purchased RECs.

2011 Generation Resource Mix
Hydroelectric   50%
Company-owned hydro 42%  
Long-term contracts 8%  
Natural gas   35%
Coal   10%
Biomass   2%
Wind contract   2%
Other contracts   1%

Installed capacity, generation capability

Net Energy Output by primary energy source

Project Name Present generation capability (MW) Nameplate rating (installed capacity) (MW) Net energy output (MWh) Primary energy source Regulatory regime*
Upper Falls 10.2 10.0 71,000 Hydro WUTC and IPUC
Monroe Street 15.0 14.8 106,000 Hydro WUTC and IPUC
Nine Mile 17.6 26.4 101,000 Hydro WUTC and IPUC
Post Falls 18.0 14.8 90,000 Hydro WUTC and IPUC
Little Falls 34.6 32.0 201,000 Hydro WUTC and IPUC
Long Lake 87.0 70.0 480,000 Hydro WUTC and IPUC
Cabinet Gorge 254.6 265.0 942,000 Hydro WUTC and IPUC
Noxon Rapids** 562.4 480.6 1,503,000 Hydro WUTC and IPUC
Total hydro 999.4 913.6 3,494,000    
Kettle Falls GS 50.0 50.7 312,000 Biomass (Wood Waste) WUTC and IPUC
Kettle Falls CT 6.9 7.2 3,500 Natural Gas WUTC and IPUC
Boulder Park 24.0 24.6 11,000 Natural Gas WUTC and IPUC
Coyote Springs 2 278.3 287.0 1,677,000 Natural Gas WUTC and IPUC
Northeast CT 56.3 61.8 12,000 w/Rathdrum Natural Gas WUTC and IPUC
Rathdrum CT 149.0 166.5   Natural Gas WUTC and IPUC
Colstrip Units 3 & 4 222.0 233.4 1,749,000 Coal (Mine Mouth) WUTC and IPUC
Total thermal 786.5 831.2 3,764,500    
Total generation properties 1776.4 1,744.8      
* Even though projects are located in Idaho and Washington, neither the IPUC nor the WUTC exercises exclusive jurisdiction since none of our company-owned generation assets are currently assigned to a specific state where they are located. Generation assets are split with about 65 percent being attributed to Washington and about 35 percent to Idaho.
** Unit upgrades at our Noxon Rapids Hydroelectric plant contributed to an incremental increase in generation capability at the plant in 2010.

Average generation efficiency of thermal plants by energy source

Thermal generation is approximately 44 percent of Avista’s total generation capability. Each facility has a specific purpose in Avista’s diversified generation portfolio—whether it is for economic or load demand efficiencies.

Plant name Energy source Heat rate (Btu/kWh)
Boulder Park Natural Gas 9,025
Colstrip Coal 11,950
Coyote Springs 2 Natural Gas 6,827
Kettle Falls Biomass 13,500
Kettle Falls CT Natural Gas 8,750
Northeast Natural Gas 12,825
Rathdrum Natural Gas 11,950
Average plant availability factor by energy source
Boulder Park* Natural Gas 95.3%
Colstrip Coal 96.2%
Coyote Springs 2 Natural Gas 94.1%
Kettle Falls Biomass 97.3%
Kettle Falls CT Natural Gas 100%
Hydroelectric facilities Hydro 91.9%
Rathdrum* Natural Gas 98.4%
Northeast CT* Natural Gas 78.2%
* Peaker unit—used only in times of significant energy demand
Total water discharge by quality and destination—thermal generation
  Annual water use
Coyote Springs 2-Natural Gas
Combustion turbine (CT) make up—For cooling; it replenishes the evaporation and blow down in the cooling tower. 398 million gallons
Evaporation pond—This is the site storm water drainage off of the pavement and outside areas. The water is only pumped off site if there is more water in the flow than can be evaporated. It dries up in the summer. 250,000 gallons
CT Blow down—This is to remove the concentrated solids that result from the evaporation rate in the CT. 87 million gallons
Waste—This is the water that is collected from the drains inside of the plant buildings and includes the water going through the sample panels and various small bleeds for coolers, air compressor, accumulator blow down, loop seal overflow, along with any leaks we might have in valves or seals. 92 million gallons
Boiler make up—This is water that is made for the steam turbine use. 3.9 million gallons
Kettle Falls-Biomass
Discharge Water 34 million gallons
Make-up Water 198 million gallons
Waste water, storm water Zero discharge plant. All water is captured and stored in facility storage ponds.
Waste Water Discharge—by National Pollution Discharge Elimination System (NPDES) permits
Cabinet Gorge hydroelectric development 50,000 gallons
Spokane service center 250 million gallons

Length of above and underground transmission by voltage


  • 18,200 miles of distribution lines
  • 685 miles of 230 kV transmission lines
  • 1,535 miles of 115 kV transmission lines
  • 500 miles of 500 kV transmission lines (11% ownership in Colstrip to Townsend, MT line)

Natural Gas

Avista owns 7,650 miles of natural gas distribution lines. The company does not own any interstate gas transportation pipelines, only contractual rights, and receives gas at over 60 points along interstate pipelines (over 40 points in the North Division and over 20 points in the South Division).

2010 Electric and Natural Gas Loads
Electric average hourly load (aMW) 1,075
Peak electric native load (aMW)  
Summer (retail) 1,556
Winter (retail) 1,704
Peak natural gas day demand (Dth) 272,517

Environmental fines and sanctions

The Environmental Protection Agency (EPA) and Avista entered into a Consent Agreement on Feb. 17, 2010 as a result of an accidental oil discharge into water at Avista’s Noxon Rapids Hydroelectric Dam in Montana in 2009. The terms of the agreement were as follows:

  • Avista agreed to pay a civil penalty in the amount of $7,500.
  • Avista agreed to undertake a Supplement Environmental Project (SEP) in the purchase of a spill response trailer for the responders in the lower Clark Fork watershed, which is now accessible to the Local Emergency Planning Committees (LEPC). Avista has provided a secure, year-round accessible location for the trailer.
  • By making available emergency oil response equipment to responders in the lower Clark Fork watershed, this SEP advances the objective of the Oil Pollution Act by minimizing the impact of oil and hazardous substances spill into the Clark Fork River.
  • The consent agreement requires Avista to state when making reference to the SEP: “This project was undertaken as part of settlement of an enforcement action.”

Avista purchased and delivered the spill trailer and all spill materials to the Clark Fork HED on Sept. 6, 2010. The total cost was $29,386. Avista submitted the Completion Report to EPA on Sept. 28, 2010 to fulfill the terms of the Consent Agreement.