The identification and analysis of new generating resources is a key step in developing a cost-effective, least-risk, adequate, and reliable strategy for the region. Generating resource technologies are defined and assessed based on their cost, operating and performance characteristics, and development potential in the region. Resources that are deemed proven and commercially available to meet future needs in the region are further developed into reference plants. Each reference plant has a designated plant size and configuration representative for the Pacific Northwest, with technical characteristics and performance parameters, cost estimates (capital, operating and maintenance, levelized), and other attributes such as estimated construction time and economic life. These reference plants become inputs to the Council’s Regional Portfolio Model (RPM) as options, along with energy efficiency and demand response, for selection to fulfill future resource needs.

For the 2021 Power Plan, utility-scale reference plants were developed for onshore wind, solar photovoltaics (PV), standalone battery storage, solar PV + battery storage, natural gas combined cycle turbine, natural gas peakers, pumped storage, and conventional geothermal. In addition, one emerging tech reference plant was developed as a proxy for the many promising new technologies (for example, offshore wind, small modular nuclear, and enhanced geothermal systems) that could provide value to the region in the future.

The costs of renewable resources – in particular utility-scale solar PV – have decreased significantly. According to the Lawrence Berkeley National Lab[1], over the past decade, the installed cost of solar has declined about 70% and the installed cost of wind has declined about 40%. Despite recent price fluctuations due to tariffs on imported materials and solar cells, the cost of solar PV is expected to further decrease in the future. While the cost of natural gas combined cycle plants has largely remained the same, the cost of a natural gas frame unit – operated in simple cycle mode as a gas peaker – has decreased due to lower equipment costs and greater competition among vendors to secure fewer project development contracts. The costs of conventional geothermal and pumped storage hydro resources are extremely site specific, and thus it can be difficult to see any major trends.

New Utility-scale Generating Resource Reference Plants: Capital Cost ($/kW) Trends

ResourceSeventh Plan (2016$/kW)2021 Plan (2016$/kW)Trend
Onshore Wind$2,382$1,450Significant decrease
Solar PV$2,566;
$1,792 (low cost)*
$1,350 (E. Cascades); $1,465 (W. WA)Significant decrease
Solar PV + Battery Storage (4 hr)$2,568
Battery Storage (4hr)$1,400
Pumped Storage$2,300
Geothermal$4,575$5,400No significant change
Natural Gas - Combined Cycle Combustion Turbine$1,220$1,150No significant change
Natural Gas – Peaker (Frame)**$859$550Decrease
Proxy Emerging Tech – Small Modular Reactor$5,400

* When the Council was evaluating solar PV in 2015 for the Seventh Power Plan, costs were dropping so quickly that a lower cost solar PV resource option was added to the model analyses.
** This price decrease also reflects a change in the reference plant technology class