The 2021 Power Plan includes utility-scale generating resource reference plants for:
- Onshore wind
- Solar PV
- Battery Storage
- Solar PV + Battery Storage
- Natural Gas
- Pumped Storage
- Conventional Geothermal
- Emerging Technology Proxy (Small Modular Reactors)
Click on any of the generating resource reference plants for high level trends in technology, cost, and development, identification of resource potential in the region, opportunities and challenges, and environmental effects, and a description of the reference plant(s).
Definitions of Reference Plant Attributes
The following attributes are used to describe the resource reference plants for the 2021 Power Plan. Note that all costs are expressed in constant 2016 year dollars.
Configuration. The number of units (and installed nameplate capacity of each unit) that make up the complete reference plant. Also includes other plant specifications such as air emissions controls, cooling (wet vs. dry).
Location. The general geographic location of the reference plant, which is important in properly accounting for plant attributes (e.g. capacity factor).
Earliest In-Operation Date (Year). The earliest date a reference plant is assumed to be in operation, taking into account development and construction. The Council’s models cannot select the resource before this date.
Construction Lead Time. The amount of time it takes from project conception to commissioning. For the 2021 Power Plan, there are two phases:
Development Period (Years). Includes planning and development, from the identification of need (for example in a utility IRP) to establishment of the engineering, procurement, and construction (EPC) contract (which includes all siting and licensing, environmental impact assessments, and preliminary engineering).
Construction Period (Years). From the Notice to Proceed (NTP) to complete construction and commissioning.
Maximum Buildout Potential. The maximum amount of reference plant units (in megawatts) that the model can select over the 20-year planning horizon. See Methodology to Develop Maximum Build-out Assumptions for more information.
Economic Life (Years). The assumed useful operating life of the plant.
Technology Vintage Year. The year in which the reference plant technology and cost estimates was based on. For the 2021 Power Plan, the technology vintage year is 2019. Forward cost, capacity factor, and heat rate multipliers can be applied to the reference plant to reflect assumed improvements to the technology from the base technology vintage year.
Financial Sponsor. Power plants can be developed by investor-owned utilities, consumer-owned utilities, and independent power producers. Each of these entities uses different project financing mechanisms. The differing financing mechanisms and financial incentives available for some resources result in different total investment costs and annual capital service requirements for otherwise identical projects. For the 2021 Power Plan, an IOU financial sponsor was assumed for all reference plants due to time limitations in developing the new MicroFin model.
Nameplate Capacity (MW). The installed nameplate capacity of a power plant is the maximum amount of electricity it can generate when it is fully functional, in optimal conditions, and, if applicable, using the maximum amount of fuel. Another way of representing nameplate capacity is the manufacturer’s rated output of the generator.
Annual Average Capacity Factor (%). An estimate of the ratio of the actual annual output to the nameplate capacity. This is a useful value when understanding the contributions of variable energy generation in different locations, such as wind and solar PV.
Capacity Factor Multiplier. Reflects assumed capacity factor improvements of reference plants over the planning period. For example, a reference plant built in 2025 would be assumed to achieve a percentage improved capacity factor over the initial reference plant capacity factor, which was based off of a specific technology vintage year (in the 2021 Power Plan, the technology vintage year was 2019).
Fuel. The primary type of fuel burned (natural gas, oil, coal, etc.), its location of origin, and cost.
Heat Rate (Btu/kWh). A measure of the efficiency of which a generator converts fuel into electricity. The reference plant heat rates are based on full load, expressed as higher heating values (HHV).
Heat Rate Multiplier. Reflects assumed heat rate efficiency improvements of reference plants over the planning period. For example, a reference plant built in 2025 would be assumed to achieve a percentage improved heat rate over the initial reference plant heat rate, which was based off of a specific technology vintage year (in the 2021 Power Plan, the technology vintage year was 2019).
Overnight Capital Cost ($/kW). An estimate of the project development and construction cost. “Overnight” refers to what the cost would be if the plant were built instantly, or over one night. This cost constitutes the engineering, procurement, and construction (EPC) costs, owner’s costs (costs incurred by the project developer – permits, licenses, land, project development costs, infrastructure, taxes, regulatory compliance costs, etc.), and decommissioning costs. It is assumed that all equipment and technology comply with existing environmental regulations, and therefore the cost of that equipment (and compliance) is included in the overnight capital cost estimate.
All-In Capital Cost ($/kW). An estimate of the total investment cost related to capital, including the cost of securing financing, interest during construction, and escalation during construction.
Tax Credits. For the 2021 Power Plan generating resource reference plants, the federal Investment Tax Credit (ITC) is available and applied for resources that meet the requirements. The ITC is a one-time tax incentive that can be claimed on corporate income taxes for a percentage credit of the cost of the project.
Fixed O&M Cost ($/kW-yr). An estimate of the fixed operation and maintenance cost for the reference plant, including operating and maintenance, labor and materials, and administrative overhead. Both routine maintenance, and major maintenance and capital replacement are assumed to be included.
Variable O&M Cost ($/MWh). An estimate of the variable operation and maintenance cost for the reference plant, including all costs that are a function of the amount of power produced. This includes consumables such as water, chemicals, lubricants, and catalysts, and waste disposal.
Forward Cost Curve. The forward cost curve represents the assumption that the technology will improve in cost (for some resources at least) if selected to be built in a future year. For example, a reference plant built in 2025 could be assumed to cost less than the reference plant cost estimate, which was based off of a specific technology vintage year (in the 2021 Power Plan, the technology vintage year was 2019).
Transmission. The assumed transmission type (e.g. long-term firm, short-term, IOU network transmission) that is incorporated into the cost of the resource.
Deferred Transmission and Distribution (T&D). A cost benefit ($/kW-yr) assigned to certain energy efficiency, demand response, and generating resources that defer the need (and cost) for new transmission and/or distribution developments. The Council used data from five transmission utilities and four distribution utilities to estimate these values: $3.08/kW-yr for deferred transmission and $6.85/kW-year for deferred distribution (both in 2016$). The Council recognizes that potential transmission and distribution systems cost savings are dependent upon local conditions. In the 2021 Power Plan, for generating resources, deferred T&D was applied to the battery storage reference plant and deferred transmission was applied to the pumped storage reference plant.
Levelized Fixed Cost ($/kW-yr). An estimate of the cost of planning, building, and maintaining a power plant over its lifetime, on an annualized cost basis.
Levelized Cost of Energy ($/MWh). An estimate of the cost per unit of energy for a resource over its productive lifetime, including fixed costs, and, under an assumed capacity factor, variable costs such as variable O&M and fuel commodity costs.