Overview
The Seven Sisters Solar Project is an operational solar farm located in the western United States, specifically within the states of Utah. This photovoltaic power station is dispersed across two distinct administrative regions: Beaver County and Iron County. The facility represents a significant deployment of solar energy infrastructure in the region, designed to feed electricity into the local grid to support regional power demand. The project is currently under the operation of TerraForm Power, which manages the day-to-day activities and maintenance of the site. The facility has been fully operational since its commissioning in 2016, marking it as an established component of the state's renewable energy portfolio.
The technical specifications of the Seven Sisters Solar Project are defined by its photovoltaic technology and dual capacity ratings. The plant has a direct current capacity of 22.6 MWp (megawatts peak) and an alternating current capacity of 20.2 MWAC (megawatts alternating current), according to project documentation. These figures reflect the output capabilities of the seven individual units that comprise the broader project. The design utilizes standard photovoltaic modules to convert solar irradiance into electrical energy, which is then conditioned for grid integration. The distinction between the DC and AC ratings is critical for understanding the plant's performance under varying load conditions and inverter efficiency.
The development and construction of the facility involved several key industry participants. The project was originally developed by SunEdison, a major player in the global solar market, which handled the initial financing, site selection, and engineering phases. The physical construction was executed by Swinerton Renewable Energy, which oversaw the installation of the solar arrays, inverters, and balance-of-system components. The project was completed in September 2016, finalizing the installation and testing phases required for commercial operation. This collaborative effort between the developer and the builder ensured that the facility met the technical and contractual requirements for its long-term operation.
The commercial structure of the Seven Sisters Solar Project is based on a series of power purchase agreements (PPAs) with a single off-taker. The electricity generated by the facility is sold to Rocky Mountain Power, a major utility provider in the Intermountain West. The sales are structured through seven separate 20-year power purchase agreements, corresponding to the seven distinct units of the project. This contractual framework provides revenue stability for the operator and a predictable source of renewable energy for the utility. The 20-year term aligns with the typical economic lifespan of photovoltaic modules and inverters, ensuring that the asset remains financially viable throughout its primary operational phase.
Why it matters
The Seven Sisters Solar Project represents a distinct operational model within the western United States' renewable energy landscape, characterized by its dispersed architecture rather than a single contiguous footprint. Located across Beaver County and Iron County, Utah, the facility does not rely on one massive solar field but instead comprises seven separate photovoltaic units. This multi-unit configuration allows the project to navigate the topographical and land-use constraints typical of Utah's high-elevation terrain, integrating solar generation into varied geographic pockets rather than requiring a single large parcel of land.
The strategic significance of this project lies in its unified commercial structure despite its physical dispersion. Although the seven units are geographically separated across two counties, they operate under a single cohesive business model. The electricity generated by these dispersed sites is sold to Rocky Mountain Power under seven separate 20-year power purchase agreements. This arrangement demonstrates how developers can aggregate smaller, site-specific solar installations into a larger, bankable asset class. By securing long-term contracts with a major utility provider, the project mitigates the market risks often associated with fragmented renewable energy developments.
Developed by SunEdison and constructed by Swinerton Renewable Energy, the project was completed in September 2016. The involvement of these specific industry players highlights the collaborative nature of mid-sized solar deployments, where specialized developers and construction firms work in tandem to execute complex, multi-site builds. The project is currently operated by TerraForm Power, which manages the ongoing performance and maintenance of the 22.6 MWp (20.2 MWAC) capacity. This operational handover and sustained management underscore the project's role as a stable, long-term contributor to the regional grid, providing consistent solar output through a structured, multi-agreement framework.
Project Development and Ownership History
The Seven Sisters Solar Project was developed by SunEdison, with construction carried out by Swinerton Renewable Energy. The facility was completed in September 2016, marking the operational start of the 22.6 MWp photovoltaic station. The project consists of seven distinct units dispersed across Beaver County and Iron County in Utah, United States.
Ownership and Power Purchase Agreements
TerraForm Power is listed as the operator of the facility. The development history involves SunEdison, which played a central role in the project’s creation before its subsequent corporate restructuring and bankruptcy proceedings, which impacted the broader solar asset portfolio.
| Year | Event |
|---|---|
| 2016 | Project completed in September |
| 2016 | Commissioning of the 22.6 MWp facility |
The project represents a significant utility-scale solar installation in the region, utilizing photovoltaic technology to contribute to the local energy mix. The structure of seven separate units allows for dispersed generation across the two counties, optimizing land use and grid integration.
Construction and Technical Specifications
The Seven Sisters Solar Project was constructed by Swinerton Renewable Energy, a specialized builder in the renewable energy sector. The development phase was led by SunEdison, which oversaw the project from inception through to its completion in September 2016. The construction resulted in a fully operational photovoltaic power station with a direct current capacity of 22.6 MWp and an alternating current capacity of 20.2 MWAC.
Technical Layout and Location
The facility is not a single contiguous array but consists of seven distinct units. These units are geographically dispersed across two counties in Utah: Beaver County and Iron County. This distributed layout allows the project to utilize specific land parcels and potentially optimize solar exposure across different microclimates within the region. The technical specifications of the plant are detailed below.
| Parameter | Value |
|---|---|
| Entity Type | Solar Farm |
| Primary Fuel/Source | Solar |
| Technology | Photovoltaic |
| DC Capacity (MWp) | 22.6 |
| AC Capacity (MWAC) | 20.2 |
| Number of Units | 7 |
| Location | Beaver County and Iron County, Utah |
| Commissioning Date | September 2016 |
| Developer | SunEdison |
| Builder | Swinerton Renewable Energy |
| Off-taker | Rocky Mountain Power |
| PPA Duration | 20 years |
Commercial Structure
The electricity generated by the seven units is sold to Rocky Mountain Power. This commercial arrangement is structured through seven separate power purchase agreements (PPAs), one for each unit, with each agreement spanning a 20-year term. This structure aligns with the physical dispersion of the project, allowing for individualized management and revenue streams for each of the seven solar installations.
What is the structure of the power purchase agreements?
The commercial framework for the Seven Sisters Solar Project is defined by a series of power purchase agreements (PPAs) that structure the revenue stream for the facility. The electricity generated by the photovoltaic units is sold to Rocky Mountain Power, which serves as the offtaker for the project's output. Rather than utilizing a single, consolidated contract for the entire 22.6 MWp capacity, the project’s commercial structure is divided into seven separate agreements. This segmentation aligns with the physical layout of the solar farm, which consists of seven distinct units dispersed across Beaver County and Iron County in Utah. Each of these seven units operates under its own individual 20-year PPA with Rocky Mountain Power.
Segmentation of Contracts
The decision to execute seven separate PPAs reflects the modular nature of the Seven Sisters Solar Project. By treating each of the seven units as a distinct commercial entity, the project developers and operators can manage the financial and operational risks associated with each specific site. This structure allows for independent tracking of energy production, performance metrics, and revenue generation for each unit. The 20-year term of these agreements provides a long-term revenue horizon, which is typical for utility-scale solar projects to ensure financial stability and attract investment. The consistency in the duration of the contracts suggests a standardized approach to the commercial terms across all seven locations.
Role of Rocky Mountain Power
Rocky Mountain Power acts as the primary buyer of the electricity generated by the Seven Sisters Solar Project. As the offtaker, Rocky Mountain Power is responsible for purchasing the power output from the seven photovoltaic units under the terms of the respective PPAs. This relationship is central to the project's operational viability, as it guarantees a market for the generated electricity. The PPAs likely specify the price per megawatt-hour, volume commitments, and performance guarantees, although the specific financial details are contained within the individual contracts. The involvement of Rocky Mountain Power integrates the solar generation into the broader regional grid, contributing to the energy mix in Utah.
Development and Completion Context
The commercial agreements were established as part of the project's development phase, which was led by SunEdison. The finalization of the seven PPAs would have been a critical milestone in the project's financial closing, ensuring that the revenue streams were secured before or during the commissioning of the units. The operational status of the project since 2016 indicates that the PPAs have been successfully executed, providing a steady income for the operator, TerraForm Power, and a consistent supply of renewable energy for Rocky Mountain Power. The structure of these agreements supports the long-term operational goals of the solar farm, aligning the interests of the developer, operator, and offtaker.
Operational Context and Maintenance
The Seven Sisters Solar Project operates under the management of TerraForm Power, which oversees the daily generation and performance monitoring of the facility. The station is fully operational, having been completed in September 2016, and continues to deliver consistent photovoltaic output to the regional grid. TerraForm Power’s operational role includes maintaining the seven distinct units that comprise the project, ensuring that each segment functions efficiently within its specific environmental conditions. The operator’s involvement ensures that the plant meets the technical requirements outlined in its commercial agreements, providing a stable power source for the local utility network.
Energy Output and Household Impact
The facility has a total installed capacity of 22.6 MWp, which translates to a net alternating current output of 20.2 MWAC. This energy production is significant for the local grid, with the output expected to impact over 4,000 homes. The electricity generated is sold to Rocky Mountain Power, the primary utility provider for the region. The project’s ability to supply power to thousands of households demonstrates the scalability of dispersed solar assets in the Utah energy market. The consistent generation helps support the growing demand for renewable energy in the state, contributing to the diversification of the local power mix.
Geographic Distribution and Commercial Structure
A defining feature of the Seven Sisters Solar Project is its geographic distribution. This strategic placement allows the project to utilize available land across different topographical zones, optimizing solar exposure and land use efficiency. The commercial framework supporting this distribution involves seven separate 20-year power purchase agreements with Rocky Mountain Power. Each agreement corresponds to one of the seven units, providing a structured financial model that aligns with the physical layout of the plant. This multi-agreement structure was established during the development phase, which was led by SunEdison and executed by builder Swinerton Renewable Energy. The dispersed nature of the units requires coordinated maintenance and monitoring by TerraForm Power to ensure uniform performance across both counties.
How does this project compare to other Utah solar developments?
The Seven Sisters Solar Project represents a distinct architectural approach within the Utah solar market, characterized by its dispersed configuration rather than the consolidated footprint typical of many regional developments. This multi-site strategy contrasts with the single-site mega-projects that often dominate utility-scale solar planning, where a single contiguous parcel hosts the entire capacity. The project’s total capacity is 22.6 MWp (20.2 MWAC), a scale that is modest compared to the gigawatt-class installations increasingly common in the Western United States, yet significant for its specific geographic distribution.
The operational model of the Seven Sisters Project further differentiates it from other developments. This contractual structure mirrors the physical layout, with each of the seven units likely corresponding to an individual agreement. Such a fragmented procurement strategy allows for phased integration into the grid and potentially diversifies geographic risk, although it may introduce administrative complexity compared to a single master agreement for a unified site. The project was developed by SunEdison and built by Swinerton Renewable Energy, highlighting the collaborative nature of its development prior to its completion in September 2016.
Within the broader context of Utah’s solar infrastructure, the Seven Sisters Project serves as an example of how solar capacity can be aggregated from multiple smaller sites to achieve utility-scale output. While many modern projects prioritize economies of scale through massive single-site installations, the Seven Sisters model demonstrates the viability of dispersed assets. This approach may offer advantages in land use efficiency, allowing solar arrays to occupy varied terrains across Beaver and Iron Counties, rather than requiring one large, contiguous tract of land. The project remains operational under the management of TerraForm Power, continuing to contribute to the regional energy mix with its specific 22.6 MWp output.