Overview
The Enterprise Solar Farm is an operational photovoltaic power station situated in Iron County, Utah, United States. Located approximately 25 miles west of Cedar City, the facility represents a significant contribution to the regional renewable energy infrastructure. The project was developed by SunEdison and constructed by Mortenson Construction, with operations commencing in September 2016. It is currently operated by Swinerton Renewable Energy. The station serves as a key component of the broader Four Brothers Project, a cluster of solar installations designed to enhance grid stability and solar penetration in the Intermountain West.
The plant has a nameplate capacity of 105 MWp (megawatts peak) and an alternating current (AC) capacity of 80 MWAC. This distinction highlights the efficiency of the photovoltaic modules and the inverter systems used to convert direct current from the solar panels into alternating current for grid integration. The 80 MWAC output is sold under a 20-year power purchase agreement to Rocky Mountain Power. This utility provider serves customers across three states: Utah, Idaho, and Wyoming. The long-term contract provides revenue stability for the project and ensures a consistent supply of solar energy for Rocky Mountain Power’s diverse customer base.
History and Development
The development trajectory of the Enterprise Solar Farm involved multiple corporate transitions and strategic financial partnerships prior to its operational status. The project's planning phase was initially initiated by First Wind, a key player in the early stages of the solar farm's conceptualization and site selection in Iron County, Utah. This initial groundwork laid the foundation for the subsequent acquisition and development efforts that would define the project's financial and structural framework.
In 2014, a significant shift in ownership and development strategy occurred when SunEdison acquired the project. This acquisition was part of a broader strategic move involving TerraForm Power, which also played a role in the 2014 transaction. SunEdison subsequently assumed the primary developer role, steering the project from planning through to construction and final commissioning. The involvement of TerraForm Power in the 2014 acquisition highlights the complex corporate structuring often seen in large-scale renewable energy projects, where investment vehicles and development firms collaborate to secure and advance assets.
Financial structuring for the Enterprise Solar Farm was further complicated by a joint venture with Dominion Resources. This partnership was established to finance the Four Brothers Project, a larger portfolio or related initiative that included the Enterprise Solar Farm. The joint venture with Dominion Resources provided the necessary capital and financial backing to move the project from paper to pavement, ensuring that the 80 MWAC photovoltaic power station could be built and commissioned on schedule. This financial collaboration was crucial for mitigating the risks associated with the construction phase and securing long-term revenue streams.
The construction of the solar farm was executed by Mortenson Construction, a major construction firm that managed the physical build-out of the facility. The project was commissioned in September 2016, marking the transition from development to operational status. Upon commissioning, the electricity generated by the Enterprise Solar Farm began to be sold under a 20-year power purchase agreement to Rocky Mountain Power. This agreement ensured a stable revenue stream for the project, with Rocky Mountain Power serving customers across Utah, Idaho, and Wyoming. The 20-year term of the power purchase agreement provided long-term financial certainty for the investors and developers involved in the Enterprise Solar Farm.
Construction and Technical Specifications
The Enterprise Solar Farm was constructed by Mortenson Construction, a major engineering and construction firm, following its development by SunEdison. The project reached commercial operation in September 2016, establishing a significant photovoltaic capacity in Iron County, Utah. The facility is situated approximately 25 miles west of Cedar City, positioning it within a region with high solar irradiance suitable for utility-scale solar generation.
Technical Specifications
The power station utilizes crystalline silicon photovoltaic technology to convert solar energy into electricity. The array consists of 1.3 million individual solar panels, arranged to optimize energy capture across the site. The total installed capacity is rated at 105 MWp (megawatts peak), which translates to an alternating current (AC) output of 80 MWAC under standard operating conditions. This distinction between peak and AC capacity is standard in utility-scale solar projects, accounting for inverter efficiency and system losses.
| Specification | Detail |
|---|---|
| Developer | SunEdison |
| Constructor | Mortenson Construction |
| Commissioning Date | September 2016 |
| Technology | Crystalline Silicon Photovoltaic |
| Number of Panels | 1.3 million |
| Peak Capacity (MWp) | 105 MW |
| AC Capacity (MWAC) | 80 MW |
| Location | Iron County, Utah (approx. 25 miles west of Cedar City) |
The infrastructure supports a 20-year power purchase agreement with Rocky Mountain Power, the primary utility serving customers in Utah, Idaho, and Wyoming. This long-term contract ensures a stable revenue stream for the operator, Swinerton Renewable Energy, while providing a consistent source of renewable energy to the regional grid. The construction phase involved significant logistical coordination to install the large number of panels and associated electrical infrastructure, including inverters and transmission lines connecting the farm to the Rocky Mountain Power grid.
What distinguishes Enterprise Solar Farm from other Utah solar projects?
The Enterprise Solar Farm is not an isolated installation but a strategic component of a larger, integrated solar development known as the Four Brothers Project. This project, located in Iron County, Utah, represents one of the most significant solar energy clusters in the western United States. The Enterprise Solar Farm, with its 80 MWAC capacity, operates alongside three other major photovoltaic stations: the Escalante Solar Project, the Cedar Solar Project, and the Goshen Solar Project. Together, these four facilities form a cohesive energy generation hub that maximizes regional land use efficiency and grid integration capabilities.
Co-location Strategy and Land Use Efficiency
The primary distinction of the Enterprise Solar Farm within the Utah solar landscape lies in its co-location strategy. Rather than developing each solar farm as a standalone entity, the Four Brothers Project groups these large-scale installations in close geographic proximity. The Enterprise Solar Farm is situated approximately 25 miles west of Cedar City, Utah, placing it within a compact corridor of solar infrastructure. This clustering approach significantly reduces the per-megawatt land footprint required for transmission infrastructure, access roads, and interconnection points.
By concentrating generation capacity in a specific region of Iron County, the project minimizes the linear distance electricity must travel to reach key substations. This efficiency is critical for large-scale solar farms, where transmission losses and right-of-way acquisitions can become major cost drivers. The co-located nature of the Four Brothers Project allows for shared infrastructure benefits, including optimized use of local grid connections and streamlined operational maintenance routines across the neighboring facilities.
Comparison with Escalante and Three Cedars Projects
While the Enterprise Solar Farm shares the Four Brothers Project umbrella with Escalante, Cedar, and Goshen, it is often compared to other major Utah solar initiatives such as the Escalante Solar Project and the Three Cedars Project. The Escalante Solar Project, another component of the Four Brothers cluster, complements Enterprise by adding substantial additional capacity to the same regional grid sector. In contrast, the Three Cedars Project represents a different phase of Utah’s solar expansion, typically involving distinct land parcels and potentially different interconnection strategies.
The Enterprise Solar Farm’s 80 MWAC output is sold under a 20-year power purchase agreement to Rocky Mountain Power, a utility serving Utah, Idaho, and Wyoming. This commercial structure is similar to other large Utah solar farms but is distinguished by its integration into the Four Brothers framework. The synergy between Enterprise and its sister projects allows for a more stable and predictable power supply to Rocky Mountain Power, enhancing the overall reliability of solar energy in the Intermountain West. This collaborative development model sets Enterprise apart from standalone solar farms that must negotiate individual grid access and land use challenges without the benefit of neighboring, co-located generation assets.
Why it matters
The Enterprise Solar Farm represents a significant milestone in the integration of utility-scale photovoltaic capacity into the Intermountain West grid, specifically within the Rocky Mountain Power service territory. As an operational facility with an 80 MWAC capacity, the project contributes directly to the renewable energy portfolio of one of the largest electric utilities in the region. The electricity generated is sold under a 20-year power purchase agreement to Rocky Mountain Power, which serves customers across Utah, Idaho, and Wyoming. This long-term contractual structure provides revenue stability for the operator, Swinerton Renewable Energy, while offering predictable clean energy supply for the utility’s diverse customer base.
Grid Integration and Regional Impact
Located in Iron County, approximately 25 miles west of Cedar City, the Enterprise Solar Farm is strategically positioned to leverage the high solar irradiance characteristic of southern Utah. The project’s 105 MWp photovoltaic array was developed by SunEdison and constructed by Mortenson Construction, reflecting the collaborative engineering efforts required to bring large-scale solar infrastructure online. Commissioned in September 2016, the facility entered service during a period of accelerated renewable deployment in the state, helping to diversify the generation mix beyond traditional hydroelectric and natural gas sources.
For Rocky Mountain Power, the integration of 80 MWAC of solar capacity enhances grid resilience and supports the utility’s broader decarbonization goals. The project’s output helps meet peak demand periods, particularly during summer months when solar generation aligns closely with residential and commercial consumption patterns. This alignment reduces the need for peaker plants and contributes to overall system efficiency across the multi-state service area.
Economic Significance for Iron County
Beyond its technical contributions, the Enterprise Solar Farm delivers measurable economic benefits to Iron County. Large-scale renewable projects typically generate substantial local tax revenue, which funds public services such as education, infrastructure maintenance, and emergency response. The presence of the facility also supports local employment during both construction and operational phases, though specific job counts are not detailed in the available grounding data.
The project’s development by SunEdison and construction by Mortenson Construction further illustrates the involvement of national and regional firms in Utah’s energy sector, bringing specialized expertise and capital investment to the area. As one of the notable solar installations in the state, the Enterprise Solar Farm serves as a case study in how utility-scale photovoltaic projects can drive local economic growth while advancing regional energy independence.
How does the power purchase agreement structure work?
This contractual structure defines the financial and operational framework for the facility, ensuring a stable revenue stream for the operator, Swinerton Renewable Energy, while securing a predictable supply of solar-generated electricity for the regional grid. The PPA locks in the terms under which the 80 MWAC (105 MWp) of photovoltaic output is sold, mitigating market volatility for both parties involved in the transaction.
Contractual Framework and Revenue Stability
Power purchase agreements are standard instruments in utility-scale solar development, designed to de-risk investments for developers and utilities alike. For the Enterprise Solar Farm, the 20-year duration provides long-term visibility into cash flows, which is critical for recouping the capital expenditure incurred during construction by Mortenson Construction and initial development by SunEdison. By committing to purchase the electricity generated by the farm, Rocky Mountain Power guarantees a buyer for the output, reducing the financial uncertainty often associated with variable renewable energy sources. This stability is essential for maintaining the operational viability of the plant located approximately 25 miles west of Cedar City in Iron County.
Regional Grid Integration and Customer Impact
The electricity generated under this agreement is integrated into Rocky Mountain Power’s broader transmission and distribution network, serving a multi-state customer base. For the utility, securing 80 MWAC of solar capacity helps diversify the generation mix, contributing to the reliability and resilience of the regional power supply. The PPA structure allows Rocky Mountain Power to pass on the benefits of solar generation to its customers in Utah, Idaho, and Wyoming, potentially influencing local energy costs and contributing to regional sustainability goals. The fixed-term nature of the agreement ensures that the financial implications of the solar investment are spread over two decades, aligning the lifecycle of the photovoltaic assets with the duration of the revenue commitment.
See also
- Pacific DC Intertie: HVDC Transmission from the Pacific Northwest to Los Angeles
- Tres Amigas SuperStation: The Proposed HVDC Hub for North American Grids
- AP1000 reactor design
- Power plant controller for wind turbine generators (US Patent 11401917)
- Capricorn Ridge Wind Farm: Texas onshore wind infrastructure