The Bighorn Solar project is a 300MW photovoltaic (PV) solar farm located in Colorado, the US. The electricity generated by the plant is used to power the EVRAZ Rocky Mountain steel mill in Pueblo.

The project was developed by Lightsource bp, a 50:50 joint venture with bp. The company is also the owner and operator of the solar facility.

Lightsource bp sells the electricity generated by the Bighorn solar project to Xcel Energy, the electrical provider for the steel mill. This electricity powers the EVRAZ North America-operated steel mill.

In September 2019, Xcel Energy, EVRAZ North America and Lightsource bp entered into a long-term partnership to develop the solar farm.

Construction works began in 2020 and the project was launched in October 2021. It commenced commercial operations two months later in December 2021.


The Bighorn Solar project is located on 1,800 acres of land on EVRAZ Rocky Mountain Steel property in Pueblo, Colorado. Some supplemental land was provided by the City of Pueblo and private landowners.

According to Lightsource bp, the project is the largest on-site solar facility dedicated to a single customer in the US.

Bighorn Solar Project Details

The solar project features nearly 750,000 solar bifacial solar panels mounted on single-axis trackers. The facility has a capacity of 300MW of direct current (DC) and 240MW of alternating current (AC).

It will produce 613,400 megawatt-hours (MWh) of electricity per year, meeting nearly all of the steel plant’s annual electricity demand. The renewable power, in turn, enables EVRAZ Rocky Mountain steel mill to produce green steel and steel products supporting more than 1,000 jobs.

During construction, the project created 300 direct jobs on site.

Overall, Bighorn Solar will help in eliminating more than 433,000 metric tonnes of carbon dioxide emissions per year.  This is equivalent to taking 92,100 fuel-powered cars off the road annually.

The Bighorn Solar project also supports the Colorado Energy Plan, which aims to trim carbon emissions by 60%. The renewable project is also aligned with Xcel Energy’s goal to deliver 100% carbon-free electricity by 2050.

As part of Lightsource bp’s efforts to boost net biodiversity at its project sites, the Bighorn Solar project shares the land with conserved shortgrass prairie habitat.

Additionally, Lightsource bp and partners determined a site-specific seed mix for the land containing staple short grasses such as western wheatgrass, buffalograss and little bluestem, as well as a low concentration of purple prairie clover.

The team also focused to minimise disturbance to the existing ground layer during construction works.

Offtake Agreement

US-based regulated electric and natural gas delivery company Xcel Energy buys the renewable power generated by Bighorn Solar under a 20-year power purchase agreement (PPA) with Lightsource bp. The electricity is used to power the EVRAZ Rocky Mountain steel mill facility.

The agreement will enable EVRAZ will receive renewable power and price certainty from Xcel Energy through 2041.


In October 2020, Lightsource bp closed a $285m financing package to build the Bighorn Solar project.

The company secured tax equity financing from Bank of America, while debt for the facility was provided by Sumitomo Mitsui Banking Corp (SMBC), Societe Generale, and Export Development Canada (EDC). The balance of the equity requirements was invested by Lightsource bp.

CohnReznick Capital was associated as the tax equity advisor for the project.

Contractors involved

Operis conducted a review of the financial model regarding the Bighorn Solar Project.

In August 2020, Lightsource bp awarded the engineering, procurement and construction (EPC) contract for the project to McCarthy Building Companies.

Canadian Solar, a PV panel manufacturer based in Ontario, Canada, supplied the solar panels for the project, while NEXTracker delivered the single-axis trackers to support the solar panels.