Nevada’s giant Gemini Solar + Storage complex comes online
In early 2024, the Gemini Solar + Storage project entered commercial operation in Clark County, Nevada, becoming the largest single-phase, co-located solar generation and energy storage system in the U.S. The project was developed by Primergy with Quinbrook Infrastructure Partners as an investment partner. The solar power plant’s installed capacity is 690 MW AC (966 MW DC), and the battery energy storage system is rated at 380 MW and 1,416 MWh. The complex can cover up to 10% of Nevada’s peak grid demand and received the prestigious POWER Top Plant award for its contribution to the clean energy transformation.
Project numbers that speak for themselves
Gemini combines a photovoltaic plant and a four-hour battery in a DC-coupled configuration, in which the batteries charge directly from the solar panels. The site has 186 battery subsystems deployed. At the start of construction and upon entering commercial operation, it was the largest project of its class in the country.
Are tourists using more and more energy—or not?
For a city that consumes a huge amount of energy and at the same time depends on tourism, this solution makes sense. Las Vegas visitor numbers remain high even despite the development of the iGaming sector, which has posted strong results in recent years.
That said, there has been some decline in popularity. For example, we recently learned that the number of tourists from Canada has decreased. And the problem, according to some experts, may lie precisely in the iGaming industry, which is actively developing in the neighboring country. Thus, data from twinspinca.com on online casinos offering no-deposit bonuses show that the number of players from Canada on gambling platforms is constantly growing. Given that Canadians were one of the main tourist categories for Vegas, it suggests waning interest on their part. The same trends are observed in neighboring Mexico, and tourists from Asia are increasingly giving preference to Macau.
But even despite such alarming trends, Las Vegas still shines. And tourists continue to affect the city’s energy use. After all, if previously mainly fans of gambling entertainment came here, today these are tourists with a wide variety of interests.
Maximum sunshine when demand peaks in Clark County
The Las Vegas area receives an average of 6.51 kWh/m² of solar insolation per day, which is about 35% more than in a “typical” U.S. city. For comparison, the same figure for Seattle is 3.57, and for Chicago it is only 3.14 kWh/m²/day. Nevada enjoys about 300 sunny days a year, and in certain seasons peak sun hours reach seven per day.
The paradox, however, was that with such a generous resource, the share of solar generation in the state’s energy mix in January 2022 barely exceeded 13.69%, according to data from the Status of Energy Report. This gap between potential and reality became the catalyst for the emergence of Gemini.
A $1.9 billion deal and record tax equity
On April 25, 2022, Quinbrook Infrastructure Partners and Primergy announced the final close of a $1.9 billion financing. The project’s financing structure included several layers:
- A $1.3 billion debt package of credit facilities, including a construction/term loan, a tax equity bridge loan, and a letter of credit facility.
- $532 million in tax equity from Truist Bank and Bank of America, described by the participants as the largest single-asset solar tax equity deal in U.S. history.
- A syndication of 19 lenders, arranged by coordinating lead arrangers KeyBanc Capital Markets, MUFG Bank, Bank of America, and Norddeutsche Landesbank (New York branch).
- $95 million in mezzanine debt raised from Voya Investment Management.
The Gemini constellation as a metaphor for two technologies
The project’s name refers to the astronomical constellation Gemini, symbolizing twins. The complex’s two “stars” work in tandem: the solar arrays collect the energy of the desert day, and the battery systems store it for the evening and nighttime hours, when Las Vegas truly comes alive.
How the solar-plus-storage pairing works
The DC-coupled configuration allows the storage system to charge directly from the panels, avoiding additional power conversions and improving overall system efficiency. Energy management systems respond within milliseconds, adapting to changes in weather and grid conditions. During periods of peak generation, the 186 subsystems capture so-called clipped energy, which under a conventional scheme would simply be lost. The distributed architecture improves fire safety, resilience, and the complex’s operational availability.
Construction amid the pandemic and global disruptions
The general contractor was Kiewit Power Constructors. The schedule was maintained even in the later stages of the pandemic thanks to pre-planned procurement, a trained team, and a proactive response to supply-chain disruptions. According to Primergy, the priority of safety and quality remained unchanged throughout construction.
Partnership with the Moapa Band of Paiutes
One of the project’s key partners was the Native American tribe, the Moapa Band of Paiutes, which has more than two decades of experience participating in solar projects on its lands. Tribal representatives worked as equipment operators, conducted biological and cultural monitoring, and their knowledge of the area and local infrastructure became, by Primergy’s admission, an indispensable resource. The engagement model was built on principles of respect and long-term, equitable stewardship, combining immediate benefits in the form of jobs and competencies with preserving the land for future generations.
A smaller footprint, more desert preserved
Environmental solutions were built in at the design stage. The panel rows follow the natural terrain, existing vegetation was preserved where possible, and site preparation methods minimized soil disturbance. For 24 months prior to construction, dust control and stormwater runoff management practices were refined. The final figures are impressive: the project’s overall “footprint” has been reduced by more than 20%, the access-road network has been reduced by 25% compared to typical solar plants, and nearly 80% of the site remains open to the sky.
Dispatchable capacity instead of “daytime-only” generation
From the grid’s perspective, Gemini operates much like a gas-fired power plant: it is a dispatchable resource capable of delivering energy at times of greatest need. The 1,416 MWh storage system provides delivery after sunset and at peak loads, and coordination with the grid operator and regulators makes it possible to use the complex with maximum flexibility.
NV Energy, in its Annual Renewable Portfolio Report filed in April 2025, separately highlighted Gemini as an important contribution to achieving the “nearly 47%” figure for electricity from renewable sources at the end of 2024.
Thirty years of desert monitoring
To confirm environmental compatibility over the long term, Primergy launched a joint monitoring program with the Bureau of Land Management and the U.S. Geological Survey, designed for 30 years. Researchers track the condition of vegetation, soils, and sensitive species on the Gemini site to develop best practices for integrating solar generation with desert ecosystems.