The regional power grid in Cochise County, Arizona, is under pressure due to extreme temperature shifts between hot days and cool nights.
Solar farms do a great job of generating power during the peak daylight hours, but after sunset, production is non-existent.
In Wilcox, a single facility is proving how to deliver clean energy to Tuscon Electric Power around the clock.
How does the project manage to switch energy sources and avoid downtime completely?
How to balance the daily energy shift
The challenge that power grid operators face with solar is constant. Generation peaks when demand is high during the day, but during the evening hours of residential demand, it is zero. Solar installations have to rely on battery storage, which is expensive, or fossil fuel backup systems have to fill the gap after dark.
In Cochise County, air-conditioning use is high because of the daytime heat. The drop in temperature in the evenings results in strong wind currents.
Near Wilcox, the Red Horse facility draws on two kinds of energy but leaves just one footprint. The 855-acre site was designed to capture sunlight and wind, maximizing its generation in a non-stop 24-hour system.
The facility is surrounded by open desert and a mountain ridge. It sees intense, clear sunlight in the day and predictable wind movement along the higher elevations when the air cools after dusk.
The geographical features make Red Horse ideal for dual generation, but how did engineers manage to integrate both kinds of power?
Scaling up dual-source generation for round-the-clock power
Normally, it would take double the land, two separate utility permits, and two purchase agreements to operate two separate power projects. This also means that the costs are duplicated. This makes multi-energy installations financially unattractive for regional utilities.
The development of the Red Horse site needed a strategy to maximize energy output without compounding the infrastructure expenses. Engineers were confident that some of the essential equipment could be shared between the two energy forms, but it was still going to be a complex undertaking with several challenges.
Normally, adding a second energy system needs the construction of an entirely new substation and high-voltage transmission system.
To justify the development, the project needed to generate high-volume output continuously while avoiding the expense of having to duplicate the grid infrastructure.
The project planners decided on placing solar panels on the valley floor and wind turbines on the mountain ridge. The intention was to create an integrated system capable of maintaining high-capacity output throughout the 24 hours of the day, and it was a unique success.
A breakthrough in shared interconnectivity
Getting Red Horse onto the grid and operating around the clock took a 55-megawatt solar array and a 30-watt wind farm operating in tandem via one point of interconnection, explains Torch Clean Energy.
Instead of building separate transmission lines, the two systems feed into one 345-kilovolt connection linked directly to Tucson Electric Power. There is only a single power purchase agreement.
Taking advantage of two different peak periods
The main mechanism relies on complementary generation timing and shared capacity. During the day, the solar array operates at maximum output while daytime winds remain light. At night, solar production winds down while thermal wind currents pick up along the mountain ridge, which is when the turbines come online.
The situation of peak solar production and peak wind production occurring at different times of day means that both systems share the maximum capacity of the single transmission line, but the grid connection does not get overloaded.
By managing both power sources under one agreement, the facility delivers a significantly higher combined capacity factor than a standalone solar or wind farm. The design maximizes existing infrastructure but lowers long-term operating costs. As power demands increase across dry regions, hybrid generation models offer a practical blueprint for utility companies seeking reliable renewable energy.
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