Geothermal heat in copper mining project progresses amidst Arizona push
The Morenci copper mine in Arizona (source: TJBlackwell, CC BY 3.0 
Carlo Cariaga
4 May 2026
The geothermal direct-use project in a copper mine is shaping up to a major part of Arizona's state-wide push to accelerate geothermal development.
A project that aims to use geothermal heating to enable and improve low-emissions extraction of copper from mined material is shaping up to be one of the biggest geothermal projects in Arizona, amidst a concerted push to push for geothermal development in the state. The project is taking place at the copper extraction operations in the Morenci and Safford sites in Southeast Arizona by the international metals company Freeport-McMoran (Freeport), with technical support provided by Zanskar.
As ThinkGeoEnergy first reported in 2024, the project aims to utilize geothermal heat to enable the recovery of residual copper from already mined material previously considered unrecoverable. Leaching at higher temperatures is a demonstrated way of improving copper recovery. Freeport had been selected by the US Department of Energy to receive a USD 80 million grant to support the project, which has an estimated total cost of USD 175 million.
The now-called MILESHIGH project will also integrate a utility-scale battery energy storage system at Morenci to increase energy resilience and reliability for the mine and the surrounding community. It is shaping up to be the largest geothermal exploration campaign at a mine site ever performed, and the largest geothermal direct-use project in the United States.
“Our geothermal project demonstrates how Arizona can leverage its natural resources and existing infrastructure to advance innovative energy solutions that support reliable, sustainable and long-term economic development,” said Francis McAllister, Freeport Vice President Energy, Land and Water.
“By exploring the direct use of geothermal heat to improve copper recovery at Morenci, we’re applying Arizona based resources and innovation to strengthen the state’s copper industry and its role in supplying critical materials.”
The MILESHIGH project will also reduce the company’s reliance on fossil fuels to power backup generators and eliminate the need to add new natural gas-fired sources of heat. Johnny Key, Director-Energy and Power Management, says that the new system will have geothermal pumping stations that look much like regular water pumping stations, and that the electrical systems will be upgraded with new equipment.
Advocating for geothermal in Arizona
“The cutting edge in geothermal development is happening right here in Arizona with the MILESHIGH Project. Our state has abundant geothermal resources and I am committed to investing in Arizona becoming a geothermal leader,” added Arizona Governor Katie Hobbes during a visit to the MILESHIGH project site.
“We’re ready to bring more geothermal projects to our state to help deliver affordable and reliable power for Arizonans.”
Within the past several months, the leadership of Arizona has made moves to accelerate geothermal development in the state. In March 2026, the Governor delivered recommendations to catalyze the development of next-generation geothermal, which followed a feedback period by the Geothermal Working Group. In early 2026, the Governor approved a $1 million investment in the Arizona Geological Survey (AZGS) to expand subsurface data collection and analysis work in aid of enhancing knowledge of the state’s geothermal resources.
Arizona was also one of the 13 member states of the Geothermal Power Accelerator, a collaboration program that aims to rapidly expand geothermal power development.
The Governor’s Office of Resiliency states that it will continue to work with local governments, industry partners, and Tribal leaders to identify more opportunities for geothermal development.
Source: Office of the Governor Katie Hobbs and Freeport-McMoran
