Big solar heat deal
 Big solar heat deal in the Chilean copper sector made possible by two people

Big solar heat deal in the Chilean copper sector made possible by two people

Construction will start on three enormous solar industrial heat plants in Chile in the next months. The Chilean power utility Gasco is investing USD 71 million in three flat plate collector fields with a total capacity of 154 MW and will deliver heat for the electrowinning baths to the two copper mines Minera Escondida and Spence. Both mines are operated by the Australian-British company BHP, which owns the majority shareholding (57.5 %) in Minera Escondida and 100 % of Spence. The mining company aims at producing its copper CO2-free. It will purchase solar heat to cover more than 80 % of its heat demand for the electrowinning. The remaining heat will be delivered by electro boilers driven with renewable electricity.

Photo: Innergex

There are two important people behind this big deal: Ian Nelson from Chile and Hans Grydehøj from Denmark. Nelson was Managing Director of the company Energia Llaima that owned and operated the 38 MW field at the Gabriela Mistral mine between 2012 and 2022 (see photo above). Grydehøj was Nelson’s joint venture partner with his former Danish company Sunmark. Grydehøj planned and built the Gabriela Mistral plant in 2012 and 2013.

Both of these experts are no longer with their former companies. Sunmark was acquired by Danish competitor Arcon in 2015, which subsequently operated as Arcon Sunmark until it closed in 2020. Nelson sold his company Energia Llaima to the Canadian company Innergex in 2021 – a renewable electricity project developer. Innergex is now owner and operator of the 38 MW collector field at the Gabriela Mistral mine.

Big solar heat deal

The two people behind the big solar heat deal: Ian Nelson from Chile and Hans Grydehøj from Denmark, two independent and very experienced solar heat experts
Photos: Private

Copper mines in Chile are ideal for solar heat usage

“What Gasco will finance and build now has four times the solar heat capacity of our first plant at Gabriela Mistral, which we put into operation in October 2013”, said Nelson. With his company INCHS (Innovative Cold & Heat Solutions), together with Grydehøj, both are supporting Gasco in the design, purchase and construction phases. But without him, these major heat purchase agreements between Gasco and the mines would not have materialized.

“Gasco trusts me because I worked with them on different energy projects over almost two decades in the 1980s and 1990s”, explained Nelson. He was also the person promoting solar heat for copper producers in Chile over the last decade. “I have been in constant contact with Minera Escondida and Spence over the last ten years.” The mines even put solar thermal energy out to tender a few years ago, but the bids ended without a contract, remembered Nelson.

Copper industry deeply concerned about green copper

Times have changed completely. Today, copper producers are under pressure to offer their product with a low carbon footprint due to the requirements of their clients and supply chain laws in some regions of the world.

Electrowinning is an ideal process for solar heat usage. It is the last stage of copper production, the electrolytic refining of the copper in an acid bath. This bath has to be kept at a temperature of 48°C at all times. Under the strong sun in Chile in the desert areas where copper is mined, the flat-plate collectors at Gabriela Mistral achieved a specific yield of 1,112 kWh/m2 annually in the first three years of operation.

The solar heat plant for Minera Escondida is divided into two collector fields (see table below). The 90 MW flat plate collector field will supply heat to two electrowinning baths and their boilers, which are referred to as “Oxides” and “Interplant” within the mine. The two process units are roughly 250 m away from each other. The second plant at Minera Escondida with 23 MW will be connected to the electrowinning process including a set of boilers known as “Sulphides”, several kilometres away from the first plant.

The first successful reference Gabriela Mistral mine enabled Arcon Sunmark to sell a second plant with 4.4 MW for a copper mine in Mexico in 2016. Grydehøj, as International Sales Executive at Arcon-Sunmark, was in charge of planning and building this turnkey project for the Mexican mining group Peñoles.

Mine, country Owner of mine Flat plate collector field area Solar capacity of the flat plate collector field* Start of operation EPC of collector field Operated by an energy service company
Gabriela Mistral, Chile Codelco 40,100 m2 38 MW 2013 Sunmark, Denmark Yes
La Parreña, Mexico Peñoles 6,270 m2 4.4 MW 2016 Arcon-Sunmark, Denmark No
Nacozari mine, Mexico
Grupo Mexico 910 m2 784 kW 2023 Flemming Jorgensen, Mexico No
Minera Escondida, Chile BHP 92,907 m2 90 MW (Oxides and Interplant) n/a Gasco, Chile Yes
Minera Escondida, Chile BHP 25,110 m2 23 MW (Sulphides) n/a Gasco, Chile Yes
Spence, Chile BHP 41,850 m2 41 MW n/a Gasco, Chile Yes

Overview of solar heat plants in the copper industry. Gasco plans to commission the three large flat plate collector fields for Minera Escondida and Spence at the end of 2025. The names in brackets represent the names of the processes/boilers within the BHP mines that will be supplied with solar heat. * The solar thermal capacity of the plants in Chile is determined by the project developers depending on the irradiation level on site and not calculated with the standard conversion rate of 0.7 kW/m2.
Source: Project developers’ information


Big solar heat deal

View into the technical room of the just finalised 0.8 MW solar thermal installation at the Grupo Mexico mine with the new control system S200 developed by the Danish company Jorgensen Thermal Solutions. The user interface is designed for operation with many employees, as is the case with mining industry. The balance of plant was prefabricated in Denmark and then shipped to Mexico.
Photo: Jorgensen Thermal Solutions

How did the preparations for the big solar heat deal with the three large new mining projects finally go? BHP put three solar fields out to tender in January 2022. This was the time when Nelson phoned Grydehøj to find out whether he would again be onboard to design the big plants.

“The mines are super concerned about the green copper now. This is why we even oversized the collector fields a bit in order to bring the solar share even above the 80% that we achieved at the Gabriela Mistral plant”, explained Nelson.

Gasco won the bid and published a press release in May 2023 confirming the signing of the two 20-year heat purchase agreements with the mines Minera Escondida and Spence. For the ownership and operation of the solar fields, Gasco founded two special purpose vehicles called Gasco Solar Térmico Uno and Gasco Solar Térmico Dos. Construction of the two plants should start in March 2024 and should be finalized in September 2025. The collectors will be purchased from Micoe, one of the brands of the Chinese Solareast Group, the largest collector manufacturer worldwide. The financial volume of USD 71 million is a purely private investment. There is no government funding available.

Nelson confirmed that together with Grydehøj they are currently developing other large-scale solar heat projects.

Websites of organizations mentioned in this news article:
SolarEast Group:
Jorgensen Thermal Solutions:

Bärbel Epp

Bärbel Epp is Founder and Director of the German communication and market research agency solrico and editor-in-chief of