Solar thermal energy for industrial heat with ENESTRA
Sample Projects - Case Studies
Case Study: Solar Thermal Energy for Copper Production at Minera Centinela (Chile)
Facts
Company Minera Centinela (formerly Minera El Tesoro)
Region Antofagasta, Chile
Industry Mining – Copper Production
Application
Providing renewable process heat for the electrowinning process in copper production.
Initial Situation
Copper production in northern Chile is one of the country’s most energy-intensive industries. For the electrolytic extraction process, the electrolyte solution must be continuously maintained at a specific temperature. Due to the extremely high levels of solar radiation in the Atacama Desert, the use of solar thermal systems is an ideal solution for reducing the consumption of fossil fuels required for this process heat.
Technological Solution
Minera Centinela installed a parabolic trough-based solar thermal system to provide industrial process heat.
The system includes:
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16,700 m² of parabolic trough collectors
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Precess heat in the range of 80–85 °C
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Integrated thermal storage
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Coverage of approximately 55% of the process heat demand
The solar heat is used to heat the electrolyte solution and replaces a significant portion of the heat previously generated by conventional means.
Results
Collector area approx. 16,700 m²
Collector type Parabolic trough collectors
Process temperature 80–85 °C
Heat storage Available
Proportion of heat provided by solar energy Approx. 55%
Annual production Approx. 24,800 MWhth
Context
Minera Centinela was one of the world’s first mining companies to use solar thermal energy on an industrial scale for process heat.
It is particularly noteworthy that solar thermal energy is not used here to generate electricity, but rather directly supports an energy-intensive production step. Heating the electrolyte solution is one of the continuous heat demands of a copper mine and is therefore very well suited for the integration of solar thermal systems.
Technology Profile
Industry Copper mining
Technology Solar thermal energy using parabolic trough collectors
Collector area approx. 16,700 m²
Temperature Range 80–85 °C
Heat Storage Available
Annual Heat Generation Approx. 24,800 MWhth
Solar Coverage Rate approx. 55%
Sources
Primary Source
Fraunhofer Chile Research – Reduction of Energy Consumption in the Mining Industry through Solar Energy (presentation by Prof. Dr. Werner Platzer, Expomin 2016). Information on Minera Centinela in the project overview, as well as explanations regarding the integration of solar thermal process heat.
Case Study: Solar-Assisted Process Heat in a Brewery
Facts
Company Badische Staatsbrauerei Rothaus AG (Germany)
Application Decarbonization of industrial process heat in the beverage industry
Initial Situation
The brewing process requires a continuous supply of high-temperature heat. The brewery was already using wood chips for its heat supply and was looking for additional ways to reduce its reliance on fossil fuels.
Solution
In 2018, a solar thermal system with approximately 1,000 m² of vacuum tube collectors was installed. Via a separate heating network, the system primarily supplies two bottle washing lines with process heat exceeding 85 °C. A 50-m³ hot water storage tank enables the temporary storage of solar heat and supports flexible operation. Due to higher production volumes during the summer months, the solar heat generated can largely be used directly.
Results
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Solar heat output of approximately 400 MWh per year
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Annual CO₂ savings of around 120 metric tons
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Reduction in the consumption of fossil fuels
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Integration of renewable heat into existing production processes
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Use of solar heat even outside of production hours to heat brewing water reserves.
Context
This case study demonstrates that solar thermal energy is not only suitable for building heating but can also support industrial processes with high temperature requirements. Its use is particularly cost-effective where heat demand coincides seasonally with solar radiation—as is the case with breweries that have higher production volumes during the summer months. The combination of solar thermal energy, thermal storage, and an existing sustainable heat supply can further reduce the use of fossil fuels and improve the carbon footprint.
Technology Profile
Industry Food and Beverage Industry
Technology Solar thermal energy for process heat
Temperature range > 85 °C
Heat storage 50 m³ hot water storage tank
Collector area approx. 1,000 m²
Annual Solar Yield approx. 400 MWh
CO₂ Savings approx. 120 metric tons/year
Source:
Brewing4EU – Transition to solar energy by the Rothaus Brewery in Germany
Case Study: Seasonal Heat Storage for a Solar District Heating Network in Vojens (Denmark)
Facts
Company Vojens District Heating (Vojens Fjernvarme), Denmark
Industry Municipal heat supply / district heating
Application
Supplying a municipal district heating network with renewable heat through solar thermal energy and seasonal heat storage.
Initial Situation
The Danish city of Vojens aims to significantly increase the share of renewable energy in its heat supply while simultaneously reducing the district heating network’s CO₂ emissions. A particular challenge was making the solar heat generated in the summer available during the winter months, when heat demand is at its highest.
Technological Solution
In 2016, a large-scale solar thermal plant with a collector area of approximately 70,000 m² and a thermal output of 49 MW was commissioned.
The centerpiece of the system is a seasonal underground storage pit (Pit Thermal Energy Storage—PTES) with a storage volume of 200,000 m³. The solar heat generated in the summer is stored in this water-filled reservoir and can be retained for several months with virtually no loss. During the heating season, the heat is extracted and fed into the district heating network.
To ensure a reliable supply, the system is supplemented by additional heat generators, including gas engines, an electrode boiler, an absorption heat pump, and gas-fired boilers.
Results
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Solar thermal collector area: 70,000 m²
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Thermal output: 49 MW
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Seasonal heat storage: 200,000 m³
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Supplies approximately 2,000 households
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More than 50% of the annual heat demand is covered by solar energy.
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Savings of approximately 6,000 metric tons per year.
Context
The facility in Vojens is considered one of the most significant international examples of the combination of solar thermal energy and seasonal heat storage. While conventional heat storage systems typically retain heat for only a few hours or a few days, the ground-source storage system enables storage over several months. As a result, a significant portion of the solar heat generated in the summer can be used in the winter.
The project demonstrates that large heat storage systems can play a key role in the decarbonization of municipal heating networks. In particular, regions with well-developed district heating infrastructure can significantly increase the share of renewable energy through seasonal storage while simultaneously reducing the use of fossil-fueled peak-load boilers.
Technology Profile
Sector Municipal District Heating
Technology Solar thermal energy with seasonal ground-source storage (PTES)
Collector area 70,000 m²
Thermal output 49 MW
Heat storage 200,000 m³
Households supplied approx. 2,000
Solar Coverage > 50%
CO₂ Savings approx. 6,000 metric tons/year
Sources
Solar Heat Europe – Solar district heating with the largest pit thermal storage globally
Solar Heat Europe – Vojens District Heating
Case Study: Solar Thermal Energy for Industrial Meat Processing
Facts
Company Fleischwaren Berger GmbH & Co. KG (Sieghartskirchen, Lower Austria)
Industry Food industry – meat and sausage production
Application
Providing renewable process heat for the production of ham and sausage products.
Initial Situation
The production of high-quality meat and sausage products requires significant amounts of thermal energy. Process heat is needed, among other things, for steam generation, cooking processes, and the operation of aging and drying facilities. The company’s goal was to permanently reduce its consumption of fossil fuels and make its energy supply more sustainable.
Technological Solution
A large-scale solar thermal system with a capacity of 750 kW and a collector area of approximately 1,067 m² was installed at the production site.
The solar heat generated is integrated into two central production processes:
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Preheating the feedwater for the steam boiler, which supplies process steam to ham production.
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Providing heat for the curing and drying processes of long-life sausage products.
A 60-m³ buffer storage tank enables the temporary storage of solar heat and ensures that the energy can be integrated into the production process as needed. This allows the solar energy yield to be used efficiently even when solar radiation fluctuates.
Results
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Collector area: approx. 1,067 m²
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Thermal output: 750 kW
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Heat storage tank: 60 m³
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Savings of approximately 62,500 liters of heating oil per year
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Reduction in CO₂ emissions of approximately 219 metric tons per year (depending on the source, figures of about 145 metric tons of CO₂ are also cited; the higher figure is published by Austria Solar.)
Context
The case study shows that solar thermal energy is not only suitable for hot water or building heating, but can also support demanding industrial production processes.
Particularly interesting is the combination of multiple applications within a single facility. At Fleischwaren Berger, solar heat is used both for steam generation and for aging and drying processes. This increases the on-site consumption of the heat generated and improves the system’s economic efficiency.
Integration into existing production facilities also demonstrates that renewable process heat can often be implemented as a supplement to existing heat generators without having to rebuild the entire energy supply system.
Technology Profile
Industry Meat processing
Technology Solar thermal energy for process heat
Collector area approx. 1,067 m²
Thermal output 750 kW
Heat storage 60 m³
Applications Steam boilers, aging and drying processes
Energy savings Approx. 62,500 liters of heating oil/year
CO₂ savings Up to 219 metric tons/year
Sources
Austria Solar – Gallery: Fleischwaren Berger
SOLID – Fleischwaren Berger Success Story
Case Study: Solar Thermal Energy for Process Heat in Dairy Processing (California)
Facts
Company A dairy processing plant in Southern California (USA)
Industry Food and beverage industry – dairy processing
Application
Providing renewable process heat for energy-intensive drying processes in the production of dairy products.
Initial Situation
The facility has been producing various dairy products for many years, including butter, drinking milk, and milk powder. A significant portion of its energy demand is attributable to thermal processes, particularly drying. The company’s goal was to meet a portion of its heat demand with renewable energy and reduce its consumption of fossil fuels.
Technological Solution
An industrial solar thermal system was installed to support the process heat supply. The system generates heat for production processes and is integrated into the existing energy system. This allows a portion of the required process heat to be provided by solar energy without fundamentally changing production processes. The solar thermal system supplements the existing heat supply and helps reduce fuel consumption.
Context
This case study illustrates that solar thermal energy is not limited to building heating or hot water. In the food industry as well, industrial heating processes can be supported by renewable energy. This is particularly interesting for facilities with a continuous heat demand throughout the year, as the solar heat generated can be directly integrated into production processes.
Milk processing is one of the industries with high thermal energy requirements. Applications such as pasteurization, cleaning (CIP), evaporation, or drying generally offer potential for the use of solar process heat. The case study shows how existing production facilities can be gradually decarbonized without having to replace the entire energy supply.
Technology Profile
Industry Dairy Processing
Technology Solar thermal energy for process heat
Application Industrial drying processes
Objective Reduction of fossil fuel-based process heat
Integration Supplement to existing heat generation
Sustainability Reduction of CO₂ emissions and energy costs
Source:
SOLID – Dairy Industry in California