Astexol II

Astexol II · Project Sheet

  • CSP TECHNOLOGY: Parabolic trough collector CSP with oils (HTF) and BOP
  • LOCATION: Olivenza (Badajoz-Spain)
  • AKOTRACE® electrical heat-tracing system turnkey solution
  • 6 engineers and 30 filters.
  • 12 km of mineral insulation heating cable.
  • 64 active circuits in oils (HTF).
  • 36 active circuits in steam (BOP).
  • Over 600 control i/o
  • 9 months of execution.


The ASTEXOL II thermosolar plant is built in the municipality of Badajoz (Spain). There are currently six thermoelectric power plants operating in Extremadura: La Risca and La Florida, in Alvarado; La Dehesa in La Garrovilla and Extresol 1 and 2 in Torre de Miguel Sesmero, all in the province of Badajoz, and Majadas in Majadas del Tiétar, in the province of Cáceres. In all of these, AKO has been chosen to supply and install its AKOTRACE® complete electrical-heat tracing solution, in both the molten salts and in the oils (HTF) and steam (BOP) part. Both are critical points of great productive importance in the operation of the thermosolar power plant.

The power plant has been launched by Dioxipe Solar, and is promoted by Elecnor, Aries Ingeniería y Sistemas and ABN AMRO Global Infrastructure Fund. The general characteristics of this parabolic-trough mirror power plant are:

  • Rated electrical power: 50MW
  • Total electricity production: 150 Gwh/year
  • The solar field has two 510,120 m² solar fields with mirrors and 624 solar collectors each, that allow reducing the energy capturing costs.
  • This power plants will supply 37,000 households with clean energy.
  • Thermal oil system that includes main and auxiliary pumpuing installations, tanks, oil boilers and ssteam generation equipment.
  • Water-stream cycle auxiliary installations (BOP).

This thermosolar power plant is a type of sustainable installation that uses solar radiation to produce clean, efficient and safe energy capable of covering the electricity supply of thousands of households, demonstrating the different factors of CSP technologies, contributing to energy safety, on using a local resource, exploiting natural resorces and without emitting greenhouse gases.

To answer this technical challenge, the promoter DIOXIPE SOLAR has trusted AKO, as a partner, to provide its electrical heat-tracing solution, AKOTRACE®. Collaboration with the FLUOR Engineering Firm has been added to this factor, to ensure the correct operation of the heat-tracing system, critical in this type of facilities, given the high operating temperatures to be maintained tha can reach 400 ºC.

Project Challenge

Technical requirements, athough largely already resolverd by AKO in many proyects executed in thermosolar plants with parabolic trough as well as HTP oil and BOP steam, added important differences such as:

  • The process working and maximum temperatures of materials in this type of plants with a risk of fire and explosion, in the circulation of the oil flow.
  • Tracing of critical points such as valves, pump heads and vertical pipelines, providing in the first case, a specific and improved solution to the one used up to the moment.
  • The scope and capacity of AKO's management in the simultaneous execution of two thermosolar power plants, that represents a total of 50 MW, applying its knowledge and experience and guaranteeing the efficiency and profitability of the on site installation.

AKOTRACE® Solution

The scope of the AKO solution has been the execution of the turnkey electrical heat-tracing system, AKOTRACE® for the overall facility. AKO's Innovation Director, Miguel Angel González, referring to this project: "Specifically, we have implemented our DCS-AKOTRACE® control solution in BOP and HTF, and not mechanical type traditional solutions, that although have lower investment costs turn out be expensive in operation.

In the AKOTRACE® solution, it is worth mentioning that we have chosen different key technical characteristics for this project:

  • Mineral insolution (MI) cable and constant power cable (according to special characteristics) for both the BOP Area and the HTF area.
  • PT100 type probes (locale) and ambient probes (according to design).
  • Installation of PLC's AKODUO Control Trace in HTF for circuit control.
  • Connectivity with de DCS.
  • Operator interface displays in the plant for quick identification of the system status.

All in an execution time of 9 months, in which other facilities have been overlapped in time and in which AKO's main qualitis have been highlighted, work capacity on several fronts.

AKO has also guaranteed all the necessary engineering documentation; flexibility, taking part in supply management and, in short, the capacity of being able to carry out the different works simultaneously.


AKO started the ASTEXOL II Thermosolar Power Plant project in August 2011 to May 2012. The results obtained in the implementation of the AKOTRACE® in such an emblematic project are:

  • Introduction of improvements in the basic engineering area: definition of the design and optimisation criteria of the process.
  • Assurance of the citricality of the system with an efficient investment, guaranteeing the circulation of the fluid at high temperatures, to prevent undesired Plant shutdowns or a loss of performance in its operation.
  • Correct operation carrying out a spares management on site, with the material and staff necessary to face any incident in the facility, as well as strictly meeting health, safety and hygiene standards.
  • Specialised training of the plant's staff on the correct operation of the tracing system and its installation.
    Transparent integration with the plant's management system to make plant maintainability easier.

The execution of this project complements the experience and knowledge acquired by AKO throughout its over 30 years of experience, which has positioned it as the world leader, committed to renewable energy future technologies in parabolig through and concentration tower Thermosolar Power Plants Projects.

About AKO

Over 30 years of innovation and with 130 people team of in-house professionals AKO Electromecànica, S.A.L. is a Spanish company leader in the Regulation and Control of Temperature with Electrical Heat Tracing Solutions for Concentrated Solar Power Plants (CSP), that offers comprehensive support from project design and manufacturing, to technical assistance, to the System commissioning (turnkey projects) and after-sales service. Electrical Heat Tracing System AKOTRACE® based the heating cable technology, providing advantages and savings on energy and the overall cost of the installation, with a reliable and secure management, ensuring the health, safety and respect for the environment.

Case Studies

Samcasol CSP

View Project »

Termosol 1&2

View Project »

Valle 1&2

View Project »

Andasol III

View Project »

Astexol II

View Project »

Gemasolar CSP

View Project »