SOLAR TRES: Molten Salt Solar Thermal Power 15 MWe Demonstration Plant

Participants:  SENER Ingeniería y Sistemas, S.A. (ES), GHER,S.A. (ES), CIEMAT-PSA (ES), Compagnie de Saint Gobain, S.A. (FR), SIEMENS Aktiengesellschaft (DE)

Contacts:    Javier Viñals (javier.vinals@sener.es), Juan Ignacio Burgaleta (ignacio.burgaleta@sener.es); Félix M. Téllez (felix.tellez@ciemat.es)

Funding:      CEC- DG TREN (ENERGIE Program, Ref.:NNE5/369/2001): 5 M€

Duration:       December 2002-December 2008

Background: The Project accumulates the experience of the former Solar Two project, but also has design innovations which have come out of work performed together by SENER and the CIEMAT as well as the technical conditions imposed by Spanish legislation on solar thermal power. The initial Solar Tres project was predesigned to meet the requisites of the Spanish legal framework in 2000. During the development of the project, national legislation on renewable energies underwent some changes, and there were also some changes in partners, which led to reorientation of the project and the promoting consortium. Finally, in 2005, the team was consolidated in an entirely European consortium led by SENER. At the same time, SENER and CIEMAT signed an agreement for the development and evaluation of new heliostat and molten salt receiver concepts and a prototype with better thermal performance, able to operate at higher flux without compromising its durability (see project below).

Purposes: The purpose of the SOLAR TRES project is to build and operate a 17‑MW commercial-scale demonstration solar thermal power plant with heliostat field, tower and molten salt thermal storage system. As allowed by recent Spanish law (RD 661/07), the facility will have up to 15% natural gas or LPG, which, which along with the molten salt heat transfer fluid and thermal storage, will make it possible to generate 105 million kWh/year. This electricity will be delivered entirely to the grid under the Special Regime for Electricity Generation established by the above-mentioned decree.

Predesign views of the Solar Tres plant

Achievements in 2007: SENER and the CIEMAT undertook “validation” of the Solar Tres receiver design, a task important to the progress of the Project, through the construction and evaluation of a prototype panel receiver with their own funding (65% SENER, 35% CIEMAT), and in October 2007, after successful experimental validation, the prototype receiver and salt loop, SENER decided to promote the plant that is now called GEMASOLAR. By that time they had already done the permitting and financing necessary for the special regime, and they had begun the environmental impact studies on the site chosen. In 2007, detailed engineering of the main components was completed: Heliostat, receiver, and thermal storage system (SENER), turbine selection (Siemens), electrical tracing, instrumentation and definition of the civil engineering work (SENER), selection of mirrors for heliostat (Saint Govain).

Diagram of the Solar Tres/Gemasolar Plant