LINE-FOCUS CONCENTRATING SOLAR THERMAL TECHNOLOGIES UNIT

Energy Storage for Direct Steam Solar Power Plants (DISTOR)


Participants: DLR (D), CIEMAT-PSA (E), Sistemas de Calor (E), INASMET (E), IBERINCO (E), DEFY Systemes (F), EPSILON Ingénierie (F), SGL Technologies GMBH (D), FLAGSOL GMBH (D), Solucar (E), ZSW (D), Weizmann Institute of Science (IL), and the Central Laboratory of Solar Energy and New Energy Sources (BLG)
Financed by: European Commission, FP6-2006-ENEGY-1
Reference: SES6-CT-2004-503526
Duration: February 2004 – October 2007
Background:
Direct steam generation in the parabolic-trough collectors absorber tubes is a very attractive option for lowering the cost of electricity generated by this type of solar thermal technology. For such solar thermal power plants to be more commercial, they must have thermal storage systems that allow electricity generation to be independent from the hours of sunlight. The thermal storage systems currently available for solar thermal power plants are based on materials that heat up (sensible heat), which are not suitable for direct steam generation concentrating solar systems, so a thermal storage system specific to solar fields with direct steam generation must be developed.
Objectives:
Development of a competitive thermal storage system suitable for direct steam generation parabolic-troughs solar power plants. Since most of the thermal energy in steam is released upon condensation, and this is a process which takes place at a constant temperature, thermal storage systems for this type of solar plants must be based on a medium that can absorb heat at a constant temperature, such as the latent heat provided by phase-change materials. Several different options for a phase-change storage system were studied and the best option selected, and in 2007, a prototype storage model with a rated power of 200-kWt and capacity of 200 kWh was installed and evaluated at the PSA.

General view of the system installed in the PSA DISS plant for evaluation of the phase-change storage module for DISTOR project.

Selected publications:

  • Bayón R, Rojas E, Valenzuela L, Zarza E, León J. Analysis of the experimental behaviour of a 100 kWth latent heat storage for direct steam generation in solar thermal power plants. Applied Thermal Engineering 2010; 30(17-18):2643-2651. http://dx.doi.org/10.1016/j.applthermaleng.2010.07.011   
  • Valenzuela L, León J, Zarza E. Testing and evaluation of the thermal storage module TES-100 kWth. Project DISTOR. Doc. ID: DISTOR-SC-QA-01, Iss. 1, 2007, Plataforma Solar de Almería, 20 pp.