Advanced concepts of concentrating solar power

Solar power, currently the fastest growing non-conventional renewable energy source, is set to play a key role in replacing fossil fuels. At present, sunlight is converted into electricity using two technologies: photovoltaic (PV), which converts solar radiation directly into electricity, and Concentrated Solar Power (CSP), which uses mirrors and optical devices to redirect and concentrate sunlight onto a receiver where heat is generated. Unlike PV and other renewable sources that are naturally intermittent, CSP makes it possible to produce energy continuously by storing the heat generated. The potential for CSP is particularly high in arid and desert regions where the solar radiation conditions could make solar thermal power a commercially attractive alternative to fossil power plants.

Project aim and results:

This programme investigates more efficient and cost-effective technological options for CSP, while encouraging constructive dialogue among all stakeholders. We assessed different technological alternatives according to their technical criteria, cost benefits, reliability and economic viability. Particular attention was paid to the optimisation of Linear Fresnel Reflectors, the choice of the heat carrier fluid, and the introduction of heat storage to minimise day/night effects. Among other research findings, we identified optimal mirror field designs based on a comparative study of Fresnel configurations and evaluated thermodynamic performance (Brayton and Rankine cycles) based on different working fluids and thermal conditions. This prompted a systemic analysis of the use of CO₂ as a heat carrier fluid.
In addition to these activities, we established important collaborations with partners from the research, policy and business communities in order to find practical solutions for CSP implementation in regions where the potential for solar power is high, particularly in Latin America. Here, the IASS, together with the United Nations (UN ECLAC) and other partner institutions, has investigated the potential for CSP in Chile (including the creation of a solar power research centre) and made a real contribution to the elaboration of Chile’s solar power strategy. The success of this process can be seen in the request for proposals for the construction of CSP systems in northern Chile (at least 10 megawatts), which has secured the financial backing of Chilean and international institutions.

Selected Publications:

• Rationale for a Latin American Solar Energy Research Center (CELES): Report prepared by the "Latin American Solar Task Force" at the IASS on the potential of CSP in Latin America, 2012.
• Muñoz-Antón, J., Rubbia, C., Rovira, A., Martínez-Val, J. M. (2015): Performance study of solar power plants with CO2 as working fluid. A promising design window. - Energy Conversion and Management, 92, p. 36-46.
• Montes, M. J., Rubbia, C., Abbas, R., Martínez-Val, J. M. (2014): A comparative analysis of configurations of linear Fresnel collectors for concentrating solar power. - Energy, 73, p. 192-203.
• Rovira, A., Rubbia, C., Valdés, M., Martínez-Val, J. M. (2014): Thermodynamic cycles optimised for medium enthalpy units of concentrating solar power. - Energy, 67, p. 176-185.