Affiliation:
1. Deutsches Zentrum für Luft‐ und Raumfahrt (German Aerospace Center DLR) Institute of Solar Research Linder Höhe Köln 51147 Germany
2. Chair of Solar Technology RWTH Aachen University Linder Höhe Köln 51147 Germany
3. Deutsches Zentrum für Luft‐ und Raumfahrt (German Aerospace Center DLR) Institute of Networked Energy Systems Carl‐von‐Ossietzky‐Str. 15 Oldenburg 26129 Germany
Abstract
Concentrating solar thermal (CST) technologies are a sustainable way to produce high‐temperature heat. Four concepts of integrating photovoltaics (PV) into CST plants, namely Rear‐PV, PV‐Mirror, bifacial PV‐Mirror and Spillage‐concentrating PV (CPV), are compared and the technological and economic outcome is discussed. The concepts are presented for the use with solar tower systems, but can also be applied to other configurations. In this work, parameters for each concept to quantify annual energy production and investment costs are derived. It is determined that implementing Rear‐PV, PV‐Mirror, bifacial PV‐Mirror, and Spillage‐CPV in a concentrating solar power tower plant leads to an additional energy yield as high as 23%, 29%, 40%, and 36%, respectively, on the same mirror aperture size. For the concepts of the Rear‐PV, PV‐Mirror, and bifacial PV‐Mirror, maximum allowable cost per aperture area can be 3.0, 4.8, and 5.7 times the cost of conventional mirrors, to reach a break‐even of the specific investment cost per annually produced energy. Such values are considered to be achievable for PV‐Mirror and bifacial PV‐Mirror, but not for Rear‐PV. For Spillage‐CPV, a break‐even of investment cost can be achieved if installed in areas with spillage radiation flux exceeding ≈350 kWm−2 at peak.