Infinitesimal etendue and Simultaneous Multiple Surface (SMS) concentrators for fixed receiver troughs

• Published in: Solar energy Vol. 97; pp. 493 - 504
• Main Authors: Canavarro, Diogo, Chaves, Julio, Collares-Pereira, Manuel
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2013; Elsevier; Pergamon Press Inc
• Subjects: Aperture; Applied sciences; Capital expenditures; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electricity generation; Electronics; Energy; Energy efficiency; Exact sciences and technology; Fixed receiver; Infinitesimal etendue; Natural energy; Optoelectronic devices; Parabolas; Parabolic trough; Photoelectric conversion; Photovoltaic conversion; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; SMS method; Solar cells. Photoelectrochemical cells; Solar energy; Portugal; Europe; Portugal, Faro; Infinitesimal etendue; SMS method; Parabolic trough; Fixed receiver; Solar cell; Performance evaluation; Profitability; Nonimaging optics; Maintenance cost; Comparative study; Message transmission
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2013.09.012

•The paper presents infinitesimal etendue and SMS optics for fixed receiver troughs.•The paper presents a calculation of the center of mass for each optic.•The paper compares the new optics with a conventional parabolic trough (PT).•The comparison is made for the same size receiver and the same acceptance angle.•Infinitesimal etendue and SMS optics have higher CAP values than the PT optic. In order to increase the cost-effectiveness of conventional parabolic trough (PT) fields it is essential to reduce Capital Expenditure (Capex) as well as Operations and Maintenance (O&M) costs, in particular the need for flexible hosing or rotating joints, which are used because the tubular receiver also tracks in a solidary way with the trough. One possible alternative is to design a different type of optic with the center of mass on the center of the tubular receiver, generating the possibility of it being fixed, thereby dispensing with flexible hosing or rotating joints, without penalizing its overall efficiency or even concentration. In this work, two possible optical solutions, combining parabolic-type primaries with second-stage non-imaging optics concentrators for fixed receivers, are presented. These concentrators are designed using the Simultaneous Multiple Surface (SMS) design method and the infinitesimal etendue limit. A performance comparison with a conventional PT in terms of optical efficiency, CAP (Concentration-Acceptance Product) and other performance data are also presented, including an estimate of the total amount of yearly collected energy (kWh/m2 of entrance aperture) for one particular location – Faro (Portugal).