Solar energy conversion with thermal cycles - Solar Energy Sciences and Engineering Applications - page 437

Figure 14.3.14 Longitudinal and transversal incidence angle modifier (IAM) trend as a function of
incidence angle (Giostri et al. 2013).
Figure 14.3.15 Annual maps of optical efficiency ratio (OR) for LFR technology (Giostri et al. 2013).
The yearly optical efficiency of the commercial collector with the performances
taken from the Thermoflex® database is in the range of 38%; this is 15% points lower
than PT. With regard to thermal losses, thermal efficiency is about 90% like PT.
To summarize, linear Fresnel collectors have good potentiality to reduce costs, but
they are affected by lower efficiencies than PT. In particular, the concept of several flat
mirrors introduces significant optical penalties compared to the parabola system.