=
H.Thomanson, energy increase of 30%
non-specular mirrors used by sherman, babor and others [11-15]
Solar collector mounted vertically
Includes correlation for reflectance at large angles of incidence
Takes into account beam and diffuse radiation
preliminary impovment of 1.6+/-0.6 over straight collector
uses spectrally averaged data for reflectivity, 0.9 new 0.7 weathered, coated with SiO
optimum performance when angle between panel and reflector is 90 degrees
focus on winter improvment
reccomends reflector length of twice the height of the panel in winter, 1.6 in summer
good graph showing enhansement factor of the array
First reflection work by Shuman [1]
McDaniels et al. [3], Seitel [4], Grassie and Sheridan [5], Baker et al. [6] and Larson [7] investigated the energy enhancements received by thermal collector–reflector systems under different conditions
Reflector attached to the top edge of the system
optimization for a single panel
does not take into account the electrical properties of the PV cell
does not take into account diffuse radiaiton
does not look at thermal effects on panel performance
assumes p=1
good derivation of radiation reflection onto a panel
gains of 71,24, 19% for December March/September and June resp.
Discussion of tracking concepts
McDaniels et al. [1], Baker et al. [2], and Larson [3]. Optimal winter tilts of reflector and collector for winter space heating
Narasimha Rao et al. [8] optimized the reflectors’ tilt angles of a two plane reflectors-collector system with the reflectors located facing East/West
South or North [4–7].
reflector located above the panel
specular reflectivity of 0.88
Considers only a single panel, therefore edge losses
Geometric interpretation including plane transformations are discussed
Summertime boost of 5%-10% wintertime of 30%-35%
once a day, once a month, once a season, twice a year, and once a year16.9%, 16.3%, 14.4%,13.3%, and 6.6%, respectively
reflector is angled towards the sky
System not optimized for yearly boost
Integrates the concentrator into the module
uses a three position tracking system, that tracks one module by itself.
Increase due to concentration: 23%, increase due to tracking , 56%
Performs economic analysis assuming the cost of modules is 3-5$/Wp, this is too high now