Development and outdoor characterization of a hybrid bifacial HCPV module

Abstract

Conversion of direct, diffuse, and albedo irradiance into electricity is demonstrated with a new kind of hybrid bifacial high‐concentration photovoltaic module named bifacial EyeCon. It consists of Fresnel lenses that concentrate the direct sunlight 321x onto III‐V triple‐junction solar cells that are mounted on the front surface of p‐PERC bifacial c‐Si cells. Thus, the Si absorbs the front and rear diffuse irradiance. Because III‐V and Si cells are electrically isolated (hence a 4‐terminal device) but thermally coupled by a dielectric adhesive, Si also acts as a heat distributing substrate. To accommodate the concentrator cells, we adapted the metallization layout and also optimized it for low intensity, ie, 200 W/m2 on the front and 100 W/m2 on the rear, using finite element network simulation. Additionally, when the concentrator cells are mounted on a bifacial Si cell instead of a metal heat distributor, their operating temperature is 16 K higher. However, we demonstrate with outdoor measurements that the power output of the bifacial EyeCon module reaches up to 326 W/m2 when the direct to global irradiance ratio is 92%. At a lower fraction of 70% the bifacial Si cells augment the power output of the III‐V string by 19%rel

Industrialization of hybrid Si/III–V and translucent planar micro‐tracking modules

“…The perspective has motivated several groups to explore the idea in various realizations: III-V cells located in-between spaced Si cells, 14 mounted on a transparent substrate above the Si cells, [14][15][16] or directly mounted on top of the Si cell. 5,12,17,18 Hybrid Insolight modules initially took the first approach. The aspherical coefficients that define the shape of the biconvex lens were optimized using ray-tracing simulations in order to maximize simultaneously the amount of direct light concentrated on a 1-mm triple-junction cell and the amount of diffuse installed.…”

“…Moreover, the laminate is compatible with bifacial Si cells, which can capture albedo from the surroundings. The benefits of using bifacial Si cells in a hybrid CPV/PV architecture were discussed by Martínez et al 17 The energy gains associated will be further discussed in Section 3.3.…”

Power rating procedure of hybrid concentrator/flat‐plate photovoltaic bifacial modules

“…Notably, these values remain below those of conventional CPV modules ( η < 38.9%) 7 because their calculation is based on GNI instead of DNI. Nevertheless, it has been demonstrated that hybrid devices are able to generate between 3.5% and 30.6% more power, relative to their CPV part, when the DNI/GNI ratio is between 92% and 57%, respectively 2,8 …”

“…Both modules concentrate DNI 321 times with a 4 × 12 array of silicone‐on glass Fresnel lenses where a single lens has a size of 4.76 × 4.76 cm 2 . Additionally, the 48 CPV cells are mounted with a dielectric adhesive onto the top surface of a flat‐plate PV array of eight bifacial positively doped passivated emmiter rear contact (p‐PERC) c‐Si solar cells 8,22 . This enables the flat‐plate PV cells to act as heat distributors for the CPV cells.…”

“…Moreover, the Si cells have a custom size of 91 × 141 mm 2 and a metallization layout optimized for absorption of diffuse and rear side irradiance. Further details about the module development and outdoor performance can be found in Martínez et al 8 …”