Semi-transparent PV: Thermal performance, power generation, daylight modelling and energy saving potential in a residential application

Caamaño‐Martín

et al. 2014

Energy and Buildings

In this paper, a methodology for the integral energy performance characterization (thermal, daylighting and electrical behavior) of semi-transparent photovoltaic modules (STPV) under real operation conditions is presented. An outdoor testing facility to analyze simultaneously thermal, luminous and electrical performance of the devices has been designed, constructed and validated. The system, composed of three independent measurement subsystems, has been operated in Madrid with four prototypes of a-Si STPV modules, each one corresponding to a specific degree of transparency. The extensive experimental campaign, continued for a whole year rotating the modules under test, has validated the reliability of the testing facility under varying environmental conditions. The thermal analyses show that both the solar protection and insulating properties of the laminated prototypes are lower than those achieved by a reference glazing whose characteristics are in accordance with the Spanish Technical Building Code. Daylighting analysis shows that STPV elements have an important lighting energy saving potential that could be exploited through their integration with strategies focused to reduce illuminance values in sunny conditions. Finally, the electrical tests show that the degree of transparency is not the most determining factor that affects the conversion efficiency.

Section: Introductionmentioning

confidence: 99%

Integral energy performance characterization of semi-transparent photovoltaic elements for building integration under real operation conditions

Caamaño‐Martín

et al. 2014

Energy and Buildings

“…Therefore, to obtain an accurate simulation outcome, visible transmittance was obtained from WINDOW 6.3 for each semi-transparent PV panel with different PV cell coverage ratio and was incorporated into Energy Plus as part of the daylight simulation. Thus, daylight illuminance was calculated and recorded in Energy Plus, allowing the simulation and calculation of lighting energy consumption [11].…”

Section: Heat Balance Modelmentioning

confidence: 99%

“…The transmittance of PV panels or glass for PV façades, which is determined by the PV cell coverage ratio, has been shown to have a profound impact on the overall energy consumption of buildings, particularly through its effects on PV electricity generation, lighting, cooling, and heating [10][11][12]. For example, Jiang et al [10] conducted a study to investigate the influence of PV cell coverage ratio on the thermal and electrical performance of photovoltaic Trombe walls and discovered that a higher PV cell coverage ratio does not necessarily result in better thermal performance.…”

Section: Introductionmentioning

confidence: 99%

“…For example, Jiang et al [10] conducted a study to investigate the influence of PV cell coverage ratio on the thermal and electrical performance of photovoltaic Trombe walls and discovered that a higher PV cell coverage ratio does not necessarily result in better thermal performance. In terms of overall energy consumption, Wong et al [11] described the minimisation of energy consumption based on combinations of semi-transparent PV transmittance and window-to-wall ratios (WWRs). Conversely, Miyazaki et al [12] found lighting control to be an important element in maximising the usage of daylight and demonstrated that the impact of solar cell transmittance on energy performance varied with WWR.…”

Section: Introductionmentioning

confidence: 99%

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Optimal PV cell coverage ratio for semi-transparent photovoltaics on office building façades in central China

Shen

Liao

Huang

et al. 2014

Energy and Buildings

Abstract:The present study investigates the optimal PV cell coverage ratio in terms of the overall energy consumption of office buildings in central China for which semi-transparent photovoltaic façades have been implemented, with various combinations of architectural variables including room depth, window-to-wall ratio (WWR), and orientation. Here, models and methods are established for the calculation of PV cell coverage ratio for a single-glazed semi-transparent PV façade and these models and methods are validated through field experiments. The established techniques are then incorporated into Energy Plus to perform a parametric analysis of the effects of different PV cell coverage ratios on overall energy consumption. The results show that PV cell coverage ratio has a pronounced effect on electricity consumption and that its impact is influenced by different combinations of room depth, WWR, and orientation. Moreover, the selection of an optimal PV cell coverage ratio is found to be an important element of the design approach in building-integrated PV (BIPV) systems: use of the optimal PV cell coverage ratio can achieve overall energy consumption savings of 13% (on average) compared to the least favourable PV cell coverage ratio.

“…When PV or Concentrating PV (CPV) are used for glazing facades or windows, they facilitate penetration of solar radiation through the active areas of the panel directly, or through gaps between opaque solar cells or concentrating units, depending on the types of PV or CPV in use. Besides generating electricity buildings incorporating PV and CPV systems may benefit from the advantage of natural space heating during winter and increased indoor illuminance from daylighting [4,5]. In recent years, many theoretical and experimental studies have been conducted to investigate the performance of Building Integrated PV and CPV systems.…”

Section: Introductionmentioning

confidence: 99%

Design and development of a reflective membrane for a novel Building Integrated Concentrating Photovoltaic (BICPV) ‘Smart Window’ system

Connelly

Chen

et al. 2016

Applied Energy

A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. Specifically, a switching temperature (Ts) of ~42 °C (6 wt. % HPC) was recorded, the measured transmittance decreases from ~ 90% to ~20%, with the temperature of the reflective layer increasing from 20°C to 60°C. No hysteresis in optical property was observed upon heating-cooling cycle of HPC membrane samples. The measured reflectivity increased with heating from ~10 % below the Ts to ~50 % above the Ts (for 6 wt. % HPC). These features indicate that the as-prepared HPC based thermotropic hydrogel layer holds great potential for application in next generation BICPV smart windows.