Can we take advantage of the solar energy received by building facades?
An experimental study by the University of Burgos assessed the solar energy potential in the vertical surfaces of buildings.
One of the articles published by DICYT refers to the experimental study carried out by the SWIFT Research Group (Solar and Wind Feasibility Technologies) and the University of Burgos UBU, which measured the solar radiation received by the facades of buildings.
Building Facades and Solar Energy
According to Cristina Alonso Tristán (Professor at UBU), the photovoltaic panels that have been developed in recent years could be adapted or integrated into buildings, such as photovoltaic glass, which replaces the traditional glass windows or can be integrated into glass facades of larger buildings or structures.
But not only these materials could be utilized, the study is also evaluating the possibility of incorporating photovoltaic awnings and canopies, or even the slats of the blinds (which we discussed recently in our article about solar blinds).
These materials can be integrated directly, or replacing part of the wall, as if it was a decorative material of the facade.
How much solar energy can be used?
According to Alonso Tristán, the maximum radiation is achieved when the solar rays strike perpendicularly on the panel. But this depends on the latitude of the installation as well as the day of the year.
On the other hand, the data that are currently used to design the photovoltaic installations are those obtained from horizontal perspective, just like ones used for measurements at meteorological stations.
Keeping this in mind and with the objective of determining the exact amount of solar irradiation obtained by the facades, the team experimentally measured the total energy received in vertical surfaces oriented in the four cardinal directions (north, south, east and west), with the help of an installation that the researchers had in the Superior Polytechnic School of Burgos.
For this photovoltaic study, measurements were carried out continuously over the course of 45 months, following very restrictive quality standards to ensure that the data were reliable.
What were the results?
The results indicate that vertical photovoltaic installations are completely viable.
According to Alonso Tristán, the facades receive energy at different times depending on their orientation. Through the study it has been verified that in winter months, the south façade receives more energy than the horizontal surface in the same location, so that an installation in that façade would produce more than hone installed on the roof.
On the other hand, the east and west facades produce approximately half of that of the horizontal surface, “because one receives the sun in the morning and the other in the afternoon,” but between the two “production could be distributed throughout the day”.
Even the northern facade, she adds, produces approximately 25 percent of the horizontal surface in the same location. In addition to the main aim of the study, the study also focused on the best procedure to obtain the vertical surface radiation data from different aggregates. To do this, they used two components of solar radiation – the direct and diffuse radiation data – measured in the same installation as well as the vertical surface data and applied different models that distinguish, among other things, the characteristics of the sky.
Part of the team compared the vertical radiation data that the models calculate with the experimentally measured and selected the model that obtains the least error.
Thus, photovoltaic installations can be efficiently installed into the facades.
At Solarnub we love this study, and we applaud the researcher’s dedication and efforts to investigate and work on how to combine different methods to take advantage of the possibilities that photovoltaics brings.
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