A five-year study in the Netherlands shows that photovoltaic panels integrated into building facades generate greater economic value and less impact on the electricity grid than conventional roof-mounted systems.
Detailed PV performance research
A group of researchers from the University of Twente in the Netherlands, in collaboration with grid operator Tennet, has conducted a comprehensive analysis of the performance ofBuilding-Integrated Photovoltaics (BIPV) systems on building facades (BIPV) in the period 2018-2023. The study included financial, technical and environmental assessments and compared the performance of these systems with that of conventional solar panels optimally oriented on roofs. The modeling of the systems was performed with the Sandia PV Array Performance Model (SAPM), using meteorological data from the locality of De Bilt, located in the central Netherlands. In all cases, 300 W Silevo Triex-U300 Black 300 W panels were used and Dutch spot energy market prices were used to calculate the economic indicators.
Results: Economic value and environmental impact
The study analyzed the performance of south-, east- and west-facing photovoltaic facades compared to conventional roof-mounted panels. The results are revealing:
- Reducing CO2 emissions per kW installed:
- South-facing facades: 1.725 kg CO2
- East-facing facades: 1,492 kg CO2
- West-facing facades: 1,335 kg CO2
- Optimally oriented conventional panels: 2,434 kg CO2
Although roof panels reduce more emissions per kW, facades have significant economic advantages.
- The economic value factor (which measures the profitability of solar energy relative to market prices) showed an interesting trend:
- Optimally oriented panels: fall to 0.73 in 2023
- Facing east: 0.87
- West-facing facades: 0.84
“We observe a decline in the value factor of solar panels over time, but this decline is slower than anticipated in the literature,” the researchers explained. “Interestingly, east- and west-facing facades have lower rates of decline, making them more economically attractive.”
Advantages of BIPV over conventional systems
The researchers concluded that photovoltaic facades offer important benefits for the electricity grid:
- Higher local consumption: the energy generated is used more efficiently, reducing pressure on the grid.
- Reducing energy peaks: Facades produce energy at different times than optimally oriented panels, which improves the energy balance.
- Harmonious integration with building architecture: BIPV adds aesthetic and functional value to buildings.
The researchers recommended that public policies should support a more diverse mix of orientations and inclinations for solar systems to maximize efficiency and sustainability.
“The integration of solar panels in facades significantly reduces the pressure on the grid due to higher self-consumption rates and reduced peak energy delivered,” said the experts.
An innovative solution for the future
The study shows that photovoltaic facades not only offer a better long-term cost-benefit ratio, but also contribute to a more stable and environmentally friendly energy system. In the context of the global energy transition, these architecturally integrated solutions could become the norm in the near future.
