When integrated into building structures, solar panels can contribute to a drastic reduction of the carbon footprint and increase in energy efficiency. They can also enhance architectural aesthetics.
Researchers are working on transparent solar panels that can be integrated into windows and glass facades without obstructing the view. This would transform buildings into self-sufficient energy generators.
Photovoltaic Tiles
Solar roof tiles, sometimes referred to as ‘solar shingles’, combine electricity generation with roofing protection in a visually seamless manner. The tiles have an attractive textured finish and use thin-film or crystalline silicon solar cells to generate energy from sunlight. The tiles are designed to match the aesthetic of traditional roof materials, and they can be used in new construction as well as retrofitted onto existing buildings.
The tiles are fitted on top of a supporting frame that is either painted black or left exposed. The cut ends of the solar tile can be capped or painted black, to further improve visual integration.
The PV cells that are integrated into the roof tiles capture the sun’s rays and convert them to DC electricity. This is then fed into an inverter to produce usable power for homes. The amount of power the tiles generate is dependent on how much sunshine they receive – they are more efficient during summer.
The tiles can also be fitted with a battery system to store the energy produced for later use, and this will help reduce electricity bills. Ideally, the batteries should be of the ‘deep-cycle’ variety that can be discharged to a low state without damage, and they should be kept cool, as heat decreases battery life. The electricity generated by the solar tiles is a renewable resource, which reduces the demand for fossil fuels like coal, gas and oil, which have a damaging impact on wildlife.
Solar Textiles
Incorporating solar power into fabrics is a way to make fabric manufacturing more energy self-sufficient and reduce carbon emissions. Using solar thermal technology, fabrics can be dyed without the need to use conventional electricity, thus significantly decreasing energy costs and carbon emissions. Moreover, innovative solar-powered textile machines can heat the water required for dyeing, reducing energy consumption and lowering carbon dioxide emissions further.
Various methods have been employed to integrate PV devices into textiles, including patterned, embroidered, printed or woven cells. However, the most promising approaches are those that allow solar energy harvesting to be integrated seamlessly into fabric structures. For example, woven photovoltaic (PV) E-textiles incorporate dye-sensitized solar cells, organic solar cell layers or thin-film CIGS solar panels. The resulting fabric exhibits normal textile properties such as bend, stretch, twist and shear, as well as moisture transfer, appearance, softness and washability.
Woven DSSC-based PV devices are capable of providing PCEs up to 2.63% and maintain 85% of their initial performance after being bent with a radius of 3 cm, making them suitable for use in garments and light structures. Yun et al. incorporated DSSC-type PV ribbons directly into fabric by replacing the wires of traditional weaving equipment, while Krebs and Hosel incorporated pre-fabricated OPV tapes into a woven structure that consisted of serially connected OPV strips.
However, it remains challenging to produce a high-performance and cost-effective PV textile that maintains the appearance and feel of a regular garment. Furthermore, it is not yet clear how these PV devices can handle the rigors of domestic washing.
Transparent Solar Panels
Solar panels that appear to be part of a building’s facade could help reduce the energy consumption of buildings while also providing alternative power. However, there are some challenges associated with this technology. For one, it needs a constant supply of sunlight in order to work properly. Additionally, it is less durable than conventional solar panels and requires a great deal of care when handling them.
The benefits of transparent solar panels are numerous, though. They offer a more efficient way to harvest solar energy because they allow more sunlight through than traditional PV panels. Additionally, they can be incorporated into existing windows and buildings, making them more cost-effective than conventional solar panels.
Transparent solar panels are made of semiconducting materials that can absorb light and convert it into electricity. These materials are typically sandwiched between layers of glass, with cadmium telluride or amorphous silicon being the most common. The material is drawn to positively-charged “holes” (spaces vacated by electrons) through an electrode, resulting in the generation of electricity.
Researchers are working to make these solar panels more effective. For instance, they have developed a buffer layer that protects the solar cell’s electrode from photodegradation. They’ve also found a way to increase the transparency of these solar cells without sacrificing their efficiency, which is currently around 10%. Companies such as Physee and Ubiquitous Energy are currently working on bringing this technology to market.
Building-Integrated Organic Photovoltaics (BIOPV)
Building-integrated organic photovoltaics (BIOPV) are photovoltaic materials and components that are integrated into the design of a building or other structure, replacing traditional material and providing both power generation and weather protection. They are designed to be aesthetically pleasing and blend into the existing design while offering the benefit of a clean, alternative energy source.
Unlike conventional PV panels that may look bulky and ugly, BIPV technologies are lightweight, offer customizable color options and can camouflage themselves as part of the facade or roof. They can also be used in retrofit applications to replace traditional roof tiles or shingles, as well as to provide an alternative way of cladding rear-ventilated rainscreens.
A range of BIPV solutions are available. Some use crystalline silicon cells, while others utilize thin-film technology. The latter may be more suitable for some designs, as they are often lighter, less expensive and can be easily integrated into a larger variety of surfaces.
As the popularity of solar energy increases and strict climate policies push us towards carbon neutrality, we are seeing an increased demand for beautiful building materials that can be used to generate renewable electricity. Thanks to innovations like these, the future looks bright for the next generation of solar-responsive construction products that will be a key driver in our collective transition to a low-carbon society.