As an important part of the "Three Major Buildings", the Grand Canal Museum (East Building of the Capital Museum), known as the "Canal Boat", has a photovoltaic glass that can generate electricity and adjust light transmittance as needed. It has been embedded between the metal roofs shaped like water waves, becoming a new highlight of the Grand Canal Museum.

     From the outside, the south side of the Grand Canal Museum looks like a huge sail, hoisted high, and the north side looks like a ship, solid and heavy, as if it is an "ancient sail" embedded in the city forest. In the hall, the sunlight shines into the room through the glass on the roof frame, forming golden shadows on the ground, as if entering the hall of an ancient Chinese building. While this kind of glass brings us a spatial shock, it also has another unique function - power generation.

  The Grand Canal Museum combines the formal characteristics of its own large roof frame with cadmium telluride thin-film photovoltaic glass distributed on the metal roof. This glass is not made by adding thin-film battery components to ordinary glass, but by laminating and hollowing out the tempered glass specially used for construction, and then adding thin-film batteries to achieve a perfect combination of building function and power generation effect.

    The first impression of traditional solar panels is that they are made up of many small blue-black squares. This type of crystalline silicon solar panel is usually independent of building components and cannot be integrated with the building, and it is difficult to meet the architect's requirements for building form and effect. The thin-film photovoltaic glass used on the roof of the Grand Canal Museum is a brand-new photovoltaic component.

    So, what are the advantages of this power-generating glass compared with traditional photovoltaic modules? Jia Chengliang, executive manager of the Capital Museum East Hall project of Beijing Urban Construction Group, unveiled the "veil" of photovoltaic glass to reporters. "Because the light-absorbing layer of thin-film solar cells is very thin, its thickness ranges from a few hundred nanometers to a few microns, while the thickness of general crystalline silicon solar cells is 150 microns to 200 microns, which is nearly 100 times the thickness of the light-absorbing layer of thin-film solar cells. Therefore, compared with crystalline silicon cells, thin-film photovoltaic power generation glass is easier to achieve building photovoltaic integration." Jia Chengliang said that unlike traditional crystalline silicon solar panels, this film has better absorption of the entire spectrum, so the luminous effect is significantly better than traditional crystalline silicon cells under weak light conditions such as early morning and evening.

    In terms of technology, thin-film solar cells are made by coating a thin film on a glass substrate, and then the film is divided into several sub-cells through a laser scribing process and connected in series. With this operation, the width of the sub-cell division is not easily visible, and has good color consistency and light transmittance consistency.

     In addition, as a new generation of solar cells, thin-film solar cells also have outstanding advantages such as saving raw materials, low energy consumption, no pollution, and large-scale production. Not only does it have excellent power output, it can also reduce the heat of the sun and regulate the incident solar radiation, reduce the energy consumption of building air conditioning, improve natural lighting effects and enhance visual comfort. It is also safer and more reliable to be applied to buildings. "The transmittance of this film can also be adjusted as needed, usually with a transmittance of 20% to 40%. Of course, the transmittance is inversely proportional to the power generation efficiency, that is, the higher the transmittance, the less electricity is generated." Jia Chengliang said.

    It is reported that the electricity generated by these photovoltaic glass will be fed into the power distribution system in the venue nearby, with an annual power generation of 50,000 to 60,000 kWh, which can provide general lighting electricity for the two exhibition halls on the second floor of the venue. Because of the "self-generation and self-use, surplus power to the grid" model, when the sunlight is insufficient in winter, the municipal power supply is used, and the municipal power and solar power are organically combined and switched freely. At present, the roof photovoltaic power generation has been basically installed.

    At the same time, during the construction, the Grand Canal Museum also adopted a number of green technologies such as high-performance enclosure structure design, regional energy technology, reclaimed water system, heat recovery technology, carbon monoxide and carbon dioxide concentration monitoring system, energy-saving lamps, level 1 water-saving appliances, energy-saving elevators, etc. to minimize energy consumption. According to calculations, the actual carbon emissions after the project is put into operation are about 79.4 kg/m2/year, and the carbon reduction ratio is about 37.5%. Compared with public buildings that have not taken energy-saving and emission reduction measures, it will reduce carbon dioxide emissions by about 4,755 tons each year.

Guangdong Mingyang Thin Film Technology Co., Ltd.

Guangdong Mingyang Thin Film Technology Co., Ltd. (hereinafter referred to as "Thin Film Technology") is committed to the research and development and application of energy-saving and environmentally friendly green building materials and building photovoltaic integrated products. The company has advanced thin-film photovoltaic technology, and the conversion efficiency of its cadmium telluride thin-film batteries certified by a third party has reached an advanced level. Current products include standard photovoltaic modules, BIPV photovoltaic glass, customizable light-transmitting, colored, glazed, hollow photovoltaic glass, etc. The products have been successfully applied to smart cities, urban landscapes, rural revitalization, low-carbon transportation, integrated light storage and other fields, which not only meet the requirements of building safety and beauty, but also provide economical and practical green energy.

     At the same time, Thin Film Technology has a first-class perovskite technology research and development team, and has invested heavily in the development of the next generation of thin-film photovoltaic and stacked power generation technology with great potential. The company has built a high-efficiency perovskite solar cell experimental center, with a complete equipment system for battery and module preparation and testing, and the conversion efficiency of the trans-structured perovskite thin-film battery certified by a third party has reached 25.11%. At present, it is accelerating the promotion of new high-efficiency goals and industrialization layout, and it is expected to achieve technology implementation in 2024-2025.