Why does roof photovoltaic need waterproof membrane? What kind of waterproof membrane? The market scale is expanding by an average of 10 billion annually, and leading waterproof companies are actively

1. What kind of waterproof membrane is needed for roof photovoltaic?

Waterproof membrane is the most common waterproof material, and polymer waterproof membrane includes PVC, TPO, EPDM, etc. Waterproof materials mainly include waterproof membranes and waterproof coatings. In my country's waterproof market in 2020, waterproof membranes will account for about 60% of the total. Waterproof membranes are mostly used for waterproofing projects on open planes. The products include modified asphalt membranes, polymer membranes and self-adhesive membranes. They are mainly used in engineering projects. Among them, the polymer coil is based on synthetic rubber, synthetic resin or a blend of the two, adding an appropriate amount of chemical additives and fillers, and adopts rubber or plastic processing techniques such as banburying, extrusion or calendering. The rollable sheet-shaped waterproof materials made of PVC, the current mainstream polymer waterproof membranes are PVC, TPO and EPDM.

The global waterproof membrane has entered the era of polymers, and China is catching up at an accelerated pace. Compared with ordinary waterproof membranes, polymer waterproof membranes have better homogeneity, higher shear strength, and stronger corrosion resistance. During production, the coil can obtain various colors by adding pigments, which can also play a decorative role while being waterproof. Foreign polymer waterproof membranes began to appear in the 1980s. After more than 40 years of research and development, they have become the main waterproof products in many countries. Currently, polymer waterproof membranes account for 30% of the total in the UK, Germany, the Netherlands and Switzerland. ～35%, 40%～45%, 40%～45% and 60%. However, my country's polymer waterproof membrane started late, and the market share of my country's polymer waterproof membrane is only 13.8% in 2020, but its catch-up trend is obvious, and the growth rate of polymer waterproof membrane production is the highest among all kinds of waterproof membrane categories , mainly due to the outbreak of underground engineering demand.

Polymer membranes have absolute advantages in the field of photovoltaic roofing and become the "best solution" for waterproof membranes. Through the above analysis, it can be seen that the waterproof membrane is one of the waterproof paths for photovoltaic roofs, but ordinary waterproof membranes are not economical compared to polymer waterproof membranes in terms of service life and subsequent operation and maintenance, so high Molecular waterproofing membranes can better match the needs of photovoltaic roofing. In detail, there are mainly the following reasons:

1) The service life of the polymer coil is 25-30 years, which can match the operation cycle of photovoltaic modules. Compared with ordinary waterproof membranes, polymer waterproof membranes have good homogeneity and can control product quality well during the production process. At the same time, they also have anti-ultraviolet and anti-aging properties, so their service life is 25-30 years. At present, the service life of photovoltaic modules is more than 25 years, and only after a certain service life is installed, can the cost be recovered to realize benefits; if leakage occurs during operation, the modules need to be dismantled and waterproofed again. damage. Therefore, the components installed on the roof of the polymer waterproof membrane can achieve a complete operating cycle, thereby maximizing economic benefits.

2) The polymer coil is laid in an exposed way to meet the load and later maintenance needs. Ordinary asphalt-based waterproofing membranes have poor weather resistance. In order to prolong their waterproof life, a protective layer needs to be added to the outside. The protective layer is usually cement mortar or fine stone concrete. The multi-layer waterproof design will increase the roof load pressure. As a result, the installation of photovoltaic modules is limited; at the same time, multi-layer waterproofing also makes it difficult for later maintenance. The polymer waterproofing membrane usually adopts a single-layer roof construction, and the membrane can achieve a long-term operation without a protective layer, and the exposed waterproofing is more convenient for later operation and maintenance, even if there is leakage, the leakage can be determined as soon as possible Click to fix.

3) TPO coils are mostly white, and their high reflectivity can improve the power generation efficiency of double-glass modules. Photovoltaic modules can be divided into single-glass modules and double-glass modules. Double-glass modules refer to photovoltaic modules whose backplane uses glass to replace the opaque backplane to achieve double-sided power generation. Since the power generation on the back depends on the refracted and reflected light formed by the light hitting the roof, the higher the reflectivity of the roof, the more the power generation efficiency of the module can be increased. Compared with the black ordinary waterproof membrane, the polymer waterproof membrane can be made into white, and its solar reflection index SRI is between 95-100 (the standard white SRI is 100), which can reflect solar energy better, thereby improving Power generation efficiency of double-glass modules.

2. How much space will be added for roof photovoltaic membranes?

2.1 Stock roofs are the main short-term demand, driving the waterproof market by nearly 10 billion annually

The stock market mainly benefits from the promotion of the whole county. It is estimated that the new waterproof market will increase by an average of 9.1 billion in the next four years. According to the "Notice on Announcing the List of Pilot Projects for Rooftop Distributed Photovoltaic Development in Counties (Cities, Districts)" Guoneng Zongtong Xinneng [2021] No. 84 officially issued by the National Energy Administration on September 14, 2021, there are 31 nationwide Provinces, municipalities, and autonomous regions (including Xinjiang Corps) submitted a total of 676 counties, all of which were listed as pilot projects for the development of distributed photovoltaics on rooftops in entire counties (cities, districts). At the same time, the document proposes that by the end of 2023, the proportion of photovoltaic power generation installed on various roofs in the pilot area will meet the requirements of the "Notice", and it will be listed as a demonstration county for rooftop distributed photovoltaic development in the whole county (city, district). Therefore, we give the following assumptions for the calculation of the advancement of the whole county:

1) The new distributed installed capacity in Shan County is 200MW. Since the projects under the county-wide promotion model have changed from the previous scattered development to packaged development, which is conducive to the entry of large enterprises, the scale of individual projects has increased. According to the assumption of the new team of CSC, the scale of a single county is 200MW, and all 676 counties provide a total of 135GW of stock market space.

2) It is estimated that all installed capacity will be completed by 2025. The document requires that all types of roof-mounted photovoltaic power generation ratios be completed by the end of 2023, but pilot project declarations are not reported at the minimum ratio, and some provinces have higher requirements than the document, so we expect new installed capacity to be released within 4 years, to In 2025, at least 33.80GW of new installed capacity will be added every year.

3) The corresponding power per square meter is 120W. Usually, a photovoltaic power station is installed on a steel structure roof with color steel tiles, and photovoltaic modules are only installed on the south-facing side. 16:00 The unshaded roof area is covered with photovoltaic modules, and the laying ratio is also 1KW corresponding to 10 square meters. In the context of the continuous improvement of module efficiency, it is assumed that the corresponding power per square meter is 120W.

4) Assume that the permeability of the waterproof membrane gradually increases from 30% to 35%. The current waterproof design scheme for photovoltaic roofs has not yet been unified, but considering the advantages of waterproof membranes, we assume that the permeability of waterproof membranes will gradually increase from 30% in 2022 to 35% in 2025.

5) Assuming that the waterproof membrane is priced at 100 yuan per square meter under the condition of contracting labor and materials

2.2 Newly built roofs can contribute medium and long-term growth, driving the waterproofing market by an average of 4 billion annually

The newly-added market mainly benefits from the goal of carbon peaking, and it is estimated that the average annual new waterproof market size will be 4 billion. According to the "Notice on Printing and Distributing the Action Plan for Carbon Peaking Before 2030" issued by the State Council on October 24, 2021, by 2025, the photovoltaic coverage rate of new public institution buildings and new factories will strive to reach 50%. Since urban residential rooftop photovoltaics are prone to property rights issues, and the penetration rate of new rural residential buildings is not required, we predict that the main new market for rooftop photovoltaics will come from the above two types of buildings. The following assumptions are given for the new market:

1) The total completed area of industrial plants and public buildings accounts for about 21.5%. According to the "2019 China Construction Industry Statistical Yearbook", the completed area of factories and buildings in 2019 accounted for 12.2% of the completed area of various buildings in the country, while the completed area of public buildings such as office buildings, scientific research, education, and medical buildings totaled The proportion is 9.27%. Assuming that the national completed area decreases by 1.5% every year, the proportion of public buildings and industrial plants remains unchanged.

2) Assume that the industrial roof area is 1/2 of the completed industrial area, and the roof area of public buildings is 1/5 of the completed area. Since land area = completed area/volume ratio, and industrial buildings have fewer floors, the volume ratio is assumed to be 2; and public buildings are mostly high-rise buildings, so the roof area is assumed to be 1/5 of the completed area.

3) The proportion of distributed photovoltaic installations in new projects will increase year by year, and will increase to 50% by 2025. According to policy requirements, it is assumed that the proportion of new factories and public buildings installing rooftop photovoltaics will be 35% in 2022, and will increase year by year to 50% in 2025 to achieve the notification target.

4) Assume that the permeability of the waterproof membrane gradually increases from 30% to 35%. The current waterproof design scheme for photovoltaic roofs has not yet been unified, but considering the advantages of waterproof membranes, we assume that the permeability of waterproof membranes will gradually increase from 30% in 2022 to 35% in 2025.

5) Assume that the waterproof membrane is priced at 100 yuan per square meter under the condition of contracting labor and materials.

To sum up, by 2025, under the joint promotion of existing and new markets, rooftop distributed photovoltaics can bring an average annual new market size of 13.1 billion yuan for waterproofing membranes.