Development Situation and Prospect of Building Integrated Photovoltaics (BIPV)

　Ju Xiaolei, Director of Solar Building Technology Research Institute of China Architecture Design Co., Ltd.

The construction of Building Integrated Photovoltaic (BIPV) has attracted the attention of more and more countries at present, and countries have also designed corresponding support policies for the development of BIPV based on their own reality. At present, the development of BIPV in various parts of the world is not perfect, and there are still problems such as unclear owners, lack of business models, and lack of cooperation mechanisms. In the future, with the continuous growth of building power consumption, the specific forms of building power consumption will become more diverse, which will put forward more requirements for BIPV construction, and will also make its development route clearer and the model more standardized.

This time I would like to share with you three parts: First, look at foreign BIPV, mainly referring to the development trend related to photovoltaic roofs; the second part, the current situation of domestic BIPV development, and related, why everyone is talking about BIPV now, but The market is not open, where is the problem. The third part, future development opportunities and future expectations.

　　Policy-oriented BIPV

First of all, let’s look at the foreign situation. Tesla’s roof was released at the end of last year, and it was officially put into the market this year, including the current product, which is not particularly advantageous in terms of technology, concept or structure, including price. But why is it so easy to promote and sell? The volume is very high, and the important point is policy promotion.

In 2011, California began to compel the installation of photovoltaics in residential buildings in California, including the requirement for residential zero energy consumption, which also involves some issues on property tax and personal income tax: if residents install photovoltaic buildings to achieve energy efficiency, they can Obtaining tax incentives has increased their enthusiasm. Driven by the policy, the sales of roofs are very good, including Musk who has been promoting their photovoltaic roofs on Weibo. He has made a calculation that the building with this kind of photovoltaic roof will be much lower than his initial installation cost in terms of overall power consumption and energy efficiency in the next 20 to 30 years.

The European Union has adopted a more radical policy. The European Union has proposed energy efficiency and renewable energy targets, requiring 32% of energy to come from renewable energy by 2030, and at the same time reducing greenhouse gas emissions by 80%, similar to the climate agreement. On the basis of this, the corresponding targets for building energy consumption are formulated, because buildings consume the most energy, both in terms of greenhouse gas emissions and energy consumption. In 2018, all public buildings owned or used by the government must achieve near-zero energy consumption, and in 2020, all clean buildings must achieve near-zero energy consumption. Buildings require to achieve zero energy consumption, which requires the building itself to generate a certain amount of energy. This architectural photovoltaic has brought the market. In Europe and the United States, building energy efficiency is required to force building owners to adopt renewable energy. The United Kingdom, Germany, and Denmark have proposed detailed indicators according to the specific conditions of each country, which are higher than the requirements of the European Union.

From the perspective of policy comparison, foreign policies and domestic policies have a similar development trend. Of course, foreign policies will be several years earlier than domestic policies. From the early photovoltaic initial installation subsidy (Golden Sun Project), to the subsequent photovoltaic power generation subsidy, from 2014 to the housing construction subsidy, to the later mandatory requirements for building energy consumption, they are all similar to European policies. Through the mandatory requirements of building energy consumption, the entire photovoltaic industry and the construction industry, including the design industry, basic material industry, and construction, will be united. Because of the existence of the market and demand, these industries will gather together to form a joint force.

This is a case of the integration of photovoltaics and the construction industry in foreign countries. Within a day, buildings can be turned into zero energy consumption and realize self-production capacity.

This is a photovoltaic system installed on the roof. Of course, there may be some time in the early stage of design, but in the end, the construction time, from transportation to the site, to the completion of installation, is actually completed in only 8 hours. Because of this kind of policy in foreign countries The promotion and the mandatory requirements of policies have led to the entire photovoltaic industry and other related industries to work together to complete this matter, which will also promote this market. There are some differences from domestic ones. At present, we talk about building photovoltaic integration, and domestically mainly rely on photovoltaics The industry promotes it independently, because the construction industry has not yet coordinated, resulting in very few projects that we can actually implement.

　　Obstacles to the development of BIPV: unknown owners, lack of business models and cooperation mechanisms, lagging standard atlas

In the second part, I will talk to you about the current domestic BIPV development trend and some existing market problems. There are mainly several aspects. First, the owners of BIPV applications are not clear, and the business model has not been established. In addition, market standards relatively lagging behind.

The owner of the application is not clear. Unlike foreign countries, domestic development mainly focuses on real estate development, which means that our construction party and the final building user are not integrated, which means that when the photovoltaic industry needs investment in the early stage, the construction party will go Investment, the final user to obtain income, involves property rights issues. The construction party invests money and cannot see the future profit point, so there is resistance, which is different from foreign countries. The foreign construction party and the investor are relatively integrated.

The entire business model has not been established. Maybe the photovoltaic industry mainly promotes BIPV now. The photovoltaic industry naturally thinks that our building photovoltaic integrated business model should be calculated based on power generation, but everyone knows how we can PK, but we can’t PK the rooftop power station. , PK is no more than a ground power station, and PK is no more than a distributed system. In short, many costs of the building cannot be balanced, and many projects, such as photoelectric curtain walls or others, have losses to a certain amount of power generation, but they have always been Not counting, when combined with the building, the power generation also contributes to the energy consumption of the building itself. For example, the use of sunlight shading and indoor temperature adjustment can reduce the use of air conditioners, expand the functional space, strengthen indoor ventilation, and reduce indoor power loads. It has been calculated that after performing the function of sunshade or building indoor sunlight control, the load and energy consumption of the air conditioner he reduces is higher than the electricity he generates. In addition, everyone did not pay attention to this point. As the experts just said, you may calculate the penny of the power station, including various costs of the power station, including the power generation that can be recovered in a few years. Even if it is not clear, our model may not be established if it is not clear.

Another question, for the construction industry, the construction industry is still a relatively conservative industry. In the early days, architects were relatively unrestrained. When we make plans, we will think of all kinds of strange shapes and good ideas in the early stage. , When it is actually implemented, there are various norms and provisions, and various regulations will restrict attempts.

At present, the photovoltaic industry and the construction industry lack communication and need point-to-point communication. The problem of lack of cooperation mechanism, because of the lack of a communication platform, our traditional buildings have different stages from the scheme, to the subsequent construction drawings, to the project construction process, and there are clear access points for different building constructions and building materials. It is controllable by the architect. When it comes to photovoltaics, the intervention point may not be so early. When the intervention is later, it must meet the architect's requirements for color, material, and size in the early stage. I have seen that many photovoltaic companies will repeat it in order to meet the final design effect. Maybe samples need to be done for 20 or 30 times for large-scale projects, including the China Pavilion project. Because it was only involved in the later stage, there is no corresponding plan. The battery used in the market is different for each battery. You can imagine how difficult it is, which brings great difficulty to photovoltaic construction companies due to the lack of cooperation mechanism.

Hysteresis for standard atlases. The photovoltaic industry is developing too fast. I worked on the first BIPV project in 2007. At that time, it was probably more than 40 yuan/watt, but now it is more than 1 yuan/watt, including my first standard "Building Photovoltaic System" in 2009. At that time, 50 kilowatts was a large-scale photovoltaic system, and now the distributed power station has reached 6 megawatts, and the distributed power station is several times worse. Our atlas includes standard hysteresis and is of limited guidance for engineering.

Development Direction: Deepen the Potential of Building Photovoltaic Integration to Meet Building Energy Demand

Some experts have said before that the power consumption of buildings will increase rapidly in the future, and the energy consumption of buildings in the future will be gradually simplified. We may have heat demand and other needs now, and we may gradually change to electrification in the future. Everyone will feel our The whole process, including the future supply, may have been mentioned by various experts before. In the future, photovoltaics will also increase by more than 10 times, and building energy consumption will also gradually shift to diversification and electrification, including the energy-saving potential of our buildings. In terms of electricity, that is to say, the demand for electricity in buildings is gradually increasing.

The potential for the integration of buildings and photovoltaics is huge. You may have seen this data. I calculated the next 10 years in 2015, including the target for 2030. Our construction area will reach 31 billion square meters. An increase of 2.3 billion square meters, all of which are our building photovoltaic resources.

Similarly, while the building area continues to grow, the prices of components and systems are also dropping rapidly. When integrated with buildings and building substrates, the price sensitivity will decrease, which means that our future application possibilities will increase. Installing a curtain wall in the same way, the gap between using glass and using photoelectric curtain wall will increase.

Extensive related policies, including the policies of the 13th Five-Year Plan and the 14th Five-Year Plan, the plans of the National Development and Reform Commission and the Energy Bureau, all focus on photovoltaics. The "Industrial Structure Adjustment Catalog" released in 2019 proposed to promote the design and manufacture of solar building integration as a key industrial structure adjustment catalog.

From the building itself, we mentioned the demand for useful electricity just now. Now our country has just released the new green building evaluation standard, because now Beijing and Hebei require new buildings to be green buildings. Of course, there are different ratios of one star, two stars, and three stars. Green Building also puts renewable energy as an important indicator. According to calculations, as long as the installation of photovoltaics can meet 4% of the use demand, you can get a full score. It is relatively easy for photovoltaics, and the investment cost is relatively low. , performed well in terms of maintenance cost, occupancy of building space, and demand for maintenance.

As mentioned earlier, relevant foreign subsidies are gradually shifting from photovoltaic installation subsidies and photovoltaic power generation grid subsidies to energy consumption needs. I think the introduction of domestic light-oriented policies will definitely go in this direction. I think it will for a while. The introduction of mandatory demand for building energy consumption will promote the growth of building photovoltaic installation demand.

With the decline of photovoltaic systems, the comprehensive benefits of photovoltaic systems will be further improved. In the future, smart or energy-saving buildings and even zero-energy buildings will be the main form of future cities, including the revolution of building energy use. The transformation to electrification is a very important component Partly, the goal of our buildings in the future must be to transform and develop towards zero energy consumption and production capacity buildings, and building photovoltaic integration will also become the main functional form of buildings.

In addition, for the construction of construction capacity, large-scale development will be achieved in the future. Now there are capacity problems, and the scale of future development will increase. There will be changes in terms of cost and electrification. Similarly, in the future, our construction industry, including the photovoltaic industry and the financial industry, will achieve better interaction, promote the integration of building photovoltaics, and be able to keep up with the needs of construction development.

Finally, I am in the construction industry, and I am also an architect. I hope that there will be closer communication between the two industries, and everyone will go together, whether it is to cultivate some projects or technologies, to pass some standards, and our Innovations in both products and applications can achieve better integration with photovoltaics.