Review of the US Vacuum Glass Summit
From April 11th to 12th, 2023, the Lawrence Berkeley National Laboratory (LBNL) of the U.S. Department of Energy held the VIG Summit. This is the first time that a vacuum glass (VIG) seminar was held in North America. The meeting exchanged and discussed how to expand the market demand for vacuum glass, how to ensure the supply to meet market demand, incentive policies, performance testing, etc., and the latest research progress of vacuum glass technology in the United States is introduced [1].
The goals of the summit include:
(1) Formulate market application strategies for expanding high-performance thermal insulation windows;
(2) Review and make recommendations for updating relevant (construction) standards;
(3) Review the current state of research and identify future research needs.
More than 90 people attended the meeting, 50 of whom attended in person, and the rest participated remotely. The participants were stakeholders from various industries, including (the construction and glass) industry, construction professionals, practitioners, academia, researchers and government departments, etc.
The meeting responded to three challenging questions in three areas through individual presentations and group discussions, namely:
(1) Three major social challenges, namely high cost, lack of publicity, and education and incentive policies;
(2) Three major market challenges, namely, financial incentives to promote green projects, tools, and models to prove return on investment and other benefits of using vacuum glass, project demonstrations verified by relevant departments, and building standards and regulations;
(3) Three major research challenges, namely, the service life and evaluation of vacuum glass, the industrialization technology of vacuum glass, and the verification of the thermal model of vacuum glass.
The next step will be to address these challenges through the joint efforts of the industry, the US Department of Energy, national laboratories, and practitioners. A five-year "VIG 5-in-30" plan is proposed to accelerate the market application of vacuum glass. The goal is for vacuum glass to account for 5% of the U.S. window market by 2030. A series of meetings will follow to discuss specific solutions and develop a roadmap for the wider use and application of high-performance thermal insulation windows.
LIJIANG Glass will put forward some thoughts and suggestions based on the content of the summit and the situation of developing countries.
1. Vacuum glass is the key direction of a new generation of high-performance energy-saving glass
Vacuum glass and airtel insulating glass will become the next-generation updated products of high-performance energy-saving glass. Airgel glass is still in the laboratory stage. From the perspective of industrialization and market supply capacity, vacuum glass is ahead of a large glass. Therefore, the focus of high-performance energy-saving glass at this stage is vacuum glass, which is the main reason for holding this summit.
Although vacuum glass in the United States is still in the stage of laboratory research and development, researchers believe that vacuum glass is the key direction for the development of energy-saving glass, which is based on the huge scale of existing building renovation needs and the excellent performance of vacuum glass.
At present, the mainstream glass in the US window market is double-layer insulating glass, and the market share of triple-glass double-cavity glass with better performance is very small, as shown in Figure 1[2]. This has a lot to do with the fact that the U.S. construction market is dominated by existing building renovations. The proportion of new buildings is very low (about 2%). A large number of existing buildings tend to choose thinner double-glazed windows when they are renovated. If the three-glass two-cavity insulating glass with better performance is used, while improving the energy-saving effect, it will face obstacles brought about by the increase in the thickness of the glass and window frame. For the energy-saving renovation of doors and windows of old buildings, the market needs energy-saving and light and thin windows and glass products, and vacuum glass can meet this demand.
Figure 1 U.S. Residential Window Glass Market Share
In Japan and Europe, there is an increasing practice of improving the thermal insulation performance and energy-saving effect of windows by retaining the original window frame and only replacing the glass. The researchers believe that this is also applicable to the United States. Secondly, building energy efficiency can be improved by installing a second layer of vacuum glass window system. Discussions on the market promotion of vacuum glass at the summit mainly revolve around these two directions.
The Lawrence Berkeley National Laboratory of the United States is affiliated with the U.S. Department of Energy and is the most authoritative research institution in energy efficiency and building energy conservation. The attention and attitude toward vacuum glass are expected to have an important impact on the development of vacuum glass in the United States.
2. Formulate market development goals for vacuum glass to expand applications
Based on the previous consensus, the summit proposed the "VIG 5-in-30" strategic plan goal for the development of vacuum glass. For the existing buildings with a stock of billions of square meters in North America, it is a very radical goal to achieve a market share of vacuum glass windows of 5%. This goal demonstrates the urgent desire to improve building energy efficiency in the double-carbon era.
Identifying this goal is to let manufacturers, construction professionals, practitioners, academia, researchers, and policymakers know where the market is going and when it will take, which is an important part of guiding the implementation and progress of the plan. To achieve this goal, the researchers discussed the demand and supply and constructed a preliminary blueprint for the development of the vacuum glass market.
Sources of market demand may include:
(1) Government or public sector buildings are not only the focus of energy-saving policy control but also can achieve public demonstration effects. By establishing a 10-year plan similar to the renovation of old buildings across the country, vacuum glass can be expanded.
(2) The U.S. General Services Administration, which manages U.S. federal government buildings, also participated in the summit. The federal government owns the most buildings. It is more effective to promote government-specified or direct procurement measures in the implementation of government building renovations.
(3) Simultaneously promote the application of vacuum glazing and the retrofit of adding a second layer of vacuum glazing, the latter being the most efficient measure for retrofitting old buildings and improving energy efficiency.
Concerning market supply, the researchers predict that the market size of vacuum glass should reach 25 million pieces per year, provided by 6-10 manufacturers. According to this calculation, the annual production capacity of each company should reach at least 2.5 million pieces (at least 1 million square meters), to meet the needs of large-scale applications in the market. At present, there are a few innovative companies in the United States that are conducting research and development of vacuum glass industrialization technology, including Luxwall, which is supported by the Bill Gates Foundation. At the summit, V-Glass proposed that it is expected to realize the industrial production of vacuum glass in 2025. This is the first company in the United States to announce that it can provide vacuum glass products.
The stock of existing buildings in developing countries is about dozens of times that of the United States, and there are hundreds of millions of square meters of new buildings every year. The application of vacuum glass in new buildings and renovation of existing buildings has broad prospects. From the perspective of the supply side, the research and development, production and application of vacuum glass technology in some developing countries have a history of more than 20 years, especially the rapid development in the past ten years. Reach the scale of the annual output of 1 million square meters. The main reason is that the demand in my country's vacuum glass market has not been stimulated, the existing production capacity of vacuum glass enterprises has not been fully utilized, and market and production capacity factors are mutually constrained, affecting the sustainable development of the entire industry. If under the guidance of the "30·60" dual-carbon target, specific energy-saving and carbon-reduction targets for buildings, doors, and windows, and energy-saving fields can be proposed to guide the accurate positioning of the building materials industry in terms of new technologies, new products, and new markets, and make the market Simultaneous efforts of supply and demand are not only conducive to the realization of the dual carbon targets in the construction sector but also create sustainable economic development momentum.
3. Improve the policy environment for the development of vacuum glass
The researchers believe that through the implementation of incentive policies step by step, by region, and by building type, the market demand for vacuum glass can be effectively stimulated, started, and cultivated. Since the 1970s, the development of insulating glass and Low-E glass in European and American countries has been inseparable from government incentive policies.
Under the premise of clarifying development plans and goals, formulate fiscal and financial incentive policies to promote the application of vacuum glass, revise building codes and upgrade policies for energy-saving standards, and study implementation strategies for demonstration projects to continuously improve the policy environment for vacuum glass development.
The researchers believe that the government's tax rebates, financing support, and other government subsidy policies, including subsidy programs for electric and gas utility companies, are conducive to balancing investment returns. Without these policies or subsidies, the return on investment calculation would be poorer.
Incentives from local governments will promote the initial development of the market, eventually reducing the cost of innovation and competition to ordinary users. It can take the lead in promoting the application of large cities in coastal areas. Due to stricter building standards and better financial incentives, the application of green high-standard building projects such as passive houses and LEED is more likely. Constructing some bright demonstration projects in some special important markets (such as San Francisco, Chicago, and New York) will help expand the knowledge of architectural professionals (architects/engineers). At the same time, the step-by-step formulation and implementation of energy-saving standard upgrades to start the market in specific regions, such as the first to promote the application of vacuum glass windows in cold climate regions, especially the northern region should be more advantageous application areas for vacuum glass, and at the same time promote Building and other energy-saving standards to achieve higher energy-saving goals.
Policy-driven is an essential element of the development environment in the initial stage of the development of new technologies and new products. The development of my country's photovoltaics, new energy vehicles, and other industries has benefited from these policy supports. Building and architectural glass is a super-large-scale market. It is necessary to learn from the experience of European and American countries in building energy conservation control policies, fiscal and financial incentive policies, improve my country's building energy conservation policy system, and use economic means to promote market growth and achieve energy conservation goals.
4. Pay attention to the performance and evaluation of vacuum glass
Excellent properties of vacuum glass, including heat insulation, sound insulation, long life, etc. Chinese vacuum glass companies pay more attention to the U value index of the heat transfer coefficient of vacuum glass, but American researchers are most concerned about the service life of vacuum glass and how to evaluate it reliably, as well as the development of software models suitable for the calculation of thermal performance of vacuum glass, authoritative detection methods and equipment, etc.
Long service life is the advantage of vacuum glass, which requires reliable evaluation and verification and the support of specific data. The researchers proposed: (1) to develop an accelerated aging test procedure to test the service life, and to prove that the accelerated test is the same as the actual effect of the product life cycle; (2) the equipment that needs to test the durability performance and general performance, such as standardized ultraviolet spectroscopy, thermal conductivity measurement, Aging room, etc.; (3) Collect test and test data, such as infrared pictures, temperature, use intensity, durability data, etc.
Vacuum glass is a brand-new product, and the current detection methods apply the detection methods and standards of insulating glass. The WINDOW simulation calculation software for insulating glass heat transfer coefficient U value, solar heat gain coefficient, and other indicators developed by the Lawrence Berwick National Laboratory (LBNL) of the United States is currently widely used in theoretical calculations of vacuum glass performance. The American Renewable Energy Laboratory (NREL), an authoritative organization, has proposed guidelines for the durability test and evaluation method of vacuum glass, which takes more into account the characteristics of vacuum glass, which is conducive to reflecting and verifying the superiority of vacuum glass performance.
Taking China as an example, the application scale of vacuum glass products greatly exceeds that of the United States, and it should have greater advantages in the performance verification of vacuum glass products, the development of testing instruments, and application data. For example, the vacuum glass heat transfer coefficient detection method and instrument developed are designed according to the national standard of vacuum glass and ISO international standard, which meets the needs of rapid detection of vacuum glass production and scientific research. However, judging from the detection method research and instrument development of the entire industry, enterprises neither pay enough attention nor have the ability. This requires national authoritative professional research institutions to concentrate the strength of the entire industry to form authoritative standards and methods and increase detection. The level of R&D and production of instruments and equipment will promote the improvement of the overall technical level and product quality of the industry.
5. Cost and return on investment of vacuum glass
The high cost of vacuum glass is an important factor affecting the application and promotion. In the process of promoting vacuum glass products in my country, the investor's consideration of income is usually limited to the benefits brought about by the direct reduction of energy consumption, which makes vacuum glass in a disadvantageous position in the competition with insulating glass due to cost factors. How to consider benefits and costs, the researchers provided a very comprehensive and valuable dimension of thinking.
Vacuum glass is not an investment with a low cost-benefit ratio, the key is how to consider the benefits. Usually, the return on investment is uncertain at the time of sale, and many factors affect the measurement of benefits. For example, the measurement model of energy consumption is not mature enough to quantify energy-saving benefits, and it is difficult to accurately quantify the value of vacuum glass in reducing the total cost of building system operations. How to consider building energy consumption reduce the saving of air conditioning system investment and other issues. In addition to quantifiable benefits, benefits that are difficult to quantify, such as comfort improvement and sound insulation effects, should also be considered in the analysis of investment returns.
Factors affecting investment returns also include preferential policies such as tax credits and uncertain subsidies, which affect the calculation of return on investment; carbon emission costs cannot be included in the return on investment model, how to consider the factors of embodied carbon, and how to complete life cycle analysis, etc.
In terms of cost, construction authorities and building materials companies need to consider how to take advantage of the large-scale market advantages and internal circulation space of some developing countries to improve the level of industrialization, and continuously promote the scale level of vacuum glass production to reduce production costs.
6. Production technology upgrade and industrialization of vacuum glass
American vacuum glass companies and research institutions introduced laboratory research on vacuum glass technology at the summit, including metal foil edge sealing, low-temperature laser edge sealing, pulse plasma degassing, etc. These technical routes are quite different from the vacuum glass technology route invented by the University of Sydney, reflecting the goals pursued by researchers and the technical exploration under the changing conditions of new materials, new processes, and new technologies. Because of the actual situation in the United States, the researchers proposed that the vacuum glass production technology should be able to adapt to the needs of large-scale market applications, and fully pay attention to the technical problems when it is integrated with the window system.
The technical routes of more than 10 vacuum glass companies are very different, and they have entered the stage of large-scale production. The main problems they are currently facing are product reliability, production efficiency and cost, and market application. To consolidate the first-mover advantages that have been obtained, my country's vacuum glass enterprises should increase investment in technology research and development, continuously improve their technical strength, realize the industrialization and scale upgrade of vacuum glass as soon as possible, and form a virtuous circle of technology, products, markets, and benefits.
Figure 2 The vacuum glass 1
7. Thoughts and Suggestions
Taking China and other developing countries as examples, the research and development of vacuum glass technology has gone through 20 years. In the new era and under the new situation, it is urgent to think about two fundamental issues.
(1) To achieve the goal of low energy consumption in the construction field, what kind of energy-saving glass is relied on?
Achieving low-energy development means that all buildings are low-energy buildings. High-performance energy-saving glass is required to improve the energy-saving level of building doors, windows, and curtain walls. Relevant departments in some developing countries should vigorously promote vacuum glass with mature industrial production technology from now on, or wait for new energy-saving glass technology that may appear in the future, or continue to rely on existing insulating glass technology? Relevant departments should plan and make choices and plans as soon as possible.
Some developed countries' vacuum glass industrial production technology has been able to achieve reliable large-scale production, and vacuum glass products are significantly better than insulating glass in terms of performance indicators, performance stability, and long life. Of course, neither insulating glass nor vacuum glass is perfect. The realization of the goal of low energy consumption development needs to exhaust the potential of each innovative technology and provide new technologies provide policy and market environment and space for development, realize product quality improvement and technological progress during development, and improve the competitiveness of the entire industry. This is the only way for all innovations to create value and achieve success.
The U.S. Vacuum Glass Summit provides developing countries with a framework for market and policy research on the development of vacuum glass. It is recommended that relevant departments determine the development direction of high-performance energy-saving glass as soon as possible, in terms of development goals, policy frameworks, technology upgrades, and industrial system construction. Carry out top-level design, give full play to the important role of vacuum glass in improving building energy efficiency and renovating existing buildings, and achieve energy-saving goals in the field of building doors and windows.
(2) Does the upgrading and high-quality development of the manufacturing industry in the field of building materials in developing countries require the development of vacuum glass?
The high-quality development of the manufacturing industry requires original technologies with independent intellectual property rights, energy-saving, and green products that can meet the needs of social and economic development and people's lives, and new industries that can drive the coordinated development of relevant upstream and downstream industries with sustainable value creation capabilities.
Vacuum glass technology is a technology with independent intellectual property rights in the field of building materials in my country, and it is also one of the rare original technologies in the field of architectural and industrial glass. At present, only Chinese companies and Japanese companies have mastered the industrial production technology of vacuum glass. Looking at the development of the vacuum glass industry from the perspective of the upgrading of the manufacturing industry in the building materials field, glass deep-processing practitioners should think about whether the technical advantages of vacuum glass that Chinese companies and Japanese companies have already obtained need to be maintained, and how to cultivate and develop vacuum glass through policy support market, how to take advantage of the large-scale building materials market advantages of some developing countries to expand the vacuum glass industry, and make the vacuum glass industry a competitive industry with global competitiveness.
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