Copper indium gallium selenide (CIGS) thin-film battery has high photoelectric conversion efficiency, better spectral dispersion ability, and weak light-adsorption characteristics, as well as shape and size flexibility. CIGS-BIPV (building integrated photovoltaic) has attracted more and more research attention with the advantages of good curvature, form and color diversity, and broad application prospects. This paper uses the classical “Porter’s Five Forces Model” to make a preliminary analysis of the competitiveness of CIGS-BIPV products. A more specific competitiveness analysis model is further built with the index modeling method, and the competitiveness of CIGS-BIPV products is thoroughly analyzed from qualitative and quantitative perspectives. Six primary research indicators are used, i.e., safety index, building aesthetics index, economic index, energy-saving and environmental protection index, innovation index, and sales force index. The weight analysis of index modeling shows that compared with a glass curtain wall, exterior stone, and silica-based BIPV, CIGS-BIPV is characterized by high product competitiveness, acceptable cost, attractive appearance, environmental benignity, high technical quality, and certain economic benefits. The product competitiveness of CIGS-BIPV could be further enhanced through the construction and promotion of sales channels.
Due to the increasing environmental protection pressure and energy deficiency, the development and utilization of solar energy and other renewable energy forms are now becoming an important part of national sustainable development strategies [
Renewable capacity growth between 2019 and 2024, from IEA [
CIGS (copper, indium, gallium, and selenium) thin-film solar cell has the advantages of strong light absorption ability, high electricity-generation capacity and stability, low production cost, and short energy recovery period, which lead to its rapid development among various thin-film solar cell production technologies [
From the perspective of the life cycle, CIGS-BIPV is currently still in the lead-in stage. A comprehensive analysis of the competitiveness of CIGS-BIPV products is crucial to the market development and capital investment for the future research direction. However, to the best of our understanding, there are few research literatures on the competitiveness of CIGS-BIPV products. In order to eliminate this gap, in this paper, “Porter’s Five Forces Model” [
Schematic diagram of CIGS-BIPV competitiveness analysis.
For product competitiveness analysis, “Porter’s Five Forces Model” is generally used, where “Five Forces” are the competitiveness of existing competitors in the industry, the ability of potential competitors to enter, the substitution ability of substitutes, the bargaining power of suppliers, and the bargaining power of buyers [
Rivalry among existing competitors is the most competing factor among “Porter’s Five Forces Model” for CIGS-BIPV product, and the major competitors include silica-based BIPV, other types of thin-film solar cells-BIPV, glass curtain wall, and exterior stone. Profits among different products are mutually related, and the goal is to make their products superior to their competitors.
The threat of new entrants affects the competitiveness of CIGS-BIPV products. In the field of BIPV, CIGS-BIPV itself is a new entrant, bringing new production capacity and new resources to the industry. In the meantime, the major obstacle of entering the market for another new silica-based BIPV primarily includes product differences, capital demand, conversion cost, development of sales channel, and government behavior and policy. The relationship among potential profit, cost of expenditure, and risks of products have to be fully considered by the newcomers of the BIPV market.
CIGS-BIPV market space can be threatened by substitutes. Current substitutes of CIGS-BIPV can be silica-based BIPV, CdTe- (cadmium telluride-) BIPV, GaAs- (gallium arsenide-) BIPV in the same industry, or even products like glass curtain wall, exterior stone in different industries. The competency strategies of CIGS-BIPV companies can be influenced by those competencies from substitutes in various forms. The competitive pressure will be higher if the substitutes of CIGS-BIPV have a lower price, better quality, and lower user costs. The competitive pressure intensity of those substitutes can be evaluated by sales growth, production capacity, and profit expansion status. Moreover, security and innovativeness also need to be fully considered.
Production expenditure of CIGS-BIPV is also impacted by the bargaining power of suppliers. Quite few suppliers exist for critical components and technologies in thin-film solar cells of CIGS-BIPV, which is an oligopoly market. Core technologies are held by some companies with plenty of patents. The profit is also shared by downstream suppliers, which is also one of the major causes of the high expenditure of CIGS thin-film solar cells. Although China has invested a lot of funds to acquire foreign-funded enterprises, how to fully master the original technology and bring forth new products to realize the localization of products is crucial. In addition, some noncore parts of CIGS-BIPV have plenty of suppliers with bad bargaining power.
The profit of CIGS-BIPV can also be impacted by customer’s bargaining power. The profitability of the product is influenced by BIPV customers’ bargain and the requirement to provide better product or service quality. At present, CIGS-BIPV is still in the lead-in period of its life cycle, and its cost is high. The buyers are mainly state-owned enterprises and private enterprises with better-operating conditions. Essentially, CIGS-BIPV is a giant monopoly field with low bargaining power. On the other hand, CIGS-BIPV is too expensive for private customers and ordinary families, who have other purchase options like glass curtain wall and exterior stone. Governmental policy support, the establishment of brand value for BIPV, and the essential promotion of sustainable building characteristics are of great importance.
Above all, the competency of CIGS-BIPV in five aspects is initially analyzed using “Porter’s Five Forces Model”. However, it is worth noting that “Porter’s Five Forces Model” has certain limitations, and it is a competitive analysis model based on a relatively fixed industry scale. CIGS-BIPV is in the lead-in period, which requires cooperation from enterprises to obtain more resources and markets. At present, output and application quantities for CIGS-BIPV are increasing rapidly both domestically and internationally. In the meantime, not only competency but also cooperation exists among different BIPV companies.
CIGS-BIPV products are now gradually recognized and accepted in the market, and the industry has begun to form and grow. At the early stage of the product lifecycle, large efforts have to be made to cultivate markets and improve products, due to the small number of related companies, low market demand, unstable product quality, and slow development. Based on the initial analysis of “Porter’s Five Forces Model,” an index modeling approach is adopted to further analyze the competency of CIGS-BIPV products. This approach can realize the combination of qualitative and quantitative analyses. The selected parameters are safety index, architectural aesthetics index, economic index, energy-saving and environmental protection index, innovation index, and sales force index.
First of all, the safety of the glass curtain wall, exterior stone, silica-based BIPV, and CIGS-BIPV is compared and analyzed. The glass curtain wall has the forms of single-layer and multilayer glasses. Glass curtain wall is composed of panel and metal frame with low deformation capacity. When the structure is experiencing lateral displacement under horizontal earthquake or wind load, the impact of excessive lateral displacement in subject structure can only be avoided through the elasticity of connectors, since the panel and metal frame of glass curtain wall cannot withstand such large displacement. A certain amount of gap has to be generated between glass and frame to ensure that glass will not be pressed and broken in case of interlayer displacement.
The exterior stone uses corrosion-resistant bolts and flexible joints to hang granite, artificial marble, and other decorative stones directly on the exterior of the building structure. A certain amount of deflection is allowed under the effect of wind and earthquake loads as parts of the loads can be absorbed to eliminate the crack and fall off. Stone materials will reset with the structure when the wind and earthquake loads disappear. The pressure resistance and shock resistance of the external stone are relatively high. The existence of brittleness, microcracks, internal nonuniform areas, and defects could result in stress concentration, which leads to the low actual strength.
In theory, the photovoltaic modules of BIPV meet the safety requirements of the designed standard, such as thin-film solar cell factory design standard (GB51370-2019), and have good temperature and humidity resistance, mechanical strength, and electrical insulation characteristics [
In terms of safety, the glass curtain wall shows better reliability than CIGS-BIPV, silica-based BIPV, and exterior stone, shown in Table
Safety index analysis of four products.
Safety index | Weight factor | CIGS-BIPV | Silica-based BIPV | Glass curtain wall | Exterior stone | ||||
---|---|---|---|---|---|---|---|---|---|
Score | Weighted value | Score | Weighted value | Score | Weighted value | Score | Weighted value | ||
Strength | 0.5 | 90 | 45 | 90 | 45 | 95 | 47.5 | 84 | 42 |
Pressure resistance | 0.3 | 90 | 27 | 86 | 25.8 | 95 | 28.5 | 90 | 27 |
Antiknock characteristic | 0.2 | 90 | 18 | 86 | 17.2 | 95 | 19 | 80 | 16 |
1.00 | 90 | 88 | 95 | 85 |
An analysis of the architectural aesthetic indexes of four products.
Architectural aesthetic index | Weight factor | CIGS-BIPV | Silica-based BIPV | Glass curtain wall | Exterior stone | ||||
---|---|---|---|---|---|---|---|---|---|
Score | Weighted value | Score | Weighted value | Score | Weighted value | Score | Weighted value | ||
Brightness | 0.3 | 90 | 27 | 90 | 27 | 95 | 28.5 | 88 | 26.4 |
Color diversity | 0.4 | 90 | 36 | 88 | 35.2 | 95 | 38 | 90 | 36 |
Surface texture | 0.3 | 90 | 27 | 86 | 25.8 | 95 | 28.5 | 92 | 27.6 |
1 | 90 | 88 | 95 | 90 |
The glass curtain wall endows the building with integrating architectural aesthetics, architectural function, architectural energy-saving, and architectural structure and makes the building display different colors from different angles. The color-adjustable feature of the glass curtain wall panel also meets various user needs. The inner side of the curtain wall’s outer glass is coated with colorful metal deposition. From the appearance, the whole exterior wall is like a mirror. Under the reflection of light, the interior space of the building is not exposed to strong light, and the vision is soft.
Generally, the slabs of the exterior stone are processed with the same vein stone. Before installation, they need to be selected and numbered to ensure that the stone texture and direction are correct, and the transition is natural without a color difference. The quality of stone and processing will have an impact on the beauty. Stone color, line, form, owner’s requirements, and structural needs such as shape and awning should be considered together with the style of the whole building. The convenience of construction is another concern in the layout. Compared with the visual enjoyment given by the glass curtain wall, the exterior stone is much lower.
The overall product design and visual enjoyment are nonnegligible for the BIPV market. Although silica-based photovoltaic cells occupy a leading position in the market share, there are many places that prefer to adopt thin-film solar cells, since thin-film solar cells have a more flexible design, arbitrarily shape and size, good curvature, and better overall characteristics. In terms of aesthetics requirements, the overall appearance of BIPV components has to be considered to coordinate with the whole building color and structure.
Apart from the attached importance to appearance, CIGS-BIPV can also preserve the functionalities of the building structure. In real applications, bypass diode, main junction box, connectors, and other devices are hidden inside the building curtain wall by BIPV to reach the aesthetic effect. In the meantime, it prevents rain erosion and direct sunlight from affecting the equipment and lines. Production of components with different colors and patterns can be customized for CIGS thin-film solar cells to accommodate different market applications and demands, especially the demand on building aesthetics by architects on colors and specifications. For buildings, light is essential, and the requirements for light and shadow are very high. Double-sided glass components made by a smooth ultrawhite tempered glass are adopted by BIPV buildings, and cell configurations can be adjusted to reach a certain transmittance. The components can be installed on the façade of the building because of the low requirement of CIGS-BIPV for a light angle. The architectural aesthetic index analysis of these four products is shown in Table
The economy is one of the very important indexes for market competency of products, which primarily includes investment, cost, and profit. Compared with exterior stone and glass curtain wall, silica-based BIPV and CIGS-BIPV have the characteristics of power output, while double-layer and three-layer structures of glass curtain wall have better thermal economy performance than exterior stone. According to the survey of our cooperation and the literature [
Although the cost for solar cells has decreased tremendously in recent years, the price of BIPV components has not decreased much. CIGS-BIPV and silica-based BIPV are both in the lead-in period of product life with high construction cost, and the current utilization goals are entering middle and high-end construction market. Based on the construction experience of our cooperation building, the average price of some high-end building materials (exterior stone and glass curtain wall) and BIPV (CIGS-BIPV and silica-based BIPV [
From the perspective of extra power generation, the profits of exterior stone and glass curtain wall are zero. For silica-based BIPV, the power generation is about 155 W/m2, and the average annual power generation is about 101 kWh/m2 if the power generation period is calculated as 650 hours per year. The annual income per square meter for silica-based BIPV is about 50.5 RMB. For CIGS-BIPV, the power generation per square meter is about 150 W if 700 power generation hours are taken into account each year. The average annual power generation is about 105 kWh/m2, and the annual benefit per square meter is about 52.5 RMB. Here, the photovoltaic electricity price is assumed to be 0.5 RMB/kWh, although it varies according to the first, second, and third resource zones to which it belongs. In addition, China’s National Development and Reform Commission stipulates in [2019] No. 761 that the total power generation subsidy for household distributed photovoltaics is adjusted to 0.18 RMB/kWh [
An analysis of the economic indexes of four products.
Economic index | Weight factor | CIGS-BIPV | Silica-based BIPV | Glass curtain wall | Exterior stone | ||||
---|---|---|---|---|---|---|---|---|---|
Score | Weighted value | Score | Weighted value | Score | Weighted value | Score | Weighted value | ||
Initial investment | 0.3 | 70 | 21 | 76 | 22.8 | 90 | 27 | 96 | 28.8 |
Composite cost | 0.3 | 70 | 21 | 80 | 24 | 90 | 27 | 96 | 28.8 |
Prospective earnings | 0.4 | 83 | 33.2 | 82 | 32.8 | 78 | 31.2 | 80 | 32 |
1 | 75.2 | 79.6 | 85.2 | 89.6 |
Green building refers to the building that can save resources (energy, land, water, and material) to the maximum extent in the whole life cycle, protect the environment and reduce pollution, provide people with healthy, comfortable, and efficient use space, and exist in harmony with nature. Extra insulation approach has to be taken for traditional exterior stone, while glass curtain wall, CIGS-BIPV, and silica-based BIPV can adopt double-layer or even three-layer structures, which is helpful for the thermal insulation of buildings and hence reduces the extra demand on fossil fuels. Regarding architectural function, too many supports and crystalline silicon batteries are huge burdens for buildings in the long term, which will cause the consumption of bearing capacity, shorten the service life of buildings, and even bring security risks. On the contrary, a thin-film battery is a piece of lightweight material that can address the above concerns.
CIGS-BIPV shows apparent advantages in energy-saving and environmental protection, and it has a lower environment demand. The BIPV system can be used wherever sunlight exists, and power transmission difficulties in a remote area can be effectively resolved. Energy consumption of a building is recognized as one of the most important energy consumption part in today’s society, accounting for about 1/3 of the total energy consumption in China. In particular, the residential area of central heating in northern China only accounts for 10% of the national urban residential area, but the building energy consumption accounts for 40%. CIGS-BIPV could reduce greenhouse gas emissions. Taken the CIGS-BIPV demonstration building in Tonghu town (Guangdong Province, China) as an example, the annual power generation is about 117,000 kWh, which will save 36.27 tons of standard coal and eliminate 64.63 tons of carbon dioxide emission annually. About 1,293 tons of carbon dioxide emission can totally be avoided for Tonghu town considering the lifespan of CIGS-BIPV as 20 years. The adoption of distributed electricity generation mode can efficiently avoid large land occupation for power stations and expensive energy storage equipments. In the meantime, cost and energy consumption can be decreased during electricity transmission. More importantly, serious air pollution caused by fossil fuel power generation can be eliminated, which is of great importance to meet the higher environmental protection requirements in the future. CIGS-BIPV shows great competitiveness than silica-based BIPV, glass curtain wall, and exterior stone from the perspective of energy-saving and environmental protection, shown in Table
Analysis of energy-saving and environmental protection indexes of four products.
Energy-saving and environmental protection index | Weight factor | CIGS-BIPV | Silica-based BIPV | Glass curtain wall | Exterior stone | ||||
---|---|---|---|---|---|---|---|---|---|
Score | Weighted value | Score | Weighted value | Score | Weighted value | Score | Weighted value | ||
Power saving | 0.6 | 96 | 57.6 | 94 | 56.4 | 80 | 48 | 75 | 45 |
Pollution reduction | 0.2 | 93 | 18.6 | 91 | 18.2 | 80 | 16 | 75 | 15 |
CO2 emission reduction | 0.2 | 94 | 18.8 | 92 | 18.4 | 80 | 16 | 75 | 15 |
1 | 95 | 93 | 80 | 75 |
The glass curtain wall of modern high-rise building adopts the hollow structure which is composed of mirror glass and common glass, and the interlayer is filled with dry air or inert gas. Insulating glass has the advantages of sound insulation, heat insulation, frost and moisture proof, as well as wind pressure resistance, etc. The external hanging stone materials are continuously optimized in cutting, fixing, and stability of plates, and the aesthetics are also improved. Compared with a glass curtain wall and traditional exterior stone building, BIPV’s main innovation lies in meeting a large part of the building’s electricity demand, which is green and energy-saving. The following is a comparative analysis of silica-based BIPV and CIGS-BIPV in terms of innovative index.
CIGS thin-film solar cell is composed of four chemical elements including Cu, In, Ga, and Se (direct gap semiconductor). Its light absorption coefficient is up to ~105 cm-1 for high-energy photons (1.5 eV), and battery absorption thickness can be as low as a few micrometers [
In terms of efficiency, based on better spectral dispersion ability, CIGS thin-film solar cell could be as efficient as silica-based photovoltaic components. Single junction cell efficiencies under 1 sun for a range of photovoltaic technologies are shown in Figure
The highest confirmed cell efficiencies of typical research cells from 1975 to the present [
CIGS thin-film solar cell not only shows comparatively high conversion efficiency under direct sunlight but also has good weak light-adsorption characteristics that other solar cells cannot match. The photoelectric conversion efficiency of CIGS thin-film solar cell is much higher than other solar cells even in areas with low intensity of solar radiation. The photoelectric conversion efficiency could be relatively high under any solar radiation intensity, which is also one of the main advantages for CIGS thin-film solar cell to realize the industrialization and commercialization.
In the silica-based BIPV photovoltaic modules, poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) (PVB) or poly(ethylene-co-vinyl acetate) (EVA) are primarily utilized by single-crystal silicon or polycrystalline silicon cells to get encapsulated among multilayer toughened glasses [
An analysis of the innovation indexes of four products.
Innovation index | Weight factor | CIGS-BIPV | Silica-based BIPV | Glass curtain wall | Exterior stone | ||||
---|---|---|---|---|---|---|---|---|---|
Score | Weighted value | Score | Weighted value | Score | Weighted value | Score | Weighted value | ||
High tech content of products | 0.5 | 95 | 47.5 | 93 | 46.5 | 82 | 41 | 77 | 38.5 |
Space for technological progress | 0.5 | 95 | 47.5 | 91 | 45.5 | 78 | 39 | 73 | 36.5 |
1 | 95 | 92 | 80 | 75 |
In comparison with exterior stone and glass curtain wall that have matured sales channels, CIGS-BIPV products still have to improve their sales competitiveness. The most basic function of BIPV is for building, and power generation is its auxiliary function. CIGS-BIPV could be more consistent with building intelligence principle, safety and stability principle, and economic suitability than silica-based BIPV. In China, silica-based solar cells are usually produced and sold by small and private companies, while CIGS-BIPV is usually developed, produced, and sold by large state-owned companies and local state-owned companies. For example, Chongqing Shenhua CIGS thin-film solar cell module project enterprise, funded by China Energy Investment Corporation and Shanghai Electric, is providing a strong technical and economic support for improvement and spread of sales force of CIGS-BIPV, which has an annual production scale of 306 MW in the first phase of the project.
Glass curtain wall and exterior stone have various sales channels with thorough manufacturer, middleman market, and retailer. Both CIGS-BIPV and silica-based BIPV are emerging, and they are at a disadvantage site in terms of the sales force competition in construction. Although the silica-based solar cell is mature in electricity generation, it lacks good large-scale demonstration and application in BIPV integration. Table
Analysis of sales force index of four products.
Sales force index | Weight factor | CIGS-BIPV | Silica-based BIPV | Glass curtain wall | Exterior stone | ||||
---|---|---|---|---|---|---|---|---|---|
Score | Weighted value | Score | Weighted value | Score | Weighted value | Score | Weighted value | ||
Corporate strength | 0.2 | 88 | 17.6 | 87 | 17.4 | 89 | 17.8 | 87 | 17.4 |
Brand value | 0.2 | 84 | 16.8 | 85 | 17 | 90 | 18 | 90 | 18 |
Price/performance ratio | 0.25 | 84 | 21 | 82 | 20.5 | 92 | 23 | 90 | 22.5 |
Customer satisfaction | 0.15 | 78 | 11.7 | 75 | 11.25 | 88 | 13.2 | 87 | 13.05 |
Sales channel construction | 0.2 | 65 | 13 | 70 | 14 | 90 | 18 | 96 | 19.2 |
1 | 80.1 | 80.15 | 90 | 90.15 |
Through the comparison of six key strategic factors in the industry, the competitive advantages of CIGS-BIPV, silica-based BIPV, exterior stone, and glass curtain wall are analyzed. By analyzing the importance of successful operation of each factor in the industry, their weights are determined, from 0 (least important) to 1 (most important), and the sum of the weights is 1. The weight can be acquired by the analytical hierarchy process (AHP) or expert discussion. The weights of safety index, building aesthetics index, economy index, energy conservation and environmental protection index, innovation index, and sales force index determined by expert discussion are 0.20, 0.10, 0.30, 0.20, 0.10, and 0.10, respectively, shown in Figure
The key index weights of the product competency model.
Through the multiplication of evaluation value for each factor and the corresponding weight, weighted evaluation values of competitiveness for CIGS-BIPV, silica-based BIPV, glass curtain wall, and exterior stone are 86.00, 86.20, 87.00, and 84.50, respectively. As shown in Table
Competitive situation matrix of four products.
No. | Key competitive factors | Weight factor | CIGS-BIPV | Silica-based BIPV | Glass curtain wall | Exterior stone | ||||
---|---|---|---|---|---|---|---|---|---|---|
Score | Weighted value | Score | Weighted value | Score | Weighted value | Score | Weighted value | |||
1 | Safety index | 0.20 | 90 | 18.00 | 88 | 17.60 | 95 | 19.00 | 85 | 17.00 |
2 | Architectural aesthetic index | 0.10 | 90 | 9.00 | 88 | 8.80 | 95 | 9.50 | 90 | 9.00 |
3 | Economic index | 0.30 | 75 | 22.50 | 80 | 24.00 | 85 | 25.50 | 90 | 27.00 |
4 | Energy-saving and environmental protection index | 0.20 | 95 | 19.00 | 93 | 18.60 | 80 | 16.00 | 75 | 15.00 |
5 | Innovation index | 0.10 | 95 | 9.50 | 92 | 9.20 | 80 | 8.00 | 75 | 7.50 |
6 | Sales force index | 0.10 | 80 | 8.00 | 80 | 8.00 | 90 | 9.00 | 90 | 9.00 |
1.00 | 86.00 | 86.20 | 87.00 | 84.50 |
In this article, industry competition structure and competition situation are for the first time analyzed through “Porter’s Five Forces Model.” The index modeling approach is further adopted to quantitatively and qualitatively analyze the competency of CIGS-BIPV through six indexes: safety index, building aesthetics index, economic index, energy-saving and environmental protection index, innovation index, and sales force index. Besides, the weight analysis method is also performed for index modeling. This work indicates that in comparison with the glass curtain wall, exterior stone, and silica-based BIPV, CIGS-BIPV has an overall score of 86.00, with acceptable cost, beautiful appearance, high technology content, and strong product competitiveness. The electrical energy produced by CIGS-BIPV is a completely zero-emission, nonpolluting clean energy. People can use this clean energy to meet the needs of daily life, while reducing the negative impacts of environmental pollution and ecological damage caused by traditional coal-fired power generation. It is conducive to positively affecting China’s adjustment of the energy industry structure and meeting the carbon emission reduction commitments of the international community as soon as possible.
The main data used to support the findings of this study are included within the article. Other data could also be available from the corresponding author upon request (Email address: Dr. Hui Kong:
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
This work was funded by the China Postdoctoral Science Foundation (No. 2019M660588), the Natural Science Foundation of China (No. 51906179), and the pilot programs for major science, technology, and innovation projects toward 2030 of China Energy Investment Corporation (No. GJNY2030XDXM-19-20.1). The authors gratefully acknowledge the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2018M1A2A2063868 and No. NRF-2018R1C1B6006854). The authors also thank Teng Luo and Yinan Yang for valuable discussions.