Renewable energy (RE) is a non-traditional energy source that includes solar energy, wind energy, biomass energy, and nuclear fusion energy [1
]. It is widely available, renewable, low-carbon and has minimal environmental impact [2
]. With the increasing scarcity of traditional energy sources, global warming, and environmental degradation, the increased use of RE has become an effective path for sustainable development [3
]. At present, RE accounts for a small proportion of the world’s energy use [5
]. However, with the continuous advancement of the RE utilization technology, it is an irresistible trend to replace traditional energy sources with RE [6
]. With a large population, China is one of the world’s largest energy consumers [8
]. As early as 2010, the RE industry was listed by China as one of the seven strategic emerging industries in the country [9
]. In 2016, China’s “13th Five-Year Plan for RE Development” proposed to accelerate the establishment of a clean, low-carbon, safe and efficient modern energy system, and to achieve the goal of non-fossil energy accounting for 15% of primary energy consumption by 2020 [10
In recent years, China’s RE industry has developed rapidly. Statistics show that China has become the world’s largest RE investor, owner of RE vehicles, and REP producer and consumer country [11
]. Correspondingly, the export of REPs has also developed rapidly. According to COMTRADE data, China’s REP exports in 2016 reached $
83.40 billion, accounting for 24.31% of the world’s export share, ranking first in the world [12
However, China’s economy has entered a new stage of “coming to a quality revolution made in China”, and the quality of export commodities is more important than quantity [13
]. In recent years, China has actively integrated into the process of economic globalization by taking advantage of its low labor resources, and many industries have already led the world in export volume [14
]. Economic theory and international development experience show that sustainable economic growth is inseparable from the continuous optimization of export technology structure [15
]. Fan et al. (2009) [16
] found that the proportion of low value-added products in China’s export structure showed a downward trend, and medium-level products gradually became the main export products. It is concerningas to whether the evolutionary trend of China’s REP exports is the same as that of China’s export technology. To this end, this paper will empirically measure the changes in export technology of China’s REPs.
Previous literature studies have focused on the export competitiveness, export challenges, and export technology measures of REPs [17
]. Wei et al. (2016) [18
] found that RE equipment is China’s second largest export-oriented environmental product, and that its export share is second only to wastewater treatment products. Solar photovoltaic cellsare one of the world’s important export REPs. Zhao et al. (2017) [19
] found that most of the world’s solar photovoltaic cell exporters are located in East Asia and Southeast Asia, and that the international trade intensity of solar photovoltaic cell is growing. Fu et al. (2013) [20
] found that the export of China’s REPs to the US, EU, and Japan markets showed a rapid growth. However, Fu et al. (2013) [20
] only analyzed the export of 4-digit Harmonized Commodity Description and Coding System (HS) coded products. Four-digit HS-coded products contain many non-renewable energy product categories, and the definition of REPs is not precise enough. This paper defines the scope of REPs from the 6-digit HS code, and partially eliminates or supplements the Fu et al. (2013) [20
] classified products. Additionally, there is no clear authoritative definition of REPs. This study defines REPs as equipment and related products that provide services for the efficient use of RE, and the development of RE industries.
Although China’s REPs have achieved good export performance, the country still faces many problems or challenges, such as lack of high technology, unsustainable government subsidy policies, and unpredictable global trade environment [21
]. Most of the global RE dispute cases since 2007 are related to China [26
]. For example, the solar photovoltaic dispute between China and USA, since 2012 has had a serious negative impact on China’s solar photovoltaic industry and its exports [27
]. This fully exposes the overcapacity of low technology products in China’s RE industry [29
]. This article will focus on the export technology structure of China’s REPs.
For the measurement of export technology, Guan et al. (2002) [30
] proposed the technology added value method. Lall et al. (2006) [31
] proposed a complex index method, and Du et al. (2007) [32
] revised the method. Hausmann et al. (2005) [33
] proposed the use of “product-relevant income levels” (PRODY
) to determine the level of product labor productivity, also known as technical complexity index. What these methods have in common is that they first determine the technical level of a single product, then they calculate the overall technical level of the economy, and assign the technology content of the product to the weighted sum of the income levels of countries (or regions). The difference between these methods is the assignment weight. The valuation weights of Guan et al. (2002) [30
] and Lall et al. (2006) [31
] are the world share of various products exported by various countries. Du et al. (2007) [32
] revised the weight of the method to the world share of various types of products produced by various countries. The valuation weights of Hausmann et al. (2005) [33
] are the export comparative advantage index after the standardization of various products in various countries. In comparison, the application of the technique complexity method of Hausmann et al. (2005) [33
] is more common, and the research data is more acquirable. These application areas involve cultural and creative industries, manufacturing, agriculture, etc., but there is a lack of research on REPs export technology [34
]. To this end, this paper chooses the technical complexity index of Hausmann et al. (2005) [33
] to empirically measure the dynamic changes of China’s REP export technology. The Hausmann et al. (2005) [33
] method does not classify PRODY
values. This study proposes a method called “Equalization Technology Classification” that divides all REPs into five technical levels: high, medium-high, medium, medium-low, and low according to the PRODY
value. This method facilitates a clearer REP technology analysis and international comparison.
Different classification criteria for PRODY
values will have different effects on the conclusions of the study. The main classification methods of the previous literature are the “Experience Sorting Method” of Tang (2012) [37
], the “Technical Fixed Classification” of Zhu et al. (2009) [38
], and the “Optimal Segmentation Method” of Wei (2015) [15
]. The method of Tang (2012) [37
] classifies the PRODY
values according to the author’s experience, ensuring that the technology classifications are as normal as possible, and the classification results of different scholars may be different. The method of Zhu et al. (2009) [38
] ignores the fact that technology changes over time. The method of Wei (2015) [15
] sorts PRODY
data, and then determines the number of categories according to the needs, which are also likely to cause people to subjectively change the technology differences between samples. To this end, the “Equilibrium Technology Method” proposed in this paper emphasizes objectivity and will avoid the classification results being influenced by time change and human experience.
The review shows that technological innovation is one of the important factors affecting the sustainable development of China’s RE industry. However, there is little research literature on the structural changes in export technologies for REPs. Moreover, the definition and technology classification of REPs need to be further improved [20
]. To this end, this paper is based on previous literature research [20
], to first refine the scope of REPs further. Then, this paper uses the technical complexity index to empirically measure the dynamic changes of China’s REP export technology. In order to ensure the objectivity of product technical complexity classification, this paper proposes the “Equalization Technology Classification” method.
(1) This paper puts forward some inspirational suggestions to promote the technological progress of China’s RE industry. First, the low proportion of high technical complex exports restricts the overall technical level of China’s REPs. China’s REP manufacturers need to abandon short-term market interests, strengthen investment in talent and technology research, and strive to enhance its position in the global RE industry value chain. Second, the form of export trade is too singular and easily causes international trade friction. Therefore, China’s REP producers should actively expand cooperation with leading technology countries, such as the docking of RE technology standards, cooperative research and development (R&D) of RE equipment, exchange of REP technology talents, etc. Third, China’s REP producers need more “going out”, making full use of foreign resources and technology.
(2) The definition of the scope of REPs has a greater impact on the conclusions of the study. The REPs belong to the category of environmental products. At present, the authoritative definition of environmental products has only been discussed by two international organizations, the Asia-Pacific Economic Cooperation (APEC) and the Organization for Economic Co-operation and Development (OECD), but the differences between the two standards are still large. In the future, this research field deserves further exploration.
(3) Different classification methods of PRODY values will also affect the conclusion of the study. This study uses the “Equalization Technology Classification” method, and if other methods are used, the research conclusions will be different. Therefore, the classification of technology structure is worthy of further exploration.
(4) The technical complexity index also has limitations. For example, the processing trade factor and the implementation of the technology export restriction policy are not considered. Therefore, the research conclusion is only used as a reference for decisionmaking. Therefore, future improvements and application studies on this method are worth exploring.