Chapter 1
Introduction to Photovoltaic
1.1 Photovoltaic
Solar power resources are abundant, widely available, one of the major renewable energy sources that have the greatest development potential. One important way to convert solar radiation into electricity occurs by the photovoltaic effect which was first observed by Becquerel. It is quite generally defined as the emergence of an electric voltage between two electrodes attached to a solid or liquid system upon shining light onto this system. Practically all photovoltaic devices incorporate a pnjunction in a semiconductor across which the photovoltage is developed. These devices are also known as solar cells. A crosssection through a typical solar cell is shown in Fig. 1.1. The semiconductor material has to be able to absorb a large part of the solar spectrum. Dependent on the absorption properties of the material the light is absorbed in a region more or less close to the surface. When light quanta are absorbed, electron hole pairs are generated and if their recombination is prevented they can reach the junction where they are separated by an electric field. Even for weakly absorbing semiconductors like silicon most carriers are generated near the surface. This leads to the typical solar cell structure of Fig. 1.1: the pnjunction which separates the emitter and base layer is very close to the surface in order to have a high collection probability for free carriers. The thin emitter layer above the junction has a relatively high resistance which requires a well designed contact grid also shown in the figure. The operating principles have been described in many publications, and will not be addressed further here. For practical use solar cells are packaged into modules containing either a number of crystalline Si cells connected in series or a layer of thinfilm material which is also internally series connected. The module serves two purposes, it protects the solar cells from the ambient and it delivers a higher voltage than a single cell which develops only a voltage of less than 1 V.
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1 Ch a pter Fig. 1.1 Typical solar cell Photovoltaic market in 2000 is about 277 MW corresponding to a value of over US$ 1 billion. This is a remarkable market but still far away from constituting a noticeable contribution to the world energy consumption. Market growth from 1990 to 2001 was between 15% and 25%. This market growth would be very satisfying for any conventional product but in the case of PV it is entirely insufficient if we consider the goals. The main motivation for developing solar energy is the desire to get away from depletable fossil fuels with their adverse effect on the environment. At the present growth rate, it will take us far into the second half of this century get a relevant contribution by PV to world energy demand. As will be pointed out below, support programs in several countries are already accelerating market growth. Besides the terrestrial market there is also the space market which has entirely different boundary conditions and also different materials requirements. In order to keep the volume of this paper at a reasonable size, space solar cell materials will not be included.
There are two major market sectors, grid connected and so called stand alone systems. The former delivers power directly to the grid. For this purpose the dc current from the solar modules is converted into ac by an inverter. The latter supplies power to decentralized systems and small scale consumer products. A major market currently being developed is in solar home systems supplying basic electricity demand of rural population in developing countries. The magnitude of this task can be appreciated if one is aware that about 2 billion persons are without access to electricity today. At present, both markets need subsidies, the grid connected installations because PV is much more costly than grid electricity, and solar home systems because the potential users lack the investment capital. On the other hand, there is also a significant industrial stand alone market which is today fully economical.
Because of its high potential the market is hotly contested and new companies are entering constantly. It is significant that several large oil companies have now established firm footholds in
1 Ch a pter photovoltaic. Indeed, a recent study of possible future energy scenarios up to the year 2060 that was published by the Shell company predicts a multigigawatt energy production by renewable energies including photovoltaic. On the other hand, the strong competition leads to very low profit margins of most participants of this market.
In 2000, the market showed an accelerated growth of more than 30%. There are good chances that this growth will continue for at least some years because some countries have adopted aggressive measures to stimulate the grid connected market. Japan’s very ambitious 70,000 roof program caused an astonishing increase by 63% of Japanese production in 1999. In Germany, a feedback law was passed which sets a rebate rate of 0.5/kWh of PV generated electricity. If this rate is combined with the already existing 100,000 roof program, PV becomes (only moderately) economical. It can be expected that other countries will follow these examples. In order to meet the growing demand, many PV companies are in the process of setting up substantial new cell and module production capacities.
From Materials Science and Engineering R, by Adolf Goetzberger, 2003. New Words and Expressions
1. photovoltaic [fәʊtәʊvɒl'teɪɪk] adj. [电子] 光电伏打的，光电的 2. resource [rɪ'sɔ s] ː n. 资源，财力；办法；智谋
3. renewable [rɪ'njuːәbәl] adj. 可再生的；可更新的；可继续的 n. 再生性能源 4. radiation [reɪdɪ'eɪʃ(ә)n] n. 辐射；发光；放射物
5. voltage ['vәʊltɪdʒ] n. [电] 电压
6. incorporate [ɪn'kɔːpәreɪt] vt. 包含，吸收；体现；把……合并 vi. 合并；混合；组 成公司 adj. 合并的；一体化的；组成公司的
7. semiconductor [7semɪkәn'dʌktә] n. [电子][物] 半导体
8. resistance [rɪ'zɪst(ә)ns] n. 阻力；电阻；抵抗；反抗；抵抗力 9. grid [grɪd] n. 网格；格子，栅格；输电网
10. module ['mɒdjuː l] n. [ 计] 模块；组件；模数
11. crystalline ['krɪst(ә)laɪn] adj. 透明的；水晶般的；水晶制的 12. ambient ['æmb ә ɪ nt] adj. 周围的；外界的；环绕的 n. 周围环境 13. depletable adj. 可耗减的
14. boundary ['baʊnd(ә)rɪ] n. 边界；范围；分界线 复数 boundaries
15. current ['kʌr(ә)nt] adj. 现在的；流通的，通用的；最近的；草写的 n. （水，气， 电）流；趋势；涌流 n. (Current)人名；(英)柯伦特
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17. appreciate [ә'priːʃɪeɪt] vt. 欣赏；感激；领会；鉴别 vi. 增值；涨价 18. stimulate ['stɪmjʊleɪt] vt. 刺激；鼓舞，激励 vi. 起刺激作用；起促进作用
过去式 stimulated 过去分词 stimulated 现在分词 stimulating
19. ambitious [æm'b ә ɪʃ s] adj. 野心勃勃的；有雄心的；热望的；炫耀的 比较级 more ambitious 最高级 the most ambitious
20. astonishing [ә'stɒnɪʃɪŋ] adj. 惊人的；令人惊讶的 v. 使……惊讶；使……诧异
（astonish 的 ing 形式） Notes
1. It is quite generally defined as the emergence of an electric voltage between two electrodes attached to a solid or liquid system upon shining light onto this system. 参考译文：这通常被定义为当光照在这个系统上时，在两个附属于固体或液体系统的电 极之间产生的电压。 2. This is a remarkable market but still far away from constituting a noticeable contribution to the world energy consumption. 参考译文：这是一个引人瞩目的市场，但是离成为世界能源消费的重要组成部分还很远。 3. There are good chances that this growth will continue for at least some years because some countries have adopted aggressive measures to stimulate the grid connected market.
参考译文：这个增长将持续至少数年，这是很好的机遇，因为一些国家已经采取了积极 的措施以促进电网连接市场。
1.2 Development of Photovoltaic in China
According to the China Meteorological Administration, China has abundant solar energy resources. The total potential for solar radiant energy of 1.7×10 12 tce (tons of standard coal equivalent) per year for the entire country. More than twothird of the country has over 2000 h of sunshine each year, which provides an equivalent annual solar radiation of over 5.02~10 6 kJ/m 2 . China’s solar energy resource distribution is shown in Table 1.1. This illustrates the amount of solar radiation available. Compared with other countries in similar latitude, the solar radiant energy in China is superior to those in Europe and Japan, and similar to those in the United States. As can be seen in Table 1.1, provinces located in different latitudes and longitudes have different levels of solar irradiations. The country can be divided into five different regions from I to V. The distribution of China’s solar energy resources in different areas varies significantly. In general, the solar resources in the western region (such as Ningxia, Gansu, Xinjiang, Qinghai, and Tibet) are higher than that in the eastern region (such as Guangdong, Shaanxi, Anhui, Heilongjiang, Zhejiang, Fujian,
1 Ch a pter Hunan, and Hubei), and the resources in the northern region (such as Hebei, Shanxi, Inner Mongolia, Shandong, He nan, Jilin, Liaoning, and Shaanxi) are higher than in the southern region (such as Sichuan, Guizhou, Chongqing, Guangxi, and Jiangxi). This does not, however, correlate with the demand for energy. China’s electricity loads are concentrated in the eastern and the southern regions, unfortunately, the solar resourcerich regions in the QinghaiTibet Plateau, North China and Northwest China are far from the regions which consume the greatest electrical power load.
Table 1.1 Solar energy resources in different regions of China
Since the 1990s, China’s PV power is developing rapidly and the installed capacity is increasing constantly. Fig. 1.2 shows the annual installed capacity and the cumulative installed capacity from 1976 to 2009. Based on current trends, the cumulative PV power installations will reach 1.8 GWp by 2020 and 1000 GWp by 2050 nationwide in China.
Fig. 1.2 Installed capacity of the solar PV power in China (19762009)
To encourage the development of renewable energy such as solar PV power, China has promulgated a series of laws, regulations and financial incentive policies, and has invested significant funds in PV power generation projects. The result of this investment is that China has a number of the world’s leading PV companies as well as the successful establishment of research and
1 Ch a pter development centers. Table 1.2 Electricity sales in China from 2004 to 2010 Another factor that will increase the market for the solar PV power industry is China’s demand for electricity, which continues to grow rapidly. The consumption of electricity in China from 2004 to 2010 is shown in Table 1.2. According to the statistics, the electricity sales value in China in 2010 is twice as much as that in 2004, and the average annual growth rate from 2004 to 2010 was more than 12%. This increasing demand for electricity, in addition to the shortage of fossil fuels and the negative impact of environmental pollution caused by the burning of fossil fuels, and the demand for renewable energy will increase which will create opportunities for the solar PV power industry.
In recent years, China has actively supported the development of PV power, and has constructed a series of PV power generation projects, mainly in China’s western and northern provinces. Table 1.3 lists the main largescale PV power generation projects in China from 2004 to 2010. The installed capacities of these projects are in the range of 5–200 MW. However, most of these projects are located in developing regions (such as Qinghai, Gansu and Ningxia) where the grid structure is relatively weak and the distance to the load centers is significant. This poses a challenge to use the generated solar power fully and efficiently.
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The solar PV power supply chain consists of silicon materials, wafers, cells, components, and applications industries that utilize the power created by the solar PV power. The solar PV power industry has a close link with the raw material producers, power generating plants, and power supply companies. China’s solar PV power industry chain and its influencing factors are shown in Fig. 1.3.
Fig. 1.3 Diagram of the solar PV power generation industry
In China, the main factors that affect the PV power industry are the technology, the industry plan, the laws, the price and the incentive policies. Technology is a key factor that affects the competitiveness of the PV power industry, especially the cost of solar PV power generation. The government plays a key role by regulating the renewable power market, especially since the current industrial environment is not mature. The Chinese government has formulated a series of industry plans for the PV power development. These industry plans serve as a strategic and directional guide to the development of PV power industry. In order to encourage the solar photovoltaic power, China also released supporting laws, policies and regulations. These laws, policies and regulations have an important impact and ensure a framework to sustain the stable, healthy and orderly operation of the PV power industry. Related policies, such as electricity price policies, tariff subsidy policies and project incentive policies, provide various advantages and favorable conditions that greatly improve the competitiveness of the industry. Therefore, this paper will review and examine the factors affecting the growth of the solar photovoltaic power industry in China based on the following five aspects: (1) the technology development, (2) the industry development plans, (3) the laws and regulations, (4) the electricity price policies, (5) the project incentive policies.
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Since the successful development of the first crystalline silicon PV cell in 1958, China’s PV power has evolved, going from small to large in scale, from single arrays to multiple arrays in type, from low to high in conversion efficiency. Milestone events in the development of China’s solar energy technology, and in the growth, research and development of the solar PV power technology are shown in Fig. 1.4.
Fig. 1.4 Milestones in the development of the solar PV power technology development in China
In China, the technology development of solar PV power can be divided into three stages, germination stage, seedling stage and growth stage.
In the germination stage (from 1958 to 1970s), the development and manufacture of the solar cells was the key goal. In 1968, an institute in Tianjin developed and manufactured the first solar cell in China using satellite technologies. In the 1970s, a few solar cell factories were set up in the cities of Shanghai, Ningbo and Kaifeng. In the seedling stage (from 1980s to 1990s), the State Scientific and Technological Commission set up China Optics and Electronics Technology Centre, which started the study of monocrystalline silicon solar cells, polysilicon silicon solar cells and the application of PV systems. In 1986, China’s first 0.56 kW wind and solar hybrid system was established in Inner Mongolia. In 1989, China’s first 10 kW PV power station began operation in Tibet. In the 1990s, the Institute of Electrical Engineering at the Chinese Academy of Sciences developed and constructed an independent PV station. A few production bases were formed in the Pearl River Delta areas and China began to export various PV products.
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In the growth stage (from 2000 to present), the Suntech Company and Yingli Green Energy Company constructed the 10 MWp solar cells production lines in 2002 and 2003, respectively. During the last few years, the output of China’s solar cells increased rapidly and accounted for 30% of the world’s production in 2005. Advances have also been made in research and development. In 2007, the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences invented and developed the physical purification method with which the purity of the solar cell silicon can reach 99.9999%. In 2010, the Shanghai Branch of the Chinese Academy of Sciences successfully developed a method of using physical process technology to produce solar cell grade polysilicon. While there have been numerous advances, China still strives to narrow the gap and make advances in selected aspects of solar power technology, including cell efficiency, components efficiency, production equipment technology and testing technology.
In recent years, China’s government issued a series of renewable energy development plans, including the ‘‘Renewable Energy Mid and Longterm Plan’’, ‘‘Renewable Energy Development Eleventh FiveYear Plan’’ and the ‘‘Economic and Social Development Twelfth FiveYear Plan’’. These plans have a significant impact on the potential growth of the solar PV industry. Milestones in the development of solar power and how these milestones related to the national plans are shown in Fig. 1.5.
Fig. 1.5 Milestones in the growth of solar PV power industry program in China
In November 2007, the National Development and Reform Commission (NDRC) issued the ‘‘Renewable Energy Middle and Longterm Plan’’ which identified the longterm goal of solar power. In the plan, China’s annual use of renewable energy will reach the equivalent of 2.7 hundred million
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tons of standard coal by 2010, with solar power contributing 300 MW to this goal. By 2020, the portion of China’s energy use, that will be served by renewable energy, will increase to 16% (compared to 7% in 2007) and the amount of energy provided by solar power will reach to 1800 MW.
One year later, in March 2008, according to the requirements of the ‘‘Renewable Energy Mid and Longterm Plan’’ and the new development of renewable energy in China, the NDRC issued a “Renewable Energy Development Eleventh FiveYear Plan”. This plan proposed to establish national standards for public lighting in urban areas using PV, and technical standards to support PV construction, including the addition of building ongrid PV, largescale ongrid PV and other technical standards. This plan identified the construction of the rooftop PV generating system in city housing and large scale ongrid PV power plant as key projects for solar energy utilization and development. The plan also outlined a development plan and technological categories for solar power in different regions.
In line with the rapid development of China’s solar energy industry and the huge market potential, the State Council published the ‘‘Economic and Social Development Twelfth FiveYear Plan’’ in March 2011. This plan clearly stated that the country will:
l promote renewable energy production,
l build a safe, stable, economical and clean modern energy industrial system,
l accelerate the development of new energy projects,
l use the traditional energy by more clean and efficient ways.
This plan also proposed that the Chinese government support and fund the research and development of the key technologies for new energy and energy conservation.
Similarly, some provincial governments also released supporting policies to promote the solar PV power development. For instance, the Jiangsu provincial government issued implementing notices on solar PV industry in 2009. This policy stipulated that the government will develop the solar power industry through supporting policies, the development of relevant standards and the provision of incentives. Other provinces such as Hebei, Shanghai, Zhejiang, Shandong, and Fujian, are taking a similar approach. The goal for the development of solar PV power generation is shifting from an emphasis on the growth rate of installed capacity to a longterm program with orderly progress of the industry.
To encourage and promote the development of the solar energy industry, China has promulgated a series of supporting laws and regulations in recent years. Fig. 1.6 illustrates the development of the laws related to the solar PV power generation. These laws created a framework of regulations and rules to protect the PV power industry.
1 Ch a pter Fig. 1.6 Legislative milestones in support of solar PV power in China
The Renewable Energy Law was approved by the Tenth National People’s Congress on February 28, 2005. This law requires the central government and each provincial government to identify medium and longterm goals for the use of renewable energy. The government encourages and supports renewable energy by regulating connections to the state power grid. The grid corporations must purchase all the electricity that is generated from renewable energy sources within the area served by their power grid. The law also promised to provide special funds, tax deduction and favorable loans as incentives for the development of renewable energy. According to the law, if the cost of renewable energy is higher than that of traditional energy sources, the gap shall be shared among the end users across the nation.
Although the full purchase of renewable energy had been regulated by the Renewable Energy Law, a conflict of interest existed between the power generation company and the grid company because the grid company was unwilling to purchase the electricity generated from renewable sources with a high price. As a result, the policy requiring the full purchase of renewable energy was difficult to implement fully. To solve this problem, in 2009, the Renewable Energy Law was amended and regulated the full purchase security system. According to the amended law, the NDRC together with the State Electricity Regulatory Commission and the Ministry of Finance shall determine the required ratio of renewable energy power to the total power generation capacity. This ratio shall be determined periodically according to the national medium and longterm plan, and shall formulate the implementation method for the grid companies, with priority to purchase the renewable energy power. This law also established a renewable energy development fund based on the experiences of the developed countries.
Furthermore, the Energy Conservation Law promulgated on October 28, 2007 explicitly stated that China recognizes saving resources as a basic longterm national strategy, and conservation and development are equally important with conservation as a top priority in the energy development strategy. The law learly states that China encourages and supports the development and use of new
1 Ch a pter energy, renewable energy and the biomass in rural areas, and China will widely promote the biomass, solar and wind and other renewable energy technologies.
As a kind of renewable energy, solar PV power competes with and complements traditional energy and other kinds of renewable energy. In China, although the ongrid price of solar PV has gradually declined, still it is highly relative to traditional energy and relative to other kinds of renewable energy. As shown in Table 1.4, the price differences have greatly weakened the competitiveness of solar PV power generation and restricted the development of largescale PV power generation.
Table 1.4 The ongrid prices of various power generation types in China (2010present)
The cost of solar cells constitutes the largest share of the total cost of PV power generation. Solar cells include crystalline silicon solar cells and amorphous silicon solar cells. The former includes monocrystalline silicon solar cells and polycrystal silicon solar cells. The development of monocrystalline silicon cells is still in the early stages, but the production cost is high due to the use of highpurity silicon, and the raw materials cost accounts for more than half of the total cost. Compared with the monocrystalline silicon cells, the cost of the polycrystal silicon cell is low because the production process is relatively simple. In recent years, the amorphous silicon solar cell has been mass produced for use as a lowcost solar cell.
The evolution of the cost of solar cell power during the last 30 years in China is shown in Fig. 1.7. In the 1970s, the solar cell power cost was as high has 200Yuan/kWh. In the1980s, China’s PV industry made progress and the cost of solar cell power reduced to 40–45 Yuan/kWh. By the end of 2000, China’s amorphous silicon solar cell power cost was 23–25 Yuan/kWh. In 2008, the cost of solar cells in China was 10–75 Yuan/kWh. In 2010, China’s solar PV cells power cost is down to approximately 1 Yuan/kWh.
1 Ch a pter Fig. 1.7 Evolution route of the solar cells power cost in China To support the solar PV power industry, the government has promulgated a series of policies to supply ongrid solar PV power.
The NDRC released the ‘‘Trial Measures on Renewable Energy Prices and Costsharing Management’’ in January 2006; this regulated the renewable energy prices and implemented the government pricing and government guiding prices. Solar power projects and prices for ongrid solar power are regulated by government pricing, with the standard price determined by the Bureau of Commodity Prices of the NDRC. In this framework, the price is based on the actual cost plus a reasonable profit. At present, the subsidy for solar power is 0.25 Yuan/kWh. The government encourages the users to buy renewable energy power. The Ministry of Finance promulgated the ‘‘Procedures for the Administration of Special Funds for Renewable Energy Development’’ in May 2006. This policy administers special funds that support the promotion and application of wind power, solar power, and ocean power, and also support the application of solar energy and geothermal energy for building energy conservation.
In January 2007, the NDRC issued the ‘‘Interim Measures on Renewable Energy Subsidy Management’’ to ensure rational use and distribution of the subsidy of renewable energy. It is stipulated that the range and standard rates of subsidy to solar PV shall be approved and announced by the Bureau of Commodity Prices of the NDRC. The subsidies for solar PV power generation projects include: (1) the excess of the ongrid price of renewable energy power over the standard ongrid price of the local desulfurized coalfired units; (2) the excess of the operation and maintenance costs of the independent solar PV power systems by public investment over the local grid average sale price; (3) the grid connections costs of the solar power projects.
The Ministry of Finance of China issued the ‘‘Interim Measures on Management of Financial Fund for Solar Building’’ in March 2009, which regulates the subsidy standard for solar buildings that will be adjusted annually according to the actual cost. This policy gives full support to the solar energy and the building integration applications, and as a result the solar power cost will reduce to 1
1 Ch a pter Yuan/kWh through use of the subsidies.
In China, the PV power prices are not the same in all regions. Different regions and different projects have different PV power prices due to the different approved prices by the government. However, with the reduction in the cost and the subsidy support by various policies, the PV power price continued to decline. The PV power prices continue to become closer to traditional power prices steadily.
PV power generation includes independent PV power system (offgrid) and gridconnected PV power system (ongrid). In the 20th century, due to the high cost of PV cells, PV power generation is mainly used in island, mountain, desert and other remote areas where the public power grid cannot reached. In recent years, the PV power, including power generation and PV construction, have been gradually extended to include both ongrid and offgrid power systems in cities and rural areas. In 2002, China launched the ‘‘Electricity Plan for Remote Villages in Western Provinces’’, by establishing PV power and other power generation projects to provide electricity for poor and remote villages. In 2009, the government issued a series of project policies such as the ‘‘Golden Sun Demostration Projects’’ and the “Solar Roofs Plan” to support solar power development, and China was ranked in the top ten of PV markets throughout the world. In the next 10 years, China’s solar PV power market will turn from independent power systems to gridconnected power systems, which will include desert power stations and city roof power systems.
In February 2006, the NDRC published ‘‘The Renewable Energy Power Administration Regulation’’ to stipulate the requirements for the power generation companies engaged in the solar PV power generation business. And power generation enterprises are encouraged to increase their investment in the renewable energy projects. Solar PV power projects are under the policies of the NDRC and can receive financial support from the NDRC. According to the regulation, the power grid companies shall invest in solar power and undertake to connect the solar power generation plants into the public grid system.
In March 2009, the Ministry of Finance and the Ministry of Housing and Urban–Rural Development issued the ‘‘Notice of Opinions on the Implementation of Accelerating the Solar PV Building Applications’’ to implement the ‘‘Solar Roofs Plan’’ which adopted a demonstration project to speed up the implementation of PV projects in urban and rural areas.
In April 2009, the Ministry of Finance and the Ministry of Housing and Urban–Rural Development published the ‘‘Application Guideline for Solar PV Building Demonstration Project’’. The guideline supports the solar PV building projects. The government will provide subsidies for solar PV building application demonstration projects, and the maximum subsidy is 20 Yuan/W.
In July 2009, the Ministry of Finance, the Ministry of Science and Technology, and the National Energy Board jointly issued the ‘‘Notice of Implementation of Golden Sun Demonstration Projects’’
1 Ch a pter which regulated that the government will provide subsidies to ongrid PV power projects at 50% of the total investment, and the subsidies for independent PV power systems will reach 70% of the total investment in remote areas without electricity. This policy illustrates the strong support that the Chinese government provides to encourage the investment and operation of solar PV power projects. This policy also launched a series of incentives for PV power generation projects. The policies are gradually shifting from encouraging the large companies to invest in PV power generation projects to implement subsidies for PV projects. The subsidies for PV power generation projects have reached as much as half of the total investment for a project. In addition, the policies for the PV projects have expanded from supporting solar PV power plant projects to encouraging the construction of solar buildings.
From Renewable and Sustainable Energy Reviews, by Zhenyu Zhao, 2013. New Words and Expressions
1. equivalent [ɪ'kwɪvәlәnt] adj. 等价的，相等的；同意义的 n. 等价物，相等物 2. distribution [dɪstrɪ'bjuːʃ(ә)n] n. 分布；分配
3. latitude ['lætɪtjuː d] n. 纬度；界限；活动范围
4. superior [suː ә 'p ɪ r ә ɪ ; sju 'p ː ә ɪ r ә ɪ ] adj. 上级的；优秀的，出众的；高傲的 n. 上级， 长官；优胜者，高手；长者
5. longitude ['lɒn(d)ʒɪtjuː d; 'l ɒŋgɪtju d] n. ː [地理] 经度；经线
6. correlate ['kɒrәleɪt; kɒrɪleɪt] vi. 关联 vt. 使有相互关系；互相有关系 n. 相关物； 相关联的人 adj. 关联的
7. capacity [kә'pæsɪtɪ] n. 能力；容量；资格，地位；生产力 复数 capacities
8. cumulative ['kjuː ʊlәtɪv] adj. 累积的 mj
9. promulgate ['prɒm(ә)lgeɪt] vt. 公布；传播；发表
过去式 promulgated 过去分词 promulgated 现在分词 promulgating 10. financial [faɪ'nænʃ(ә)l; fɪ'nænʃ(ә)l] adj. 金融的；财政的，财务的 11. consumption [kәn'sʌm(p)ʃ(ә)n] n. 消费；消耗；肺痨
12. environmental pollution 环境污染
13. opportunity [ɒpә'tjuː ɪtɪ] n. 时机，机会 n 复数 opportunities 14. efficiently [ɪ'f ә ɪʃ ntli] adv. 有效地；效率高地（efficient 的副词形式） 15. formulate ['fɔ mj ː ʊleɪt] vt. 规划；用公式表示；明确地表达
过去式 formulated 过去分词 formulated 现在分词 formulating 16. strategic [strә'tiː ʒɪk] adj. 战略上的，战略的 d
1 Ch a pter 18. polysilicon [pɔli'silikәn] n. [晶体] 多晶硅 19. rooftop ['rʊf't p] n. ɑ 屋顶 adj. 屋顶上的 20. utilization [7ju t ː ɪlaɪ'ze ә ʃ n] n. 利用，使用
21. category ['kætɪg(ә)rɪ] n. 种类，分类；[数] 范畴 复数 categories
22. implement ['ɪmplɪm(ә)nt] vt. 实施，执行；实现，使生效 n. 工具，器具；手段 23. provision [prә'vɪʒ(ә)n] n. 规定；条款；准备；[经] 供应品 vt. 供给…食物及必需品 24. conflict ['kɒnflɪkt] n. 冲突，矛盾；斗争；争执 vi. 冲突，抵触；争执；战斗 25. periodically [7p ә ɪ rɪ'ɒdɪkәlɪ] adv. 定期地；周期性地；偶尔；间歇
26. priority [praɪ'ɒrɪtɪ] n. 优先；优先权；[数] 优先次序；优先考虑的事 复数 priorities 27. rural ['r ә ʊ r(ә)l] adj. 农村的，乡下的；田园的，有乡村风味的
比较级 more rural 最高级 the most rural
28. biomass ['ba ә ɪ (ʊ)mæs] n. （单位面积或体积内的）[生态] 生物量 29. traditional [trә'dɪʃ(ә)n(ә)l] adj. 传统的；惯例的
比较级 more traditional 最高级 the most traditional
30. evolution [7i v ː ә'luːʃ(ә)n; 'evә'luːʃ(ә)n] n. 演变；进化论；进展 Notes
1. Compared with other countries in similar latitude, the solar radiant energy in China is superior to those in Europe and Japan, and similar to those in the United States.
参考译文：与相似纬度的其他国家相比，中国接收到的太阳辐射能量比欧洲和日本多， 与美国相似。
2. To encourage the development of renewable energy such as solar PV power, China has promulgated a series of laws, regulations and financial incentive policies, and has invested significant funds in PV power generation projects.
参考译文：为了鼓励太阳能光伏发电等可再生能源的发展，中国已经颁布了一系列法律、 法规和财政激励政策，并已在光伏发电项目中投入大量资金。
3. In recent years, China has actively supported the development of PV power, and has constructed a series of PV power generation projects, mainly in China’s western and northern provinces.
参考译文：近年来，中国大力支持光伏发电的发展，并在中国西部和北部省份建设了一 系列光伏发电项目。
4. Technology is a key factor that affects the competitiveness of the PV power industry, especially the cost of solar PV power generation.
参考译文：技术是影响光伏发电竞争力的一个关键因素，尤其是太阳能光伏发电的成本。 5. The government plays a key role by regulating the renewable power market, especially since
1 Ch a pter the current industrial environment is not mature. 参考译文：政府对可再生能源市场的调控起着关键性的作用，尤其是在当前工业环境还 尚未成熟时期。 6. Since the successful development of the first crystalline silicon PV cell in 1958, China’s PV power has evolved, going from small to large in scale, from single arrays to multiple arrays in type, from low to high in conversion efficiency. 参考译文：自从 1958 年第一块晶体硅光伏电池问世以来，中国光伏发电经历了从小到大 的规模、从单一阵列到多阵列型式、从低到高转化率的发展。 7. Although the full purchase of renewable energy had been regulated by the Renewable Energy Law, a conflict of interest existed between the power generation company and the grid company because the grid company was unwilling to purchase the electricity generated from renewable sources with a high price.
参考译文：尽管可再生能源全额收购已经由可再生能源法来规范，但是在发电公司和电 网企业之间还存在利益冲突，因为电网公司不愿用高价格购买来自可再生能源生产的电力。
8. This ratio shall be determined periodically according to the national medium and longterm plan, and shall formulate the implementation method for the grid companies, with priority to purchase the renewable energy power.
参考译文：该比例应根据国家中长期计划定期确定，并应制定本公司的实施方法，以优 先购买可再生能源生产的电力。
9. Different regions and different projects have different PV power prices due to the different approved prices by the government.
参考译文：由于政府批准的价格不同，不同地区和不同的项目有不同的光伏发电价格。
1.3 Status of Photovoltaic in China
The research and development of photovoltaic started from 1958 in China. It began to enter into application stage in the 1970s, but it was not actually industrialized until the middle of the 1980s when two single crystalline silicon solar cell production lines were introduced and the largescale utilization period was coming. Since 1993, the output of domestic crystalline silicon solar cells soared by 20%–30% annually, the total installed capacity of photovoltaic systems in China was approximately 22MWp at the end of 2002. Through long time of hard work, production equipment, technology of cells and modules and balanceofsystem components have been improved significantly.
Work on research and development of photovoltaics is carried out by various institutes and universities. The active research work in China includes single crystalline silicon solar cells with
1 Ch a pter practical type, high efficiency single crystalline silicon solar cells, multicrystalline silicon solar cells, amorphous silicon solar cells, GaAs solar cells, CuInSe2 and CdTe compound thin films solar cells, terrestrial silicon concentrator solar cells. The high conversion efficiencies of various solar cells in China are shown in Table 1.5.
Table 1.5 Efficiency of different solar cells for laboratory levels in China
At present, main products of photovoltaic are single crystalline silicon solar cells and amorphous silicon solar cells, multicrystalline silicon solar cells are in the small amount pilot production, the size of single crystalline silicon solar cells consists of mainly 100mmdiameter wafer, 100 × 100 mm 2 pseudosquare and 125×125 mm 2 pseudosquare. The thickness of wafer is between 280 and 400 um.
The conversion efficiency of single crystalline silicon solar cells ranges from 12% to 14% for production, the efficiency of 100×100 mm 2 multicrystalline crystalline silicon solar cells is 10%12%. The photovoltaic industry uses cheap reject material from the microelectronics industry. In 2001, multicrystalline silicon casting and wafer processing had been introduced to avoid frontend bottlenecks and reduce, to a certain extent, cell costs. In the laboratory, PESC, PERC, LGBC and MGBC solar cells, gettering and passivation technology have been studied extensively. The development of modules fabrication has progressed over the last 15 years to yield a highly reliable and durable package for the interconnected cells, much of the technology used today was originated in the efforts of the US Department of Energy program active in the early 1980s. Only a few modules used for garden light are encapsulated by transparent resin. The silver inks and aluminium inks for metallization of crystalline silicon solar cells have been produced by some institutes with
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high quality. The ethylene vinyl acetate (EVA) used for encapsulation of crystalline silicon solar cells has been produced by native major factory, the adhesive intensity of EVA/Glass is 30 N/cm, the adhesive intensity of EVA/TPT is 20 N/cm. EVA has recently been shown to discolor, in some situations, after several years in the field, particularly when modules reach high temperatures. Discoloring is associated with the deterioration of ultraviolet absorbers added to the EVA. The tempered, lowiron content glass and the TedlarPolyesterTedlar trilayer used in the rear surface of the modules mainly depend on import from abroad. The area of amorphous silicon solar modules is 305×915 mm 2 , the conversion efficiency is 4%–6%, high degeneration is the key problem for this single junction module.
Development of production and research equipment for photovoltaic is still encouraged and supported by China government. In 2000, Institute of Solar Energy of Shanghai Jiaotong University developed own solar tester financed by the Ninth FiveYear Plan. Tianjin Institute of Power Sources is one of four laboratories in the world, who is qualified for World photovoltaic scale (WPVS).
Before 2000, China did not have capacity of making production equipment used for solar cells, The past equipments were imported from developed countries 15 years ago. Technologies and the equipment used for photovoltaic production have been out of date. In 2000, in collaboration with Institute of Solar Energy of Shanghai Jiaotong University, Shanghai GoFly Green Energy Co. Ltd., installed a production line of crystalline silicon solar cells. Some main equipment such as Solar cell Selector, Module Simulator, Laminator, RTP furnace, etc., are designed by themselves. The laminator is adapted to efficient mass production, and has a low maintenance cost, the effective lamination area is 1000 × 800 mm 2 . The module simulator uses a PC with Windows 98, it has a high accuracy and fast data acquisition speed, light intensity uniformity is complied with the ASTM and JIS standards, light source is pulseXe lamp, the light uniformity is within 75%, the light spectrum is AM1.5, the effective area of module simulator is 1500 × 1000 mm 2 . At present, Shanghai GoFly Green Energy Co., Ltd., is improving process integration and implementing statistical process control and data systems, the improvements are directed at reducing yield losses in areas of electrical and mechanical performance and reducing chemical waste. This progress reduces the gap between Chinese manufacturers and the world’s leading manufacturers, in terms of technological advancement and production volumes.
The photovoltaic industry continues to rapidly expand at rates comparable to the telecommunications and computer industries, the massive growth in the industry is leading to many manufacturers installing new manufacturing capacity. In 2002, some manufacturers expand their volumes, and five new module assembly plants have emerged out.
In summary, China has a capacity of building photovoltaic production line, this is a significant development for future photovoltaic industry in China. Table 1.6 shows the information of main
1 Ch a pter solar cell manufacturers in China. Table 1.6 The information of main solar cell manufacturers in China
Batteries are used in solar electric systems to store electricity generated during daylight hours for later use, the operation of a battery used in a photovoltaic system can be summarized by two types of cycling: a shallow cycle each day and deep cycles over several days or weeks during cloudy weather or winter. The deep cycles occur when charging during the day is not enough to replace the amount of charge used by the appliances over the whole day. Therefore, the state of charge after each daily cycle is reduced slightly and this builds up to a deep cycle over a period of several days. When the weather improves or the days lengthen, there is extra charging and the state of charge after each daily cycle gets higher. Most solar electric systems use leadacid batteries for storage, today in China, there are hundreds of small sealed and starter battery manufacturers, but there is no deep cycle and long lifetime leadacid battery specially designed for photovoltaic systems, the most frequent problem comes from photovoltaic and hybrid system is the battery failure.
A power inverter is used in a photovoltaic system to convert lowvoltage DC to mains voltage AC. This is needed when using appliances that only work from a mains voltage AC supply. At present, the small and middle power compact inverter developed for photovoltaic have been used widely, most of them have high efficiency and reliability. Inverter with large capacity were developed, supported by State Science and Technology Commission (SSTC). 1520 kVA inverters have been provided to the photovoltaic plants with capacity of 20 kVA in Gaize and Cuoqin counties, in Tibet. 90% of conversion efficiency is available with less than 5% of harmonic deformation. The inverters were provided working normally in bad ambient temperature. And now, we plan to complete design enhancements to produce 100–1000 kVA inverters, that are easily manufactured and are suitable for use in residential applications, these products will use the transformerless, phaseleg topology.
A controller is used to provide these protections: risk of cable damage and fire from short circuits, overdischarge of leadacid batteries, excessive charging of batteries. Microcontrollerbased charge controllers for photovoltaic system have been developed and used. Charge controllers used for solarpowered communication systems have dataacquisition system. And now, there are some specialized controller manufactures in China, their products are costeffective.
1 Ch a pter China is perhaps the largest potential market for photovoltaic in the world, China has untapped solar resources, particularly in its western region which boasts about 3000 h of sunshine annually, taking into account the vast areas and the low population density, small energy units such as photovoltaic form a more costeffective solution than expansion of the electricity grid. So, there are many encouraging signs, as well as many critical challenges, for both the international and indigenous photovoltaic industries in the energy markets in China. The terrestrial markets are very diverse, using different products and often with different criteria for defining the ‘‘best’’ product. To analyze the market for photovoltaic, it is essential to divide it into market segments, that are consumer products, industrial markets, remote communities.
Consumer products include domestic power supplies, individual power supplies, indoor applications. Domestic power supplies are used to provide power for houses remote from the grid, holiday homes, mobile homes, boats, and so forth. In this category, the purchaser is the homeowner using his or her own money. Individual power supplies include garden lights, fountains, home security systems, fans for cars, battery chargers, and personal electronics. In this category the consumer is buying a product in order to enjoy a specific services, the manufacturer of the product has incorporated photovoltaic because it makes the product cheaper, enhances its market appeal, or allows a novel product to be developed. Indoor applications include calculators, watches and clocks, toys, instruments, and novelties. In this category, sizing photovoltaic to provide even tens of milliwatts can be difficult because of the small areas available and the low power in indoor lighting, however, many of these applications call for microwatts at a few volts, and a few integrally interconnected cells each of a small area are sufficient. Consumer products are marketled in a purely commercial environment, the growth of the market is influenced by general economic factors.
The industrial market is not homogeneous, and there are three broad categories that need to be considered: communications, cathodic protection, and remote power. Photovoltaic is costcompetitive in these markets because of the high costs associated with refuelling and maintaining internal combustion engines or in changing batteries or liquid gas cylinders. Communications application includes relay and repeater stations for telecommunications, monitoring control and reporting stations, and so on. The market of remote power includes applications such as electrified fencing, intruder detection, perimeter security at large sites. The customers for this category are companies and military.
Photovoltaic can provide electricity for remote communities in China, the range of services supplied is very wide and includes water pumping and water treatment, village supplies for domestic and small industry use, medical uses, educational uses, and communications via telephone, television, and radio, and so forth. In this case, the equipment is purchased by a utility, government agency, or international agency for deployment in the community.
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A large amount of experience has been gathered on technical, economic, social and management issues, an analysis of the experience shows that solar photovoltaic technology can be a viable alternative to extension of grid lines to electrify villages, especially in remote and difficult areas. Organizations such as railways, telecommunication, oil and natural gas commission in very specialized applications are using photovoltaic systems as the most viable option.
There is still a large gap between the potential of photovoltaic based on available resources and current levels of market development. Factors contributing to commercialization barriers for photovoltaic in China include government policy and planning, at the national government level there is a lack of a systematic and comprehensive policy structure tailored for photovoltaic development, coordination among agencies responsible for photovoltaic planning is weak. Other factors include the high cost. Costs remain high and the photovoltaic industry is only now making the jump from niche markets which is difficult and expensive. Low customer density in a given service territory makes sales, installation service and payment collection expensive and difficult, resulting in transaction costs that are about 30% of the total system costs. This reduces affordability, undermines sustainability of systems and reduces the market impact of even dramatic cost reduction in photovoltaic modules.
After the UN summit conference on Global Environment and Development held in Reo de Janeiro, 1992, China developed a quick response towards implementing a sustainable development strategy. They issued “Agenda of China 21st century”, a white paper of China’s sustainable development strategy in the 21st century. In this programmatic document, it is stressed that ‘‘renewable energy is the basis of future energy pattern’’. It is also stated that: ‘‘priority should be given to the development of renewable energy in the state energy development strategy’’, and ‘‘to encourage energysaving, energy efficiency and developing renewable energy should become the fundamental state policy’’.
The policy of government is clearly directed towards a greater thrust on all aspects of photovoltaic technology and application. Under the framework of National Sixth, Seventh, Eighth, Ninth and Tenth FiveYear Plan, the government has been actively supporting the development of photovoltaic in China. In 1996, the Chinese State Development Planning Commission launched the Brightness Program, with the overall objective of providing renewable power for 20 million Chinese without electrification by the year 2010. In 2002, China government accelerates this plan, about 1.8 billion RMB yuan will be provided for rural electrification at remote town level by installing photovoltaic and wind systems, 4.25 MWp photovoltaic systems of the first batch bidding will be installed in five provinces or autonomous regions (1.03 MWp for Gansu, 0.206 MWp for inner Mongolia, 1.68 MWp for Qinghai, 0.2 MWp for Shaanxi, 1.13 MWp for Xinjiang).
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agencies have supported the photovoltaic program from time to time. One example is a 10 MWp solar home system program being developed by the World Bank for western China. The Shell Company is implementing a largescale solar home system project in the Province of Xinjiang. The systems are expected to be purchased mainly by households and institutions living in isolated rural areas without access to electricity, subsidies come from different organizations. The previous National Photovoltaics Program Plan placed heavy emphasis on cell research, and now, major government programs have been focused on reducing the production costs associated with crystalline silicon module production and were instrumental in financing programs in thinfilm technologies.
Such efforts have resulted in the emergence of a commercial sector for photovoltaic systems and have opened up a market for many enterprises to sell their innovative designs and products. Marketing in true commercial sense has emerged, a lot of small enterprises is joining. The ‘‘Risk business’’ has been doubted by more and more people.
From Energy Policy, by Hong Yang, 2003. New Words and Expressions
1. industrialized [ɪn'dʌstr ә ɪ laɪzd] adj. 工业化的 v. 使工业化； 将……组成产业 （industrialize 的过去分词）
2. utilization [7ju t ː ɪlaɪ'ze ә ɪʃ n] n. 利用，使用
3. output ['aʊtpʊt] n. 输出，输出量；产量；出产 vt. 输出
过去式 outputted 或 output 过去分词 outputted 或 output 现在分词 outputting 4. domestic [dә'mestɪk] adj. 国内的；家庭的；驯养的；一心只管家务的 n. 国货；
佣人 5. annually ['ænj ә ʊ lɪ; 'ænjʊlɪ] adv. 每年；一年一次 6. approximately [ә'prɒksɪmәtlɪ] adv. 大约，近似地；近于 7. component [kәm'pәʊnәnt] adj. 组成的，构成的 n. 成分；组件；[电子] 元件 8. carry out 执行，实行；贯彻；实现；完成 9. institute ['ɪnstɪtjuː t] vt. 开始（调查）；制定；创立；提起（诉讼）n. 学会，协会；
学院 过去式 instituted 过去分词 instituted 现在分词 instituting 10. thin films solar cells 薄膜太阳能电池
11. terrestrial [tә'restr ә ɪ l] adj. 地球的；陆地的，[生物] 陆生的；人间的 n. 陆地生物； 地球上的人
12. single crystalline silicon solar cells 单晶硅太阳能电池
1 Ch a pter 14. reject material 剔除料 15. microelectronics industry 微电子行业 16. cast [k ɑː st] vt. 投，抛；计算；浇铸；投射（光、影、视线等）n. 投掷，抛；铸件， [古生] 铸型；演员阵容；脱落物 vi. 投，抛垂钓鱼钩；计算，把几个数字加起来 17. bottleneck ['bɒt(ә)lnek] n. 瓶颈；障碍物 18. passivation [pæsi'vei ә ʃ n] n. [化学] 钝化；钝化处理 19. fabrication [fæbrɪ'keɪʃ(ә)n] n. 制造，建造；装配；伪造物 20. reliable [rɪ'la ә ɪ b(ә)l] adj. 可靠的；可信赖的 n. 可靠的人
比较级 more reliable 最高级 the most reliable
21. durable ['dj ә ʊ rәb(ә)l] adj. 耐用的，持久的 n. 耐用品
22. encapsulate [ɪn'kæpsjʊleɪt; en'kæpsjʊleɪt] vt. 压缩； 将……装入胶囊； 将……封进内部； 概述 vi. 形成胶囊
23. transparent resin 透明树脂
24. adhesive intensity [әd'hiː ɪv; әd'hi z s ː ɪv] n. 粘合剂；胶黏剂 adj. 粘着的；带粘性的 25. deterioration [dɪ7t ә ɪ r ә ɪ 'reɪʃn] n. 恶化；退化；堕落
26. in the rear surface of 在后面的表面
27. degeneration [dɪ7dʒenә'reɪʃ(ә)n] n. 退化；[医] 变性；堕落；恶化 28. junction ['dʒʌŋ(k)ʃ(ә)n] n. 连接，接合；交叉点；接合点 29. data acquisition 数据采集
30. uniformity [juː ɪ'fɔ m n ː ɪtɪ] n. 均匀性；一致；同样 复数 uniformities 31. simulator ['sɪmjʊleɪtә] n. 模拟器；假装者，模拟者 32. manufacturer [7mænjʊ'fæktʃ(ә)rә(r)] n. 制造商；[经] 厂商 33. telecommunications ['telɪkә7mju n ː ɪ'ke ә ɪʃ nz] n. 通讯行业：服务类型变更，缴纳话费， 账户总览等所有业务均可通过移动设备完成 34. battery ['bætri] n. [电] 电池，蓄电池 n. [法]殴打 n. [军]炮台，炮位 35. transformerless [trænz'fɔmәlɪs] adj. 无变压器的；不使用变压器而产生的 36. short circuit 短路；漏电 37. remote [rɪ'mәʊt] adj. 遥远的；偏僻的；疏远的 n. 远程 比较级 remoter 最高级 remotest
38. domestic [dә'mestɪk] adj. 国内的；家庭的；驯养的；一心只管家务的 n. 国货； 佣人
39. perimeter security 周边安全
40. viable ['va ә ɪ bl] adj. 可行的；能养活的；能生育的 41. sustainable development strategy 可持续发展战略 42. innovative design 创新设计
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Notes
1. Work on research and development of photovoltaics is carried out by various institutes and universities.
参考译文：各个研究院所和高校正开展对太阳能电池的研究和开发工作。 2. Only a few modules used for garden light are encapsulated by transparent resin. 参考译文：花园的灯只用几个由透明树脂包裹的模块制成。
3. The photovoltaic industry continues to rapidly expand at rates comparable to the telecommunications and computer industries, the massive growth in the industry is leading to many manufacturers installing new manufacturing capacity. 参考译文：光伏产业继续以与电信和计算机行业相媲美的发展速度高速增长，行业的大 规模增长使得众多制造商安装新设备以提高生产能力。 4. This is needed when using appliances that only work from a mains voltage AC supply. 参考译文：当使用的设备只从一个交流电源得到电力供应的情况下这样是必要的。 5. In addition to financial support from the government of China, various international funding agencies have supported the photovoltaic program from time to time. 参考译文：除了中国政府的资金支持外，各种国际基金机构也时常对光伏项目进行资助。
1.4 The Future of Photovoltaic
Though the photovoltaic industry has experienced a phenomenal annual 20% growth rate over the last decade, it has just started to realize its potential. While over a million households in India alone get their electricity from solar cells, more than two billion still have no electrical service. The continuing revolution in telecommunications is bringing a greater emphasis on the use of photovoltaics. As with electrical service, the expense of stringing telephone wires keeps most of the developing world without communication services that people living in the more developed countries take for granted. Photovoltaicrun satellites and cellular sites, and a combination of the two, offer the only hope to bridge the digital divide. Photovoltaics could allow everyone the freedom to dial up at or near home and of course, hook up to the Internet.
Opportunities for photovoltaics in the developed world also continue to grow. In the U.S. and Western Europe, thousands of permanent or vacation homes are too distant for utility electric service. If people live in a vacation home that is more than 250 yards from a utility pole, paying the utility to string wires to their place costs more than supplying their power needs with photovoltaics. Fourteen thousand Swiss Alpine chalets and thousands of others from Finland to Spain to Colorado get their electricity from solar energy.
