Arnaud De La Tour

Matthieu Glachant

Yann Ménière

Innovation and international technology transfer: The case of the Chinese photovoltaic industry

China is the largest solar photovoltaic cell producer in the world, with more than one third of worldwide production in 2008, exporting more than 95 percent of what it produces. The purpose of this paper is to understand the drivers of this success and its limits, with a particular emphasis on the role of technology transfers and innovation. Our analysis combines a review of international patent data at a detailed technology level with field interviews of ten Chinese PV companies. We show that Chinese producers have acquired the technologies and skills necessary to produce PV products through two main channels: the purchasing of manufacturing equipment in a competitive international market and the recruitment of skilled executives from the Chinese diaspora who built pioneer PV firms. The success of these firms in their market is, however, not reflected in their performance in terms of innovation. Rather, patent data rather highlight a policy-driven effort to catch up in critical technological areas.

Introduction

There is a large consensus in the international community that effective mitigation of climate change will require the massive deployment of carbon-friendly technologies on a global scale i .

Yet the very notion of technology diffusion remains a tricky issue in climate negotiations, as evidenced by the creation of a working group under the United Nations Framework Convention on Climate Change (UNFCCC) dedicated to this issue ii .

In international discussions, the precise scope of technology diffusion remains ambiguous. It refers to the deployment of technology-based solutions to reduce greenhouse gas (GHG) emissions, such as wind turbines, solar panels, and nuclear power plants. But it also alludes to the transfer of the technical knowledge required to produce these turbines, panels or plants by local firms in developing countries. The latter interpretation of transferring knowledge is favoured by developing countries, and explains their request in climate talks for relaxing intellectual property rights (IPR). Although the deployment of technological goods is what matters to address climate change, the transfer of technological capabilities is indeed the key to developing countries obtaining a share of the green business pie. From a general interest point of view, it also reduces costs through increased competition.

The case of the Chinese photovoltaic (PV) industry is particularly interesting in this respect. In 2009, the deployment of solar panels in China had hardly started. Yet with more than 35 percent of worldwide production capacity in 2008 (of which 98 percent was exported), the Chinese domestic industry is the world leader in the production of PV cells and modules. In a nutshell, China has succeeded in acquiring the technologies for producing solar PV, without deploying PV systems in its territory. This case suggests that technology deployment and the diffusion of production technology are two distinct issues.

The purpose of this paper is to understand the drivers and limitations of this Chinese success in mastering a production technology that had initially been developed in developed countries. More precisely, we will address questions such as: How did Chinese firms manage to acquire production technologies and skills? Have IPR impeded this process? Is China now able to produce new technologies domestically? The underlying goal of this case study is to derive policy lessons on how technology can diffuse successfully in emerging countries.

We combine both quantitative and qualitative evidence. On the quantitative side, we rely on a dataset comprising 79,642 PV-related patents to analyse cross-country innovation and technology transfers in the different segments of the PV industry. To supplement this quantitative analysis, we carried out a series of field interviews with PV actors in China iii . These interviews allowed us to further understand specific details of the economics of the Chinese PV industry, and provided qualitative information concerning the innovation and technology transfers to China.

Our analysis also draws on the available literature on the photovoltaic industry. This includes the works of [START_REF] Ruoss | Global Photovoltaics Business and PV in Malaysia, Envision report[END_REF] and [START_REF] Marigo | The Chinese Silicon Photovoltaic Industry and Market: A Critical Review of Trends and Outlook[END_REF]. We also exploit a substantial body of professional literature published by public organizations (European Commission PV status report 2003, 2005, 2008and 2009;IEA, 2009;REDP, 2008), industry associations (EPIA, 2009, REN21, 2008) and consulting groups (McKinsey, 2008).

The paper is organized into four sections. In Section 1, we highlight the position of China in the global PV market. We then characterize and explain how technology transfer is occurring from developed countries to China in Section 2. Then, in Section 3, we focus on the innovation process in order to see whether China is now a major innovator. Section 4 presents our conclusions.

1

The global PV industry This section yields an economic analysis of the PV sector in order to recast our understanding of the role of China in the rapid development of the PV industry on a global scale.

The demand

The large-scale deployment of PV generation capacity, and consequently the existence of a mass market for PV modules, is a very recent phenomenon. Until the late nineties, PV systems have been installed almost exclusively off of the grid, for marginal uses (communication devices, satellites, remote habitations) for which PV electricity was competitive compared to other available off-grid electricity sources. As illustrated in Figure 1, the photovoltaic market took off around 1997 and it has been growing exponentially since 2003. Over the 2003-2009 period, the average annual growth rate was 45%. This acceleration is chiefly in industrialized countries, and mainly comprises on-grid installation. In 1996, 7.9% of PV systems were installed on-grid; by 2007, it had reached 80% (REN21, 2008).

Figure 1 Photovoltaic installation per year from 1997 to 2009

Source IEA, 2009 andEPIA, 2009. * forecasted. This fast deployment of on-grid PV systems has been entirely driven by incentive policies initially implemented in a limited number of industrialized countries (mainly Germany, Japan, Spain, and the US). PV electricity cannot compete on the power grid because it is more expensive than traditional electricity sources. Therefore, the development of national markets requires economic incentives.

Besides various tax credits where the financial burden falls upon taxpayers, the main instrument aimed at stimulating the PV is the Feed-In Tariff (FIT). FITs consist of setting administrativelyfixed guaranteed prices at which electricity suppliers must purchase renewable electricity from producers. FITs have been used since 1994 in Japan and then introduced in Germany in 2000, inducing the healthy growth from 2000 shown by Figure 1. Spain also adopted a FIT in 2006 which was so generous that it led to a market boom in the country in 2008. Spanish authorities reacted in 2009 by setting a cap limiting the deployment of PV systems to 500 MW per year.

Along with the economic downturn, this policy change explains why the market growth slowed down in 2009.

The majority of developed countries have now implemented FITs. A notable exception is the US in which 29 states have opted instead for the use of Renewable Portfolio Standards (RPS). RPS are mandates requiring each utility to have a minimum percentage of power that is sold or produced be provided by renewable energy sources. That is, they prescribe a quantity, not a price as in the case of FIT.

In contrast, policies promoting solar energy hardly exist in developing countries. Their priority is to find the cheapest source of energy to feed economic development, and therefore PV energy is mostly used in off-grid installations. In particular, China accounts for a very small share of the global PV demand (around 2.2% in 2009, Source: EPIA 2010). The production of PV modules involves four technical steps:

The supply

1. Silicon purification from silica (SiO2) found in quartz sand. The ultra high purity required for the photovoltaic industry ( > 99.999% pure) is obtained through heavy and highly energyconsuming chemical processes.

2. Ingot and wafer manufacturing. An ingot -a cylinder or a brick of silicon -is grown from the pure silicon. It can be a single crystal, called monocrystalline silicon or monosilicon, or multiple silicon crystals that are smaller; a material called polycrystalline silicon or polysilicon iv . Then, using a saw, ingots are sliced into thin layers called wafers. Secondary processes like polishing are involved.

3. Cell production. To form the cell, two differently doped wafers are assembled together to form a so-called p-n junction responsible for the photovoltaic effect, and the top and rear metal contacts are applied. Many treatments or modifications in the process can be applied to increase the efficiency.

4. Module assembling. Cells are soldered together, the electrical junction being done by hand or automatically, and the cells are encapsulated in glass sheets to form a module which will be cooked in a laminating machine.

Table 1 shows the market share of Chinese producers in the different segments. In 2007, China was the world leader in cell production and module assembling (35%). China is followed by the UE (29%), Japan (18%), and Taiwan (12%). This is relatively new: in 2003, China's market in cell and module production share was only 1.6%.

In contrast, its market share in upstream segments is much lower. China produced just 2.5% of the world's silicon in 2007 [START_REF] Winegarner | Report 1 Silicon Industry 2008, A comprehensive report on the use of silicon wafers, silicon ingot[END_REF] while the US, Germany, and Japan account for more than 80%. Chinese firms are however planning important capacity increases that will allow them to produce 15% of the world's silicon in 2010 (REDP, 2008). These projects are strongly supported by the Chinese government, as we will see later. The pattern is similar for ingots and wafers: China still represents a minor part of world production, but it is developing quickly, the annual average rate of increase in ingot production was more than 116% from 2004 to 2007 (REDP, 2008). Source: [START_REF] Ruoss | Global Photovoltaics Business and PV in Malaysia, Envision report[END_REF], REDP 2008, authors' calculations It is interesting to relate these patterns to the economic characteristics of the different segments presented in Table 2. China is strong in cell and module manufacturing, the most competitive segments, with the lowest concentration as shown by the Herfindahl-Hirschman Index (HHI) v , and where profitability is low compared to the more upstream segments.

Technological barriers to entry are relatively low in downstream segments, which have made possible the strong presence of Chinese firms in these segments. The cell production technology is easily accessible because, contrary to upstream segments, turnkey production lines can be bought and run without much prior experience in manufacturing cells. In this context, the relative low price of energy in China has spurred the creation of local firms in this energy intensive segment of the PV industry. Note that the size of investment costs in cell production has not prevented Chinese producers to enter the market. Module assembling is technologically simpler and it is labour-intensive, which gives Chinese firms a competitive advantage vi . In contrast, silicon purification requires advanced technologies and very specific know-how to control all the parameters of the chemical reactions, in order to be able to produce silicon at a competitive price. We will examine technology issues at length in later sections. a Excluding the cost of ancillary equipments and the installation cost.

b Investment for a plant with an annual production capacity of 1,000 tonnes for silicon purification, and 100MW for the downstream segments. c % of the whole profit along the supply chain Sources: [START_REF] Ruoss | Global Photovoltaics Business and PV in Malaysia, Envision report[END_REF], REDP 2008, adapted by the authors.

Technology transfers to China

We have seen that China has strong positions in downstream segments, and has plans to increase its market share dramatically in more technology-intensive activities located upstream in the production chain. We show in this section that the rapid development of the Chinese PV industry has been made possible by the successful transfer of technologies form industrialized countries during the last decade. We discuss in decreasing order of importance the different channels through which the technology was introduced in China.

The markets for manufacturing equipment

From purified silicon to solar panels, products along the PV supply chain are very standardized.

Market competitiveness mainly derives from the capability to manufacture products that satisfy a standard level of quality at an affordable cost. In this context, successful entry into each of the market segments requires access to state-of-the-art production technology. This in turn requires international markets for production equipment that is competitive.

The number of manufacturing equipment producers registered on ENF website serves as a proxy of competition intensity in the market for PV manufacturing equipment. Table 3 presents each PV industry segment in November 2009 vii . The first line gives the total number of providers while the second gives only the number of firms which provide turnkey production lines.

There are a significant number of suppliers in each segment of the supply chain. However, the number is significantly higher in the downstream segments where Chinese firms have mostly entered the PV business, and thus the competition is fiercer. Downstream segments also present more suppliers offering integrated turnkey production lines that make it possible to start production with a minimum level of technical knowledge. By contrast, equipment suppliers are scarce in upstream segments, which is a factor in why Chinese companies have difficulties entering this segment.

Source: ENF website

Besides the importing of equipment goods, the purchase of manufacturing equipment usually involves the transfer of complementary know-how through training sessions of engineers and technicians operating the production line. This in turn progressively enables PV manufacturers to adapt their production chain to local conditions -for instance, substituting some equipment with a cheaper workforce. Several of our interviewees moreover indicated that large PV manufacturers tend to develop partnerships with equipment suppliers, sharing know-how and feedback to improve the manufacturing process. Although they may include temporary exclusivity clauses, such partnerships make it possible for equipment suppliers to redistribute this know-how to other customers, thereby accelerating the circulation of knowledge across the industry.

Another evidence of the diffusion of technology generated by the international trade of equipment goods is the progressive emergence of equipment goods suppliers that are solely Chinese. This is illustrated in Figure 3, which shows the nationality of manufacturing equipment suppliers in each of PV segment in 2009. Although almost no Chinese firms are able to produce turnkey production lines, there exist a significant number of Chinese firms selling specific equipment. This has important implications as it allows Chinese firms manufacturing PV products to buy cheaper production equipment, provided that they are able to customize their production line by integrating specific Chinese equipment. The circulation of a skilled workforce has been another key factor aiding the emergence of the Chinese PV industry. Recall that a major part of the technology concerns the operation of manufacturing processes, which mainly consists of know-how. In this context, the manufacturing experience of skilled employees is a key asset.

Chinese PV companies have benefited strongly from the arrival of highly skilled executives, who brought capital, professional networks, and technology acquired in foreign companies or universities to China. For instance, the founder and CEO of Suntech, the China largest PV company, had been studying at the University of New South Whales in Australia, and then worked for the Australian company Pacific Solar. In addition, four out of the six members of the Suntech Board studied or worked in the US or in the UK. The CEO of the second largest company, Yingli, also studied abroad. In Trina Solar, half of the 12 person management team have studied or worked abroad: 4 in the US, 2 in Singapore. At Solarfun, the figure is 7 out of 10. On average, 61% of the board members of the three largest Chinese PV firms have studied or worked abroad ix . This highlights the importance of the Chinese Diaspora: 8 million Chinese people live in foreign industrialised countries (source: Overseas Compatriot Affairs Commission, R.O.C).

Turn-key system Specific equipment

To a large extent, this prevalence of executives with foreign training results from aggressive recruitment strategies pursued by Chinese firms in a context of scarce skilled labour locally.

Suntech has a special program for recruiting foreign Chinese, while Trina Solar has created special "international staffing teams".

The local mobility of Chinese employees has also accelerated knowledge diffusion within China.

Although the phenomenon is hard to quantify, representatives of three Chinese companies complained during our interviews about their employees being hired by other companies or creating their own company. Moreover, we also learnt that Chinese firms are developing specific programs to attract middle level management employees. There even exist agreements between the 9 biggest Chinese solar firms to prevent hiring each other's skilled employees.

Foreign direct investment

The economic literature has shown for a long time that investment by a multinational firm in a productive asset such as factory in a foreign country also induces a transfer of knowledge, since the technology is operated directly in the recipient country.

In 2009, China had attracted about one third of the global foreign direct investment (FDI) flows in the PV industry. Although massive, this is a rather recent phenomenon, which has not been a decisive factor in the emergence of the Chinese industry. Table 4 presents the top 9 PV manufacturers located in China. Only three of them feature investment links with foreign companies. Moreover, these FDI-based firms turn out to be late entrants, whose creation has followed in the footsteps of strictly Chinese pioneer firms.

Although it was not decisive for the emergence of Chinese pioneers, incoming FDI is nevertheless likely to accelerate technology transfers to China. Figure 4 moreover shows that the proportion of joint ventures with respect to fully owned subsidiaries is much more important in China than in other countries. This reflects a general feature of the Chinese economy, where public authorities often force foreign investors to accept joint ownership. Such joint ventures are likely to induce more knowledge spillovers than the creation of mere subsidiaries, because they involve a local partner.

Licensing

Another classical market channel of technology diffusion identified in the economic literatureand the most self-evident -is licensing. But it has played no role in our story as licensing is almost inexistent the PV industry. We are aware of only one case: Germany's Johanna Solar Technology granted a license to the Chinese company Shandong Solar Technology in 2008 to build a production line.

Chinese innovation

We have just seen that China has mainly acquired foreign technologies to create a domestic PV industry mostly through the international trade of manufacturing equipments and the hiring of top level managers trained in industrialized countries. In this section, we investigate whether China is now able to generate locally new technologies and inventions.

A study of PV patents

As a first measure of innovation in the PV industry, we tabulate patent applications x . Although patents do not provide a measure of all innovation, they offer a good indication of innovative activity and allow for interesting cross-country comparisons. Data on patents were extracted and filtered from the espacenet website, a free online service developed by the European Patent Office for searching information on patents and patent applications, available at http://ep.espacenet.com. Using International Patent Classifications combined with key word searches, we created separate patent indicators for each segment of the PV supply chain. More information on our dataset is available in Appendice 2.

Figure 5 represents major countries' shares of innovation patented worldwide for each segment of the PV industry in 2006-2007. China's performance is impressive as it ranks third in all segments. But in silicon production it is all the more so, where it leads with 37% of world patents. Comparing these percentages with the market shares presented above in Table 1 leads again to distinguishing between upstream and downstream segments. China's patenting activity is significantly higher in silicon production, ingot and wafer manufacturing than its contribution to world production (respectively, 2.5 and 5%). The reverse is true in downstream segments in which China is the second largest producer with a 27% market share (leader since 2008 with 35%) whereas it generates around 15% of worldwide inventions. This suggests different roles for innovation in silicon production, ingot and wafer manufacturing on the one hand, and cell production and module assembling on the other.

Figure 5 Percentage of world patented innovation by segment and country in 2006-2007

Source: Authors' calculations

Innovation in cells and modules

The important share of China in globally patented innovation has to be put in perspective. Indeed, only 1% of Chinese patents are also filed abroad as compared to 15% for Germany, 26% for Japan, and 7% for the US. Since the foreign extension of patent applications is usually reserved for the most valuable inventions xi , this reinforces the hypothesis that the value of the average Chinese patented invention is quite low. This is in line with the low percentage of revenue that Chinese firms devote to R&D in comparison to western companies, as indicated by Table 5, which gives R&D expenditure for a selection of big PV cell and module manufacturers. Chinese firms then have a higher propensity to patent than their foreign competitors -they file more patent applications for an equivalent innovation output. Our field investigations in China confirm that local companies patent minor inventions intensively. The reason is not to protect the inventions -critical inventions are usually kept secret -but to send a signal to public authorities. In particular, the allocation of public subsidies by the National Development and Reform Commission (NDRC) is significantly influenced by the quantity of patents.

However, concluding from this low patent value that Chinese firms don't innovate could be misleading. As the interviews suggested that Chinese innovation focuses more on process, which is often not carried out in specific R&D departments but directly on the production lines, and protected by secrecy rather than patenting.

Innovation in silicon production, ingot and wafer manufacturing

We have seen that China's patenting performance in upstream segments is impressive. This is particularly true for silicon, with 37% of the world's patented inventions as shown by Figure 6, this results from a specific effort initiated in 2002.

Figure 6 Share of China in world innovation in each segment of the PV industry

Source Authors' calculation

Why is it so? China only accounts for 2.5% of 2007 world production, but the government has voiced its ambition to dramatically rise production capacities in the coming years. Domestic production of purified silicon has already grown 16.5 times from 2007 to 2008 (from 1,100 to 18,000T, REDP 2008).

The Chinese patenting activity in silicon technology is related to this strategic objective. Besides capital investment in production facilities, the main barrier to entry in the silicon feedstock market is technological. The purification of metallurgical grade silicon into electronical grade silicon is based on the Siemens process -the principles of which have been public information for decades. The key to purifying silicon at reasonable cost, however, is in the efficiency of the silicon purification process, which requires precisely controlling the parameters of all the chemical reactions. Major western and Japanese silicon producers have developed advanced know-how in this domain, which they usually keep secret. In this context, the creation of a competitive branch of the Chinese PV industry in the silicon segment hinges on its domestic R&D effort to develop economically efficient refining processes. These efforts are chiefly funded by public authorities. Private patents represent less than 40% of total Chinese patented innovation, against around 85% in industrialized countries.

To summarize, the Chinese weight in patent applications in silicon purification, far from proving a technological leadership, actually denotes a massive domestic effort to break a technological lock in a strategic segment where the Chinese industry is still dependent on a small number of foreign suppliers.

Conclusion

China has become in just a few years a major player of the global PV industry. In this paper, we have tried to understand how this has occurred, and in particular, how Chinese producers get access to the technologies and skills necessary to produce PV systems.

A first finding is that the economic importance of Chinese producers should not be overestimated. They are mostly active in downstream segments of the PV production chain -cell production and module assembling -where barriers to entry are low, competition is tough and profit margins are thin. Western companies continue to lead upstream markets -in silicon purification, ingot and wafer manufacturing -where technological skills are key assets. This global division of labour between China and developed countries in this industry is observed in many industrial sectors. Note that China has ambitious plans of new production capacities in upstream segments, in particular silicon production, in the coming years.

China has acquired the technologies to produce cells and modules through two main channels: the purchase of manufacturing equipment -in particular turnkey production lines -on a competitive international market and the recruitment of skilled Chinese entrepreneurs from the Chinese Diaspora who have managed to build pioneer PV firms, exploiting China's comparative advantage of cheap labour and energy in PV cells and module segments. In contrast, the lack of competitive supply of production equipment appears to have been a significant barrier to the development of Chinese firms in the upstream silicon segment.

Foreign Direct Investments, mainly through the establishment of joint-ventures with western partners, are another potential channel for importing technologies. They are very significant in the Chinese PV industry but they are quite recent and they do not involve pioneering Chinese companies. This suggests that they have played a minor role in the emergence of the industry. The trade of intellectual property rights such as licensing has played no role. More generally, the existence of property rights has not impeded the emergence of the Chinese industry.

As measured by patent statistics, the innovative performance of China denotes a policy-driven effort to catch up rather than a dynamism of local companies. Chinese producers of cells and modules invest less in R&D than their competitors in Japan and Western countries, and consequently file fewer patents that are of lesser value. By contrast, the important share of China in world patents in the silicon, ingot and wafer segments is largely accounted for by public research institutions, denoting an effort to break the technology barriers preventing firms from entering these segments. Although it is too early to predict a success, this trend highlights the ability of the Chinese public authorities to intervene selectively when the market fails to generate technology transfers.

In terms of policy implications, our research suggests that, in order to diffuse clean technologies to emerging economies, a key issue is the need to create an attractive environment for investment and international trade. In this respect, the focus of international discussions on intellectual property seems misplaced. Of course, one should be very cautious when generalizing results obtained from one particular sector. But this is in line with other works by [START_REF] Barton | Intellectual Property and Access to Clean Energy Technologies in Developing Countries. An Analysis of Solar Photovoltaic, Biofuel and Wind Technologies[END_REF] and by [START_REF] Kirkegaard | It Should Be a Breeze: Harnessing the Potential of Open Trade and Investment Flows in the Wind Energy Industry[END_REF] who studied solar, biofuel and wind technologies. In fact, the underlying reason is the same: the competition is sufficient in these sectors to prevent a single company from creating a lock on the technology with patents.

Here at the end of this paper, it is also possible to address a more fundamental question: what is the rationale for promoting the transfer of production technologies to the South, from a general interest perspective? The example of the PV sector shows that this transfer does not necessarily induce GHG emissions abatement in emerging economies: China has successfully entered the PV market without deploying panels at home. In fact, the real justification is that the transfer of technology is necessary in order to transfer production capacities to emerging economies and this relocation can decrease production costs and prices through fiercer competition, as is true in many other industrial sectors. Ultimately, technology transfers will reduce the cost of mitigating greenhouse gas emissions.

From the perspective of industrialized countries, this is disturbing. Of course, they benefit from these cost reductions, as demonstrated by the commercial success of Chinese panels in Spain and Germany. But while they drive the demand trough costly incentive policies, their companies face tougher competitors and lose market shares -again, see the situation of the German PV company Q-Cells which have faced severe difficulties in the last years. Appendice 2 Methodology: The patent as an indicator of the innovation and technology transfer

Innovation cannot be measured directly like other variables. Several indicators have therefore been developed to measure it. One is the measure of the input (R&D expenditure, number of staff in the R&D department), but such information is difficult to find, is aggregated, and only measures the input while the output can be preferable [START_REF] Dechezleprêtre | What Drives the International Transfer of Climate Change Mitigation Technologies? Empirical Evidence from Patent Data[END_REF]. Measure of the output can be done by studying the data on patents. This indicator has many advantages as it allows to have disaggregated information by technology, and also gives information about where the innovation is patented, which is necessary to study technology transfer.

As represented in Figure 6, if a person (or firm) innovates, it can decide to patent the invention in one or several countries, which will give him the exclusive right to commercially exploit that invention in those countries. In a single country, one or several patents can be granted to protect the invention according to its importance and the characteristics of the patent office of the country. The heterogeneity of national patent laws makes it difficult to make reliable crosscountry comparisons. We deal with this classical problem by counting patent families, i.e. the set of patents granted for the invention in the different countries.

Figure 7 Schema of a patent family

Following the method developed by [START_REF] Dechezleprêtre | What Drives the International Transfer of Climate Change Mitigation Technologies? Empirical Evidence from Patent Data[END_REF], the indicator used to measure the quantity of innovation or technology diffusion process is then based on the number of families, that is to say the number of inventions.

However, a variable quantity of innovation can be embedded in those inventions. To take that into consideration, we use as a proxy of the "size" of the invention the number of patents granted in one country for this invention multiplied by the average patent breath in this country. The patent breadth of one country is the average "size" of the patents registered in the patent office of the country. In our example, the same invention has been protected by three patents in country A, while only 2 in country B. That it to say that with this single case, patent breadth in country A is 2/3 of that of country B. In our study, countries patent breadths have been computed using the US benchmark: for each countries "c", we kept only the patent families where patents have been at least granted in the US and in country c, and the patent breadth of country c is then defined as

(1)

If the invention i has been patented in only one country (most of the case), the "size" of this invention (quantity of innovation embedded the invention) is then approximated by:

(

Where is the number of patents granted for invention i in country c.

If the invention has been patented in several countries, the size of the invention is then approximated by the average of ( 2), that is:

(3)

Having this information, one can then approximate the innovation done by one country c in one year y in one segment s by summing the sizes of all the inventions done by this country, this year, in this segment ( )

The technology transfer can be approximated the same way by keeping only the inventions that have been patented in a chosen country.

Limits of the indicator

Inventions do not have uniformly equal value, but this value can be approximated by the percentage of international families (meaning a patent that has been granted in at least two countries). Indeed, after the first patent application, the applicant has two years to patent the invention in other countries. The first application can only be an option for future commercial application while if the invention is patented in other countries, it proves that the applicant really shows some commercial interest in it. There is then a big gap in value between a patent that has been granted only in one country, and patents that have been granted in two or more countries.

A second, more difficult methodological issue is due to the fact that not all innovations are patented in practice. This is especially true for process innovations, which are often kept secret [START_REF] Cohen | Protecting their Intellectual Assets: Appropriability Conditions and Why U[END_REF]. Since an important part of PV innovations concern manufacturing processes, this implies that our patent indicators probably do not account for all inventions.

Database used

We built our dataset by downloading patent information from the espacenet website xii . For this purpose, we choose research criteria designed for all PV segments in order to obtain the biggest part of the relevant patents (corresponding to the technology) while having as few irrelevant patents as possible. Not having every patents doesn't matter as the sample is still representative, but having too much irrelevant patents is more problematic. This can be limited by using proper research criteria. Here are the research criteria used: We note that the fact that we obtain a different proportion of the patents really granted in each segment doesn't matter, as no absolute comparison will be done for the reasons explained in the previous section. We obtained 79,642 patents, published before 2010, covering the PV industry from silicon purification to module assembling.

Keyword(s)
i The Bali Road Map mentions for instance technology diffusion as a strategic objective.

ii As the Ad Hoc Working Group on Long-term Cooperative Action under the Convention (AWG-LCA) created in 2009 under the UNFCCC (see http://unfccc.int/meetings/items/4381.php)

iii You can refer to Annex 1 for more information concerning interviewed actors.

iv The monosilicon conversion leads to more efficient PV cells, but has large power consumption and is thus more expensive than the polysilicon process. Dopant impurity atoms such as boron or phosphorus can be added to the molten silicon in precise amounts in order to dope the silicon, thus changing it into n-type or p-type silicon.

v The HHI is defined as the sum of the squares of the market shares of the largest firms within the industry, where the market shares are expressed as fractions. The result is proportional to the average market share, weighted by market share. As such, it can range from 0 to 1, moving from a huge number of very small firms to a single monopolistic producer.

vi According to Chinese Firms that we interviewed, the labour represents 1-2% of the total cost in China in module production segment; in developed countries it represents 5-10%. vii http://www.enf.cn/ is an online Solar company database.

viii The number of equipment providers is the only, admittedly rough, indicator available to measure the country market shares as turnover data are seldom available. ix Information obtained on the companies' website: http://www.suntech-power.com; http://www.trinasolar.com ; http://www.solarfun-power.com.

x You can refer to annex 2 for more information concerning the methodology used.

xi For further details, see annex 2, Limits of the indicator xii http://ep.espacenet.com is a free online service developed by the European Patent Office for searching information on patent and patent application.

Figure 2

 2 Figure2presents the PV supply chain. The industrial production process includes four technical stages that are briefly described in Box 1. Then the deployment of the PV system requires combining the modules with complementary equipment (such as batteries or inverters) into integrated systems which, once installed, can generate power. As explained in the introduction, we focus our analysis on the first four production stages, Silicon, Wafers/Ingots, PV Cells, and PV Modules. They account for 60% of the average global cost of installed PV systems in 2006.

Figure 2

 2 Figure 2 PV supply chain

Figure 3

 3 Figure 3 Countries shares in the number of equipment providers in each segment viii (2009)

Table 1 China market share in different PV industry segments in 2007 Segment China Market share

 1

	Silicon	2.5%
	Ingot and wafer	< 5%
	Cells Module	27%

Table 2 PV industry segments economic features in 2007

 2

	Segment	% cost in a	Market	Investment	Technological	% of
		panel	a	concentration	cost	b	barrier height	profit c
				(HHI)	(millions/USD)
	Silicon	13%		0.19	140		High	41%
	Ingot and wafer	27%		0.24	95		Medium/High	41%
	Cells	27%		0.04	125		Medium/Low	11%
	Module	33%		<0.04	25		Low	7%

Table 3 Count of manufacturing equipment providers in the PV industry

 3

		Ingot	Wafer	Cell	Module
	All firms*	70	178	335	234
	Firms providing turnkey production lines	1	9	15	26

* Firms

selling specific equipment that are part of the production lines

Table 4 Top 9 PV companies in China

 4

		Output (MWp) Creation	FDI-Joint Venture links
	Suntech	327	2001	None
	Yingli	142	1998	None
	JingAo	113	2005	Australia
	Solarfun	88	2004	None
	Sunenergy	78	2004	Australia
	Canadian Solar	55	2001	Canada
	Ningbo Solar	45	2003	None
	Trina Solar	37	1997	None
	Jiangsu Junxin	35	-	None
	Source European Commission (2008 and 2009)

Figure 4 Regional repartition of the two types of FDI

	Source: Authors

Table 5 . R&D expenditure in some major cell and module companies.

 5

	Companies	Country of origin	R&D intensity (% of 2008 turnover)	Segments
	Schott Solar	DE+US	5.0%	Cells
	Q-cells	DE	2.0%	Cells
	SunPower	US + PH	1.7%	Cells+ modules
	Solar World	DE	1.4%	Cells

  in title or abstract:

	International Patent Classification (IPC)
		code:
	Silicon purification
	Silicon	C01B33 not C01B33/02
	Ingot
	Silicon	C01B33/02 OR C30B
	Wafer
	silicon wafer not semiconductor ?	H01L21
	wafer	B24 OR B28
	Cell
	(solar cell?) or photovoltaic not module	H01L
	Module
	PV or solar or photovoltaic and module	H01L


Dimitri Masson

Alexandre Demeure

Gaelle Calvary
email: gaelle.calvary@imag.fr

Magellan, an Evolutionary System to Foster User Interface Design Creativity

Keywords: Model-based User Interface design, interactive genetic algorithm, creativity, Magellan. ACM Classification H.5.2 [Information interfaces and presentation]: User interfaces -prototyping

Fostering creativity in User Interface (UI) design is challenging for innovation. This paper explores the combination of model-based approaches and interactive genetic algorithms to foster the exploration of the design space. A user task model is given in input. Magellan produces sketches of UIs that aim at inspiring the designer. Later on, appropriate tools may be used to tune the right design into the design right. Magellan is a proof of concept that deserves further exploration. Currently it is implemented using COMETs but it is not dependent of this technology.

INTRODUCTION

"Getting the right design" and "getting the design right" [START_REF] Tohidi | Getting the right design and the design right[END_REF] are complementary challenges in Human Computer Interaction (HCI). Whilst most of research focuses on how "getting the design right", this paper aims at "getting the right design" by fostering creativity. The need of a support for creativity is crucial in model-based approaches.

Transformations are complex to specify, as a result discouraging designers from defining new ones. This limits the exploration of the design space.

We explore how Interactive Genetic Algorithms (IGA) can support the generation of transformations for a given task model. Our goal is not to provide the final User Interface (UI) but to generate "sketches" for inspiring the designer. Appropriate tools have then to be used to "get the design right". This paper presents related works first. It then describes the core principles of our approach. These principles have been implemented into Magellan, an early prototype.

RELATED WORKS

Model-based approaches support the generation of Concrete UIs (CUI) from a given task model and for a given context of use [START_REF] Berti | Teresa: a transformation-based environment for designing and developing multi-device interfaces[END_REF][START_REF] Berti | Teresa: a transformation-based environment for designing and developing multi-device interfaces[END_REF][START_REF] Gajos | Supple: automatically generating user interfaces[END_REF]. They ensure that the generated CUIs are compliant with the task model and make it possible to automatically maintain consistency between the two models (task and CUI). Some tools support the edition of CUIs by designers to explore alternatives [START_REF] Gajos | Preference elicitation for interface optimization[END_REF], but they do not foster creativity. Genetic Algorithms (GA) is a search technique used to find exact or approximate solutions. They were formalized in 1975 by Holland [START_REF] Holland | Adaptation in natural and artificial systems[END_REF]. GA deal with a population of candidate solutions for a given problem. Each solution is encoded within a sequence of genes. GA are made of four main steps. First, an initial population is generated. Then, iteratively, each candidate solution gets a score that evaluates its fitness with regard to the problem (step 2). Then, some solutions are selected (step 3) and reused to generate a new population (step 4). The generation consists in applying operations on solutions (e.g., mutation, inbreeding). Sims [START_REF] Sims | Artificial evolution for computer graphics[END_REF] applied GA to artistic creation and replaced automatic evaluation with human evaluation. This approach is referred to as Interactive GA (IGA) [START_REF] Takagi | Interactive evolutionary computation as humanized computational intelligence technology[END_REF]. The main drawback of IGA is the user fatigue induced by the selection of the best individuals over generations. Usually, users can't go beyond 20 generations of 16 individuals [START_REF] Takagi | Interactive evolutionary computation as humanized computational intelligence technology[END_REF].

In 2008, IGA provided outstanding results for image creation as demonstrated in Picbreeder [START_REF] Secretan | Picbreeder: evolving pictures collaboratively online[END_REF]. The success of Picbreeder relies on two mainstays: storage and complexification. Keeping trace of generated individuals (i.e. automata that produce images) is an efficient means to tackle the user fatigue and to share individuals among a community. Individuals can be complexified along the IGA process: it is possible to obtain complex shapes (e.g., faces, car side views) from individuals that barely generate circles. This work motivates the exploration of IGA for UI generation.

In HCI, IGA have been explored by Monmarché to generate HTML web pages. In these works, individuals represent either Cascading Style Sheets (CSS) [START_REF] Monmarché | Imagine: a tool for generating html style sheets with an interactive genetic algorithm based on genes frequencies[END_REF] or CSS plus webpage layout [START_REF] Oliver | Interactive design of web sites with a genetic algorithm[END_REF]. The population is composed of 12 individuals. Each of them is used to generate a web page. The set of web pages is scaled to fit on a single screen. Individuals can be edited by designers for saving time (e.g., colors customization). At each IGA iteration, designers select best candidates among the 12 web pages. These works suffer from three main limits. First the selectors that identify HTML elements on which to apply CSS transformations are predefined (e.g., titles of level 1, paragraphs, images). It is impossible to generate new groupings along the IGA process (e.g., even paragraphs and images). In addition, there is no high level description (e.g., no task model) which the IGA could rely on to generate more complex transformations (e.g., replace an entry text with a calendar). Last, individuals can not be complexified along the IGA process. Only parameters can be tuned, but no new parameter can be added (e.g., no insertion of texts or images to enhance existing elements).

Quiroz explores IGA to generate XUL UIs [START_REF] Quiroz | Human guided evolution of xul user interfaces[END_REF]. He uses wider populations (hundreds of individuals) but only presents a subset of the population to designers. The designers have to select the best and the worst individuals. Then, an interpolation/extrapolation algorithm is applied to the rest of the population to automatically evaluate individuals. Although at a first glance this approach seems to be promising with regard to the user fatigue, it raises a fundamental question that is not answered by the author so far: can a UI be automatically compared with "bad" and "good" samples? In [START_REF] Quiroz | Human guided evolution of xul user interfaces[END_REF], the evaluation is based on a basic criteria only: the UI blueness. As automatic evaluation is not solved so far, we prefer not to base our proposition on a so strong hypothesis. In addition, the layout is simplistic in [START_REF] Quiroz | Human guided evolution of xul user interfaces[END_REF] and it is not possible to replace interactors. Last, there is no complexification of individuals along the IGA process.

In conclusion, IGA seem to be powerful for improving designer creativity. We believe that IGA coupled with model-based approaches can be of a great interest in HCI for facilitating the design space exploration. Model-based approaches may also make it possible to support complexification (e.g., adding an image to improve an input field guidance).

CORE PRINCIPLES

The architecture of Magellan is roughly presented in Figure 1. Magellan takes a task model in input. It then processes it using a customizable flowchart of GA operations to create and make evolve a population of transformations. Transformations are applied to the task model to generate CUIs. We assume that the task model improves transformations. For instance, if the system knows that an input field corresponds to a "select date" task, it will be able to replace it with a calendar along a mutation. To support the process, we rely on an external database (Figure 1) that explicits the interactors that can be used to represent a task. The individuals used in the IGA are tailored transformations that overcome the limitations identified in the state of the art. First, the selectors are not predefined. They can evolve. Second, thanks to the external database, it is possible to render a task using different interactors. Last, transformations can be complexified, resulting in more sophisticated UIs.

For flexibility, Magellan is based on a modular, fully customizable, flowchart architecture. We make it possible for designers to build their own IGA. We propose a toolbox of five flowchart component types: the four classical operations in GA (i.e., initialization of a population, genetic operation, evaluation of individuals and selection of individuals) plus the flowchart control. Control components support the creation of branches (e.g., if then else), union, merging, etc. Such a workflow architecture enables designers to program different evolution processes such as convergent/divergent thinking [START_REF] Kelly | Interactive genetic algorithms for use as creativity enhancement tools[END_REF].

EARLY PROTOTYPE

This section describes the implementation choices we made in Magellan. A simplified instant messenger interactive system serves as illustration.

Technological choices

Magellan is based on the COMET toolkit [START_REF] Demeure | A Software Architecture Style and an Interactors Toolkit for Plastic User Interfaces[END_REF]. COMETs are polymorphic task level interactors that cover both tasks and task operators. COMETs are multi-rendering multi-technological interactors (WIMP and post-WIMP, Web and non Web as well as vocal). The COMET architecture ensures that the renderings are consistent. Figure 2 presents the graph of COMETs of the case study. A top level interleaving (Instant messenger) gives access to three COMETs. The first one (Chat Gaelle-Bob) is an instance of a "Chat" COMET. Its "Logs" child contains the messages Gaelle and Bob exchanged. The "Send new message" child contains two COMETs: a text entry and a "Send" command. The "Manage contacts" COMET gives access to Gaelle's contacts (Bob, Momo, etc.) and makes it possible to add or delete contacts. Last, the "Manage profile" COMET enables the management of Gaelle's photo, name and status. As presented in [START_REF] Demeure | The Comets Inspector: Towards Run Time Plasticity Control based on a Semantic Network[END_REF], we use a semantic network to implement the database that stores the possible presentations of a given task. The semantic network enables queries such as "Find a presentation for task T that is close to the P presentation". Such queries are useful in case of transformations mutations. For instance, the semantic network can inform Magellan that "Choice of a date tasks are represented with text entries" can be mutated into "Choice of a date" tasks are represented with a calendar. The transformation is updated accordingly.

The COMET toolkit comes with CSS++ as transformation language. A CSS++ transformation sheet is composed of a set of rules. Each rule is composed of two elements: a selector and a translator. The selector identifies the COMETs to be translated (e.g., all the top level interleavings). The translator specifies the way the selected COMETs are translated (e.g., set the background to white, display interactors as tabbed panes). The interactors choice for representing a given task can rely on the semantic network.

Magellan user interface

The UI of Magellan is divided into two pieces: a workflow editor (Figure 3) dedicated to users who need to tune the IGA, and a web based UI (Figure 4) for exploring the design space based on the current IGA. The workflow editor is composed of three parts: at the center, a canvas is dedicated to build the workflow. Components can be placed, removed and connected. The active components are highlighted. On the left, a list makes it possible to drag and drop evolution components onto the canvas. The three top buttons (Reset, Play/Pause and Step) control the flow.

Magellan IGA

We first describe the representation we chose for individuals. Then we describe the Magellan components: initialization of the population, genetic operations, evaluation, selection and flow control.

Individuals

Individuals encode a set of transformations. Each transformation specifies a part of the UI. Transformations are encoded in a tree. Nodes (respectively edges) represent translators (respectively selectors). By default, the root node of each individual is associated with the root of the COMETs graph. To ensure visual consistency, we decorate individuals with a global color theme (i.e., a palette of five colors C1 to C5). For instance, in Figure 5, the background of the root is colored with C1 (the first color of the palette).

The selector of each edge applies to the set of elements selected in its source node. For instance, the edge between the root and the node A selects the containers that are children of the root COMET. With respect to Figure 2 the COMET associated to the node A are "Manage contacts" and "Manage profile". They are translated into accordion containers.

Figure 5: Example of an individual and the resulting UI.

Initialization has to deal with two concerns: the size of the population, and the generation mechanism. The size of the population is crucial: if too small, there is a risk to converge towards "bad" or undesired solutions; if too large, evaluation of solution becomes time consuming. Picbreeder [START_REF] Secretan | Picbreeder: evolving pictures collaboratively online[END_REF] shows that it is possible to obtain good results with 16 elements. In Magellan, the size of the population is one parameter.

We envision several initialization mechanisms. We briefly describe them below and indicate whether they have been implemented or not.

• Random generation (implemented): Individuals are randomly generated by successive mutations of a default tree.

• Manual specification (implemented): Transformation trees can either be manually produced or imported from previous uses of Magellan. This is useful for supporting scenarios such as importing external transformations from other tools as well as collaborative work [START_REF] Banerjee | A Model of Creative Design Using Collaborative Interactive Genetic Algorithms[END_REF].

• Guidance based on existing UIs (planned): Designers could guide the system by providing UIs or UI sketches.

This is useful to explore design options that are close to the given one in terms of mutations.

Genetic operations

Genetic operations are means to modify individuals. We describe the ones we implemented or planned to implement in Magellan.

• Mutation (implemented): Mutations can be applied at three levels: nodes, edges and the tree structure. The mutations are parameterized with the former value to control the evolution degree. Nodes mutations modify the COMET presentations. They can be applied to attributes (e.g., background color, layout, width, height, etc.). In the case of a color mutation, Magellan ensures that the contrast between the foreground and background colors remains high enough. Colors mutations can modify the color theme as well as a color of the theme by lightening or darkening it. Nodes mutations can also change the presentation of the COMET. For instance, in Figure 5, the "Type: Accordion" in node A can be mutated into a "Type: Frame". Mutations can also compose presentations to enhance the UI. In Figure 6 the sentences sent by Gaelle are composed of her photo and a label displaying the sentence. Composition of COMETs presentations is a powerful means to add complexity to individuals (Figure 6). Edges mutations modify the related selectors. The modification can lead to a broader selection (e.g., select children is generalized into select all descendants), a more narrow one (e.g., select all descendants is restricted to select children) or a completely different one (e.g., select children becomes select descendant containers). By doing so, we avoid the predefinition of selectors, unlike Monmarché [START_REF] Monmarché | Imagine: a tool for generating html style sheets with an interactive genetic algorithm based on genes frequencies[END_REF] and Quiroz [START_REF] Quiroz | Human guided evolution of xul user interfaces[END_REF]. Tree structure mutations add or remove nodes and related edges. By doing so, it is possible to complexify the individuals and thus the transformations to be applied to the COMETs graph. • Inbreeding (implemented): There are several ways to achieve inbreeding between two (or even more)

individuals. So far we have implemented a mechanism which randomly selects branches of each parent to create a new individual. Another option for the future would be a guidance-based inbreeding. The idea is to promote interesting branches from each parent. The selection can be based on several criteria. For instance, the designer elicits the interesting parts of the resulting UI during the evaluation. The corresponding transformations are marked as interesting.

• Edition (planned): We plan to make it possible for the designer to directly edit transformations. This could be done in different ways: by editing transformations trees directly, or the resulting CUIs and then inferring the corresponding transformations. Being able to edit transformations would favor a quicker convergence. For instance, along the evolution process, the designer could discover which background color is the most suitable and fix it directly.

• Local optimization (planned): We plan to add some local optimization components to Magellan. At some point, it can be interesting to apply algorithms such as layout optimization [START_REF] Gajos | Supple: automatically generating user interfaces[END_REF]. The risk is to skip solutions that are locally not optimal but would be later on. In Magellan, the modular architecture puts the decision under the control of the designer.

Evaluation of individuals

In Magellan, the evaluation relies on the designer. The designer scores the UIs that are specified by the individuals. There are several ways to score candidates. The simplest scale is a binary notation, as done in Picbreeder [START_REF] Secretan | Picbreeder: evolving pictures collaboratively online[END_REF]. An extension of this notation is to attribute scores on a wider range (e.g., 1 to 10, or a real between 0 and 1). These two solutions are modeled with evaluation components in Magellan. It is also possible to mark some parts of the UI as interesting. We plan to explore other evaluation approaches such as tournament evaluations.

Tournaments consist in comparing series of two candidates, and building a partial order between solutions.

In addition to human evaluation, we believe it is useful to provide designers with some automatically computed scores. Computation can be based on ergonomic and performance criteria like it is done in SUPPLE [START_REF] Gajos | Supple: automatically generating user interfaces[END_REF].

Selection of individuals

Several selection methods exist in the literature. One can cite rank selection (best candidates are selected) or roulette wheel selection (selection probability proportional to the score). Elitist strategies may be applied. They consist in keeping the best individuals unchanged through generations in order to avoid regression. Resurrection enables the designer to recover an ancestor candidate and re-inject it into the current generation.

Control of the workflow

The workflow editor (Figure 3) makes it possible for designers to add and link components. Populations of individuals are conveyed along the links. We propose several components to control the workflow: conditional components such as filters and loop structures for building sophisticated IGA; shufflers and population controllers components to respectively randomize the order of individuals and to increase or decrease the population size; merge components to concatenate individuals from different populations into a single one. Shufflers and population controllers are particularly useful before inbreeding sources that are either identical or of a different size.

We propose two execution modes of an IGA: 1) a step-bystep mode for a precise control over the workflow ; 2) a run mode for going through all non interactive components, and stop only when user evaluation is needed.

We plan to support the control of the evolution process at a finer granularity. Parts of the UIs can be close to the designer expectations. As a result the designer may appreciate to stop or decrease the evolution process for these parts whilst increasing it in other parts. For instance, he/she would like to let a menu bar evolve whilst keeping the rest of the UI unchanged. In other words, the evolution process may be locally tuned. So far Magellan makes it possible to mark some parts of the UI as interesting. The corresponding branches of the individual are promoted during the inbreeding and are less subject to mutations.

CONCLUSION AND FUTURE WORK

This paper addresses the need of a support for stimulating creativity. Model-based approaches provide a powerful support for saving development and maintenance costs but they somehow kill creativity. Magellan explores the combination of model-based approaches and interactive genetic algorithms to tackle the problem while keeping benefit of models. Figure 7 and Figure 8 show UIs evolved from a task model describing an instant messenger. Figure 7 highlights the potential of the selector evolution whilst Figure 8 illustrates the interactors replacement. We believe that such mutations are key for future works. The modular architecture of Magellan enables the designer to define his own IGA process. Up to now, additional components such as the manual edition and the local optimization are to be implemented. Magellan is an early prototype that serves as a technical proof of concept. We are yet setting up an evaluation study to validate the approach. In the future, we plan to use the approach to facilitate comparative evaluation [START_REF] Gajos | Supple: automatically generating user interfaces[END_REF] by generating mutants from existing designs.

Figure 1 :

 1 Figure 1: Overview of the Magellan architecture.

Figure 2 :

 2 Figure 2: The graph of COMETs of the case study.

Figure 3 :

 3 Figure 3: The Magellan workflow editor.

Figure 4

 4 Figure4shows the web based UI of the user evaluator component. The three top left buttons (Reset, Play/Pause and Step) control the flow. The "Validate scores and continue" button enables to validate user choices and to go to the next step. The table of images represents the UIs produced by evaluated individuals (i.e., transformations). By clicking on images, the user selects the ones he/she prefers.

Figure 4 :

 4 Figure 4: The web based UI of Magellan.

Figure 6 :

 6 Figure 6: Example of mutation: the photo stored in the user profile is added to each sentence.

Figure 7 :

 7 Figure 7: Example of UI where chat sentences are differentiated by color depending on the speaker.

Figure 8 :

 8 Figure 8: Example of UI where the top level interleaving has been represented using a tabbed panel.