2010-03-30 13:27
This is the 14th in a series of articles introducing the Korean government`s R&D policies. Researchers at the Science & Technology Policy Institute will explain Korea`s R&D initiatives aimed at addressing major socioeconomic problems facing the nation. - Ed.
By Yoo Eui-sun
If global warming continues on its present course, the temperature of the planet is projected to rise by 6.4 degrees Celsius by 2100. However, in order for the global community to effectively manage the risks caused by climate change, it needs to keep the temperature rise below 2 degrees Celsius by 2050. To achieve this goal, it is essential to step up our efforts to increase energy sustainability through a diffusion of solar energy technologies across the world. As the growth of the renewable energy sector is gathering pace, the number of green jobs is on the rise. This paper aims to present a brief overview of the current state and features of solar energy technology, which is crucial to tackle climate change, and to discuss the future outlook and challenges, with the focus on solar photovoltaic technology.
The technical solutions to mitigate the threats of climate change can be divided into the following three categories - energy efficiency, decarbonization and natural sink. PV technology belongs in the decarbonization category. Improving energy efficiency is considered a powerful solution in the short and mid-term. Decarbonization is seen as a mid- and long-term solution. In particular, decarbonization should be first applied to the electricity supply sector, since the marginal cost incurred from carbon emissions reduction is relatively low in this sector when compared to other fields.
The total amount of solar energy that hits the earth`s surface is more than 8,000 times the amount of energy consumed by all human activities. Despite its low energy conversion efficiency, solar energy technology is reckoned by many to have the greatest potential to serve as a viable alternative. Solar energy technology posts the fastest growth rate among other renewable energy technologies, with the annual growth rate of 70 percent from 2006-2008.
Solar energy technology paints a rosy picture in terms of reduction in greenhouse gas emissions and energy acquisition. Throughout the entire life cycle of solar cells, the greenhouse gas emission of PV is very low - in the range of 1/10 to 1/40 of that of electricity production by fossil fuels.
The cost per watt of PV technology is widely expected to achieve grid parity in 2015. Grid parity is the point at which renewable electricity is equal to or cheaper than grid power. The development of PV technologies, the economies of scale, and the optimization of solar cell production processes will contribute to the achievement of grid parity. Once grid parity is attained, it will encourage widespread proliferation of PV technologies.
PV technology is foreseen to experience a "double technology shift," where the first-generation technology shifts to the second-generation and to the third at the same time. Crystalline silicon solar cells represent the first-generation technology. Thin-film technology lies in the core of the second-generation technology, which aims to lower the cost by reducing previously-used silicon materials and replacing those materials with non-silicon materials. The third-generation technology pursues a "low-cost, high-efficiency" strategy, which aims to improve technology efficiency at a low cost.
The future direction of PV technologies will be determined by how the competition among the first-, second- and third-generation technologies proceeds in the future. From the mid-term perspective, we expect an intensification of competition between crystalline silicon technology, which is by far the predominant technology now, and thin-film technology, which is gradually increasing its market share. In the long run, competition between thin-film technology and the third generation technology will become the main issue.
The proliferation of renewable energy sources, including PV, is closely associated with the development of smart grid technologies. Substantial automation and intelligence in the smart grid will facilitate the realization of a renewables-driven grid including PV. Furthermore, smart buildings and vehicles will increase applications of PV.
In addition, the development of energy-storage technologies complements the intermittent surges of electricity supply by PV cells, thereby facilitating the expansion of the PV markets. In this regard, the "ubiquitous energy storage" technology, which permits energy to be saved anytime, anywhere, is required. In the meantime, with the proliferation of hybrid and electric cars, it is likely that plug-in car batteries become a practical storage options.
Germany, Japan and the United States are the biggest players in the PV technology industry, with China rapidly catching up. Germany achieved rapid growth in this field by introducing a "feed-in tariff" system at an early stage. Japan has led the pack in terms of solar cell manufacturing and accumulated installation capacity, but has recently witnessed a slowdown in its growth rate.
China`s production volume of PV cells has recently skyrocketed. If combined with Taiwan`s output, China accounted for 44 percent of the global PV market in 2008. Korea also has great potential for future development of PV technology, taking into consideration its top-notch semiconductor and nano technologies.
Let me suggest some of the technical and policy-level agenda to speed up the diffusion of PV technologies. First, it is necessary to improve performance and economic efficiency of the first- and second-generation technologies in addition to the continuous development of next-generation technologies. We need to focus on improving efficiency of crystalline silicon solar cells (first-generation) while reducing the input of resources. Also, it is necessary to increase the efficiency and lifespan of thin-film solar cells (second-generation).
Furthermore, Korea needs to develop a variety of advanced new models for third-generation PVs. To this end, it is necessary to develop PVs with advanced new materials and structures (ex: nanomaterials), highly-efficient dye-sensitized solar cells and organic solar cells, as well as solar concentrator technologies. Another urgent task ahead of us is to develop super-efficient solar cells (an efficiency of over 40 percent) and ultra low-cost cells. Under these circumstances, Korea should focus on expanding research and development in the second- and third-generation technologies in the mid- and long-run.
Second, complementary research and development to support the proliferation of PV technologies needs to be further strengthened. We need to prioritize improving solar cell`s capability to be integrated into the structure of buildings. In addition, we need to promote R&D to complement possible drawbacks of PV technologies and to expand their applicability by using ubiquitous energy saving, smart grid, smart green buildings and smart transport technologies. We need to enhance our cross-sectional research in the areas which penetrates overall PV technologies, such as performance measurement standard.
Third, we need to promote "solar city," "solar fund," and "solar knowledge" projects to advance toward the "tipping point" for PV. Under the existing and dominant "high carbon society" paradigm, it is necessary to put in place a sustainable and effective incentive mechanism offsetting the disadvantages of solar-cell introduction. One solution is continuing the "feed-in tariff" system, while gradually scaling back financial support from the government, or introducing a "renewable portfolio standard." The RPS mechanism generally requires electricity supply companies to produce a specified fraction of their electricity from renewable energy sources.
In addition, the "solar city" program needs to be implemented at an early date. A pilot program to build a "carbon-zero eco-city" and eco-remodeling programs for old cities are other options. These programs will make use of PV in their design.
We need to focus on the possibility of promoting the proliferation of "green buildings" built on PV technologies. We can push programs to build 1 million green homes, develop green buildings standards and provide various incentives for those who over-achieve them.
In addition, an optimal solution for incorporating the PV system into the structure of buildings needs to be explored, taking into account the requirements of construction technologies. Moreover, we need to set up a "solar fund," an investment vehicle mobilizing public and private R&D capital to support the development of new third-generation PV technologies. Also, ensuring social and ecological sustainability of PV technologies should not be neglected.
Ecological effect assessments on PV technologies need to be carried out to minimize the adverse impact of new technologies on our ecosystem. It is also essential to revitalize "solar knowledge flow" by developing a database for the PV technology application process and materials, or sharing information and experience on the best practices for PV applications.
Fourth, strengthening cooperation among nations is required in setting international standards for PV technologies. To this end, it is necessary to establish a technology cooperation mechanism which supports the application and manufacturing of solar cells in developing nations.
At the same time, we need to actively pursue close international cooperation in carrying out R&D in next-generation PV technologies, while encouraging active participation of advanced nations. We also need to work closely together to come up with a performance measurement standard for PV modules and systems.
Fifth, launching the cross-Asian "Super Grid Initiative" needs to be reviewed. As in case of Europe, we need to expand the deployment of our solar energy technologies on a large scale to other parts of Asia, moving beyond our territorial boundaries. In the mid and long term, the "Super Grid Initiative" linking Mongolia, China and India is worth our consideration. The main purpose of this initiative is to strengthen international cooperation in jointly developing and using the solar energy abundant in Asian deserts or tropical regions.
Yoo Eui-sun is associate research fellow at the Future Study Team of the Science and Technology Policy Institute in Seoul. His research interest is climate change, sustainable development, environmental technology and policy, and foresight. He is now working to develop a "green index" to systematically assess the realization of a low-carbon society. He achieved his Ph.D. in environmental engineering at Technical University of Berlin. He can be reached via email at esyoo@stepi.re.kr - Ed.
