The “International Forum on Green Electric Energy,” which was jointly　organized by NTU’s newly established Green Electric Energy Research Center and the Institute of Electrical Engineering, had a grand debut On November 5th in the Po-li Hall. The theme of this year’s forum was　solar photovoltaic energy, and the agenda included four lectures and a　comprehensive discussion. Professor Javier Uceda, a renowned IEEE fellow and Chancellor of the Polytechnic University of Madrid, was specifically　invited to attend the forum along with many experts in the photovoltaic　field from home and abroad. The Forum aimed to converge the latest knowledge on solar photovoltaic energy conversion and look for better　initiatives for the green energy industry of Taiwan.

Solar cell power generation system can produce electricity without producing carbon dioxide, therefore, it is considered as the best renewable　energy in nature’s resources. Currently the capacity for installed solar　cells has an annual growth rate of about 42%, and several member states of the United Nations tried to expedite the installment rate of solar cells power generation systems by providing subsidies for its production or tax relief for recycled powers. In the future, solar cell　power generation systems have long term development potentials.

Professor Dan Chen, Director of NTU Green Electric Energy Research　Center points out that, climate change, carbon reduction and renewable　energy are the most serious issues facing mankind in the 21st century. Taiwan, in its pursuit of sustainable development and international competitiveness, must face these issues as well. That is why, in keeping with the national energy policies, the College of Electrical Engineering and Computer Science of NTU set up a “Green Electric Energy Research Center”　in the last March. The purpose of the Center is to integrate all relevant　research personnel and resources within the College to actively engage in the R & D of critical technologies, and to foster elite talents for the green energy industry.

Professor Dan Chen took one step further to explain that , with the funding support from the National Science Council and the Institute of Electrical Engineering, the Green Electric Energy Research Center specifically　invited Professor Javier Uceda to talk about the European viewpoints and experiences. Professor Uceda was a member of the editorial board of European Power Electronics and Drives Journal, an editor of IEEE Industrial　Electronics, Vice President of the European Power-electronics and Drives　Association, Science and Technology consultant for CPES, the Spanish　Representative of the Management Committee of the European Research Program in Information Technology, and an IEEE fellow. His research areas　cover power electronics and digital electronics systems, and has participated　in many national or international projects in these areas. The main contributions　of Professor Uceda lie in the switch mode power supplies used in telecommunications and aerospace applications and in the DC to DC　power converters. He has published over two hundred and fifty articles　in international journals and acquired several national and international　patents. Of all the honors that Professor Uceda has received so far, perhaps the most glorious one was the IEEE Third Millennium Medal.

In his presentation, Professor Uceda introduced the evolution of solar　power industry in Spain, which has been growing by leaps and bounds in recent years. Spain became the first nation in the world to have 2500　megawatts of solar power generating capacity in 2008, primarily due to its tax relief measures. In Spain, the tax rate for solar power is only 3%, while the tax rate for other types of power is 13%. This policy, however, was revised recently, and such a revision would have a significant impact on the later developments of solar cells. Professor Uceda went to great lengths in introducing how the tax relief measures affected the solar cells market in Spain.

Dr. Robert Luo indicated that in this Forum two types of megawatt class solar power systems would be discussed in terms of their design, construction, experiment, and operation. The first one was the building integrated photovoltaic system (BIPV), which basically puts solar panels on the roof of buildings to collect sunlight. The other one is the tiled solar power system, which is often found near coal-fired power plants. For BIPV systems, we can cite the semi-spiral roofs of the World Games Stadium as an example. Because every piece of solar panel is placed at a different angle, therefore the space that its needs is also different, so the greatest challenge lies in how to get the maximum amount of sunlight. Aside from the original design concept and the electrical structure, the most controversial part of solar power is its performance. So, in this forum, the efficiency of these two different systems was discussed. Additionally, the control and monitoring frameworks of solar power systems were also explored in full detail.

The Green Energy & Environment Research Laboratories of the Industrial Technology Research Institute is by far the most influential unit in the history of Taiwan’s pursuit of solar power. For this year’s Forum, the organizing agencies specifically invited Dr. Yohsihiro Konishi, a senior research fellow at the Institute, to share the research achievement. Dr. Konishi is a member of Japan’s IEEJ and JIPE. He has considerable experience in the development of power electronics equipments, having published more than 100 professional articles.

Dr. Konishi said he would give an introduction to the recent developments and the future trends of solar cell power generation systems when he participated in the Forum. As the use of solar power is contingent upon the storage of power, so grid-connected type of photovoltaic power generation systems are the majority in the market. The components of a solar cell power generation system consist of solar modules, inverters, and a control unit. Among them , the inverts techniques play the most pivotal role in the system.

The representative from the academia for this year’s Forum was Dr. Ching-Fuh Lin, who was the Director for the Institute of Photonics and Optoelectronics of NTU. He explained that, the cost of directly converting sunlight into electricity is still several times higher than burning coal to produce electricity, so the growth of solar power is greatly impeded as a result. Normally, the techniques for solar power generation have to be considered from four aspects: cost, productivity, efficiency, and life. For privately owned solar power industries, the cost of solar power generation must be competitive with coal-fired power generation.

From the production point of view, we must take into account that the placement of solar panels requires a lot of space. For example, suppose that 20% of the world’s energy comsumption is replaced by solar power, and suppose the conversion efficiency of solar energy stays at 10%, then we would need a configuration area of 30,000 square kilometers. In order to assemble such a large area of solar panels, we would have to spend 3000 years based on our current IC technology or 300 years based on our current LCD technology. Such time requirement is too long for our purpose and we are still unable to solve our energy crisis. Therefore, we need some specific techniques to increase photovoltaic production. Improving the conversion efficiency of solar cells is the most direct way.

As the outdoors solar panels will be used for more than 20 years, so we must consider their life expectancy. In order to address these issues, two types of thin-film solar cells should be considered: the organic metal oxide layer sandwiched solar cells and the nano-structured silicon solar cells. The advantages of organic metal oxide layer sandwiched solar cells are that the production cost can be greatly lowered and its life expectancy can be lengthened when its folder structure can provide activity or better protection. For nano-structured silicon solar cells, the advantanges are that the techniques for nano structure transfer can greatly reduce the cost for producing thin film nano silicon solar cells, so the cost would be minimal.

To promote university/industry cooperation among participants to the Forum, to broaden the level of international cooperation and academic exchange, the Green Electric Energy Research Center of NTU invited many scholars from home and abroad to discuss the developing trends and future initiatives of the solar photovoltaic industry. Through lectures, panel discussions, and academic exchanges, the Forum expects to add fuel to the development of green energy in Taiwan by combining the wisdom and power from all concerned.