慶應義塾大学 - 電気自動車研究室
Energy Systems
Why did you decide on solar cells?
Because they are the most efficient form of natural energy using the sun as an energy source. Under practical conditions they can convert solar energy into electricity at approximately 10% efficiency. By contrast, plants store solar energy at only 0.1-0.2% efficiency. Furthermore, if we try to obtain electricity from existing sources, we can meet less than 10% of the earth’s energy needs. If solar cells were installed on 1.5% of the earth’ s land surface, all of the world’s seven billion people could use the amounts of energy now enjoyed in the U.S.
How far have solar cells advanced?
Major improvements in efficiency take a long time. However, development of new manufacturing methods, greater efficiency, and increased demand will lead to sharply falling prices. Increased mass production is expected to bring costs down below conventional generation methods in the not-too-distant future. Moreover, we will be able to supply electricity to people who have never had it before.
What are Japan’s technical advantages?
Our technology and production capacity are world class. However, ancillary systems are behind the times and our global market share is on a downward trend.
What initiatives are taking place around the world, and how fast is the technology being adopted?
Thanks to large subsidies, the technology is being adopted rapidly in Europe, especially Germany and Spain. Production capacity in China is growing at a remarkable rate.
What are the obstacles to wider adoption and how can they be overcome?
High prices are an obstacle at present. Subsidies, including those for individual households and construction of large-scale generating systems using idle land, can bring prices down. Major leaps in adoption require introduction of electricity storage equipment and construction of national networks to transfer power from regions with good weather to those with less favorable climates.
What resources are required to make the cells?
Silicon is the main component of solar cells. The earth has plenty of silicon, but materials often run short due to lack of refining capacity. However, if refiners can project stable demand, they will expand their operations, which will solve this problem.