Fundamental Technologies for Extended Solar Energy Utilization - Solar Cells and Solar Hydrogen Production -/CRDS-FY2008-SP-03
Executive Summary

This strategic program proposes an R&D strategy for establishing a basis to extend the solar energy utilization through such technologies as the development of new materials and the utilization of photosynthesis function.

Various global problems have been emerging in the 21st century. Among others, it is an urgent and long-last important issues for us how to manage both the sufficiency of the increasing energy demand and the reduction of CO2 that is the main reason for the climate change. A basic revolution scenario for energy configuration is as follows.

(1) Implementation of energy conservation
(2) Maximum utilization of renewable energy including natural energy
(3) Effective use of fossil fuel, and CO2 capture & isolation
(4) Maximum use of nuclear power

As the solar energy is mostly promising for its inexhaustible and clean feature in the natural energy (2), the energy generation technology by the conversion of the solar energy is reported in this proposal.

The practical use of the solar energy has been already advanced focusing on the silicon solar battery with the government investment for the improvement of its efficiency. However, as the cost reduction is limited, a dramatic expansion of the usage is difficult with the present technology.

On the other hand, in terms of the organic solar cell expected for significant cost reduction and the promising hydrogen generation technology using solar light, the systematic investment for basic R&D has not been made in the private sectors, leaving various R&D issues behind. Although there are technical seeds at some universities/national institutes , no full-fledged government investment has been made.

As the universities/national institutes in Japan possesses high potential in such fields as material science, chemistry, and biotechnology, the integration of those potential and the engagement in the research issues may result in satisfactory achievement with the formation of a basis to extend the solar energy utilization.

Specific R&D issues to which the government should invest to solve are shown as follows, which should be promoted in mid- and long-term basis as a technology package through integration and cooperation.

(1) Fundamental technology of solar photovoltaic generation using organic materials
(2) Fundamental technology of solar hydrogen generation
(3) Construction of design theory as energy conversion system (common issues for (1) and (2) )

It is extremely important to solve these issues by applying cutting-edge technology of material science and biotechnology and through the fusion of research in physics, electronic engineering, chemistry and biology. An R&D system to promote the fusion and cooperation must be arranged to execute this R&D project. It is also necessary for success to establish the cooperation system among different ministries that would be supplemented with related and simultaneously executed projects such as those of NEDO etc.

This proposal is an investment strategy for the basic research issues for highly innovative influence utilizing the strong points of Japan. After the establishment of the technological basis and diffusion of practical use, the returns to be gained in future are as follows:

(1) Contribution to the maintenance of global environment
(2) Direct contribution to the improvement of energy self-sufficiency rate of Japan
(3) Creation of new energy industry with high competitiveness.

This strategic program should be started urgently and carried out in the mid- and long-term scope.