PV Power in Japan

Reprinted by permission of the International Energy Agency CADDET Renewable Energy Programme as it appeared in Issue 4/01 of the InfoPoint Renewable Energy News bulletin. (www.caddet-re.org) Photographs were supplied by Takuo Umezawa and Takashi Sekine of the NEDO Information Center.

The generation of power from PV technologies is an attractive energy option for Japan, where energy resources are scarce. As well as improving the security of energy supply, it also offers environmental benefits.

Japan is integrating Photovoltaic systems with industrial, government and residential buildings. The cover shows an aerial view of a business building with a large sloping array on the roof. With over 317 MW of installed capacity in 2001, Japan leads the world in PV.

An eight story building is the home of a company which is using its own products in the sloping PV panels covering the full length of the roof.

To solve this problem, the former Ministry of International Trade and Industry (MITI) - today the Ministry of Economy, Trade and Industry (METI) - launched the Sunshine (SS) Project in 1975 to develop oil-alternative energy technologies, including renewable energy. It aimed to promote the development of solar thermal technology for power generation systems, and various solar systems for industrial use (solar thermal energy utilization systems). But, it did not include PV power generation.

The development of PV technology for power generation systems started in 1980 when the former New Energy Development Organization (NEDO) - now called the New Energy and Industrial Technology Development Organization - was founded after the second oil crisis (in 1979), under the jurisdiction of MITI.

This two story brown dwelling is a public welfare house which is being operated by the local town government. The south and west facing roofs are covered with PV arrays ( The right side of the roof shown above is facing north.)

In 1978, the Moonlight Project was launched to develop energy- saving technologies, and in 1988 a research and development (R&D) program began, focusing on global environmental technologies. In 1993 those two were integrated to form the New Sunshine Program (NSS), which was launched to promote R&D in both the energy and environmental areas.

The development of technologies for the practical application of PV power generation systems is currently being carried out under the NSS. It focuses on solar cell module technologies for electric power supply, including peripheral equipment and system construction. Since a government reorganization in January, the NSS work is continuing under the jurisdiction of METI, although the name NSS is no longer used.

PV power generation is an attractive option in Japan. It converts inexhaustible and clean solar energy into electricity in a country where energy resources are scarce. It also does not contribute to global warming, as it emits no carbon dioxide (CO2).

R&D activities have significantly reduced the amount of energy (mostly electricity) required to manufacture PV power generation systems. The energy payback time (EPT) - i.e. the amount of energy required to manufacture a PV system divided by the amount of energy produced annually by the system -has been reduced. For commercial technologies, the EPT has been shortened to between five and six years. For state-of-the-art technologies it can be as little as one to two years. This has greatly enhanced the effectiveness of PV systems in reducing greenhouse gas emissions.

The Long-term Energy Outlook, drawn up in 1998 after COP-3 in Kyoto, set the 2010 target for PV power generation systems at 5,000 MW and specified that a self-sustainable PV industry is essential. To achieve these objectives, technology development and various measures have been undertaken to promote the widespread use of PV.

PV power generation has entered a phase of expansion - mainlyfor domestic applications. The total installed capacity of PV systems in Japan reached a world- record figure of 317 MW in March 2001, and solar cell production in 2000 was estimated at 128 MW - this represents a 40% share of the world market. Although these figures demonstrate the success of many years’ work promoting PV power generation, they are still far off the targets set for 2010.

The key to the widespread uptake of PV power generation systems is reducing equipment costs to make the costs of PV systems comparable with those of conventional generating systems. If developed technologies are fully utilized and solar cells are produced with a capacity of 100 MW/year, PV module manufacturing costs of JPY 140/W (where JPY is the Japanese yen) can be achieved. Using such low-cost PV modules can reduce PV power generation costs to around JPY 30/kWh. With costs at this level, combined with an increasing awareness of environmental issues and PV power generation, a considerable number of Japanese households are expected to introduce PV power generation even without a subsidy.

However, to date, R&D results have not included technologies for mass production and improved productivity. Therefore, the Development Program of Advanced Manufacturing Technology for Photovoltaic Power Generation Systems was launched in 2000 through NEDO. It aims to help bring technological results to production and to assist companies in the commercialization of PV power generation systems. Its work is to encourage mass production, reduce the cost of PV systems, improve productivity and promote the self-sustaining expansion of the PV market.

R&D for the future

PV power generation in Japan is on the way to achieving self-sustaining development. As the diagram above shows, the principal aims are technical development to achieve the short and mid-term targets for an installed capacity of 5,000 MW by 2010 and an established self-sustainable PV industry. Additional aims include research on next-generation PV systems, the transfer of research results to industry, and the further reduction of costs. Long-term goals include mass domestic installation and contributions to the international PV market.

Each adopted theme will be promoted as a joint project between the company making the proposal and NEDO. R&D costs will be shared equally by both parties.