Renewable energy use in Japan: national policy, critical response and alternative paradigms
Recent national renewable energy policy in Japan is informed by a very real, severe and continuing energy security crisis and by the perceived need for a national response to global warming. The recent history of this policy response is described, as are the socio-political and economic circumstances which have shaped and constrained it. The substance of the critiques from significant RE energy generator and advocacy groups in light of perceived policy failures is provided. These critiques are based on the research evidence these groups have produced which demonstrates how the full range of RE resources available in Japan have been under-emphasized or ignored. These same groups and sub-national organizations have undertaken alternative RE policy development and implementation strategies which underpin a larger concern for the long-term sustainability of Japanese society. Several of the more striking of these alternatives, the Tδkyδ-Regional Network, the Energy in My Yard concept, and Sustainability Zones, are described.
EIMY (ENERGY IN MY YARD) A CONCEPT FOR PRACTICAL USAGE OF RENEWABLE ENERGY FROM LOCAL SOURCES
A group was set up to devise a strategy for geothermal development that conforms with global environmental expectations for the 21st century. The group developed the concept of EIMY-Energy In My Yard, which proposes that local energy demands should be met by an optimum combination of local, renewable sources to the maximum degree permitted by technical and economic considerations. Shortfalls and surpluses in local energy production would be accommodated by interfacing with the national grid. The group also discussed the roles that the various types of renewable energy could play within the EIMY framework, according to their nature, ubiquity, and capacity. An integrated renewable energy simulator was used to identify optimum combinations of sources for different situations. Installation and operating costs were assigned at current market rates without weighting for advantages such as low CO 2 emissions. The results demonstrated that integrated renewable energy systems are cost-effective in the medium and long term. Geothermal energy plays a key role as a source of heat in such systems.
FIFTEEN YEARS OF REINJECTION IN THE LARDERELLO-VALLE SECOLO AREA: ANALYSIS OF THE PRODUCTION DATA
Intensive exploitation of the Larderello-Valle Secolo area has depleted the fluid inside the reservoir and caused the reservoir pressure to fall to about 0.5 although the reservoir temperature remains 240-250∞C. Under these conditions a large fraction of themial energy remains stored in the reservoir rocks. Water injection tests in this "superheated" area started in 1979 and demonstrated that an enhancement of heat recovery through the boiling of injected water is feasible. Starting in 1984, reinjection of waters discharged from power plants became an important part of the exploitation strategy for this area. Analysis of the well production parameters the positive effects of reinjection with a significant increase in steam flow-rate and reservoir pressure. light of the positive results, a supplementary injection program was planned and put into operation in 1994 in order to increase secondary heat recovery in the Valle Secolo area.