Organic photovoltaics (OPVs) are next-generation photovoltaics. The industrialization of low-cost photovoltaics will be achieved by employing OPVs as polymer materials fabricated without a vacuum process roll-to-roll (R2R) process because of the low running cost and high throughput of the R2R process. Recently, some estimates for the manufacturing cost of OPVs have been reported. However, most of the reports predicted a high cost. We estimated the cost of fabricating a newly designed low-cost module by an all-wet process. In addition, we discovered a technical problem regarding the industrialization of OPVs.

View full abstract

This study carried out LCA of the project which cultivates high-yield rice in an abundant land and produces ethanol from the harvested rice. It is effective for high-yield rice cultivation to incorporate the nitrogen fixation crops in rotational system, and to adopt a dehumidifying drying system. GHG emission of cultivation system with these strategies is 20.7 g-CO₂eq/MJ. Ethanol production system generates steam with the dual fuel boiler using the gas by rice husk gasification and fuel oil A. when gasification is operated stably, fuel oil A consumption decrease and minimum GHG discharge is 62.7 g-CO₂eq/MJ. The amount of GHG emission of cultivation and ethanol production system and a gasoline are 83.4 g-CO₂eq/MJ and 81.7 g-CO₂eq/MJ, respectively. It is required for the GHG emission reduction to improve the thermal energy conversion efficiency of the steam production which has only been 53%. GHG emission of methane from paddy field is estimated to be 16.5-72.1 g-CO₂eq/MJ by the difference in soil species and existence organic fertilization. The GHG emission by methane from paddy fields has a high impact on research object system.

View full abstract

Energy environmental education is an important matter to establish a sustainable society. Technology innovations or social improvements must be supported by education to achieve the most performance. Numerical evaluation of people's behavior changes caused by education is important to analyze the effects of education and to improve educational methods. In this study the mothers were chosen as monitors for the behavior analyses. Monitor's significant behavior changes as power consumption reductions after the energy environmental workshop were obtained from the daily energy consumption data collection by themselves. The changes are analyzed numerically using the residuals of multi-regression analyses; the explanatory variables are weather data and activity time in the house of whole monitor families. The maximum percentage decrease of power consumption after workshop was 22%. In this study it is found that detailed data collections of lives make it possible to evaluate numerically the behavioral changes of the people.

View full abstract

To decontaminate radioactive substances on agricultural land and in forests, densification experiments using comminution and pelletization on a laboratory were carried out for woody branches and leaves as primal study. Consequently, densification ratios were ranged from 3.5 to 8.6 by comminution and 9.5 to 27 by pelletization. By mixing the woody portion with leaves and branches, the mixed pellet showed sufficient durability as well as reduced radioactive cesium concentration without decreasing the feed rate. A densification test for herbaceous and woody biomass on a larger scale (200 kg/h of feedstock) is underway at Fukushima prefecture, to design the practical plant.

View full abstract

An energy balance analysis was performed to determine the energy efficiency of cassava bioethanol production in the Philippines. The analysis was based on a commercial scale production system and covered four segments in cassava bioethanol production: cassava production and cultivation, cassava processing, ethanol conversion and transportation. The values used for the analysis were sourced from local and foreign references. Results showed that a large portion of the total input energy for cassava bioethanol production comes from fossil fuels and used in the ethanol conversion process while human effort is concentrated to cassava production and cultivation. A net energy gain (NEG) of 9.27 MJ/L ethanol and a net energy ratio (NER) of 1.78 were obtained in the energy performance estimation. These values indicate that cassava bioethanol production in the Philippines can be energy efficient.

View full abstract