しhe estimation ofhourly direct or diffUse irradiation have been developed boLh in Qur c 〔 ， untry and everseas countries ． This report compares the models in order しo ［ ind the most appropriate model applicable to the estimation orhourly direc し irradlaLio 冂 and ditT

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The models fer estimation efglobal irradiance on tilted sur 魚ces are evaluated ，

It would be useful for building designers to consider future climate change by using building thermal simulations to construct a building adaptable to global warming. Future weather data including future changes to climate are needed as input data to conduct building thermal simulations. In this report, a method to produce hourly future weather data is presented. The method combines real current hourly weather data with results from climate models. Hourly future weather data at 833 stations for 2040s and 2090s have been developed and applied to heat load calculations of office buildings.

In this report, we examined influences of solar incident angle on the power generation efficiency of photovoltaic (PV) modules based on a measurement, during winter, at Kagoshima in Japan (31.570˚N, 130.545˚E). It was indicated that the power generation efficiency of PV modules deteriorates with time depending on the solar incident angle, and that there are cases where the power generation efficiency sharply drops if the incident angle exceeds 60˚ and the reflectance of cover glass exceeds 0.2. Such drop of power generation efficiency dependent on incident angle clearly appears at clear time when the proportion of direct components of solar radiation increases. Furthermore, it was pointed out that the average value of power generating efficiency during winter including all weather conditions produces differences of 10% or so, depending on the difference of average value during the period of incident angle.