Abstract
The human race depended on the fossil fuel, and gave rise to the international problem such as the exhaustion of fossil fuels and global warming. We will have to change its focus from nonrenewable fossil fuel technology to renewable power source. The authors focused on solar energy and have developed a collector unit. There is variously use of the solar heat. The authors especially paid attention to the solar still and made its prototype. The reason is the shortage of water raised as one of the international problems. It is forecast that the world population exceeds 9 billion in 2050, and is requested securing a further drinking water (1). This device utilizes solar heat and it warms seawater. The generated steam is condensed and the fresh water is obtained. It thinks about an ideal solar still in this study, as part of effective use of the solar heat.
