Greenstar is designed for long-term reliability and durability, and requires a minimum of supervision and management. A two-person crew can run the system and provide all support. In a one-week intensive training course, people with modest literacy skills can be trained to maintain Greenstar themselves. The photovoltaic solar array which comprises the entire roof surface is intended to face south (in the northern hemisphere) or north (in the southern hemisphere) in order to capture the most radiation from the sun. Its angle can be easily adjusted through the year to further optimize its efficiency. Greenstar also includes high-band two-way telecommunications, with a two-way satellite connection provided by eSat. Where satellite is not available, it may be replaced by a spread-spectrum digital radio, or by conventioanl cellular connection. Most points on earth can be reached by satellite communications. A vital function provided by Greenstar is clean water: this is the foundation of a healthy community. Solar power drives an ultra-violet water purifier. Where necessary, this unit may be replaced with a desalination unit, to produce safe water from the ocean or inland salt seas. Greenstar can also serve as a community hub, a place for people to gather for education and community events. To this end, it includes a large surrounding floor surface and streetlamps, encouraging people to gather there after dark. On the outside at one end is a large rear-projection video screen, which allows showing of education video for adult health and job education.