Sustainable development will require replacement of older technologies and increased use of both renewable energy and telecommunications. The world-leading tele- and data-communications systems supplier, Ericsson, is increasingly offering solar powered solutions. Radio base station site solutions such as the Ericsson SunSite are already in use. Ericsson has long been using life cycle assessments (LCA) to evaluate its products and systems. Solar powered systems are expected to reduce carbon dioxide emissions. Ericsson presents a carbon dioxide balance for a solar powered base station in use and compares it with a grid-powered alternative. The study is based on data collected from internal LCA. The SunSite technical solution is briefly described. Our findings are that the benefits clearly increase with the remoteness of the site from the power grid. An evaluation has been made about where, when and how solar powered solutions should be implemented in order to achieve maximum environmental gains. Key parameters are solar panel efficiency, distance from power grid, backup power system and grid power source. The study also discusses future challenges and outstanding issues for solar powered telecommunications systems as seen from both the environmental and energy perspectives.