Appropriate battery technology for a new, rechargeable, micro-solar lantern

A detailed market survey in Kenya has assessed the performance of currently available domestic lighting systems, for example, kerosene 'hurricane' lam ps and (generally poorly constructed) solar lanterns, against end-user expe ctations. Following this survey, the UK Government's Department for Interna tional Development approved a project to design and develop an affordable, reliable and efficient solar lantern, which would provide improved lighting to rural households. This paper provides an overview of the end-user requi rements, and corresponding lantern design features. The suitability of thre e commercially available alternative battery technologies, viz., nickel - m etal-hydride, nickel - cadmium, and valve-regulated lead - acid (VRLA), for use in this PV application are discussed. Finally, improvements to the VRL A batteries are proposed, which would further enhance their cycle-life and reduce the energy cost per cycle. (C) 2000 Elsevier Science S.A. All rights reserved.