ABSTRACT
A frequent issue is the module energy feed back ie how long it takes to a photovoltaic module to give back the energy necessary for the full process of its manufacture. The same question is applied to batteries in stand-alone PV systems. This paper presents an evaluation the energy necessary for the full process of making the batteries. In the best conditions, battery energy pay-back time is quite similar to modules pay-back time: 4,5 years for original batteries and 2,5 years and half for recycled batteries. But tubular plate life-time is more than three times shorter than module life-time, and SLI automotive or deep cycle batteries life-time 6 up to 15 times shorter. The apparently cheapest solution ie SLI automotive batteries, is by far the worst solution in terms of energy pay-back time. It is also the most expensive one, whatever the approach ie economical or ecological. However, for two main reasons, it could remain the most popular solution in developing countries. The initial cost is lower and the local availability much higher. High quality and long life-time batteries such as tubular plate stationary batteries could be recommended, especially in remote areas and even for small SHS application.
