The paper addresses planners and decision-makers in the field, of international development cooperation and also institutions concerned,with the impacts, of project- and technology promotion. The primary aim of the dissemination of Solar Home Systems (SHS) in off grid areas in developing countries is to improve the living conditions of the population in a cost-effective manner. A large-scale dissemination is essential both for significant contributions to development and for climate effectiveness. However, the contribution of SHS to climate protection is disputed. This analysis presents the most important parameters affecting the contribution of SHS to climate protection and quantifies the influence of those parameters. The case considered presupposes the commercial dissemination of SHS. Greenhouse gas (GHG) emissions are affected by the marketing decisions of the supplier of SHS. With regard to the impact on GHG emissions, a comparison is made between traditional lighting with petroleum lamps and the use of dry cell batteries to operate small devices (baseline case) on the one hand and SHSs on the other. The comparison shows GHG savings of around 9 tonnes Of CO2 equivalent GHG emissions within a 20-year period of use of one single 50 Wp SHS compared with the baseline case. The result is robust with respect to variations in GHG-affecting variables. Petroleum consumption and dry cell batteries dominate GHG emissions balances to such an extent that scarcely any importance can be attached to GHG emissions from the transportation and manufacture of SHS. Therefore, it is permissible to use simplified GHG inventories which ignore the GHG emissions arising from the transportation and manufacture of SHS. Therefore the conclusion is, if SHS are commercially disseminated and used cost efficiently to substitute kerosene and dry cell batteries they reduce GHG emissions effectively. In that case SHS can make a significant contribution to climate protection by the dissemination of large numbers. (C) 2002 Elsevier Science Ltd. All rights reserved.