Real Costs Assessment of Solar-Hydrogen and Some Fossil Fuels by means of a Combustion Analysis

In order to compare solar-hydrogen and the most used fossil fuels, the evaluation of the “external” costs related to their use is required. These costs involve the environmental damage produced by the combustion reactions, the health problems caused by air pollution, the damage to land from fuel mining, and the environmental degradation linked to the global warming, the acid rains, and the water pollution. For each fuel, the global cost is determined as sum of the market price and of the correspondent external costs. In order to obtain a quantitative comparison, the quality of the different combustion reactions and the efficiency of the technologies employed in the specific application sector have to be considered adequately. At this purpose, an entropic index that considers the degree of irreversibility produced during the combustion process and the degradation of surroundings is introduced. Additionally, an environmental index that measures the pollutants released during the combustions is proposed. The combination of these indexes and the efficiency of the several technologies employed in four energy sectors have allowed the evaluation of the total costs, highlighting an economic scenario from which the real advantages concerning the exploitation of different energy carrier are determined.