CO$_{2}$-reduction potential through rational energy utilization and use of renewable energy sources in the Federal Republic of Germany

This paper is devoted to a quantitative analysis of the reduction potential of CO$_{2}$-emissions of the entire energy sector of the Federal Republic of Germany through rational use of energy exclusively by technical measures and the utilization of renewable sources of energy. Consequences of changes of consumer behaviourand of energy demand values are not included in this study. The paper analyses the most important reduction potentials of the private passenger car transportation, of the space heat sectors, of the electricity production sector, of the various industrial sectors and of electricity applications in the industrial, commercial and residential sectors. Additionally the effect of an exploitation of the potential of the renewable energy sector is investigated. Reference is the emission of the energy sector in 1987 of about 770 mill, t CO$_{2}$. The identified technical reduction potential for private passenger car transportation is about 19 mill, t CO$_{2}$/a at maximum, for the industry about 20 mill, t CO$_{2}$/a, through improvement of the efficiency of electrical appliances in the residential and commercial sector about 34 mill, t CO$_{2}$/a and for the space heat technically at least 120 mill, t CO$_{2}$/a. The exploitation of the renewable energy sector could reduce the emissions by about 31 mill, t CO$_{2}$/a and the maximum reduction through the improvement of efficiency of electricity production is about 20 mill, t CO$_{2}$/a without substitution of energy carriers. It is important to notice that this above mentioned figures cannot be added up to a total figure because of partly mutual substitution of the different identified measures. The calculated individual reduction figures are maximum values derived under the ceteris - paribus - rule. But substitution effects were beyond the scope of this paper. The identified C$O{2}$-reduction options in the space heat sector and the majority of the technologies for the utilization of renewable sources of energy are not economically viable at present and in the medium term. Whether they become economic in the long term depends amoung other things on the oil price development and on the progress of the state of the art for renewable energy technologies. But selecting smaller conservation potentials thanthe assumed ones could also lead in the space heat sector to a CO$_{2}$ reduction without additional costs. Except for most renewable energies and the heat sectors nearly all identified measures seem to be economically feasible in the medium and long term with no additional costs for the CO$_{2}$-emission reductions:The identified technical substitute measures are in most cases more expensive than the presently applied ones, but amortize within the life time through the reduced energy consumption. The associated CO$_{2}$ emission reduction is a cost-free side effect, but depends on the actual market introduction of these measures.It should be noted that nevertheless the economic potnetials for CO$_{2}$-emission reduction through rational utilization of energy and application of renewable energy sources seem to be relatively limited, especially if the demand for energy services continues to increase noticeably