No abstract

No abstract

In this study, which aims to examine the effects of non-controllable factors as well as input parameters on the efficiency performances of Turkish Coal Mine Enterprises, eight enterprises within Turkish Coal Enterprises (TCE) were examined. In order to keep the study as up-to-date as possible, data from the latest year (2005) was examined. For each enterprise, the outputs consisted of the amount of the production sold and the total income gained in the corresponding year; the controllable inputs consisted of investment expenditure, overburden stripping and number of staff; and non-controllable inputs consisted of total reserve and low heat values. In order to measure the effects of non-controllable inputs on enterprise efficiency, three-stage modified data envelopment analysis (DEA) model was employed. In the first stage, information concerning the efficiency of the enterprises was gained by using only the controllable inputs and outputs. In the second stage, the effects of non-controllable inputs on controllable inputs in inefficient enterprises were examined. Lastly in the third stage, the new efficiency values were calculated by means of DEA where controllable inputs and outputs modified according to non-controllable inputs were used. Considering the non-controllable inputs as a result of the analyses conducted with three-stage DEA model, it was determined that the average efficiency value of Turkish Coal Enterprises increased from 87.5% to 92.3%.

As the most important kind of energy needed in the world, electrical energy is one of the major means of contemporary civilization which has contributed to the economic, social, and cultural development of communities. Effective use of resources, environmentally friendly production, keeping up-to-date with technology, and demand are significant factors in electricity generation. In this respect, considering the influence of the existence and feasibility of fossil resources, new, and renewable resources on nations' energy policies, the aim of this study is to evaluate efficiency developments of the 13 largest electricity generation firms in the member countries of the Organization for Economic Co-operation and Development. In the study, the analytic hierarchy process and the data envelopment analysisMalmquist productivity index approaches were integrated to assess qualitative and quantitative factors together. The efficient/inefficient firms in 2008 and 2009 were determined, and a development of 7.7% in 2009 due to technological change was found.

The demand for electrical energy in Turkey, which is increasing due to population growth and industrialization like in the rest of the world, can only be met by either increasing the amount of energy produced with existing resources or by reducing energy consumption, on the basis of energy efficiency at every stage of production to consumption in other words. Use of primary energy resources in Turkey, which has to meet a large portion of its energy needs through imports, between the years 2000-2009 was examined with the Malmquist total factor productivity index (MPI). The analyses determined a decrease of 5.4% in electrical energy production due to inefficient use of indigenous resources and the current installed capacity. This study can be considered as an effort to draw attention to use of indigenous resources in terms of both contributions to the national economy and energy security.