Selçuk Bilgen

Renewable Energy for a Clean and Sustainable Future

This article discusses the growing need of energy in both developed and developing countries, and the acute population growth, which will exceed 10 billion by the year 2050. How can a world of 10 billion people be provided with adequate supplies of energy, cleanly, safely and substantially? There is a growing consensus that renewable energy sources will be a very important part of the answer. The growing interest in renewables has been prompted, in part, by increasing concern over the pollution, resource depletion and possible climate change implications of our continuing use of conventional fossil and nuclear fuels. Recent technological developments have also improved the cost-effectiveness of many of the renewables, making their economic prospects look increasingly attractive. It describes the achievement and progress made in hydropower, biomass conversion, geothermal, solar thermal technology, wind energy conversion, and the increasing usage of photovoltaics. It is evident that global warming is setting in and is going to change the climate, as well as the terrain of many countries, unless drastic measures are taken. The Kyoto meeting emphasized the importance of limiting CO2 emissions and to abide by some form of agreement to reduce emissions. The present study concludes that renewable energy penetration into the energy market is much faster than was expected in recent years and by 2030, 15–20% of our prime energy will be met by renewable energy.

Energy utilization, environmental pollution and renewable energy sources in Turkey.

In this study, energy utilization and its major environmental impacts are discussed from the standpoint of sustainable development, including anticipated patterns of future energy use and subsequent environmental issues in Turkey. Several aspects relating to energy utilization, renewable energy, energy efficiency, environment and sustainable development are examined from both current and future perspectives. Turkey is an energy importing country, more than half of the energy requirement has been supplied by imports. Domestic oil and lignite reserves are limited, and the lignites are characterised by high ash, sulfur and moisture content. Because of increasing energy consumption, environmental pollution is becoming a serious problem in the future for the country. In this regard, renewable energy resources appear to be one of the most efficient and effective solutions for sustainable energy development and environmental pollution prevention in Turkey. Turkeys geographical location has several advantages for extensive use of most of these renewable energy sources. Especially hydropower, biomass, geothermal, solar and wind energy should be considered and seriously supported by governments and private sectors. � 2003 Elsevier Ltd. All rights reserved.

Second Law Analysis of Various Types of Coal and Woody Biomass in Turkey

This article presents a first and second law, or exergy and energy analysis, of various types of wood and coal samples with Turkish origins. The projected increase in coal utilization in power plants and wood utilization in domestic heating makes it desirable to evaluate the energy content of coal and wood both quantitatively and qualitatively, which will result in proper design, matching, and installation of equipment. In any process, it is thought useful to obtain work of the second law analysis or exergy analysis, as well as the first law analysis.

Thermodynamic Aspects of Renewable and Sustainable Development

Abstract Exergy analysis enables one to evaluate quantitatively the causes resulting in increases of exergy due to thermodynamic imperfections of thermal and chemical processes. Exergy express the quality of energy and can be defined as the minimal work necessary to produce a material in its specified state from materials common in the environment in a reversible way, heat being exchanged only with the environment. On the other hand, achieving sustainable solutions to todays energy and environmental problems needs long-term planning and actions. Energy issues are particularly prevalent at present and renewables appear to provide one component of an effective sustainable solution. Discussed in this article are possible future energy-utilization patterns and related environmental impacts, potential solutions to current environmental problems, renewable energy technologies and their relations to sustainable development, and how the principles of thermodynamics via exergy can be beneficially used to evaluate energy systems and technologies as well as environmental impact. Throughout the article, current and future perspectives regarding thermodynamics and sustainable development are considered.

Second Law (Exergy) Analysis of Cogeneration System

Abstract The thermal performance of power generating and consuming devices can be improved significantly, both during design and operation. Turkeys electric energy demand is growing at an average of 6–8% yearly. Cogeneration facilities have an important role in the countrys energy strategy, because a substantial amount of Turkeys energy need has been met by cogeneration facilities in recent years. In the present study, the chemical and physical exergy and exergy destruction of the cogeneration system was calculated with the BASIC program by using second law analysis. Performance of the cogeneration system is also discussed, based on the second law (exergy) concept.

Energy related environmental policies in Turkey

Abstract There is increasing consensus in both the scientific and political communities that significant reductions in greenhouse gas (GHG) emissions are necessary to limit the magnitude and extent of climate change. Renewable energy systems already reduce GHG emissions from the energy sector, although on a modest scale. Turkey is heavily dependent on expensive imported energy resources (oil, gas, and coal) that place a big burden on the economy, and air pollution is becoming a great environmental concern in the country. In this regard, renewable energy resources appear to be one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkeys geographical location has several advantages for extensive use of most of these renewable energy sources. This article presents a review of the energy related environmental policies in Turkey.

Thermodynamic Aspects of Energy Systems and Sustainable Development

Abstract Achieving sustainable solutions to todays energy and environmental problems requires long-term planning and actions. Energy issues are particularly prevalent at present and renewable energy resources appear to provide one component of an effective sustainable solution. An understanding of the thermodynamic aspects of sustainable development can help in taking sustainable actions regarding energy. In this article, possible future energy-utilization patterns and related environmental impacts, potential solutions to current environmental problems, energy efficiency, renewable energy technologies and their relations to sustainable development, and how the principles of thermodynamics via exergy can be beneficially used to evaluate energy systems and technologies as well as environmental impacts are discussed. Throughout the article, current and future perspectives regarding thermodynamics and sustainable development are also considered. The results will likely be useful to scientists and engineers as well as decision and policy makers.

The Estimation of Chemical Availability (Exergy) Values for Various Types of Coals in Geographical Regions of Turkey

Anxiety concerning the problems of energy and resources has led to a rapid increase in the interest in describing and understanding the conversion processes of energy and other resources in society. To be able to understand the procedure of these conversion processes, it is important that useful concepts, such as the chemical availability, are available. Exergy was introduced in Turkey long ago but not enough attention has been given to it until recently. The objective of this article is to present a calculation of the chemical availability of coal-based fuels in geographical regions of Turkey. In this regard, it has based the necessity of this study on solid and valid arguments on the advantages of second-law analyses compared to first-law analyses and has presented a correct chemical availability calculation.

Comparison of Physico-chemical Properties of Various Coals as Thermodynamics: First and Second Law Analysis

In energy transformation processes, such as combustion of fossil and renewable fuels, the conservation of energy (first law of thermodynamics) as well as the quality of energy (second law of thermodynamics) is important. The objective of this article is to present a calculation of standard chemical exergy of coal-based fuels. In this regard, the necessity of this study has been based on solid and valid arguments on the advantages of second-law analyses compared to first-law analyses and a correct chemical exergy calculation is presented. A formula has been developed for estimating the chemical exergy of coals from their ultimate analysis values. In order to obtain this formula, 33 samples from different geographical regions in Turkey were analyzed to calculate chemical exergy values by using ultimate analyses and calorific values. Also, chemical exergy values of these coal samples obtained from different Turkish sources were calculated from a formula in the literature. The mean differences between these values range from −0.798 to 0.646%. The formula developed for estimating the chemical exergy of coals from their ultimate analyses and calorific values had a correlation coefficient (R2 = 0.99), and the prediction of this formula is good, as well as expected.

Correlation for estimation of the chemical availability (exergy) from ultimate analysis of pyrolytic oils obtained from fast pyrolysis of biomass

ABSTRACT The purpose of this study is to evaluate the chemical exergy (ECH) of liquid products obtained from fast pyrolysis of biomass. I have calculated the chemical exergy values from a formula in literature and have developed a formula for estimating the chemical exergy of biomass from the higher heating value and their ultimate analysis values. The mean differences between these values range from –0.391% to 0.460%. The formula developed for estimating the chemical exergy of biomass from the higher heating value and their ultimate analyses had a correlation coefficient (R2 = 0.9999), and the prediction of this formula is good. The goal is to identify desirable attributes that may serve as the basis for decision-making for future biofuel options. Studies on the pyrolytic oils showed that the oils obtained from chestnut cupulae and maple fruit can be used as a renewable fuel and chemical feedstock.