Feasibility study of renewable energy sources for developing the hydrogen economy in Pakistan

Hydrogen energy can play a pivotal part in enhancing energy security and decreasing hazardous emissions in Pakistan. However, hydrogen energy can be sustainable and clean only if it is produced from renewable energy sources (RES). Therefore, this study conducts feasibility of six RES for the generation of hydrogen in Pakistan. RES evaluated in this study include wind, solar, biomass, municipal solid waste (MSW), geothermal, and micro-hydro. RES have been evaluated using Fuzzy Delphi, fuzzy analytical hierarchy process (FAHP), and environmental data envelopment analysis (DEA). Fuzzy Delphi finalizes criteria and sub-criteria. FAHP obtains relative weights of criteria considered for choosing the optimal RES. Environmental DEA measures relative efficiency of each RES using criteria weights as outputs, and RES-based electricity generation cost as input. The results revealed wind as the most efficient source of hydrogen production in Pakistan. Micro-hydro and Solar energy can also be used for hydrogen production. Biomass, MSW, and geothermal achieved less efficiency scores and therefore are not suggested at present.     

Governmental policy and prospect in electricity production from renewables in Lithuania

In Lithuania, the generation of electricity is based on the nuclear energy and on the fossil fuels. After the decommissioning of Ignalina nuclear power plant in 2009, the Lithuanian Power Plant and other thermal plants will become the major sources of electricity. Consequently, the Lithuanian power sector must focus on the implementation of renewable energy projects, penetration of new technologies and on consideration of the future opportunities for renewables, and Government policy for promoting this kind of energy. Production of electricity from renewable energy is based on hydro, biomass and wind energy resources in Lithuania. Due to the typical climatic condition in Lithuania the solar photovoltaics and geothermal energy are not used for power sector. Moreover, the further development of hydropower plants is limited by environmental restrictions, therefore priority is given to wind energy development and installation of new biomass power plants. According to the requirements set out in the Directive 2001/77/EC of the European Parliament and of the Council of 27 September 2001 on the promotion of electricity produced from renewable energy sources in the internal electricity market [Official Journal L283, 33–40, 27 October 2001], 7% of gross consumption of electricity will be generated from renewable energy by 2010 in Lithuania. The aim of this paper is to show the estimation of the maximum renewable power penetration in the Lithuanian electricity sector and possible environmental impact.     

Renewable energy capability to save carbon emissions

The present R&D approach to new renewable energy sources includes a drawback which could negate their environmental significance. New renewable energies are affected by a technical limitation because of the random intermittent nature of their power generation which hinders them from fully expanding into the electricity market. As a consequence, the contribution which renewable electric energy sources make is just significant in terms of world electricity generation and only marginal in terms of total energy consumption. Thus, in spite of expectations, the practical achievable amount of environmental benefits arising from new renewable energy would not be enough to counteract the environmental crisis. It is known that the intermittence of energy supply can be removed by implementing grid-tied power systems, adding a further stage aimed to chemically store the intermittent solar energy by producing clean synthetic fuels. Until now this chance was considered of little importance, on the contrary, it should become a compulsory solution so that renewable energy can acquire an actual and environmentally consistent significance.     

Global Renewable Energy Resources

Renewable energy sources (RES) supply 14% of the total world energy demand. RES are biomass, hydropower, geothermal, solar, wind, and marine energies. The renewables are the primary, domestic and clean or inexhaustible energy resources. The percentage share of biomass was 62.1% of total renewable energy sources in 1995. Large-scale hydropower supplies 20 percent of global electricity. Wind power in coastal and other windy regions is promising as well.     

Exergy analysis of solar energy applications

Solar energy is a clean, abundant and easily available renewable energy. Usage of solar energy in different kinds of systems provides scope for several studies on exergy analysis. In the present work, a comprehensive literature review has been carried out on exergy analysis of various solar energy systems. The systems considered under study are solar photovoltaic, solar heating devices, solar water desalination system, solar air conditioning and refrigerators, solar drying process and solar power generation. The summary of exergy analysis and exergetic efficiencies is presented along with the exergy destruction sources.     

Study on electrical energy and prospective electricity generation from renewable sources in Australia

Nowadays renewable sources are being used as clean sources to generate electricity and to reduce the dependency on fossil fuels. The uses of renewable sources are being increased in electricity generation and contributed to reduce the greenhouse gas emission. The function of any electrical power system is to connect everyone sufficiently, clean electric power anywhere and anytime of the country. This can be achieved through a modern power system by integrating electrical energy from clean renewable sources into the nation's electric grid to enhance reliability, efficiency and security of the power system. The paper on the status of review the driving force of the generation of renewable energy and proposing electrical energy generation from renewable sources to be ensured at least 20% of total energy of Australia. This paper has been studied the existing electricity generation capacity of Australia from renewable and non-renewable sources. Optimal electricity generation from renewable sources has been examined. The environmental impact of electricity generation from renewable sources has been considered. Under this paper the yearly average wind data of past 20 years and above for some meteorological stations of Australia have been used. The prospective electricity generation from wind turbines and solar photovoltaic panels has been proposed in the paper that will increase electrical energy of the power grid of Australia. It was estimated the capital cost of prospective electricity generation farms from wind and solar PV sources.     

Renewable energy sources in Turkey for climate change mitigation and energy sustainability

In Turkey, there is a much more potential for renewables, but represent about 37% of total energy production and 10% of total energy consumption. This share is not enough for the country and the governments should be increase to this situation. Renewable energy technologies of wind, biomass, hydropower, geothermal, solar thermal and photovoltaics are finally showing maturity and the ultimate promise of cost competitiveness. With respect to global environmental issues, Turkey's carbon dioxide emissions have grown along with its energy consumption. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Certain policy interventions could have a dramatic impact on shaping the relationship between geological, geographic and climatic conditions and energy production. This study shows that there is enough renewable energy potential in Turkey for fuels and electricity. Especially hydropower and biomass are very well.     

Energy production and sustainable energy policies in Turkey

Turkey's demand for energy and electricity is increasing rapidly. Turkey is heavily dependent on expensive imported energy resources that place a big burden on the economy and air pollution is becoming a great environmental concern in the country. Turkey's energy production meets nearly 28% of its total primary energy consumption. As would be expected, the rapid expansion of energy production and consumption has brought with it a wide range of environmental issues at the local, regional and global levels. With respect to global environmental issues, Turkey's carbon dioxide (CO₂) emissions have grown along with its energy consumption. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases (GHGs). In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey presently has considerable renewable energy sources. The most important renewable sources are hydropower, biomass, geothermal, solar and wind. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Turkey has a great and ever-intensifying need for power and water supplies and they also have the greatest remaining hydro potential. Hydropower and especially small hydropower are emphasized as Turkey's renewable energy sources. Turkey's hydro electric potential can meet 33–46% of its electric energy demand in 2020 and this potential may easily and economically be developed. This paper presents a review of the potential and utilization of the renewable energy sources in Turkey.     

Waste-to-energy: A way from renewable energy sources to sustainable development

Nowadays, energy is key consideration in discussions of sustainable development. So, sustainable development requires a sustainable supply of clean and affordable renewable energy sources that do not cause negative societal impacts. Energy sources such as solar radiation, the winds, waves and tides are generally considered renewable and, therefore, sustainable over the relatively long term. Wastes and biomass fuels are usually viewed as sustainable energy sources. Wastes are convertible to useful energy forms like hydrogen (biohydrogen), biogas, bioalcohol, etc., through waste-to-energy technologies.In this article, possible future energy utilization patterns and related environmental impacts, potential solutions to current environmental problems and renewable energy technologies and their relation to sustainable development are discussed with great emphasis on waste-to-energy routes (WTERs).     

Geothermal energy in Turkey: the sustainable future

Turkey is an energy importing nation with more than half of our energy requirements met by imported fuels. Air pollution is becoming a significant environmental concern in the country. In this regard, geothermal energy and other renewable energy sources are becoming attractive solution for clean and sustainable energy future for Turkey. Turkey is the seventh richest country in the world in geothermal energy potential. The main uses of geothermal energy are space heating and domestic hot water supply, greenhouse heating, industrial processes, heat pumps and electricity generation. The district heating system applications started with large-scale, city-based geothermal district heating systems in Turkey, whereas the geothermal district heating centre and distribution networks have been designed according to the geothermal district heating system (GDHS) parameters. This constitutes an important advantage of GDHS investments in the country in terms of the technical and economical aspects. In Turkey, approximately 61,000 residences are currently heated by geothermal fluids. A total of 665 MW_t is utilized for space heating of residential, public and private property, and 565,000 m² of greenhouses. The proven geothermal heat capacity, according to data from existing geothermal wells and natural discharges, is 3132 MWt. Present applications have shown that geothermal energy is clean and much cheaper compared to the other fossil and renewable energy sources for Turkey.     

Integrated hydrogen production options based on renewable and nuclear energy sources

Due to varied global challenges, potential energy solutions are needed to reduce environmental impact and improve sustainability. Many of the renewable energy resources are of limited applicability due to their reliability, quality, quantity, and density. Thus, the need remains for additional sustainable and reliable energy sources that are sufficient for large-scale energy supply to complement and/or back up renewable energy sources. Nuclear energy has the potential to contribute a significant share of energy supply with very limited impacts to global climate change. Hydrogen production via thermochemical water decomposition is a potential process for direct utilization of nuclear thermal energy. Nuclear hydrogen and power systems can complement renewable energy sources by enabling them to meet a larger extent of global energy demand by providing energy when the wind does not blow, the sun does not shine, and geothermal and hydropower energies are not available. Thermochemical water splitting with a copper–chlorine (Cu–Cl) cycle could be linked with nuclear and selected renewable energy sources to decompose water into its constituents, oxygen and hydrogen, through intermediate copper and chlorine compounds. In this study, we present an integrated system approach to couple nuclear and renewable energy systems for hydrogen production. In this regard, nuclear and renewable energy systems are reviewed to establish some appropriate integrated system options for hydrogen production by a thermochemical cycle such as Cu–Cl cycle. Several possible applications involving nuclear independent and nuclear assisted renewable hydrogen production are proposed and discussed. Some of the considered options include storage of hydrogen and its conversion to electricity by fuel cells when needed.     

Renewable energy market conditions and barriers in Turkey

Decentralized wind, hydropower, biogas and biomass, geothermal, solar thermal and solar electricity energy systems are the most commonly found renewable energy technologies promoted for rural energy supply within sustainable developments programs. They are, therefore, seen to have a central place in the practice of sustainable development and in allowing less development countries to bypass the environmentally damaging fossil fuel intensive paths made by industrialized countries. On the political front, many less development countries are critical of pressure on them to adopt environmental energy technologies.Turkey is situated the meeting point of three continents (Asia, Europe and Africa) and stands as a bridge between Asia and Europe. The country is located in southeastern Europe and southwestern Asia. As Turkey’s economy has expanded in recent years, the consumption of primary energy has increased. Presently in order to increase the energy production from domestic energy resources, decrease the use of fossil fuels as well as reduce of green house gas emissions different renewable energy sources are used for energy production in Turkey. The share of energy production from renewable energy sources has increased during the last 10 years. Turkey must import most of the energy to meet her needs. Turkey also has a large potential for renewable energies. The lack of knowledge about renewable energy technologies by most policy-makers, potential consumers, and energy firm managers has played against renewable energy developments. The paper presents renewable energy used in Turkey and Europe Union and evaluation of the market conditions and barriers of renewable energy use in Turkey.     

Energy diversification in Finland: achievements and potential of renewable energy development

Finland was an early adopter of several alternative energy technologies, particularly in biomass and hydropower energy for many years. The main policy in the Finnish energy and climate sectors is to increase the exploitation of renewable energy sources while reducing CO₂ emissions. Meanwhile, a successful energy policy should achieve three conflicting objectives: clean, cheap, and secure energy. The development of renewables in Finland has lagged that of other EU countries, particularly in fields such as wind power in recent years. This article discusses about the history, current status, and potentials of the major renewable and local energy in order of utilisation in Finland. It is seen that the major contributors to replacing carbon-based fuels are likely to be biomass and wind power, with geothermal and solar energy sources to play a lesser role.     

Status and outlook of China's free-carbon electricity

Global warming, increased energy demand, and tremendous air pollution are forcing China to revise its energy structure of electricity generation dominated by coal (80% of total electricity) towards low-carbon electricity. Vigorous development of carbon-free energy resources of electricity is a practical way towards low-carbon electricity in China. In this paper, we shall outline renewable power generation (hydropower, wind power, solar energy, biomass energy, nuclear power, ocean energy and geothermal) together with nuclear power for China, present a reserves assessment, the current status, and barriers for further development, and finish with an outlook towards the future. In our view, China has plenty of free-carbon energy resources to revolutionize its electricity structure and redirect it towards low-carbon electricity systems. Needed are the effective energy policies to get to the way.     

电力部门要承担起发展清洁能源的重任

我国"十二五"期间要实现能源结构调整和电力发展方式的转变,大力发展清洁能源。应当说,新能源、可再生能源、非化石能源和新兴能源都是清洁能源,它包括洁净煤、天然气(含煤层气、页岩气、致密砂岩气等)、核电、水电、风能、太阳能、生物质能等。由于清洁能源大部分需要通过电力来实现,所以在清洁能源发展中电力部门必然是主力军。电力部门一是要研究开发清洁能源新技术,把清洁能源转变成安全、稳定、经济的电力;二是要使清洁能源生产出来的电力能为广大用户所接受。只有达到这两个条件,由清洁能源转变而来的电力才能提高其在电力总供应量中的比重。在IEA和BP的世界一次能源统计中,中国"非化石能源+天然气"的比重都非常低,均不到20%。统计数据反映出的中国能源结构的突出问题是煤炭比例太高,石油、天然气、核电比例太低。因此,与发达国家不同,中国改善能源结构、发展清洁能源的重点应该是主攻洁净煤技术(包括CCS),同时加快发展天然气、核能和水电。     

Evaluation of a new geothermal based multigenerational plant with primary outputs of hydrogen and ammonia

Increasing environmental concerns and decreasing fossil fuel sources compel engineers and scientists to find resilient, clean, and inexpensive alternative energy options Recently, the usage of renewable power resources has risen, while the efficiency improvement studies have continued. To improve the efficiency of the plants, it is of great significance to recover and use the waste heat to generate other useful products. In this paper, a novel integrated energy plant utilizing a geothermal resource to produce hydrogen, ammonia, power, fresh water, hot water, heated air for drying, heating, and cooling is designed. Hydrogen, as an energy carrier, has become an attractive choice for energy systems in recent years due to its features like high energy content, clean, bountiful supply, non-toxic and high efficiency. Furthermore in this study, hydrogen beside electricity is selected to produce and stored in a hydrogen storage tank, and some amount of hydrogen is mixed with nitrogen to compound ammonia. In order to determine the irreversibilities occurring within the system and plant performance, energy and exergy analyses are then performed accordingly. In the design of the plant, each sub-system is integrated in a sensible manner, and the streams connecting sub-systems are enumerated. Then thermodynamic balance equations, in terms of mass, energy, entropy and exergy, are introduced for each unit of the plant. Based on the system inputs and outputs, the energy and exergy efficiencies of the entire integrated plant is found to be 58.68% and 54.73% with the base parameters. The second part of the analysis contains some parametric studies to reveal how some system parameters, which are the reference temperature, geothermal resource temperature and mass flow rate, and separator inlet pressure in the geothermal cycle, affect both energy and exergy efficiencies and hence the useful outputs.     

Hydrogen production through renewable and non-renewable energy processes and their impact on climate change

The urbanization and increase in the human population has significantly influenced the global energy demands. The utilization of non-renewable fossil fuel-based energy infrastructure involves air pollution, global warming due to CO₂ emissions, greenhouse gas emissions, acid rains, diminishing energy resources, and environmental degradation leading to climate change due to global warming. These factors demand the exploration of alternative energy sources based on renewable sources. Hydrogen, an efficient energy carrier, has emerged as an alternative fuel to meet energy demands and green hydrogen production with zero carbon emission has gained scientific attraction in recent years. This review is focused on the production of hydrogen from renewable sources such as biomass, solar, wind, geothermal, and algae and conventional non-renewable sources including natural gas, coal, nuclear and thermochemical processes. Moreover, the cost analysis for hydrogen production from each source of energy is discussed. Finally, the impact of these hydrogen production processes on the environment and their implications are summarized.     

Potential of renewable hydrogen production for energy supply in Hong Kong

Hong Kong is highly vulnerable to energy and economic security due to the heavy dependence on imported fossil fuels. The combustion of fossil fuels also causes serious environmental pollution. Therefore, it is important to explore the opportunities for clean renewable energy for long-term energy supply. Hong Kong has the potential to develop clean renewable hydrogen energy to improve the environmental performance. This paper reviews the recent development of hydrogen production technologies, followed by an overview of the renewable energy sources and a discussion about potential applications for renewable hydrogen production in Hong Kong. The results show that although renewable energy resources cannot entirely satisfy the energy demand in Hong Kong, solar energy, wind power, and biomass are available renewable sources for significant hydrogen production. A system consisting of wind turbines and photovoltaic (PV) panels coupled with electrolyzers is a promising design to produce hydrogen. Biomass, especially organic waste, offers an economical, environmental-friendly way for renewable hydrogen production. The achievable hydrogen energy output would be as much as 40% of the total energy consumption in transportation.