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.     

可再生能源联合发电技术

近年来,随着国家倡导低碳经济,以风电、水电、太阳能、生物质能为代表的新能源得到了快速的发展。风能、水能、太阳能、生物质能等多种可再生能源联合发电是一种有效的可再生能源利用方式。简述了风能、水能,太阳能和生物质能的发电原理,并探讨了目前国内关于多种能源联合互补发电系统的设计研究成果。     

The role of hydrogen and fuel cells to store renewable energy in the future energy network – potentials and challenges

The penetration of renewable energy sources is expected to rapidly increase from 15% to 50% in 2050 due to their vital contribution to the global energy requirements, sustainability and quality of life in economical, environmental and health aspects. This huge rise highlights the necessity of development of energy storage systems, especially for intermittency renewable energies such as solar photovoltaic and wind turbine, in order to balance the energy network. In this study, renewable energy options including pumped hydro, pressurized air, flywheels, Li ion batteries, hydrogen and super-capacitors are compared based on a specific set of criteria. The criteria considered are energy/power density, ease of integration with the existing energy network, cost effectiveness, durability, efficiency and safety. Our study showed that storing renewable energy sources in the form of hydrogen through the electrolysis process is ranked as the most promising option considering the mentioned criteria. It brings about several benefits suggesting that hydrogen and fuel cells are promising contributors towards a more sustainable future, both in energy demand and environmental sustainability.     

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.     

Analysis of hydrogen production from combined photovoltaics, wind energy and secondary hydroelectricity supply in Brazil

In this work, the technical and economical feasibility for implementing a hypothetical electrolytic hydrogen production plant, powered by electrical energy generated by alternative renewable power sources, wind and solar, and conventional hydroelectricity, was studied mainly trough the analysis of the wind and solar energy potentials for the northeast of Brazil. The hydrogen produced would be exported to countries which do not presently have significant renewable energy sources, but are willing to introduce those sources in their energy system. Hydrogen production was evaluated to be around 56.26 × 10⁶ m³ H₂/yr at a cost of 10.3 US$/kg.     

Wind energy status in renewable electrical energy production in Turkey

Main electrical energy sources of Turkey are thermal and hydraulic. Most of the thermal sources are derived from natural gas. Turkey imports natural gas; therefore, decreasing usage of natural gas is very important for both economical and environmental aspects. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Turkey has very high wind energy potential. The estimated wind power capacity of Turkey is about 83,000 MW while only 10,000 MW of it seems to be economically feasible to use. Start 2009, the total installed wind power capacity of Turkey was only 4.3% of its total economical wind power potential (433 MW). However, the strong development of wind energy in Turkey is expected to continue in the coming years. In this study, Turkey's installed electric power capacity, electric energy production is investigated and also Turkey current wind energy status is examined.     

Wind energy status in electrical energy production of Turkey

Main electrical energy sources of Turkey are thermal (lignite, natural gas, coal, fuel oil, etc.) and hydraulic. Most of the thermal sources are derived from natural gas. Turkey imports natural gas; therefore, decreasing usage of natural gas is very important for both economical and environmental aspects. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Turkey has very high wind energy potential. However the installed wind power capacity is only 0.22% of total economical wind potential. In this study, Turkey's installed electric power capacity, electric energy production is investigated and also Turkey current wind energy status is examined.     

Geothermal resources in Iran: The sustainable future

Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Iran has geothermal energy potential. The Iranian government is considerable attention to the utilization of renewable energy, especially wind, solar and geothermal energies. Due to recent advancements in geothermal energy, many investors in the country have become interested in investing in this type of energy. Geothermal studies in Iran started in 1975 with a cooperative between the ministry of Energy of Iran and ENEL Company from Italy. Preliminary studies indicated potential for geothermal power generation in four areas in northern Iran (Khoy-Maku, Sabalan, Sahand and Damavand at Azarbaijan Gharbi, Ardebil, Azarbaijan Sharghi and Tehran provinces), respectively. Geothermal development in Iran has gained momentum in the last five years with increased exploration and industry growth in the country. Iran is developing a geothermal plant for power production. Iran government plans to build 2000 MW of renewable energy capacity over the next five years. Total projected use (geothermal capacity) has been estimated 100 MW at the end of 2010. Exploration drilling is currently in-progress for Meshkinshahr project in North-Western Iran. The Sabalan geothermal power plant is expected to produce 50 MW electric powers in 2011. The plants are planned by Iran Ministry of Energy and the Renewable Energy Organization of Iran (SUNA). This study presents a brief introduction to the resource, status and prospect of geothermal energy in Iran.     

Current status of renewable energy in Nepal: Opportunities and challenges

Energy is indispensible in modern society and is one of the most important components of socio-economic development. Nepal is one of the least developed countries with more than 80% of its population residing in rural communities. Per capita energy usage – often viewed as a key index of the development – in the country is far less than the global average per capita energy usage. The energy sector is dominated by the traditional energy sources such as fuel woods, crop residues and animal dung mainly for domestic usage contributing to about 86% of the national energy consumption. Currently 40% of the population has access to electricity, and the rural electrification accounts for only 29%. The majority of rural populations are meeting their energy needs by burning biomass in traditional stoves which has several environmental and public health issues. Nearly all fossil-derived fuels consumed in the country are imported in a refined form, and the perpetual increase in petroleum imports has adversely impacted the existing fragile economy of the country. Despite a huge potential in harnessing various renewable energy resources such as hydropower, solar power, wind energy and biofuels/bioenergy, these resources have not been sustainably captured due to geographical, technical, political and economical reasons. This paper presents a brief account of Nepal's renewable energy resources and the current status of various renewable energy technologies (RETs) such as micro-hydro, solar power, wind energy, biofuel/bioenergy, improved cook stoves, and improved water mill. It also highlights the opportunities and barriers for the development of RETs. Finally this paper presents some recommendations for the promotion, development and implementation of RETs in the country.     

An assessment of exploiting renewable energy sources with concerns of policy and technology

In recent years, the Taiwanese government has vigorously promoted the development of renewable energy to engage the challenges of gradual depletion of fossil fuels and oil, as well as the intensification of the greenhouse effect. Since the Sustainable Energy Policy Principles were announced in 2008, Taiwanese government has declared that the development of renewable energy should take into account goals that pertain to energy, the environment, and the economy (3E goals). This study aims to assess the 3E goals and renewable energy sources regulated by the Renewable Energy Development Bill that passed in 2009. The fuzzy analytic hierarchy process (FAHP) is used to resolve the multi-goal problem for achieving our research purposes. That is, this research attempts to reveal the suitable renewable energy sources for the purposes of meeting the 3E policy goals. The results first show that environmental goal is the most important to the development of various renewable energy technologies in Taiwan, followed by the economic and energy goals. Additionally, hydropower, solar energy, and wind energy would be the renewable energy sources utilized in meeting the 3E policy goals.     

Wind energy status in India: A short review

Renewable energy represents an area of tremendous opportunity for India. Energy is considered a prime agent in the generation of wealth and a significant factor in economic development. Energy is also essential for improving the quality of life. Development of conventional forms of energy for meeting the growing energy needs of society at a reasonable cost is the responsibility of the Government. Limited fossil resources and associated environmental problems have emphasized the need for new sustainable energy supply options. India depends heavily on coal and oil for meeting its energy demand which contributes to smog, acid rain and greenhouse gases’ emission. Last 25 years has been a period of intense activities related to research, development, production and distribution of energy in India.Though major energy sources for electrical power are coal and natural gas, development and promotion of non-conventional sources of energy such as solar, wind and bio-energy, are also getting sustained attention. The use of electricity has grown since it can be used in variety of applications as well as it can be easily transmitted, the uses of renewable energy like wind and solar is rising. Wind energy is a clean, eco-friendly, renewable resource and is nonpolluting. The gross wind power potential is estimated at around 48,561 MW in the country; a capacity of 14,989.89 MW up to 31st August 2011 has so far been added through wind, which places India in the fifth position globally. This paper discusses the ways in which India has already supported the growth of renewable energy technologies i.e. wind energy and its potential to expand their contribution to world growth in a way that is consistent with world's developmental and environmental goals. The paper presents current status, major achievements and future aspects of wind energy in India.     

Prioritization of potential locations for harnessing wind energy to produce hydrogen in Afghanistan

Due to the devastating ecological effects and constrained reserves of fossil fuels, renewable energies are now globally accepted as viable alternative sources of energy. Among renewable energy sources, wind energy has become globally popular, primarily because wind farms can be rapidly built and easily maintained at a relatively low cost. Wind-powered hydrogen production is an effective solution for storing the excess energy output of wind farms. The hydrogen produced in this way can be used not only in fuel cells but also in cooling, oil, gas, and petrochemical fields. As a country devastated by war and instability, Afghanistan has major energy generation challenges and a substantially large power supply deficiency. However, there are good wind energy potentials in several parts of this country. There are also several hydrogen-consuming fields in Afghanistan that can benefit from hydrogen production from wind energy. This paper endeavored to distinguish the appropriate areas in Afghanistan for harvesting wind energy for hydrogen production using multi-criteria decision-making techniques. Eleven criteria were utilized to prioritize 20 Afghan provinces with wind energy potential. The Step-wise Weight Assessment Ratio Analysis (SWARA) was utilized to weight the criteria and Evaluation based on Distance from Average Solution (EDAS) were utilized to prioritize the provinces. Then, ARAS, TOPSIS, and VIKOR methods were used to validate the resultants. For criteria weighting with SWARA, “wind speed”, “wind power density” and “area of windy regions” with weights of 0.1423, 0.1356, and 0.1221 were introduced as the most significant criteria for this ranking. In all the rankings, Herat, Farah, and Jowzjan were identified as the top three most suitable provinces for wind power generation. The power output and hydrogen output to be achieved in Herat province using a 900-kW turbine were estimated to 2558.4 MW per year and 41.4 tons per year, respectively.     

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.     

Prospects of renewable energy - a feasibility study in the Australian context

Given the recent increasing public focus on climate change issues, there is a need for robust, sustainable and climate friendly power transmission and distribution systems that are intelligent, reliable, and green. Current power systems create environmental impacts as well as contributing to global warming due to their utilization of fossil fuels, especially coal, as carbon dioxide is emitted into the atmosphere. In contrast to fossil fuels, renewable energy is starting to be used as the panacea for solving climate change or global warming problems. This paper describes a feasibility study undertaken to investigate the potentialities of renewable energy including the prospective locations in Australia for renewable energy generation, in particular solar and wind energy. Initially, a hybrid model has been developed to investigate the prospects of wind energy for typical Australian region considering production cost, cost of energy, emission production and contribution from renewable energy using the Hybrid Optimization Model for Electric Renewable (HOMER), a computer model developed by the USA’s National Renewable Energy Laboratory (NREL). This model also explores suitable places around Australia for wind energy generation using statistical analysis. Subsequently, the usefulness of solar energy in the Australian context and suitable locations for solar energy generation are also investigated using a similar hybrid model. Finally, the model has been developed to investigate the prospects of renewable energy in particular wind and solar energy including specific locations in Australia that would be suitable for both wind and solar energy generation. From simulation analysis it is clearly observed that Australia has enormous potentialities for substantially increased use of renewable energy; a large penetration of renewable energy sources into the national power system would reduce CO₂ emissions significantly, contributing to the reduction of global warming.     

The achievement,significance and future prospect of China's renewable energy initiative

China's high-speed economic growth and ambitious urbanization depend heavily on the massive consumption of fossil fuel. However, the over-dependence on the depleting fossil fuels causes severe environmental problems, making China the largest energy consumer and the biggest CO₂ emitter in the world. Faced with significant challenges in terms of managing its environment and moving forward with the concept of sustainable economic development, the Chinese government plans to move away from fossil fuels and rely on renewables such as hydropower, wind power, solar power, biomass power and nuclear power. In this paper, the current status of China's renewable energy deployment and the ongoing development projects are summarized and discussed. Most recent developments of major renewable energy sources are clearly reviewed. Additionally, the renewable energy development policies including laws and regulations, economic encouragement, technical research and development are also summarized. This study showcases China's achievements in exploiting its abundant domestic renewable energy sources to meet the future energy demand and reducing carbon emissions. To move toward a low carbon society, technological progress and policy improvements are needed for improving grid access (wind), securing nuclear fuel supplies and managing safety protocols (nuclear), integrating supply chains to achieve indigenous manufacture of technologies across supply chains (solar). Beyond that, a preliminary prediction of the development of China's future renewable energy developments, and proposes targeted countermeasures and suggestions are proposed. The proposal involves developing smart-grid system, investing on renewable energy research, improving the feed-in tariff system and clarifying the subsidy system.     

Current status of research on optimum sizing of stand-alone hybrid solar–wind power generation systems

Solar and wind energy systems are omnipresent, freely available, environmental friendly, and they are considered as promising power generating sources due to their availability and topological advantages for local power generations. Hybrid solar–wind energy systems, uses two renewable energy sources, allow improving the system efficiency and power reliability and reduce the energy storage requirements for stand-alone applications. The hybrid solar–wind systems are becoming popular in remote area power generation applications due to advancements in renewable energy technologies and substantial rise in prices of petroleum products. This paper is to review the current state of the simulation, optimization and control technologies for the stand-alone hybrid solar–wind energy systems with battery storage. It is found that continued research and development effort in this area is still needed for improving the systems’ performance, establishing techniques for accurately predicting their output and reliably integrating them with other renewable or conventional power generation sources.     

Growth and future trends of wind energy in India

In India, the wind power generation has gained a high level of attention and acceptability compared to other renewable energy technologies. New technological developments in wind power design have contributed for the significant advances in wind energy penetration and to get optimum power from available wind. The yearly percentage increase in wind energy installation is highest for India and now ranks fourth in the world with an installed capacity of 6018 MW. This paper reviews the development of wind energy in India and five potential Indian states. The future growth pattern and time period to achieve the technical wind potential are predicted and analysed.     

Renewable electricity in Sweden: an analysis of policy and regulations

This study aims to analyse the developments in renewable energy policy making in Sweden. It assesses the energy policy context, changes in the choice of policy instruments, and provides explanations behind policy successes and failures. Swedish renewable energy policy has been developing in a context of uncertainty around nuclear issues. While there has been made a political decision to replace nuclear power with renewables, there is a lack of consensus about the pace of phasing out nuclear power due to perceived negative impacts on industrial competitiveness. Such uncertainty had an effect in the formulation of renewable energy policy. Biomass and wind power are the main options for renewable electricity production. Throughout 1990s, the combined effect of different policy instruments has stimulated the growth of these two renewable sources. Yet, both biomass and wind power are still a minor contributor in the total electricity generation. Lack of strong government commitment due to uncertainty around nuclear issues is a crucial factor. Short-term subsidies have been preferred rather than open-ended subsidy mechanisms, causing intervals without subsidies and interruption to development. Other factors are such as lack of incentives from the major electricity companies and administrative obstacles. The taxation system has been successful in fostering an expansion of biomass for heating but hindered a similar development in the electricity sector. The quota system adopted in 2003 is expected to create high demand on biomass but does not favour wind power. The renewable energy aims are unlikely to be changed. Yet, the future development of renewable energy policies especially for high-cost technologies will again depend strongly on nuclear policies, which are still unstable and might affect the pace of renewable energy development.     

How to achieve a 100% RES electricity supply for Portugal?

Portugal is a country with an energy system highly dependent on oil and gas imports. Imports of oil and gas accounted for 85% of the country’s requirements in 2005 and 86% in 2006. Meanwhile, the share of renewable energy sources (RES) in the total primary energy consumption was only 14% in 2006. When focusing only on electricity production, the situation is somewhat better. The share of RES in gross electricity production varies between 20% and 35% and is dependent on the hydropower production in wet and dry years. This paper presents, on a national scale, Portugal’s energy system planning and technical solutions for achieving 100% RES electricity production. Planning was based on hourly energy balance and use of H₂RES software. The H₂RES model provides the ability to integrate various types of storages into energy systems in order to increase penetration of the intermittent renewable energy sources or to achieve a 100% renewable island, region or country. The paper also represents a stepping-stone for studies offering wider possibilities in matching and satisfying electricity supply in Portugal with potential renewable energy sources. Special attention has been given to intermittent sources such as wind, solar and ocean waves that can be coupled to appropriate energy storage systems charged with surplus amounts of produced electricity. The storage systems also decrease installed power requirements for generating units. Consequently, these storages will assist in avoiding unnecessary rejection of renewable potential and reaching a sufficient security of energy supply.     

我国可再生能源发展对策

可再生能源的开发利用是应对气候变化和满足能源需求持续增长的最现实的举措。2009年我国风电和太阳能光伏发电保持了快速发展势头,其中风电装机容量估计达到约2200×104kW,但非化石能源消费量在能源消费总量中所占的比重仍然很低。2009年,我国能源消费总量约为31×108t标煤,其中水电、核电、风电等商品化非化石能源消费量约为2.3×108t标煤,约占能源消费总量的7.4%。要完成到2020年我国非化石能源在能源消费总量中所占比例达到15%的目标,任务非常艰巨。加快开发利用可再生能源是能源发展的重要任务之一,到2020年,可再生能源开发利用总量将在2008年的基础上增加2倍以上。我国目前和今后10多年时间内,可再生能源发展的重点是水电、风电、太阳能和生物质能。加快发展我国可再生能源的举措有:①继续做好水电建设工作,促进水电持续健康发展;②有序推进风电的规模化发展,显著提高风电在电力结构中的比重;③加快推广太阳能利用技术,扩大太阳能开发利用规模;④因地制宜开发利用生物质能,提高生物质能利用的现代技术水平。