Alternatives to grid extension for rural electrification: Decentralized renewable energy technologies in Vietnam

This paper examines the economic viability of stand-alone, household-sized renewable energy technologies, namely wind generator and solar PV for application in remote and rural areas of Vietnam. Three reference technologies are chosen. These are two solar PV systems of 130 and 100 Wp for solar conditions in the North and the South, respectively, and one 150 W wind turbine. It is found for all regions that levelized costs of PV energy are lower than the cost of energy from gasoline gen-set, and are cost-competitive with grid extension, especially for areas with low load density and low number of households to be electrified. Regarding wind energy, the viability is dependent on the location due to the wide variation of wind resource to topography. However, in locations with proper resources, wind energy is even more cost-competitive than solar PV. Thus, the use of either wind generator or solar PV is economically feasible in rural villages and remote areas of Vietnam. Policy recommendations for promoting the market development of renewable energy technologies are discussed in the final section of the paper.     

Estimating global hydrogen production from wind

It is likely that intermittent renewable sources such as wind and solar will provide the greatest opportunity for future large-scale hydrogen production. Here, on-shore wind is examined. Global wind energy is estimated by placing one 2 MW turbine/km² over the surface of the earth. Wind energy production is based on monthly mean wind speed data. Wind turbines are grouped to form arrays that are linked to local hydrogen generation and transmission networks. Hydrogen generation is done via low-pressure electrolysis and transmission via high-pressure gas pipelines. The wind/hydrogen system is considered within a global energy system that must not only provide hydrogen, but also energy for electricity consumption at the local generation site. The technical potential of the hydrogen produced is estimated to be 116 EJ. Uneven distribution of the hydrogen-rich sites results in the need to export much of the hydrogen produced to energy-poor regions. To overcome system losses, a combined wind/HVDC/hydrogen system is considered.     

Wind energy potential of the region of Trás-os-Montes and Alto Douro, Portugal

The main objective of this paper is to present a study on the wind energy potential that is being developed in the Region of Trás-os-Montes and Alto Douro. This study started in July 1996 and will continue until the end of 1998.In order to have an adequate characterisation of the wind energy potential in this region it is necessary to measure the wind speed and direction in several places. At this moment the data are being collected at nine places. Due to lack of space, only four places will be addressed in this article.The Region of Douro and Alto Trás-os-Montes has an area of 12,235 km². It is located in the Northeast part of Portugal and represents 57.7% of the North Region.Other projects refer to this region as having great potential in the field of renewable energies. From the analysis of the collected data, it seems that wind energy in Marão and Alvão mountains is one of the most interesting renewable energies.     

Germany’s wind energy: The potential for fossil capacity replacement and cost saving

Wind energy has become the major renewable energy source in Germany with an installed capacity of more than 20 GW and an annual output of about 40 TW h in 2007. In this paper we analyze the extent to which wind energy can replace fossil capacities based on wind injection and demand data for 2006 through June 2008. The results indicate that the wind potential in Germany will not allow a significant reduction of fossil capacities. We also assess the potential savings due to wind energy. The German market is modeled with and without wind input to estimate the net savings of fossil fuels in the observation period. We find that the cost-saving potential for electricity production is quite significant and exceeds the subsidies.     

Offshore wind development in China and its future with the existing renewable policy

Based on independent studies, this paper focuses on the significant discrepancy of 15 GW between the installed onshore wind generation capacity and what has been actually connected to the power network to reveal the challenges in meeting the Chinese renewable energy target. The recent accidents in Chinese North-Western transmission network (in February–April, 2011) demonstrated the urgent need for a fundamental review of the Chinese renewable energy policy. Offshore wind has been identified as the most feasible alternative to onshore wind to help deliver electricity to Eastern China during the summer peak time. By investigating and summarizing first hand experiences of participation in the Chinese renewable market, the authors provide the economic figures of the first cohort of Chinese offshore wind schemes. Large state owned enterprises (SOE) are dominating the offshore wind development, repeating their previous practices on the land. While this paper acknowledges the critical role of offshore wind generation in meeting Chinese renewable energy targets, it envisages an installed offshore capacity of approximately 2000 MW by 2015, much less than the 10000 MW governmental estimation, which can be attributed to the lack of detailed energy policy, network constraints, offshore wind installation difficulties and quality issues in the manufacture of turbines.     

A framework for reviewing the trade-offs between, renewable energy, food, feed and wood production at a local level

High fuel prices and concerns about energy security and anthropogenic climate change are encouraging a transition towards a low carbon economy. Although energy policy is typically set at a national level, tools are needed for people to engage with energy policy at regional and local levels, and to guide decisions regarding land use, distributed generation and energy supply and demand. The aim of this paper is to develop a per-capita approach to renewable energy demand and supply within a landscape and to illustrate the key trade-offs between renewable energy, food, (animal) feed and wood production. The chosen case study area (16,000 ha) of Marston Vale, England is anticipated to have a population density midway between that for England and the UK. The daily per capita demand for energy for heat (31 kWh), transport (34 kWh) and electricity (15 kWh) when combined (80 kWh) was seven-fold higher than the combined demand for food (2 kWh), animal feed (6 kWh), and wood (4 kWh). Using described algorithms, the combined potential energy supply from domestic wind and photovoltaic panels, solar heating, ground-source heat, and municipal waste was limited (<10 kWh p⁻¹ d⁻¹). Additional electricity could be generated from landfill gas and commercial wind turbines, but these have temporal implications. Using a geographical information system and the Yield-SAFE tree and crop yield model, the capacity to supply bioethanol, biodiesel, and biomass, food, feed and wood was calculated and illustrated for three land-use scenarios. These scenarios highlight the limits on meeting energy demands for transport (33%) and heat (53%), even if all of the arable and grassland area was planted to a high yielding crop like wheat. The described framework therefore highlights the major constraints faced in meeting current UK energy demands from land-based renewable energy and the stark choices faced by decision makers.     

Wind energy and assessment of wind energy potential in Turkey

In this study, the potential of wind energy and assessment of wind energy systems in Turkey were studied. The main purpose of this study is to investigate the wind energy potential and future wind conversion systems project in Turkey. The wind energy potential of various regions was investigated; and the exploitation of the wind energy in Turkey was discussed. Various regions were analyzed taking into account the wind data measured as hourly time series in the windy locations. The wind data used in this study were taken from Electrical Power Resources Survey and Development Administration (EIEI) for the year 2010. This paper reviews the assessment of wind energy in Turkey as of the end of May 2010 including wind energy applications. Turkey's total theoretically available potential for wind power is around 131,756.40 MW and sea wind power 17,393.20 MW annually, according to TUREB (TWEA). When Turkey has 1.5 MW nominal installed wind energy capacity in 1998, then this capacity has increased to 1522.20 MW in 2010. Wind power plant with a total capacity of 1522.20 MW will be commissioned 2166.65 MW in December 2011.     

Wind energy,electricity, and hydrogen in the Netherlands

The curbing of greenhouse gases (GHG) is an important issue on the international political agenda. The substitution of fossil fuels by renewable energy sources is an often-advocated mitigation strategy. Wind energy is a potential renewable energy source. However, wind energy is not reliable since its electricity production depends on variable weather conditions. High wind energy penetration rates lead to losses due to power plant operation adjustments to wind energy. This research identifies the potential energetic benefits of integrated hydrogen production in electricity systems with high wind energy penetration. This research concludes that the use of system losses for hydrogen production via electrolysis is beneficial in situations with ca. 8 GW or more wind energy capacity in the Netherlands. The 2020 Dutch policy goal of 6 GW will not benefit from hydrogen production in terms of systems efficiency. An ancillary beneficial effect of coupling hydrogen production with wind energy is to relieve the high-voltage grid.     

Impacts of wind power generation and CO2 emission constraints on the future choice of fuels and technologies in the power sector of Vietnam

This paper examines the impacts of wind power generation on the future choice of fuels and technologies in the power sector of Vietnam. The study covers a time frame of 20 yr from 2005 to 2025 and the MARKAL model has been chosen to be adaptable to this specific task. The results of the study show that on a simple cost base, power generated from wind is not yet competitive with that of fossil fuel-based power plants. In order to make wind energy competitive, either carbon tax or an emission reduction target on the system must be imposed. The presence of wind power would affect not only the change in generation mix from coal-based power plants to wind turbines but also an increase in the capacity of other technologies which emit less carbon dioxide. It thus helps reduce fossil fuel requirement and consequently enhances energy security for the country. The study also shows that wind turbine in Vietnam could be a potential CDM project for annex I party countries.     

A review on energy scenario and sustainable energy in Indonesia

The global energy consumption is likely to grow faster than the population growth. The fuel consumption was growing from 6630 million tons of oil equivalents (Mtoe) in 1980 to 11,163 Mtoe in 2009. This projected consumption will increase 1.5% per year until 2030 and reach 16,900 Mtoe and the main drivers of this growth are mostly developing countries in Asia. Indonesia is one of the developing countries and energy supply is an important factor for all-around development. The country's energy consumption still depends on non-renewable energy such as crude oil, coal and natural gas as sources of energy. Utilization of fossil fuel continuously contributes to huge amount of greenhouse gases emission that leads to climate change. Facing such an unfavorable situation, the government of Indonesia prioritizes on energy supply securities by diversification of energy resources. The energy mixes in Indonesia based on five main resources; these are crude oil, natural gas, coal, hydropower, and renewable energy. Although the country encourages utilizing renewable energy, the contribution is only around 3%. Considering natural condition and geography, this country is blessed with great potential of renewable energy such as solar energy, wind energy, micro hydro and biomass energy. Noting the potential of renewable and sustainable energy resources in the country, the government must pay more attention on how to utilize it. Many efforts have been done to promote renewable energy such as to create energy policy and regulations, yet it still did not give any satisfactory result. Government, non-government agencies and the public should take a more proactive step to promote and use renewable energy in order to achieve the secure and environmentally sustainable energy resources.     

Renewable energy sources in the Egyptian electricity market: A review

This review paper presents an appraisal of renewable energy RE options in Egypt. An appraisal review of different REs is presented. The study shows that electric energy produced from REs in Egypt are very poor compared with other energy sources. The utilization of the renewable energies can also be a good opportunity to fight the desertification and dryness in Egypt which is about 60% of Egypt territory. The rapid growth of energy production and consumption is strongly affecting and being affected by the Egyptian economy in many aspects. It is evident that energy will continue to play an important role in the development of Egypt's economy in coming years. The total installed electricity generating capacity had reached around 22025 MW with a generating capacity reached 22605 MW at the end of 2007. Hydropower and coal has no significant potential increase. During the period 1981/82-2004/05 electricity generation has increased by 500% from nearly 22 TWh for the year 1981/1982 to 108.4 TWh in the year 2004/2005 at an average annual growth rate of 6.9%. Consequently, oil and gas consumed by the electricity sector has jumped during the same period from around 3.7 MTOE to nearly 21 MTOE. The planned installed capacity for the year 2011/2012 is 28813 MW and the required fuel (oil and gas) for the electricity sector is estimated to reach about 29 MTOE by the same year. The renewable energy strategy targets to supply 3% of the electricity production from renewable resources by the year 2010. Electrical Coverage Electrical energy has been provided for around 99.3% of Egypt's population, representing a positive sign for the welfare of the Egyptian citizen due to electricity relation to all development components in all walks of life. The article discusses perspectives of wind energy in Egypt with projections to generate ∼ 3.5 GWe by 2022, representing ∼9% of the total installed power at that time (40.2 GW). Total renewables (hydro + wind + solar) are expected to provide ∼7.4 GWe by 2022 representing ∼ 19% of the total installed power. Such a share would reduce dependence on depleting oil and gas resources, and hence improve country's sustainable development.     

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.     

An optimization model for a mechanical vapor compression desalination plant driven by a wind/PV hybrid system

A renewable hybrid system to produce domestic water is presented. It consists of a photovoltaic module, a wind turbine, a mechanical vapor compression desalination plant and a storage unit. An optimization model based on a mathematical programming is developed to control the energy flows exchanged among the system components in order to satisfy the domestic water demand. The model has been solved for three specific case studies in Morocco, where two of them are located in Rabat which aim to satisfy the hourly and monthly water demand of 20 households, whereas, the last one is in Essaouira, which aims to ensure the monthly water demand of 40 households. The main motivations behind selecting these specific case studies are the evaluation of the efficiency and feasibility of such system in two coastal sites having different characteristics of renewable energy sources. The obtained results show that the domestic water demands are satisfied in each time interval at a reasonable economic cost comparable to the current average cost of water in Morocco which is about 0.7 € m⁻³.     

Stand-alone PEM water electrolysis system for fail safe operation with a renewable energy source

A complete stand-alone electrolyser system has been constructed as a transportable unit for demonstration of a sustainable energy facility based on hydrogen and a renewable energy source. The stand-alone unit is designed to support a polymer electrolyte membrane (PEM) stack operating at up to ∼4 kW input power with a stack efficiency of about 80% based on HHV of hydrogen. It is self-pressurizing and intended for operation initially at a differential pressure of less than 6 bar across the membrane electrode assembly with the hydrogen generation side being at a higher pressure. With a slightly smaller stack, the system has been operated at an off-site facility where it was directly coupled to a 2.4 kW photovoltaic (PV) solar array. Because of its potential use in remote areas, the balance-of-plant operates entirely on 12 V DC power for all monitoring, control and safety requirements. It utilises a separate high-current supply as the main electrolyser input, typically 30–40 V at 100 A from a renewable source such as solar PV or wind. The system has multiple levels of built-in operator and stack safety redundancy. Control and safety systems monitor all flows, levels and temperatures of significance. All fault conditions are failsafe and are duplicated, triggering latching relays which shut the system down. Process indicators monitor several key variables and allow operating limits to be easily adjusted in response to experience of system performance gained in the field.     

Techno-economical study of hybrid power system for a remote village in Algeria

The share of renewable energy sources in Algeria primary energy supply is relatively low compared with European countries, though the trend of development is positive. One of the main strategic priorities of NEAL (New Energy Algeria), which is Algeria's renewable energy agency (government, Sonelgaz and Sonatrach), is striving to achieve a share of 10–12% renewable energy sources in primary energy supply by 2010.This article presents techno-economic assessment for off-grid hybrid generation systems of a site in south western Algeria. The HOMER model is used to evaluate the energy production, life-cycle costs and greenhouse gas emissions reduction for this study. In the present scenario, for wind speed less than 5.0 m/s the existing diesel power plant is the only feasible solution over the range of fuel prices used in the simulation. The wind diesel hybrid system becomes feasible at a wind speed of 5.48 m/s or more and a fuel price of 0.162$/L or more. If the carbon tax is taken into consideration and subsidy is abolished, then it is expected that the hybrid system will become feasible. The maximum annual capacity shortage did not have any effect on the cost of energy, which may be accounted for by larger sizes of wind machines and diesel generators.     

Performance investigation of hydrogen production from a hybrid wind-PV system

In this study, a hybrid system consisted of 10 kW wind and 1 kWp PV array is built to meet the load demand of a raise chucker partridge raising facility by renewable energy sources. The facility has an average energy consumption of about 20.33 kWh/day, with a peak demand of 2.4 kW. The solar radiation data and wind data of the region are analyzed for sizing of the renewable energy system. The performance of each alternative system is examined in terms of energy efficiency, and H₂ production capacity of the hybrid system from due to excessive electrical energy is studied. A Matlab-Simulink Software is used for analyzing the system performance. The average range of state of charge varies between 56.6% and 88.3% monthly from April to July. The amount of hydrogen production by excess electricity is 14.4 kg in the month of July, due to the high wind speed and solar radiation. Energy efficiency of the electrolyser is found to be varying between 64% and 70% percent. Energy efficiency of each hybrid system is calculated. The overall energy efficiency of wind-electrolyser system varies between 5% and 14% while the energy efficiency of PV-electrolyser system changes within a narrower range, as between 7.9% to and 8.5%, respectively.     

Review on wind power development and relevant policies in China during the 11th Five-Year-Plan period

Since 2005, there has been dramatic progress in China's wind power industry. The annual growth rate of newly constructed capacity reached a miracle of 105% and the total installed capacity has increased from 1.27 GW in 2005 to 44.73 GW in 2010, which has exceeded the target of China's energy long-term planning for 2020. During the 11th Five-Year-Plan (FYP), the Chinese government has issued a series of polices to promote and regulate the development of wind power industry, which is the underlying force driving its rapid development. This paper is a systematical review on the current status and policies of wind power industry in China. Firstly the current status including achievements and shortcomings is presented, and then the relevant polices and regulations released during the period of 11th FYP are reviewed. Meanwhile, the main approaches of the policies and regulations in promoting the development of wind power industry are discussed and the issues of the current policies are analyzed. Finally, the paper concludes on the perspectives of wind power policies in China.     

The wind/hydrogen demonstration system at Utsira in Norway: Evaluation of system performance using operational data and updated hydrogen energy system modeling tools

An autonomous wind/hydrogen energy demonstration system located at the island of Utsira in Norway was officially launched by Norsk Hydro (now StatoilHydro) and Enercon in July 2004. The main components in the system installed are a wind turbine (600 kW), water electrolyzer (10 Nm³/h), hydrogen gas storage (2400 Nm³, 200 bar), hydrogen engine (55 kW), and a PEM fuel cell (10 kW). The system gives 2–3 days of full energy autonomy for 10 households on the island, and is the first of its kind in the world. A significant amount of operational experience and data has been collected over the past 4 years. The main objective with this study was to evaluate the operation of the Utsira plant using a set of updated hydrogen energy system modeling tools (HYDROGEMS). Operational data (10-min data) was used to calibrate the model parameters and fine-tune the set-up of a system simulation. The hourly operation of the plant was simulated for a representative month (March 2007), using only measured wind speed (m/s) and average power demand (kW) as the input variables, and the results compared well to measured data. The operation for a specific year (2005) was also simulated, and the performance of several alternative system designs was evaluated. A thorough discussion on issues related to the design and operation of wind/hydrogen energy systems is also provided, including specific recommendations for improvements to the Utsira plant. This paper shows how important it is to improve the hydrogen system efficiency in order to achieve a fully (100%) autonomous wind/hydrogen power system.     

Techno-economic analysis of a wind–solar hybrid renewable energy system with rainwater collection feature for urban high-rise application

The technical and economic feasibility study of an innovative wind–solar hybrid renewable energy generation system with rainwater collection feature for electrical energy generation is presented in this paper. The power generated would supply part of the energy requirements of the high-rise building where the system is installed. The system integrates and optimizes several green technologies; including urban wind turbine, solar cell module and rain water collector. The design was conceptualized based on the experiences acquired during the development and testing of a suitable wind turbine for Malaysian applications. It is compact and can be built on top of high-rise buildings in order to provide on-site renewable power to the building. It overcomes the inferior aspect on the low wind speed by channeling and increasing the speed of the high altitude free-stream wind through the power-augmentation-guide-vane (PAGV) before it enters the wind turbine at the center portion. The shape or appearance of the PAGV that surrounds the wind turbine can be blended into the building architecture without negative visual impact (becomes part of the building). The design improves the starting behavior of wind turbines. It is also safer to people around and reduces noise pollution. The techno-economic analysis is carried out by applying the life cycle cost (LCC) method. The LCC method takes into consideration the complete range of costs and makes cash flows time-equivalent. The evaluations show that for a system with the PAGV (30 m diameter and 14 m high) and an H-rotor vertical axis wind turbine (17 m diameter and 9 m high) mounted on the top of a 220 m high building, the estimated annual energy savings is 195.2 MW h/year.     

The 2 °C scenario—A sustainable world energy perspective

A target-oriented scenario of future energy demand and supply is developed in a backcasting process. The main target is to reduce global CO₂ emissions to around 10 Gt/a in 2050, thus limiting global average temperature increase to 2 °C and preventing dangerous anthropogenic interference with the climate system. A 10-region energy system model is used for simulating global energy supply strategies. A review of sector and region-specific energy efficiency measures resulted in the specification of a global energy demand scenario incorporating strong energy efficiency measures. The corresponding supply scenario has been developed in an iterative process in close cooperation with stakeholders and regional counterparts from academia, NGOs and the renewable energy industry. The 2 °C scenario shows that renewable energy could provide as much as half of the world's energy needs by 2050. Developing countries can virtually stabilise their CO₂ emissions, while at the same time increasing energy consumption through economic growth. OECD countries will be able to reduce their emissions by up to 80%.