Hydrogen production from idle generation capacity of wind turbines

This paper is concerned with the hydrogen production from wind energy. It is motivated by the new regulations for wind farms that compel them to operate normally with idle generation capacity. The idea is to use the excess wind power to produce hydrogen. The operation of a proposed system configuration, which essentially consists in incorporating an electrolyzer between the electronic converters of a conventional wind turbine, is analyzed. In particular, the control requirements to simultaneously achieve the grid and electrolyzer specifications are investigated. In this context, a control strategy for the different operating modes of the system is developed.     

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.     

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.     

Decision-making between a grid extension and a rural renewable off-grid system with hydrogen generation

Most populations in rural Africa have no access to electricity, in this study, a comparative analysis between grid extension and the implementation of renewable off-grid hybrid power system is carried out. The objective of the study is to determine the best feasible option. Napier, a farming village in the Western Cape province of South Africa was selected as the site for the comparative analysis and HOMER PRO software was used to develop an optimal system using the wind and solar resources of the selected site. The load profile considered in the analysis includes lighting, cooking and hot water demands. The best feasible option is determined based on the Net Present Cost of each feasible scenario. Sensitivity analysis on the current cost and the projected cost of hydrogen storage w conducted to observe the impact of the cost of hydrogen storage on the renewable off-grid system cost of energy.     

Network benefits of embedded solar systems: A case study from western Sydney

This paper presents a simulation study based on actual load, sunshine and wind data. A distribution feeder simulation model was constructed using this data to determine what potential benefit embedded wind, solar and storage elements could give to the distribution network. The results were compared to earlier studies. It was discovered that over the past 5–10 years, the hot weather peak load has extended from 3 pm to 6 pm and that a more northwesterly orientation of solar panels is of assistance. It was also found that wind is of little assistance in hot weather peaks, in contrast to data for the NSW central tablelands region; however solar contributes at least 50% of its nominal peak capacity. As hot weather peaks are now extending into the early evening, it was found that storage would be of great benefit and would enhance the use of renewable energy sources. As part of the feeder model, the optimal method of Var control from the embedded sources was also studied.     

Educational electrolyzer prototype: Improving engineering students' knowledge in renewable energies

This article aims to demonstrate the process of building a low-cost water electrolyzer using common materials and to analyze the influence of practical experiments on students' knowledge. Practical classroom experiments are of great importance to students' learning and problems such as bureaucracy in the teaching department, high cost of equipment and lack of teacher time are some of the factors responsible for the delay in performing them in the classroom. Applying the Advanced Product Quality Planning methodology, Active Learning, thermodynamic and electrochemical modeling, it was possible to build an electrolyzer with about 150 US$. In the electrolyzer, the electrolytic solutions with 1 M concentration of NaOH and KOH were used, i.e., 39 g L^?1 and 64 g L^?1, respectively, to produce the gases hydrogen and oxygen. The flow of hydrogen and oxygen for the KOH electrolytic solution was 1.22 L min^?1 and for the NaOH solution, 1.07 L min^?1 was found using a 9–12 V and 8–15 A adjustable transformer. Among the undergraduate students who were interviewed, 54% did not know electrolysis and 46% knew just the basic concepts. After the practical experiment, it was observed that 94% of the students understood the concepts of the electrochemical reaction. Based on the averages of the two tests applied to students, before and after the practical experiment, an increase of 58% in the correctness of the questions was found for students who had not heard of electrolysis before and a 13% increase was observed for those who already knew the basic concepts. With this experiment, it was possible to observe how much practical activities in the classroom can positively influence the understanding of electrolysis and make students aware of this renewable energy production process.     

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.     

Renewable energy in India: Historical developments and prospects

Promoting renewable energy in India has assumed great importance in recent years in view of high growth rate of energy consumption, high share of coal in domestic energy demand, heavy dependence on imports for meeting demands for petroleum fuels and volatility of world oil market. A number of renewable energy technologies (RETs) are now well established in the country. The technology that has achieved the most dramatic growth rate and success is wind energy; India ranks fourth in the world in terms of total installed capacity. India hosts the world's largest small gasifier programme and second largest biogas programme. After many years of slow growth, demand for solar water heaters appears to be gaining momentum. Small hydro has been growing in India at a slow but steady pace. Installation of some of the technologies appears to have slowed down in recent years; these include improved cooking stoves (ICSs) and solar photovoltaic (PV) systems. In spite of many successes, the overall growth of renewable energy in India has remained rather slow. A number of factors are likely to boost the future prospects of renewable energy in the country; these include global pressure and voluntary targets for greenhouse gas emission reduction, a possible future oil crisis, intensification of rural electrification program, and import of hydropower from neighbouring countries.     

Optimizing transmission from distant wind farms

We explore the optimal size of the transmission line from distant wind farms, modeling the tradeoff between transmission cost and benefit from delivered wind power. We also examine the benefit of connecting a second wind farm, requiring additional transmission, in order to increase output smoothness. Since a wind farm has a low capacity factor, the transmission line would not be heavily loaded, on average; depending on the time profile of generation, for wind farms with capacity factor of 29–34%, profit is maximized for a line that is about 3/4 of the nameplate capacity of the wind farm. Although wind generation is inexpensive at a good site, transmitting wind power over 1600 km (about the distance from Wyoming to Los Angeles) doubles the delivered cost of power. As the price for power rises, the optimal capacity of transmission increases. Connecting wind farms lowers delivered cost when the wind farms are close, despite the high correlation of output over time. Imposing a penalty for failing to deliver minimum contracted supply leads to connecting more distant wind farms.     

Education and training in renewable energy sources in Serbia and Montenegro

This paper reports the status of Education and Training in Renewable Energy Sources (RES) in Serbia and Montenegro (SAM) at the end of May 2003. It was found that universities in SAM do not give diplomas in RES. RES subjects primarily solar and wind energy are taught at graduate levels. RES units are taught as a part of some classical engineering disciplines at undergraduate level especially in solar and biomass energy. Teaching is mainly at encyclopedic level and staff is mainly trained in general fields. This education may be regarded as unsatisfactory and should be expanded and intensified in future.     

Island wind-hydrogen energy: A significant potential US resource

Islands offer the advantages of notional deep ocean wind stations without the problems of mounting wind turbines in a hostile marine environment. In principle, island wind-power stations could take advantage of rich (up to Class 7) wind resources. Because connection to an electricity grid will be difficult for most island-based systems, electrical energy could be converted into hydrogen (by electrolyzing seawater) and stored for use on the island or shipped to the mainland. To attain the benefits of high-speed wind-turbine systems, several technical and policy issues, dealing with wind resources, specialized wind-turbine equipment, and the political and economic potential of island wind stations, need to be addressed. Until such multifaceted research can be completed, the technical potential for island-based wind turbines will remain just that—potential.