Wind energy and the hydrogen economy—review of the technology

The hydrogen economy is an inevitable energy system of the future where the available energy sources (preferably the renewable ones) will be used to generate hydrogen and electricity as energy carriers, which are capable of satisfying all the energy needs of human civilization. The transition to a hydrogen economy may have already begun. This paper presents a review of hydrogen energy technologies, namely technologies for hydrogen production, storage, distribution, and utilization. Possibilities for utilization of wind energy to generate hydrogen are discussed in parallel with possibilities to use hydrogen to enhance wind power competitiveness.     

Moving towards municipal energy planning — The case of Palermo: The importance of non-technical issues

Since the end of 1993, when a new administration took the lead of the city of Palermo, the energy and environmental issues started to rank quite high in the priority list.Several initiatives are being implemented, such as the municipal energy plan, the development of energy conscious building regulations, the diffusion campaign for solar water heaters, the introduction of (indirectly) solar powered electric cars, the strong push in the participation to E.U. programs dealing with energy and the creation of a development agency for renewable energy and ecologically viable water use. These and other successful initiatives are described, as well as the ones that failed and the reasons for successes and failures are discussed.     

Feasibility study for the installation of HVAC for a spa by means of energy recovery from thermal water—Part I: Analysis of conditions

The use of a low temperature geothermal spring together with the heat energy still contained in waste water from the different therapy systems installed in a spa (shower, jets, bathrooms, Jacuzzis, pools, ventilation processes) can significantly reduce the operating and maintenance costs of the installation, covering part of the air conditioning needs of the building and the heating of thermal water to the appropriate temperature for therapeutic use. The object of the present work is to study the possible energy use of two sources of thermal hot water (spring and waste water) by restructuring of the existing spa so that it is more efficient from both a technical and economic point of view. In this first part, hot water needs are calculated and consumption presented according to the operation schedule on different types of day. Comparison is then made with the contribution that the spring is capable of making and the evolution of the thermal water in the tanks is studied. In a second work, energy and economic analyses will be presented.     

Energy use in the rural areas of India: setting up a rural energy data base

Aggregating and forecasting demand are crucial parts of energy planning. While a large number of energy consumption surveys have been conducted in the past in the rural energy sector of India, the lack of sufficient data and its compilation, coupled with doubt about the quality of data, has made the task extremely difficult. This paper summarizes our recent effort to compile, computerize and analyze data from 638 village energy consumption surveys covering over 39,000 households, carried out by different organisations between 1985 and 1989. The details of the level of information provided in the survey reports, area of survey, land use pattern, asset ownership, etc., of the collated studies are presented. Results based on the analysis of the energy consumption data compiled are then discussed. The national average for rural domestic thermal energy consumption (excluding water and space heating) estimated through this work (629 kcal or 2.63 MJ per capita daily) is much similar to the rural domestic thermal energy requirement assumed in most energy planning exercises in India in the past. The useful thermal energy consumption varies from 325 to 1065 kcal/cap/d (1.36-4.46 MJ/cap/d) in the East Coast Plain and Hills and the Eastern Himalayan Regions, respectively. Reconfirming the predominance of firewood, the data reveals that the contribution of firewood to the domestic thermal energy consumption has remained at about 58% over the last three decades; dungcake and agricultural residues contribute almost equally in the remaining share. At the national level, our estimates indicate that at least 180 million tonnes of firewood, 40 million tonnes of dungcakes and 30 million tonnes of agricultural residues were consumed in the rural sector for meeting the domestic thermal energy requirement in 1991. The paper also compares the estimates with those based on other surveys in India.     

State of the art on high-temperature thermal energy storage for power generation. Part 2—Case studies

Power generation systems are attracting a lot of interest from researchers and companies. Storage is becoming a component with high importance to ensure system reliability and economic profitability. A few experiences of storage components have taken place until the moment in solar power plants, most of them as research initiatives. In this paper, real experiences with active storage systems and passive storage systems are compiled, giving detailed information of advantages and disadvantages of each one. Also, a summary of different technologies and materials used in solar power plants with thermal storage systems existing in the world is presented.     

State of the art on high temperature thermal energy storage for power generation. Part 1—Concepts, materials and modellization

Concentrated solar thermal power generation is becoming a very attractive renewable energy production system among all the different renewable options, as it has have a better potential for dispatchability. This dispatchability is inevitably linked with an efficient and cost-effective thermal storage system. Thus, of all components, thermal storage is a key one. However, it is also one of the less developed. Only a few plants in the world have tested high temperature thermal energy storage systems. In this paper, the different storage concepts are reviewed and classified. All materials considered in literature or plants are listed. And finally, modellization of such systems is reviewed.