Showing papers on "Renewable energy published in 1994"
TL;DR: In this article, the authors proposed to use the simultaneous saccharification and fermentation (SSF) process for producing ethanol from the major fraction of lignocellulosic biomass, cellulose, because of its low cost potential.
502 citations
TL;DR: In this article, the authors proposed a thermal energy storage method for renewable energy source utilization, as in solar photothermal systems, which is one of the most favorable kinds of thermal storage methods.
Abstract: Latent thermal energy storage is one of the favorable kinds of thermal energy storage methods considered for renewable energy source utilization, as in solar photothermal systems. Heat is ...
362 citations
TL;DR: In this article, the authors investigated the amount of energy required to construct buildings and the resulting carbon dioxide emissions to the atmosphere from the fossil fuel components of that energy and compared them with typical commercial, industrial and residential buildings, using New Zealand as an example.
311 citations
163 citations
TL;DR: The potential of various renewable or solar energy technologies to supply the United States with its future energy needs is analyzed and a projection of the amount of energy that could be supplied by solar energy is made.
Abstract: This article analyzes the potential of various renewable or solar energy technologies to supply the United States with its future energy needs. Diverse renewable technologies are assessed in terms of their land requirements, environmental benefits and risks, economic costs, and a comparison of their advantages. In addition a projection of the amount of energy that could be supplied by solar energy is made. Topics covered include: assessment of renewable energy technologies; biomass energy systems; liquid fuels; ethanol; methanol; hydrogen; hydroelectric systems; wind power; photovoltaics; solar thermal conversion systems; passive heating and cooling of buildings; comparing solar power to coal and nuclear power; transition to solar energy and other alternatives. 84 refs.
128 citations
30 Jun 1994
TL;DR: A new solar radiation data manual is nearing completion by the National Renewable Energy Laboratory's (NRELs) Analytic Studies Division under the Solar Radiation Resource Assessment Project and the Photovoltaic Solar Radiation Research Task as mentioned in this paper.
Abstract: A new solar radiation data manual is nearing completion by the National Renewable Energy Laboratory’s (NREL’s) Analytic Studies Division under the Solar Radiation Resource Assessment Project and the Photovoltaic Solar Radiation Research Task. These tasks are funded and monitored by the Photovoltaics Branch of the Department of Energy’s Office of Energy Efficiency and Renewable Energy. The new manual is entitled Solar Radiation Data Manual for Flat‐Plate and Concentrating Collectors. For designers and engineers of solar energy related systems, it gives the solar resource available for various types of collectors for 239 stations in the United States and its territories. The data in the manual are modeled using diffuse horizontal and direct beam solar radiation values from the National Solar Radiation Data Base (NSRDB). The NSRDB contains modeled (93%) and measured (7%) global horizontal, diffuse horizontal, and direct beam solar radiation for 1961–1990. This paper describes what is contained in the new data manual and how it was developed.
120 citations
TL;DR: In this paper, the importance of biomass to obtain high-grade heat through the use of pulverized biomass in cyclone combustors is emphasized, along with comparison of its energetics with fossil fuels.
74 citations
TL;DR: In this paper, the authors present fuel cell designs require more development before they can make a large impact on future energy conversion markets, and they must therefore be integrated with chemical plants which may be regarded as dispersed refineries.
70 citations
31 Jan 1994
TL;DR: In this paper, the authors examine the evidence on the historic and projected costs of selected renewable energy technologies and assesses developments, including photovoltaics, solar-thermal, and biomass for liquid fuels and electricity production.
Abstract: This paper examines the evidence on the historic and projected costs of selected renewable energy technologies and assesses developments. It reviews estimates of more than 50 studies and expresses the costs on a common basis for photovoltaics, solar-thermal, and biomass for liquid fuels and electricity production. Findings show that there has been a decline in the cost of ethanol production since the 1970's, attributable to technology improvements and a shift toward cheaper crops. The technology developments to convert low-cost cellulosic materials to ethanol promise further reductions in cost. The costs of electricity from biomass show great variability. Costs are site-specific and vary with raw material costs but still compare well with the costs of fossil-fired generation and even hydro generation in favorable situations. Costs of electricity from solar-thermal technologies show much variability because--with the notable exception of the parabolic trough technology--all are in the experimental stage. However, experience to date and engineering analysis both point consistently to costs in the 5 to 10 cents per kilowatt hour range in the next generation of schemes. Furthermore, the possibilities for low-cost storage, high conversion efficiencies, and short lead times make this an attractive option. Costs of photovoltaic modules have decreased by a factor of 10 over the past fifteen years and by more than 50 since the early 1970s. The possibilities for further cost reduction are far from being exhausted. Key developments with concentrator cells and multijunction devices, commercialization of new thin-film devices, and introduction of batch production processes in manufacturing promise further reductions.
65 citations
05 Dec 1994
TL;DR: Analyzes the energy performance of PV modules using six different energy calculation techniques and compares the results to the measured amount of energy produced and indicates which methods are the most effective for predicting energy output in Golden, Colorado, under prevailing meteorological conditions.
Abstract: The rating of photovoltaic (PV) modules has always been a controversial topic in the PV community. There is no industry standard methodology to evaluate PV modules for energy production. This issue must be discussed and resolved for the benefit of system planners, utilities, and other consumers. Several methodologies are available to rate a module's peak power, but do any accurately predict energy output for flat-plate modules? This paper analyzes the energy performance of PV modules using six different energy calculation techniques and compares the results to the measured amount of energy produced. The results indicate which methods are the most effective for predicting energy output in Golden, Colorado, under prevailing meteorological conditions.
TL;DR: The Fraunhofer Institute for Solar Energy Systems has built a completely self-sufficient solar house (SSSH) in Freiburg, Germany as discussed by the authors, where the entire energy demand for heating, domestic hot water, electricity, and cooking is supplied by the sun.
Journal Article•
TL;DR: The status of a photovoltaic hydrogen energy system development project at Helsinki University of Technology at the end of June 1992 is described in this paper, where a pilot plant has been designed for a 1-2 kWh day−1 constant electric load in the climate of Helsinki (60°N), and the work so far has included component and subsystem testing, as well as optimization of the total system and its control through comprehensive numerical modelling.
TL;DR: In this article, the authors discuss the role of renewable energy technologies in addressing the energy problems of sub-Saharan Africa and encourage large-scale dissemination of renewable energies technologies.
Abstract: 1.0 THE ENERGY SECTOR IN SUB-SAHARAN AFRICA . . . . . . . . . . . . . . . . . . . . . . 387 1.1 Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 1.2 Potential Role of Renewables in Addressing the Energy Problems of SSA . . . . . . 393 2.0 BIO-ENERGY TECHNOLOGIES .... . ......... .. . .. . . . . . . .. . . . . . . . . .. . .. 395 2.1 Large-Scale Bio-Energy Technologies 396 2.2 Small-Scale Bio-Energy Technologies 399 3.0 SOLAR PHOTOVOLTAIC SySTEMS . .. . . . . . . . . . . .. .. . . . . .. . . .. . .. . . . 403 4.0 SOLAR THERMAL SYSTEMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 5.0 WIND ENERGY TECHNOLOGIES . .. . . .. . . . . . . ... . . . . . . . . ... . . . . . . . . . . , 410 6.0 RENEW ABLE ENERGY TECHNOLOGIES IN SUB-SAHARAN AFRICA-THE WAY FORWARD . . . .. .. .. . . . . . . . . . . . . . .. . . .. . ... . . . . . . . . . . . .. . . 411 6.1 Overcoming the Barriers to Widescale Dissemination. . . . . . . . . . . . . . . . . . . . . . 4 1 1 6.2 Encouraging Large-Scale Dissemination of Renewable Energy Technologies. . . 4 1 3
31 May 1994
TL;DR: The successful experience of the Pacific islands in using and maintaining solar photovoltaic systems (PV) indicates that such systems could come to play a substantial role in the electrification of rural areas in many developing countries as mentioned in this paper.
Abstract: The successful experience of the Pacific islands in using and maintaining solar photovoltaic systems (PV) indicates that such systems could come to play a substantial role in the electrification of rural areas in many developing countries In particular, the Pacific island experience suggests that present-technology household-sized PV systems can provide reliable power at costs less than those of the more commonly used diesel systems in small, remote villages for consumers with a limited number of appliances It also suggests that the long-term success of solar PV programs will depend on the establishment of effective institutional approaches for maintaining the systems, and it indicates that ownership and maintenance of the systems by utilities appears to be the soundest option In the Pacific islands, solar PV programs encountered a variety of difficulties in their early phases Most of the early systems suffered from technical deficiencies - stemming primarily from unreliable controllers, batteries, and appliances rather than the PV panels themselves The lesson drawn is that systems must be appropriately designed, use reliable even if initially high-cost components, and be properly installed and adequately maintained Tuvalu provides a case study illustrating the potential effectiveness of solar PV systems in remote areas for rural electrification under appropriate institutional arrangements A comparison of solar PV and diesel systems on the basis of life-cycle costs of providing the final services that the customer desires for a number of years shows that the life-cycle costs of solar PV systems are marginally lower than those of diesel systems for households in remote rural areas The difference in overall costs is about 1 to 14 percent, with the higher savings applicable to households with low energy consumption and lower savings applicable to households with higher energy consumption
TL;DR: In this paper, different possible desalination techniques are proposed in association with wind, tidal, and solar energy sources to set possible practical operating limits to set limits of useful operation.
TL;DR: In this article, the characteristics of the building's energy consumption in Southern Europe were analyzed and the energy potential of solar energy for heating and lighting purposes as well as the potential of passive energy for passive energy saving.
Abstract: The characteristics of the building's energy consumption in Southern Europe are analysed. The energy potential of solar energy for heating and lighting purposes as well as the potential of passive ...
TL;DR: The concept of a hydrogen-based, clean, renewable energy system is currently being investigated by European and Canadian industries, coordinated by the Joint Research Centre Ispra of the Commission of the European Communities and the Government of Quebec as discussed by the authors.
TL;DR: In this article, the current status of renewable energy driven water desalination projects built or designed in North America is summarized, and a discussion of advances in development of components that have been used in such systems.
TL;DR: In this paper, a probabilistic method for predicting the economic performance and reliability of autonomous energy systems, consisting of diesel generators and fixed pitch wind generators, is described, using the duration curves of the load and the wind speed.
Abstract: A probabilistic method for predicting the economic performance and reliability of autonomous energy systems, consisting of diesel generators and fixed pitch wind generators, is described. The method uses the duration curves of the load and the wind speed. Several constraints are applied among them the most significant are the following: load and wind speed are statistically independent; and there is a limitation of wind power penetration due to load and minimum diesel plant output. The quantities that are computed are: wind and diesel energy production; diesel fuel consumption; loss of load probability; and expected unserved energy. Results are presented for two Greek islands. >
TL;DR: In this paper, the authors developed a molecular photovoltaic device based on the sensitization of nanocrystalline films by transition metal charge transfer sensitizers, achieving an overall efficiency of 10% for solar energy conversion to electricity.
Book•
12 Dec 1994
TL;DR: In this article, the effects of alternative fuels on ozone in Ontario, Canada, R.G. Nix and J.L. Renne have been analyzed. But the authors did not consider the effect of wind energy on ozone.
Abstract: Ocean Thermal Energy Conversion (OTEC): A Status Report on the Challenges, A.R. Trenka. Geothermal Energy, M.J. Reed and J.L. Renner. Total Fuel Cycle Emissions Analysis of Biomass-Ethanol Transportation Fuel, C.J. Riley and K.S. Tyson. Organic Carbonyl Compounds in Albuquerque, New Mexico, Air, C.J. Popp, L. Zhang, and J.S. Gaffney. The Effects of Oxygenated Fuels on the Atmospheric Concentrations of Carbon Monoxide and Aldehydes in Colorado, L.G. Anderson, P. Wolfe, R.A. Barrell, and J.A. Lanning. Modeling the Effects of Alternative Fuels on Ozone in Ontario, Canada, R. McLaren, G. Paraskevopoulos, and D.L. Singleton. Solar Photochemistry, J.S. Connolly. Molecular Approaches to Artificial Photosynthesis, D. Gust, T.A. Moore, and A.L. Moore. Photovoltaic Technology Thin-Film High-Efficiency Devices, D. Ginley, K. Zweibel, and J. Benner. Solar Processes for the Destruction of Hazardous Chemicals, D.M. Blake. The Detoxification of Wastewater Streams Using Solar and Artificial UV Light Sources, J.R. Bolton, A. Safarzadeh-Amiri, S.R. Carter. Photoelectrochemical Production of Hydrogen, A.J. Nozik. Renewable Energy, Today and Tomorrow-An Overview, T.D. Bath. Mitigation of Environmental Impacts at Hydroelectric Power Plants in the United States, G.F. Cada and J.E. Francfort. An Overview of Wind Energy in the United States, R.G. Nix. Assessing Renewable Energy Resources-Views Concerning the Federal Role, D.S. Renne. A Real Wind Resource Assessment of the United States, M.N. Schwartz and D.L. Elliott. The Biomass Resource Potential of Energy Crops, L.L. Wright, J.H. Cushman, and S.A. Martin.
TL;DR: In this article, the potentials of solar and wind energy were identified and the prime sites for wind energy are coastal area, arid zone and hill terrains, while solar energy is abundant over most part of the country, maximum being received over Quetta valley.
01 Nov 1994
TL;DR: The growing of biomass energy crops can be either detrimental or beneficial to the environment, depending on how it is done as mentioned in this paper, and the most promising sites for biomass plantations in developing countries are degraded lands that can be revegetated.
Abstract: Advanced technologies such as gasifier/gas turbine systems for electric power generation and fuel cells for transportation make it possible for biomass to provide a substantial share of world energy in the decades ahead, at competitive costs. While biomass energy industries are being launched today using biomass residues of agricultural and forest product industries, the largest potential supplies of biomass will come from plantations dedicated to biomass energy crops. In industrialized countries these plantations will be established primarily on surplus agricultural lands, providing a new source of livelihood for farmers and making it possible eventually to phase out agricultural subsidies. The most promising sites for biomass plantations in developing countries are degraded lands that can be revegetated. For developing countries, biomass energy offers an opportunity to promote rural development. Biomass energy grown sustainably and used to displace fossil fuels can lead to major reductions in carbon dioxide emissions at zero incremental cost, as well as greatly reduced local air pollution through the use of advanced energy conversion and end-use technologies. The growing of biomass energy crops can be either detrimental or beneficial to the environment, depending on how it is done. Biomass energy systems offer much more flexibility to design plantations that are compatible with environmental goals than is possible with the growing of biomass for food and industrial fiber markets. There is time to develop and put into place environmental guidelines to ensure that the growing of biomass is carried out in environmentally desirable ways, before a biomass energy industry becomes well established.
TL;DR: In this paper, the authors presented a project undertaken in Mexico to electrify the remote village of San Antonio Agua Bendita (SAAB) using a custom designed hybrid power system.
Abstract: This paper presents a project undertaken in Mexico to electrify the remote village of San Antonio Agua Bendita (SAAB) using a custom designed hybrid power system. The hybrid power system will provide grid quality electricity to this community which would otherwise not have been electrified via traditional distribution lines. The hybrid power system was designed to electrify the entire community, incorporate multiple sources of renewable power with on-demand power, operate autonomously, and be cost effective in dollars per watt of electricity generated over the system's usable life. A major factor in the success of this project is the use of renewable energy for economic development and community partnership. Many rural electrification projects have provided power for domestic use but few have successfully provided power to improve the economic condition of the people served by the system. The SAAB hybrid avoids this pitfall by providing 120 VAC power at 60 Hz to anticipated industrial loads in the village, as well as providing grid quality power for domestic use. The system consists of the following modules: a controller, battery storage, a PV array, two 1O kW wind turbines, a diesel generator, a micro-hydro generater, power output control. >
Book•
01 Mar 1994
TL;DR: In this paper, the authors surveyed the environmental and economic costs and benefits of alternative fuels, finding that ethanol, methanol, and natural gas can serve, at best, as transitional options.
Abstract: In this book the author surveys the environmental and economic costs and benefits of alternative fuels, finding that ethanol, methanol, and natural gas can serve, at best, as transitional options. These carbon-based fuels may make the air a bit cleaner, but as they are now produced, they will neither reduce carbon-dioxide emissions enough to slow global climate change nor shrink fuel imports. Electric vehicles will do better. With their use, air pollution would be cut drastically and, if fueled by electricity from natural gas plants or the current mix of electric power plants in the United States, these vehicles would emit only half as much carbon dioxide as gasoline-fueled alternatives. Emissions would fall to zero if the electricity came from photovoltaic, wind, or other renewable energy technologies. Since the nation's electric power grid is fueled by domestic resources, electric vehicles can also help hold the line on fossil fuel imports. The author explores the status of electric vehicle research and technology--including batteries, flywheels, ultracapacitors, and hydrogen fuel cells--in the United States, Japan, and Europe. To move electric vehicles toward the marketplace in the United States, the author recommends the following policy shifts: reforming fuel prices; shared-cost research and development; infrastructure development; and stimulating the market.
TL;DR: Different renewable energy sources can be used for greenhouse heating, but several problems have to be solved before renewable energies can substitute fossil fuels as mentioned in this paper. But these problems are not addressed in this paper.
07 Oct 1994