Certain materials, generally metal oxides, can sustain the unassisted photo-electrolysis of water into H2 and O2. The energy contained in the photons that are absorbed by these materials can in many cases be efficiently converted into energy stored into the chemical fuels produced by the photo-electrolysis system. However, these materials have optical absorption thresholds (band gaps) that are too large to permit effective absorption of the visible and infrared portions of the solar spectrum, thereby wasting a large fraction of the incident solar energy and yielding overall energy conversion efficiencies of o 1%. Modification of metal oxide materials has been claimed to be much more promising, with a modified TiO 2 photo-anode yielding 8% efficiency in the photo-assisted splitting of water into H2 and O2 . (more…)
Several molecular systems have been constructed that mimic various aspects of photosynthesis. Two of these utilize molecular system ...
The basic processes that occur in such a system are well understood. The semiconductor electrode efficiently absorbs light, produci ...
The issues of hydrogen storage run through the hydrogen production, hydrogen transport, supply and demand for end use of hydrog ...
Hydrogen has many applications when it comes to fuel. It can be used both in internal combustion engines and hydrogen fuel cells. ...
All of today’s hydrogen conversion products, demonstration models, and prototypes possess some deficiencies; they cannot yet pr ...
The energy efficiencies of various fuel production pathways from well to pump. The efficiencies shown are defined as the energy in a given fuel (available at pumps in vehicle refueling stations) divided by total energy inputs during all Well-to-Pump activities, including the energy content of the fuel. One way to interpret the Well-to-Pump efficiencies in the figure is as the difference between 100% and the energy efficiencies, which roughly represent energy losses during Well-to-Pump stages for making a given fuel available at the pump. As stated in Section 3, Well-to-Pump activities include biomass feedstock production; feedstock transportation and storage; fuel production; and fuel transportation, storage, and distribution. (more…)
The combination of well-to-pump results and the energy use and emissions associated with vehicle operation (also called the pum ...
It shows Well-to-Wheels Greenhouse Gas emissions of the 23 vehicle/fuel systems. For each system, the bottom bar represents CO2 ...
Because different studies have different system boundaries and parametric assumptions, the studies described in Section 7 resulted ...
There are different types of vehicle propulsion systems and the transportation fuels that have been studied for their potential ...
At present, in the United States and worldwide, motor vehicles are fueled almost exclusively by petroleum based gasoline (or re ...
All electromagnetic suspension-based systems employ some type of feedback control mechanism to maintain stable levitation. (An interesting exception to the above rule, which has been demonstrated in the laboratory, consists of a permanent magnet suspended below a block of high-temperature superconducting material held below its critical temperature. Stable suspension results from a property of the superconducting state that immobilizes magnetic field lines in the superconducting material.) (more…)
In contrast to electromagnetic suspension systems, electrodynamic suspension systems can provide stable suspension without a feedba ...
Electromagnetic Suspension (EMS) system in which an array of magnets is attracted upwards to a steel rail. It is possible to de ...
A propulsion alternative is to transfer power to the vehicle and then have a magnetic structure on the vehicle that can create ...
Electrodynamic Suspension (EDS) can be viewed as an array of magnets moving over a conducting sheet and being pushed upwards by ...
High-speed maglev technology offers four main advantages: non-contact operation; low-mass vehicles (on a per seat basis, maglev veh ...
Electric and gas utilities’ Research & Development activities deal nearly exclusively with energy conversion, distribution, and energy usage (at least to the extent that these firms still focus on these core businesses). Although detailed data on utility Research & Development are not collected systematically, it seems that Energy R&D spending by many utilities has declined during the past decade or so. For example, a 1996 survey by the U.S. General Accounting Office (GAO) found that the combined Research & Development spending of the 112 largest operating utilities in the United States dropped from $708 million in 1993 to $476 million in 1996. (more…)
Government expenditures on energy R&D, energy conservation have risen steadily over the past decade, but only two countries, Japan ...
Not surprisingly, most Energy Research and Development takes place in industrialized countries where both the public and private se ...
Nuclear fission and fusion Research and Development continues to account for nearly half of the total spending by IEA countries, al ...
Japan has the largest Photovoltaic installed capacity in the world as a result of the sustained investments made by the country thr ...
The aim of this broad sweep through the area of energy innovation, highlighting the main actors, activities, policies, institutions ...
Interest in rating the real-life energy performance of buildings has increased in recent years, and the real life efficiency performance rating of buildings is important for any sustainable energy future. (more…)
As the need for energy efficiency becomes more pronounced, the drive toward efficiency in the commercial sector will be impeded by ...
Energy performance ratings tell what the energy performance of a building is, but if the energy performance of a building is to be ...
Current forecasts call for solid growth in world energy use over the next 20 years, potentially increasing 60% above current energy ...
There are only a few compulsory energy efficiency programs aimed at industrial facilities. It is only recently that the EU introduc ...
The amount of energy consumed in the commercial sector often must be estimated as a fraction of energy use in the combined resident ...
The aim of this broad sweep through the area of energy innovation, highlighting the main actors, activities, policies, institutions, and their interactions that eventually underlie energy technology development and deployment, was to present an overview of the current state of and challenges to energy innovation. (more…)
Not surprisingly, most Energy Research and Development takes place in industrialized countries where both the public and private se ...
Many readers may be unfamiliar with the way economists typically view the process of technological change, thus it is useful to fir ...
Government expenditures on energy R&D, energy conservation have risen steadily over the past decade, but only two countries, Japan ...
Now it is possible to move back in the process of technological change from diffusion to innovation. In the energy efficiency area, ...
In the absence of useful and established patterns of practice, a search is under way for new means of reconciling local government’ ...
Foundations have made good progress on the energy front, but huge gaps remain. Promising technologies in energy production and use today prove that the prospects for an affluent but low-carbon society are good. But the U.S. and the world economies continue to run primarily on oil and coal. As the largest consumer and producer of energy in the world, the United States has the responsibility to lead the transition to cleaner energy technologies. (more…)
Not surprisingly, most Energy Research and Development takes place in industrialized countries where both the public and private se ...
World energy use has increased steadily over the past several decades. Much of the growth in world energy consumption has been ...
The development of the ‘‘new’’ wind and solar technologies is of great importance for the future contribution of RESs to energy sup ...
Germany is considered a world leader in wind energy deployment, with electricity production from wind having gone up more than eigh ...
Recently, attention to energy efficiency has been gaining momentum. The attention given by policy maker is mainly due to concer ...
Estimation of the future technical potential of biomass as an energy source is dependent on assumptions with respect to land availability and productivity as well as conversion technologies. With the emergence of energy crops as the major source of biomass fuel, land use conflicts, especially in relation to food production, may arise. However, with efficient agricultural practices, plantations and crops could supply a large proportion of energy needs, with residues playing a smaller role without compromising food production or further intensifying agricultural practices. (more…)
The future development of energy crops, to the level at which they would replace residues as the major bioenergy fuel source, will ...
Bioenergy produced from biomass is sometimes called a carbon-neutral energy source, because the same quantity of carbon released wh ...
The quantification of the actual reduction in green house gases sourcess emissions resulting from the substitution of fossil fu ...
To date, most discussion and research relating to the various of biomass role in mitigating CO2 emissions has been focused around i ...
Over the last decade, the number of countries researching the potential of biomass and bioenergy for energy services rose rapid ...
Not surprisingly, most Energy Research and Development takes place in industrialized countries where both the public and private sectors are involved in the development of energy technologies. Given that most energy technologies are deployed through the marketplace, the predominant focus of Energy Research and Development is within firms. Still, governments have historically played an important role in the Research and Development of new energy technologies through direct financial support (e.g., gas turbines) as well as through policies that promote Energy Research and Development within firms. (more…)
Government expenditures on energy R&D, energy conservation have risen steadily over the past decade, but only two countries, Japan ...
The aim of this broad sweep through the area of energy innovation, highlighting the main actors, activities, policies, institutions ...
Nuclear fission and fusion Research and Development continues to account for nearly half of the total spending by IEA countries, al ...
Fossil fuels, had a broader impact in current society, still oil is the one that have far reaching effect. Oil, in all its forms is ...
Electric and gas utilities’ Research & Development activities deal nearly exclusively with energy conversion, distribution, and ene ...
The growth in air transportation volume has important global energy sustainable development
associated with the potential for greenhouse gases sources. On local to regional scales, noise, decreased air quality related primarily to ozone production and particulate levels, and other issues, such as roadway congestion related to airport services and local water quality, are all recognized as important impacts. (more…)
Fuel efficiency gains due to technological and operational change can mitigate the influence of growth on total emissions. Incr ...
Although the focus of many policy studies of climate change is on establishing the causal links between anthropogenic systems, emis ...
The outlook for reductions in future energy use is necessarily based on the potential for increased technological and operati ...
Climate change caused by the enhanced greenhouse effect is one of the most significant global environmental issues. Increased emiss ...
Although some scientists and critics still dispute that human caused greenhouse gases are causing climate change, the majority of s ...