The basic processes that occur in such a system are well understood. The semiconductor electrode efficiently absorbs light, producing an excited electronic state. In this excited state, the electron and the electron vacancy (the ‘‘hole’’) are both more energetic than they were in their respective ground states. The photo-excited electrons and holes are generally not tightly bound to an individual atom or set of atoms in the solid. (more…)
Several molecular systems have been constructed that mimic various aspects of photosynthesis. Two of these utilize molecular system ...
Today, photovoltaic cells only contribute a small proportion (approximately 0.04 percent) of total electricity in the United St ...
Certain materials, generally metal oxides, can sustain the unassisted photo-electrolysis of water into H2 and O2. The energy co ...
The fuel cell can trace its roots back to the 1800s when a Welsh-born, Oxford-educated barrister, Sir William Robert Grove, realize ...
A fuel cell is an electrochemical device that combines hydrogen with oxygen to generate electricity, heat and water to produce. ...
Several molecular systems have been constructed that mimic various aspects of photosynthesis. Two of these utilize molecular systems that are derived from natural photosynthesis but that incorporate chemically based modifications to produce artificial photosynthetic devices. These devices use artificial photosynthetic pigments to drive chemical reactions across lipid bilayers or use noble metal catalysts to change the function of the photosynthetic process to produce hydrogen and oxygen instead of sugars ethanol and oxygen. Neither of these systems are sufficiently robust to be operated for extended periods of time as energy unit conversion devices, but they have shown that it is possible to produce artificial photosynthetic assemblies that function well in a laboratory setting. (more…)
The basic processes that occur in such a system are well understood. The semiconductor electrode efficiently absorbs light, produci ...
Certain materials, generally metal oxides, can sustain the unassisted photo-electrolysis of water into H2 and O2. The energy co ...
A fuel cell is an electrochemical device that combines hydrogen with oxygen to generate electricity, heat and water to produce. ...
A fuel cell is an electrochemical device that directly converts a fuel to electricity by means of reactions on the surfaces of ...
The fuel cell can trace its roots back to the 1800s when a Welsh-born, Oxford-educated barrister, Sir William Robert Grove, realize ...
Although technology change (usually involving an improvement in energy efficiency) is not inherently a geographic process, it does not occur uniformly over geographic space. Consequently, mathematical modeling and behavioral and innovation diffusion studies by geographers have improved our understanding of the pervasive phenomenon of technology energy efficiency change in energy markets. Similarly, creative government policies in Germany since 1990 have led to a faster rate of adoption of renewable energy sources, compared to the United States. (more…)
The development of the ‘‘new’’ wind and solar technologies is of great importance for the future contribution of RESs to energy sup ...
Renewable energy sources cannot run out and causes so little damage to the environment that its use does not need to be restric ...
In Europe, modern renewable energy sources technologies were explored thoroughly for the first time after the oil embargo/ price cr ...
Government expenditures on energy R&D, energy conservation have risen steadily over the past decade, but only two countries, Japan ...
"Spain has great potential but lack geothermal legislation and investment." Besides being clean, renewable and friendly, easily man ...
Air-blown circulating fluidized bed gasifiers are of interest because they produce a good quality, low calorific value (LCV) gas (4–6 MJ/Nm 3 ) and possess a very high carbon conversion efficiency while allowing high capacity, good tolerance to variations in fuel quality, and reliable operation. The high and homogeneously distributed temperatures and the use of particular bed materials, such as dolomite, favor tar cracking. Successful tar cracking can also be achieved using secondary circulating fluidized bed reactors. Also, successful tests on catalytic tar cracking have been performed, for example, by introducing nickel compounds into the gasifier. Sulfur control is made easier because of the significant reduction that can be achieved by adding limestone or dolomite to the gasifier bed. (more…)
The moisture content of the feedstock affects the gas composition and the energy balance of the process since gasification is an en ...
Thermo chemical processing of biomass yields gaseous, liquid, and solid products and offers a means of producing useful gaseous ...
A combination of legislation and technology has helped clean up many of the world’s coal-burning plants. Both developed and develop ...
Biomass Storage Biomass storage is required to ensure the continuous operation of the facility. To limit the space required for ...
Gasification is a thermo chemical process that has been exploited for more than a century for converting solid feedstocks to ga ...
A fuel cell is an electrochemical device that combines hydrogen with oxygen to generate electricity, heat and water to produce. In many ways, the fuel cell is similar to an electrochemical cell. Instead of a regular charge, a continuous supply of oxygen and hydrogen is supplied from outside. Oxygen is produced in the control of air and hydrogen as a fuel made from a pressure instrumentation container. Alternatively, methanol, propane, butane, natural gas supply and diesel are used. (more…)
Alkaline fuel cell, often known as the Bacon fuel cell following the British inventor’ name. It has become the most created fue ...
The fuel cell can trace its roots back to the 1800s when a Welsh-born, Oxford-educated barrister, Sir William Robert Grove, realize ...
Fuel cells are typically classified according to type of electrolyte. While many varieties of fuel cells have been demonstrated ...
Transport applications tend to demand rapid start-up and instant dynamic response from fuel cell systems, so a high-temperature ...
A fuel cell is an electrochemical device that directly converts a fuel to electricity by means of reactions on the surfaces of ...
Gasification is a thermo chemical process that has been exploited for more than a century for converting solid feedstocks to gaseous energy carriers. The first gasifier patent was issued in England at the end of the 18th century and producer gas from coal gasification was mainly used as lighting fuel throughout the 19th century. At the turn of the 20th century, the main use of producer gas, obtained essentially from coal, switched to electricity generation and automotive applications via internal combustion engines. The use of producer gas was gradually supplanted by the use of higher energy density liquid fuels and as a result confined to areas with expensive or unreliable supplies of petroleum fuels. (more…)
The product gas can be burned in boilers to generate heat and raise steam, in internal combustion engines to generate electricity a ...
Thermo chemical processing of biomass yields gaseous, liquid, and solid products and offers a means of producing useful gaseous ...
Biomass Storage Biomass storage is required to ensure the continuous operation of the facility. To limit the space required for ...
Estimation of the future technical potential of biomass as an energy source is dependent on assumptions with respect to land av ...
The moisture content of the feedstock affects the gas composition and the energy balance of the process since gasification is an en ...
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 ...
Fuel cells are typically classified according to type of electrolyte. While many varieties of fuel cells have been demonstrated in the laboratory, five major types are seeing development for commercial applications:
* Polymer electrolyte membrane (PEM) cells use a plastic (polymer) membrane that becomes electrically conducting when hydrated (saturated with water); they operate near 1001C.
* Alkaline fuel cells use a caustic electrolyte such as potassium hydroxide (KOH); they also operate near 1001C. (more…)
Transport applications tend to demand rapid start-up and instant dynamic response from fuel cell systems, so a high-temperature ...
Polymer Electrolyte Fuel Cells have high-power density, rapid startup, and low-temperature operation (around 80 to 120 C), and ...
Alkaline fuel cell, often known as the Bacon fuel cell following the British inventor’ name. It has become the most created fue ...
The fuel cell can trace its roots back to the 1800s when a Welsh-born, Oxford-educated barrister, Sir William Robert Grove, realize ...
A fuel cell is an electrochemical device that combines hydrogen with oxygen to generate electricity, heat and water to produce. ...
The energy that people use every day comes from many different sources. The resources are divided into two main groups: renewable energy and nonrenewable energy. Renewable energy sources are those that can be used again and again. Renewable energy resources have unlimited supply. (more…)
In Europe, modern renewable energy sources technologies were explored thoroughly for the first time after the oil embargo/ price cr ...
During the US Presidential Election 2008 Campaign, the renewable portfolio standard was one of the main agendas for Presidentia ...
The broad range of home solar energy systems are mostly known as Photovoltaic Systems (PV) or Thin Film Solar Technology. The s ...
The hydrogen can come from various sources including fossil fuels, wind, solar, biomass, nuclear, solar thermo-chemical reactio ...
Renewable energy sources cannot run out and causes so little damage to the environment that its use does not need to be restric ...
It is a rare company prospectus that begins with a quotation from Goethe: “Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it.” But Lovins is not a normal entrepreneur, as anyone who has met this eccentric and disheveled but unmistakably visionary thinker knows. The founder of the Rocky Mountain Institute, a leading green think tank based in Old Snowmass, Colorado, thinks the car industry’s incremental approach to cutting emissions and improving fuel efficiency will never amount to much. He wants a complete redesign of the automobile, from the bottom up, and intends to show the big boys how it should be done. (more…)
The leading automotive brands are being focused to produce electric vehicles because they believe they represent a harmony to the e ...
Mercedes-Benz presented at Geneva Style F800 Concept (the F stands for Mercedes: technology, design and art), a prototype that ...
Under both former President Bush and new President Obama, the U.S. government has vowed to reduce reliance on imported oil. The ...
This latter form of new car taxes can actually serve as an impediment to higher fuel economy to the extent that increased energ ...
There are different types of vehicle propulsion systems and the transportation fuels that have been studied for their potential ...