Primary Energy Use and Clean Coal Technology

clean coal technology
Transportation is another sector that has increased its relative share of primary energy use. This sector has serious concerns as it is a significant source of CO2 emissions and other airborne pollutants, and it is almost totally based on oil as its energy source. An important aspect of future changes in transportation depends on what happens to the available oil resources, production and prices. At present, 95% of all energy for transportation comes from oil. (more…)

Global Energy Consumption & Energy Demand in Electricity and Transportation

global energy demand
Global energy consumption in the last half century has increased very rapidly and is expected to continue to grow over the next 50 years. However, we expect to see significant differences between the last 50 years and the next. The past increase was stimulated by relatively “cheap” fossil fuels and increased rates of industrialization in North America, Europe, and Japan; yet while energy consumption in these countries continues to increase, additional factors are making the picture for the next 50 years more complex. These additional complicating factors include the very rapid increase fuel economy in energy use in China and India (countries representing about a third of the world’s population); the expected depletion of oil resources in the not-too-distant future; and the effect of human activities on global climate change. (more…)

UK Energy Demand: The United Kingdom Trends in Energy

uk energy demand
The long-term prospects for the U.K. economy are inevitably uncertain, and the most recent Department of Energy long-term projection puts forward three scenarios for the next 30 years with GDP growth rates of roughly 2.5, 1.5 and 0.5% p.a. The highest value corresponds to slightly less than the 1948 - 72 average, the central value is close to the long-run average over the last 80 years, and the lowest figure is similar to the performance during the current recession since 1973. (more…)

Nuclear Generating Capacity In The United Kingdom

nuclear united kingdom
Following the recent completion of three nuclear power plants, there is now some 9.6 GW of nuclear capacity in the United Kingdom. The nuclear share of electrical output, which has stood at around 13% for many years, should rise to around 20% when this capacity is in full operation. A further two reactors are currently under construction which will increase the British nuclear capacity to more than 12 GW by the late 1980s, which could bring the nuclear share of electrical output to around 25%. (more…)

Photoelectrolysis Using Metal Oxides And Other Semiconductors

Photoelectrolysis
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…)

Aerodynamic Drag Force: Laminar Flow & Turbulent Flow

One of the most important aerodynamic effects on energy consumption required to keep a body moving through a fluid is the aerodynamic drag force. The drag must be overcome by the thrust of a propulsion mechanism, which in turn is consuming energy. Everything else being equal, the higher the drag, the more energy is consumed. Therefore, for energy efficiency, bodies moving through a fluid should be low drag bodies. To understand how to obtain low drag, we have to first understand the nature of drag, and what really causes it. (more…)

Aerodynamic Force Sources: Pressure & Shear Stress

The next time you hear an airplane flying overhead, look up, and pause for a moment. What you see is a machine that is heavier than air, but which is somehow being sustained in the air. This is due to the airflow over the airplane. This airflow exerts a lift force which counteracts the weight of the airplane and sustains it in the air—a good thing. The airflow also exerts a aerodynamic drag force on the airplane which retards its motion—a bad thing. The drag must be counteracted by the thrust of the engine in order to keep the airplane going. The production of thrust by the engine consumes energy. Hence, the energy efficiency of the airplane is intimately related to aerodynamic drag. This is just one of many examples where the disciplines of aerodynamics and energy interact. (more…)

Photo-Electrochemical Energy Conversion Device

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…)

Artificial Photosynthetic Devices

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…)

Household Fuel Use Patterns In Developing Countries

Indoor air quality (IAQ) research deals with the presence, levels, health effects, and control of physical, chemical, and biological factors in indoor environments, including homes, workplaces, and vehicles. IAQ research in industrialized countries has examined hundreds of specific factors (e.g., temperature, various chemicals, and mold), sources of pollution environment (e.g., environmental tobacco smoke, occupational factors, consumer cleaning products, and moisture), and control technologies (e.g., ventilation). (more…)

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