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…)

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…)

Exposure to air pollutants and air pollution problem are very high in indoor environments in developing countries. Smith has estimated that at the aggregate level (i.e., without accounting for particle size, chemical composition, and source), approximately 80% of total global exposure to airborne particulate matter occurs indoors in developing nations. Details of exposure for various household members, and the roles of both pollution and behavior (e.g., location with respect to stove and activities), have been studied and evaluated using new tools and technology. (more…)

With ethanol’s future uncertain, many commentators see the transportation debate evolving into a war between two other technologies—hydrogen-powered fuel cells and battery powered electric vehicles. Some alternative fuel advocates are putting their support behind hydrogen, the most abundant element on Earth. Water, for example, is composed of hydrogen and oxygen molecules. Hydrogen can be produced from water by electrolysis, which separates the oxygen from the hydrogen. It can be used to power hydrogen fuel cells for vehicles (or to provide heat and electricity for buildings). Hydrogen fuel cells work by recombining hydrogen and oxygen—a process that produces electricity, heat, and water. Hydrogen-powered cars, therefore, could be an ideal transportation solution—nonpolluting, zero-emission vehicles that release only water, a natural and completely safe waste product. Also, fuel cells are highly efficient and powerful, and unlike typical batteries, fuel cells will never lose their charge as long as hydrogen fuel is supplied.

Hydrogen fuel cell technologies, however, must overcome many stubborn challenges before they can become a practical source of energy. Perhaps the biggest obstacle is cost; it currently takes more energy to make hydrogen than is produced, and production relies on expensive catalysts made from platinum, a scarce metal. And like biofuels, hydrogen is currently made using fossil fuels, so it is not emissions-free. In addition, liquid hydrogen fuel is highly flammable and must be stored at very low temperatures or under very high pressure, making transport and storage difficult. Switching vehicles to hydrogen fuel cell power also would require building a whole new infrastructure similar to the chain of gas stations that currently dot the landscape. Researchers are hoping to find answers to these problems by searching for other types of catalysts, studying other ways to improve production, and developing better hydrogen storage options.

Hydrogen researchers, however, have been promising breakthroughs since the 1990s with little progress to show for their efforts. Many observers are thus coming to the conclusion that the hydrogen fuel cell is a technology that will not be perfected in the near future. As physicist and climate expert Joe Romm explains, “Neither government policy nor business investment should be based on the assumption that these technologies will have a significant impact in the near or medium-term.” The Obama administration apparently agrees; it submitted a budget for 2010 that sharply cut back on government support for hydrogen projects. U.S. Energy Secretary Steven Chu explained the administration’s problems with hydrogen technology:

Right now, the way we get hydrogen primarily is from reforming [natural] gas. That’s not an ideal source of hydrogen. . . . The other problem is, if it’s for transportation, we don’t have a good storage mechanism yet. Compressed hydrogen is the best mechanism [but it requires] a large volume. We haven’t figured out how to store it with high density. What else? The fuel cells aren’t there yet, and the distribution infrastructure isn’t there yet. So . . . to get significant deployment, you need four significant technological breakthroughs. That makes it unlikely

Congress promptly reversed President Obama’s decision, however, restoring more than $200 million to 190 hydrogen projects around the country.

Electric utility deregulation offers the great promise of market forces leading to lower electric rates, lower air pollution environment, greater energy (and economic) efficiency, and perhaps greater use of renewable energy sources. Ideally, deregulation involves the restructuring of a previously monopolized or nationalized electric utility into separate generation, transmission, distribution, and marketing companies, and allowing wholesale and retail choice of generation company or power marketer. Deregulation has occurred to varying degrees since 1989 in the United Kingdom, Norway, Australia, New Zealand, Chile, Argentina, and about 20 states in the United States. There have been promising results in a few countries and in some U.S. states in some respects, especially lower rates and lower air pollution problems. In most cases, competitive markets have yet to be realized and lower rates can be attributed to other causes, such as previously planned amortization or retirement of expensive power plants, unexpected surplus in natural gas, rate caps, etc. In addition, deregulation has had only a slight beneficial effect on the use of renewable electricity sources. The promise of electric utility deregulation is thus unfulfilled and deserves further study.

Geopolitical considerations have played a major role in many renewable energy policy decisions, e.g., in domestic debates over gasoline taxes, pipeline construction, radioactive waste disposal, and acid rain control legislation in the United States, and in petroleumrelated violence in Nigeria. The most prominent role for geopolitics in energy policy has probably involved international discussions on controlling greenhouse gas emissions, and in oil markets. In the cases of the Kyoto Protocol of 1997 and the 1992 Framework Convention on Climate Change, nations carefully considered their national economic interests, domestic politics, and international trade during the negotiations. European countries, with the lowest rates of population and economic growth along with strong domestic environmental lobbies, have pursued a greater rate of greenhouse gas reduction.

The United States, in contrast, has been stubbornly cautious and backed out of the treaty in 2001 (arguing it is not in its economic best interests), and the oil-rich nations of the Middle East have been least supportive of any emissions controls. In the case of oil markets, with the United States now dependent on imports for over half its supply, energy policy and trade strategy have played major roles in the pursuit of new oil discoveries in Alaska and in warfare in Kuwait, Iraq, and perhaps Afghanistan.

air pollution problems created by coal combustion. Meanwhile, coal-fired power plants and industrial boilers spewed out tons of gaseous and particulate pollutants into the atmo- sphere. During combustion, the small amounts of sulfur and nitrogen in coal combine with oxygen to form sulfur dioxide (SO2), sulfur trioxide (SO3), and the oxides of nitrogen (NOx). (more…)

Options for dealing with the threats of climate change include both adaptation to inevitable changes and mitigation, or lessening, of those changes that we can still affect. One possible adaptation would be to adjust our agricultural practices to the changing regional patterns of temperature and rainfall. Another would be to build coastal defenses against the inundation from sea-level rise. Only mitigation, however, can prevent the most threatening changes. (more…)

A combination of legislation and technology has helped clean up many of the world’s coal-burning plants. Both developed and developing countries have adopted increasingly stringent environmental regulations to govern emissions from coal-fired power plants. In the United States, all coal-fired power plants built after 1978 must be equipped with postcombustion cleanup devices to capture pollutants before they escape into the atmosphere. Cyclones, baghouses, and electrostatic precipitators filter out nearly 99% of the particulates. Flue gas scrubbers use a slurry of crushed limestone and water to absorb sulfur oxides from flue gas. The limestone reacts with the sulfur dioxide to form calcium sulfate, which may be used to produce wallboard. Staged combustion and low-NOx burners are used to burn coal to minimize NOx formation. Another strategy, selective catalytic reduction, reacts ammonia with NOx over a catalyst to produce nonpolluting nitrogen and water vapor.

Conventional coal-fired power plants capture pollutants from the flue gas after it leaves the boiler. Circulating fluidized bed (CFB) combustors capture most of the pollutants before they leave the furnace. Crushed coal particles and limestone circulate inside the CFB combustor, suspended by an upward flow of hot air. Sulfur oxides released during combustion are absorbed by the limestone, forming calcium sulfate, which drops to the bottom of the boiler. The CFB combustor operates at a lower temperature (14001F) compared to pulverized coal (PC) boilers (27001F), which also helps reduce the formation of NO x .

Precombustion coal cleaning is another strategy to reduce sulfur emissions by cleaning the coal before it arrives at the power plant. Sulfur in coal is present as pyrite (FeS2 ), which is physically bound to the coal as tiny mineral inclusions, and as ‘‘organic sulfur,’’ which is chemically bound to the carbon and other atoms in coal. Pyrite is removed in a coal preparation plant, where coal is crushed into particles less than 2 inches in size and is washed in a variety of devices that perform gravity-based separations. Clean coal floats to the surface, whereas pyrite and other mineral impurities sink. Additional cleaning may be performed with flotation cells, which separate coal dust from its impurities based on differences in surface properties. Precombustion removal of organic sulfur can be accomplished only by chemical cleaning. So far, coal combustion emissions and chemical cleaning has proved to be too costly, thus flue gas scrubbers are often required to achieve near-complete removal of sulfur pollutants.

The tightening of environmental regulations is likely to continue throughout the world. In the United States, for example, by December 2008, it is anticipated that coal-fired power plants will have to comply with maximum emission levels for mercury. Emissions of mercury and other trace metals, such as selenium, are under increasing scrutiny of coal combustion emissions because of suspected adverse effects on public health.

Coal is sometimes combusted with waste material as a combined waste reduction/electricity production strategy. The disposal of waste from agriculture and forestry (biomass), municipalities, and hospitals becomes costly when landfill space is limited. Some wastes, particularly biomass feedstock, are combustible, but their low energy density (compared with coal) limits their use as an electricity production fuel. Blending coal with these fuels provides an economical method to produce electric power, reduce waste, and decrease coal plant emissions. Most wood wastes, compared to coal, contain less fuel nitrogen and burn at lower temperatures. These characteristics lead to lower NO x formation. In addition, wood contains minimal sulfur ( o 0.1% by weight) and thus reduces the load on scrubbers and decreases scrubber waste biomass.

Numerous electric utilities have demonstrated that 1–8% of woody drying biomass can be blended with coal with no operational problems. Higher blends may also be used, but require burner and feed intake modifications as well as a separate feed system for the waste fuel. Cofiring in fluidized bed boilers may avoid some of these drawbacks, but the economics of co-firing are not yet sufficiently attractive to make it a widespread practice.

The spark-ignition and compression-ignition engine and internal combustion engines technologies that are currently employed in motor vehicles were developed more than 100 years ago. These conventional vehicle technologies are fueled by petroleum-derived gasoline and diesel fuels (the socalled conventional fuels). Over the past 100 years, the conventional technologies have been dramatically improved, reducing cost and increasing performance. (more…)

<
The operations on-board an oil tanker transportation are radically different from those on other types of ships, primarily due to the physical properties of the cargo. The entire cargo operations are highly automated and proceed with no one on-board the ship or shore seeing the cargo physically. Even minor misunderstanding of an order or a miscalculation can cause a major spill in pristine locations. By the same token, a tanker crewed by properly trained seafarers under good management could very well be the safest ship afloat. Although most tanker voyages today are completed safely and go unreported, even a minor tanker pollution accident often gets widespread attention from the media, and the image of a polluted beach laden with dead flora and fauna is a sad and telling picture. (more…)