Options For A Hydrogen Infrastructure

Hydrogen Underground

Energy companies could manufacture and distribute hydrogen fuel in many ways. In the near term, the most likely option is extracting hydrogen from natural gas, either in centralized reformers that supply fueling stations by delivery truck or in smaller on-site reformers located at the stations. The fueling stations could also use electricity from the power grid to make hydrogen by electrolyzing water. All these options, however, would produce greenhouse gas emissions (assuming that fossil fuels...

Thl Nuclear

A threefold expansion of nuclear power could contribute significantly to staving off climate change by avoiding one billion to two billion tons of carbon emissions annually BY JOHN M. DEUTCH AND ERNEST J. MONIZ Nuclear power supplies a sixth of the world's electricity. Along with hydropower which supplies slightly more than a sixth , it is the major source of carbon-free energy today. The technology suffered growing pains, seared into the public's mind by the Chernobyl and Three Mile Island...

An Advanced Turbine Design For Versatile Missiles By Steven Ashley

Rolls Royce Yj102r Jet Engine

Suppose that U.S. intelligence finds indisputable evidence that a major terrorist leader is dining right now in a remote farmhouse in central Asia. Say also that local political sensitivities prohibit calling in bombers for an air strike and that the meal is unlikely to last the two hours it would take a Tomahawk cruise missile to reach the site from its maximum range. How to respond Pentagon weapons procurers hope to have an answer in an advanced turbine engine that can shrink a cruise...

Ask The Experts

What do butterflies do when it rains Michael Raupp, professor of entomology at the University of Maryland, enlightens. Subscribe to Scientific American Digital 13-year archive with more than 150 issues Visit www.sciamdigital.com THE MAY ISSUE underscored the maxim that scientific research typically raises more questions than it answers. For instance, in the cover story The First Few Microseconds, Michael Riordan and William A. Zajc described collider experiments that slammed gold nuclei...

Energy Efficiency

Uses 50 percent less energy than a conventional office building Natural ventilation and lighting systems External louvers provide shade on hot sides of building Unshielded windows on cool sides improve natural light Long, narrow structure minimizes solar heat Naturally ventilated stairwells Open floor plan and operable windows harness breeze Uses 50 percent less energy than a conventional office building Natural ventilation and lighting systems External louvers provide shade on hot sides of...

By Jeffrey D Sachs

Encouraging lower fertility in the developing world will pay off for everyone. How do batteries store and discharge electricity Does damp weather make arthritis pain worse Cover image by Phil Saunders, Space Channel Ltd. photograph at left by Honda Motor Company. Scientific American ISSN 0036-8733 , published monthly by Scientific American, Inc., 415 Madison Avenue, New York, N.Y. 10017-1111. Copyright 2006 by Scientific American, Inc. All rights reserved. No part of this issue may be...

Stirling Engine

Free Energy Engine

A high-performance Stirling engine shuttles a working fluid, such as hydrogen gas, between two chambers a . The cold chamber blue is separated from the hot chamber orange by a regenerator that maintains the temperature difference between them. Solar energy from the receiver heats the gas in the hot chamber, causing it to expand and move the hot piston b . This piston then reverses direction, pushing the heated gas into the cold chamber c . As the gas cools, the cold piston can easily compress...

The Least Bad Fossil Fuel

Although renewable energy sources offer the best way to radically cut greenhouse gas emissions, generating electricity from natural gas instead of coal can significantly reduce the amount of carbon added to the atmosphere. Conventional coal-fired power plants emit 0.25 kilogram of carbon for every kilowatt-hour generated. More advanced coal-fired plants produce about 20 percent less carbon. But natural gas CH4 has a higher proportion of hydrogen and a lower proportion of carbon than coal does....