Posts Tagged ‘Climate / Environment’ ( text size - + )
sciam.com: By Matthew L. Wald
The need to tackle global climate change and energy security makes developing alternatives to fossil fuels crucial.
Renewable energy, such as from photovoltaic electricity and ethanol, today supplies less than 7 percent of U.S. consumption. If we leave aside hydroelectric power, it is under 4.5 percent. Globally, renewables provide only about 3.5 percent of electricity and even less of transportation fuels.
But increasing that fraction for the U.S.—as seems necessary for managing greenhouse gases, trade deficits and dependence on foreign suppliers—has at least three tricky components. The obvious one is how to capture the energy of wind, sun and crops economically. After that, the energy has to be moved from where it is easily gathered, such as the sunny American Southwest or the windy High Plains, to the places it can be used. And the third is to convert it into convenient forms. Most prominently in the last category, electricity for transportation has to be loaded into cars and trucks, either through batteries or perhaps as hydrogen. [ read more ]
sciam.com: By David Biello
Molten salts can store the sun’s heat during the day and provide power at night
Near Granada, Spain, more than 28,000 metric tons of salt is now coursing through pipes at the Andasol 1 power plant. That salt will be used to solve a pressing if obvious problem for solar power: What do you do when the sun is not shining and at night?
The answer: store sunlight as heat energy for such a rainy day.
Part of a so-called parabolic trough solar-thermal power plant, the salts will soon help the facility light up the night—literally. Because most salts only melt at high temperatures (table salt, for example, melts at around 1472 degrees Fahrenheit, or 800 degrees Celsius) and do not turn to vapor until they get considerably hotter—they can be used to store a lot of the sun’s energy as heat. Simply use the sunlight to heat up the salts and put those molten salts in proximity to water via a heat exchanger. Hot steam can then be made to turn turbines without losing too much of the original absorbed solar energy. [ read more ]
sciam.com: By Eitan Haddok and David Biello:
The enhanced system at Soultz in France is the first such artificial geothermal power plant. Since the 1920s The Geysers geothermal power plant 72 miles (115 kilometers) north of San Francisco has been pumping out electricity harvested from hot rocks deep within Earth’s crust. But there are only so many natural volcanic formations to be tapped. In locations that are not blessed by easy access to this natural resource, drilling into the hot rock bed and pumping fluid through it has the potential to unleash 2,000 times the total annual consumption of energy in the U.S., according to a 2007 report from the Massachusetts Institute of Technology. [ see more ]
discovermagazine.com: by Dava Sobel
One remarkable forest is busy purifying the planet. A legacy of the Argonne National Laboratory’s early foray into atomic energy lies buried here on its campus, about 25 miles southwest of Chicago. Although solid wastes from all sorts of experiments have been sealed in a landfill, certain liquids, mostly chlorinated solvents, still taint the water that runs under the site. The ongoing attempt to remove these contaminants occupies an enormous experimental facility that covers four acres and looks like a forest.
“I like to brag that I have the biggest lab at Argonne,” says agronomist Cristina Negri, indicating an expanse of 900 poplars and willows growing in rows. The trees stand about 30 feet high. More important, their roots extend 30 feet down, where they tap the contaminated aquifer and literally pull pollutants out of the ground. [ read more ]
washingtonpost.com: By Kari Lydersen
When a 1991 cholera outbreak that killed thousands in Peru was traced to plankton blooms fueled by warmer-than-usual coastal waters, linking disease outbreaks to epidemics was a new idea. Now, scientists say, it is a near-certainty that global warming will drive significant increases in waterborne diseases around the world. [ read more ]
wired.com: By Alexis Madrigal
When geologists wanted a better look at a Yosemite rock face in years past, they only had one option: climb the cliff.
But now, thanks to super-high resolution gigapixel images created by a team of 70 photographers using GigaPan robotic imagers and a laser-mapping airplane, park geologist Greg Stock now has unprecedented access to the geological features of one of the world’s most famous parks. And all from the comfort of his laptop.
[ read more ]
washingtonpost.com: By David A. Fahrenthold
Carbon-Offset Sales Brisk Despite Financial Crisis
This is strange territory. The Dow is down. Wall Street needs a bailout. But in the Washington area and across the country, there is still a bull market in environmental guilt. Sales of carbon offsets — whose buyers pay hard cash to make amends for their sins against the climate — are up. Still. In some cases, the prices have actually been climbing. [ read more ]
bloomberg.com: By Adam Satariano
asmanian salmon farmers are trying to breed a new species that can flourish in warmer ponds. Along the coast in Britain the National Trust, a charity, is moving electricity sockets halfway up the wall in several buildings to safeguard against flooding from the sea.
Preparing for global warming also demands government action because temperature increase is unavoidable and will affect everyone, European scientists said in a study published today by the U.S. National Academy of Sciences. [ read more ]
University of Calgary climate change scientist David Keith and his team are working to efficiently capture the greenhouse gas carbon dioxide directly from the air, using near-commercial technology.
In research conducted at the U of C, Keith and a team of researchers showed it is possible to reduce carbon dioxide (CO2) – the main greenhouse gas that contributes to global warming – using a relatively simple machine that can capture the trace amount of CO2 present in the air at any place on the planet.
“At first thought, capturing CO2 from the air where it’s at a concentration of 0.04 per cent seems absurd, when we are just starting to do cost-effective capture at power plants where CO2 produced is at a concentration of more than 10 per cent,” says Keith, Canada Research Chair in Energy and Environment. [ read more ]
technologyreview.com: By Kevin Bullis
With catalysts created by an MIT chemist, sunlight can turn water into hydrogen. If the process can scale up, it could make solar power a dominant source of energy.
“I’m going to show you something I haven’t showed anybody yet,” said Daniel Nocera, a professor of chemistry at MIT, speaking this May to an auditorium filled with scientists and U.S. government energy officials. He asked the house manager to lower the lights. Then he started a video. “Can you see that?” he asked excitedly, pointing to the bubbles rising from a strip of material immersed in water. “Oxygen is pouring off of this electrode.” Then he added, somewhat cryptically, “This is the future. We’ve got the leaf.” [ read more ]





