Stories tagged Flow of Matter and Energy
Another tidal generator: But this one is hiding underwater. This is why I didn't know what they look like.Courtesy FundyAlong with wind and solar, harvesting power from tidal forces comes up a lot in discussions of alternative energy sources.
Was that a horrible sentence? I think it was. What I meant to say is this: we can generate electricity from tides, and lots of it. "Tidal power" is often brought up alongside solar power and wind power, but while I can easily picture windmills and solar panels, I'm not always sure what sort of device we'd use to harness the power in the tides.
This sort of device! For those of you too afraid to click on a strange link (who knows... I could be linking to an image like this!), the article depicts something that looks sort of like a thick, stubby windmill, with blades on its front and back. It's a tidal turbine, and at 74 feet tall and 130 tons it's the world's largest. It should be able to supply electricity to about 1,000 households. Pretty impressive.
Tidal turbines, apparently, are so productive because water is so much denser than water, and so it takes a lot more energy to move it. An ocean current moving at 5 knots (that's a little shy of 6 miles per hour, for the landlubbers) has more kinetic energy, for example, than wind moving at over 217 miles per hour.
At least according to that article, the United States and Great Britain each have enough tidal resources (areas where this kind of generator could be installed) to supply about 15% of their energy needs.
More info on the tidal turbine, which I am calling "the Kraken," because it's big, underwater, and will occupy your mind for only a very short time.
Tags : 
Aurora borealis above Lake Harriet in Minneapolis, MN: The white streak visible in the lower right of the timed exposure is an aircraft taking off from the Minneapolis-St. Paul airport.Courtesy Mark RyanOld Sol could be stirring up the atmosphere this evening with a display of northern lights (aurora borealis). Scientists have recorded a significant burst of plasma shooting from the Sun’s surface that could mean we earthlings are in for a light show tonight or early Wednesday morning. The solar wind particles are headed right toward us, and when they reach the Earth’s magnetic field they’ll interact with atoms of nitrogen and oxygen in the atmosphere and - hopefully - produce glowing sheets and fingers of green, red, blue, or even yellow in a wonderful display in the northern skies. The southern hemisphere experiences the same phenomenon but down there it’s known as the aurora australis (southern lights).
Lately, here in the Twin Cities, the air has been supersaturated with humidity so I don’t know how crisp a view we’ll get but it could be worth stepping outside tonight to see what’s up.
SOURCE and LINKS
CNN.com report
Univ. of Alaska’s Geophysical Institute Aurora Forecast page
Michigan Tech’s Aurora page
Solar flares
Slow boat to China: Cargo ships are cutting their sailing speeds to reduce costs.Courtesy mikebaird
Save 40% on fuel costs by slowing down 20%
Slower speeds also reduce pollution. Too bad that is not why the shipping companies are slowing down. The tough economic times has forced many to think of ways to cut costs.
$100 million in fuel savings
It is believed that Maersk, the world's largest shipping line, with more than 600 ships has saved more than $100 million on fuel since it began its go-slow policy. Instead of the standard 25 knots to 20 knots, some container ships are slowing down to 12 knots (about 14 mph). This is slower than the speed of sailing clippers such as the Cutty Sark more than 130 years ago.
Works for cars and trucks, too
Driving too fast or rapid acceleration wastes money.
You can lower your gas mileage by 33 percent at highway speeds and by 5 percent around town.
You can assume that each 5 mph you drive over 60 mph is like paying an additional $0.24 per gallon for gas. fueleconomy.gov
There should be a law
Saving money and reducing pollution should be a no-brainer but people with too much money often choose to speed. I think slowing down should be mandatory.
Learn more about speed vs saving
Source Modern cargo ships slow to the speed of the sailing clippers The Guardian
…of climate control systems...
Ever notice the plumes of smoke rising from many buildings, factories, and power plants on a cold day? That smoke is actually water vapor, which still contains usable energy, muahahahaha! Our buildings use lots of energy. Electricity, for example, powers everything from lights to computers to copy machines to coffee makers. Electricity eventually degrades into heat—you can feel that heat coming off of electric appliances. Current building energy management systems expel this excess heat energy instead of using it for other purposes, such as building the ultimate tilt-a-whirl of doom. Dave Solberg, an energy miser and consulting engineer-ahem-secret advisor, wants to change all that using the concept of exergy. He envisions a future where energy is used as efficiently as possible, and he has been working with Xcel Energy and organizations in the St. Paul area to re-engineer buildings.
We all know that mad scientists with plans for world domination need money and power. Well, current climate control systems are expensive to build and operate, and they're bad for the environment. But retrofitting old buildings and creating the infrastructure to support Solberg's systems has a higher up-front cost than following the status quo. If Solberg can demonstrate the effectiveness and cost savings of his plan below at SMM, your regional science museum will become a model for climate control systems all over the world--I mean it will take over the world! HAHAHAHAHAHA!
At Science Museum of Minnesota, Solberg wants to make two big changes in the way we use energy:
Solberg's Plan - Phase 1
Like all large buildings, SMM takes in outdoor air, cools it to dehumidify it, then reheats the air and sends it throughout the building to control the climate. Unlike most buildings, which use giant air conditioners and boilers, SMM uses hot and cold water piped in from Saint Paul District Energy to do that job. You can learn more about District Energy in an outdoor exhibit to the left of SMM's main entrance--and you can see the building right next to us!
District Energy burnin' the biomassCourtesy Andrew Ciscel
The first change Solberg proposes is to re-use the waste heat that SMM generates from cooling down fresh outside air. Currently, SMM's ventilation system cools outside air down to about 50 degrees F with cold water from District Energy, dehumidifies it, and then reheats that air back up to a comfortable indoor temperature with hot water from District Energy.
Solberg would have us cool the air with cold District Energy water, then use that same water (now warmer) to reheat the air back up to 65 degrees F on its way to the ventilation ducts. This change would eliminate the need to use hot water from DE to reheat air, and it would reduce use our demand on DE’s cooling system, because we would send water back to their chilled water plant at a lower temperature than we currently do.
Solberg's Plan - Phase 2
District Energy makes electricity by burning waste wood. DE then uses the heat energy still available after making electricity to produce hot and cold water, making District Energy 50% more efficient than coal-fired power plants. But at the end of the day, DE has 95-degree F water left over. Right now this excess heat is released into the atmosphere from cooling towers on top of the building (see the plume rising from the building in the image?), but that 95-degree water could meet most of SMMs heating needs. Solberg wants us to tap into that wastewater as our primary heating source, replacing the 180-degree water we currently get from DE. This would put an oft-wasted energy source to work, and it would allow the 180-degree water now being used by SMM to be used elsewhere within DE’s hot water distribution system.
This plan is so good it must be evil. In the long run, if the kinds of changes being pursued by SMM were replicated widely, they would amount to lower emissions and lower energy bills everywhere, which is ultimately healthier for our environment (not that mad scientists care about that sort of thing). In fact, we found out that if we had implemented this system when the current building was constructed, we could have saved $1.5 million in infrastructure (which we could have really used for that giant laser in the--end of message truncated--
Brown gold!: This is actually the solid byproduct of a manure-to-methane operation. As you can see, it holds no fear for the owner of this bare hand.Courtesy kqedquestWe’ve talked about the delights of cow feces before on Science Buzz, but mid-July always puts me in the mind of “brown gold” (coincidentally, the last occasion it came up was exactly four years ago today), and any time there’s talk of turning an animal into a fuel source, I get excited. (Remember that fuel cell that ran on the tears of lab monkeys? Like that.) Why not take another look?
So here you are: another wonderful story of cows trying their best to please us, before they make the ultimate gift of allowing their bodies to be processed into hamburgers and gelatin and cool jackets.
Poop jokes aside (j/k—that’s impossible), it is a pretty interesting story. The smell you detect coming from cattle farms is, of course, largely from the tens of thousands of gallons of poop the cattle produce every day. The decomposing feces release lots of stinky methane. (Or, to be more precise, the methane itself isn’t smelly. The bad smell comes from other chemicals, like methanethiol, produced by poop-eating bacteria along with the methane.)
Aside from being, you know, gross, all of that poop is pretty bad for the environment. The methane is released into the atmosphere, where it traps heat and contributes to global warming (methane is 20 to 50 times more potent than carbon dioxide as a greenhouse gas), and the poop itself is spread onto fields as fertilizer. Re-using the poop as fertilizer is mostly a good idea, but not all of it gets absorbed into the soil, and lots of it ends up getting washed away into rivers, lakes, and streams, where it pollutes the water.
Some farms have managed to address all of these problems, and make money while doing it.
Instead of spreading the manure onto fields right away, the farms funnel all the poop into swimming pool-sized holding tanks, where it is mixed around and just sort of stewed for a few weeks. All of the methane gas produced by bacteria as it breaks down the manure is captured in tanks. What’s left is a fluffy, more or less sterile, solid that can be used as bedding for the animals, or mixed in with soil, and a liquid fertilizer that can be spread onto fields.
The methane can then be used on-site to generate electricity, either by burning it in a generator, or using it in a fuel cell. (The methane is broken apart and combined with oxygen from the air to produce electricity, water, and carbon dioxide.) A large farm will produce enough electricity to power itself and several hundred other houses. (The extra electricity is just put back into the power grid and sold to the power company.)
Whether the methane is burned or used in a fuel cell, the process still creates carbon dioxide. However, CO2 isn’t nearly as bad as methane when it comes to trapping heat, and because the original source of the carbon was from plant-based feed, the process can be considered “carbon-neutral.” (Although one might argue that the fossil fuels involved in other steps of the cattle farming process could offset this. But let’s leave that be for now. It’s complicated.)
The downside is that setting up an operation to capture and process manure, and to generate power by burning it is expensive—it took about 2.2 million dollars to do it at the farm covered in the article, with about a third of that coming from grants. Still, the byproducts (electricity, fertilizer, soil/bedding) are profitable enough that the system could pay for itself over the course of a few years.
It’s amazing, eh? Out of a cow’s butt we get soft, clean bedding, liquid fertilizer, and electricity, all without the bad smell. What a world.
Roooaaaarrrr!!!: I have the poison in me!Courtesy http://www.flickr.com/photos/kuroha/638778686/Like all ogres, Shrek is a greedy and covetous beast. He has millions of fine, fine goblets, but should you attempt to drink from any one of them, you risk becoming the target of one of his powerful cancer spells.
“But, Shrek,” you say. “You have so many wonderful cups, brought to us by McDonalds and Shrek 4 Eva. Why can’t I drink from just one of them?”
“Because,” Shrek would surely reply, “they’re all mine. All of them! That’s why I put cadmium in them. Ogres are immune to cadmium, but it is a carcinogen in humans.”
“A carcinogen? In your cups?” you ask.
“Yes, a carcinogen. With long term exposure, carcinogens can increase your chances of developing cancer!” says Shrek.
“Cancer?” you say.
“Yes. Cancer,” says Shrek.
And it’s not only Shrek’s goblets that are cursed; drinking from the cups of Princess Fiona will soften your bones, and sipping from the vessels of Puss in Boots will cast the hex of severe kidney damage upon you. And you should never drink out of something called “Donkey,” no matter what it’s made of.
Fortunately, all of the cups are being recalled to Ronald McDonaldland, to become a part of Ronald’s personal collection. Because clowns feed on poison.
Assorted rubbish may be pumped into the leaking oil well: To make it more fun.Courtesy obiwanjrYou know, when that oil rig went down and started spilling hundreds of thousands of gallons of crude oil into the Gulf of Mexico, I thought, “What a downer. My reruns of ‘Yes, Dear’ are going to be interrupted with news footage of crying beavers and stuff for months now.”
But then BP came up with that idea for the containment dome, and I thought, “This is so crazy… it just might work. This could be more entertaining than ‘Yes, Dear.’ If such a thing is possible.”
But, no. The dome failed. Petrochemicals and near-freezing ocean water combined to form crystals in the dome, and it didn’t work. And it was super far underwater, so the failure couldn’t even be set to Benny Hill music or anything. Not entertaining.
I was just resigning myself to the fact that such a horrible accident might not actually be funny, when the jokers at BP let slip that they might have another hilarious trick or two up their sleeves. The dome didn’t work? Let’s try a giant “top hat”!
Yes, BP will be sinking a giant top hat onto the leaking oil pipe. It’s not really a top hat, of course; it’s actually a smaller version of Friday’s giant failure. I’m guessing it’s a sort of a bonus joke. But BP claims that the smaller contraption should have better chance of success, except that even if it does work, it won’t work as well as the dome was supposed to. (The dome was supposed to capture something like 85% of the leaking oil. But it captured 0%, so that’s sort of academic. Or, again, a bonus joke.)
And BP even has another plan, a Plan C, if you will, in the works, in case this one flops. Sort of how they filmed the second and third Matrix movies at the same time. According to my sources, the discussion behind plan C went sort of like this:
“So… what does everyone hate?”
“Nazis.”
“Yes, for sure Nazis. What else?”
“Um… oil spills?”
“Correct! Oil spills.”
“Ooh! We should do one of those!”
“No, people hate them. Plus we already have one. So what does everyone like?”
“Top hats.”
“Top hats, obviously. So we should throw one of them in the mix. But, if someone doesn’t like top hats, what do they probably like?”
“Everybody likes… ball pits?”
“Ball pits! Exactly! Let’s do something like that!”
“And tires! Old tires!”
“Yes, old tires too!”
So, in case the top hat doesn’t work, BP is considering injecting the leaking system with golf balls. And old tires. And then they would cap it off with some cement. Oh, right, and there’s this part too:
“What should we call it?
“A ‘junk shot.’ Duh.”
“Oh, my God. Totes perfect.”
And then, I assume, everybody else in the room had to go wash their ears out after hearing the unfortunate term “junk shot.”
Others have warned that such a “junk shot” could have repercussions beyond the phrase appearing in print: damaging the huge valve system at the base of the well could result in oil leaking out even faster—as much as 12 times the current rate.
Performing a junk shot against the flow of oil and the under the pressure at that depth will be extremely challenging, too. According to an expert from Tulane University, such an operation would have to cope with 2,200 pounds per square inch of upward pressure, which would make pumping golf balls and tires down very tricky.
However it turns out, it’s sure to be a barrel of laughs. Or oil. Thousands and thousands of barrels of spilled oil.
(I don’t have any better ideas, by the way. Except not to have a leaking pipeline a mile underwater. But you know what they say about hindsight.)
Is this house a biogeochemical hotspot?Courtesy monkeyc.netTo ecologists who study the environment, cities and suburbs are fascinating places. For one thing, they're full of people, and people take-up space, consume materials and energy, and create waste every single day. When people do this together in concentrated areas like cities and suburbs, they create what scientists call "biogeochemical hotspots" - places where chemical and energy reaction rates are much faster than in surrounding areas.
Individual houses are also hotspots. A group of scientists at the University of Minnesota, led by researchers Sarah Hobbie and Kristen Nelson, are trying to understand more about urban ecosystems and how chemicals and energy cycle through different people's homes.
They've begun to study a small group of people whose homes are here in Minnesota - asking them questions about their behavior and taking surveys and samples on their property.
What they've found might surprise a few people. It turns out that not everyone uses energy and chemicals the same way. Small numbers of individuals and families consume and waste much more than others - creating a bigger footprint in their ecosystem.
So who are these disproportionate polluters? There is a lot that scientists still don't know, especially about why people make the choices they do, but one thing seems to be clear - generally speaking, the more money that a family makes, the bigger their ecological footprint.
These bigger impacts come from a few behaviors that wealthier Americans tend to exhibit more than their less-wealthy counterparts. Flying in airplanes, buying a much larger home, having more pets and driving a car more often all contribute to a family's impact on their ecosystem.
While studying the role individuals play in urban ecosystems, another thing these scientists found to be true was that small individual actions - for example, turning down the thermostat in the winter just a few degrees, or using less chemicals on lawns, did have a significant impact on the environment.
You can see a recording of two of the researchers involved this study .
![NASAAlgae: An illustration of a NASA's offshore algae harvesting and turning into fuel. "The blue is turning green," said a team leader, Jonathan Trent, a bioengineer at NASA Ames Research Center.](/sites/default/files/images/NASA_Algae.jpg "NASAAlgae: An illustration of a NASA's offshore algae harvesting and turning into fuel. "The blue is turning green," said a team leader, Jonathan Trent, a bioengineer at NASA Ames Research Center.")
NASAAlgae: An illustration of a NASA's offshore algae harvesting and turning into fuel. "The blue is turning green," said a team leader, Jonathan Trent, a bioengineer at NASA Ames Research Center.Courtesy NASA
AlgaeStock: The tiny green creatures - algae - the bright future for biofuel alternative.Courtesy Amy WesterveltRemember the illuminating, healing Tree of Soul from the movie Avatar? Imagine similar light-absorbing creatures in glowing Olympic pool or convoluted, green blankets floating in the oceans of Pandora. But within the next decade, we’ll see those just off the coast of California. The age of alga[e]tar, algae-derived substitute for gasoline, is rising.
Jan 15, 2010, the U.S. Department of Energy (DOE) funds $80 million to develop "sustainable commercialization" of algae-based gasoline, diesel and jet fuel. Several start-up companies like Dow Chemical and Algenol Biofuels have developed pilot plants, using CO2 to grow algae which produce biofuel. The plants are now in Freeport, TX, Bonita Spring, FL, and even in Kailua-Kona, HI.
Via photosynthesis, algae convert CO2 and water into oxygen, water, and hydrocarbons, one of which is ethanol. Ethanol is for vehicle fuel or an ingredient in plastics, replacing natural gas-derived plastic industry. Oxygen is fed into a chamber to burn coal. Unlike traditional coal plants, which have nitrogen as the main input and produce nitrogen exhaust, the exhaust from oxygen-input plants is mainly CO2. CO2 then goes back to the tanks to stimulate the growth of algae, doubling their mass several times a day and making15 times more fuel than palm.
But can’t soybean and sugar cane do the same job? Yes, they can but not as efficient. Compared to the yield of only hundreds of gallons from oil palm, sunflower and soybeans, according to DOE, biofuel yield from algae ranges between 1,000 - 4,000 gallons per acre per year. Those yields can be double when NASA steps in. Jonathan Trent, a bioengineer at NASA Ames Research Center, takes advantage of the ocean waves and open spaces to grow freshwater algae in biodegradable plastic bags offshore. Feeding on nutrients in sewage at typical cities’ dump sites, the algae would clean the wastewater. So, we are not only getting green energy, but clean water from the algae as well. Algae farms resolve an issue plaguing the corn ethanol industry which takes farmland out of food production. Deserts and ocean are out there, waiting to turn into green.
The win-win situation holds the promise of cleaner fuels, scrubbing CO2 off the atmosphere. However, 3 big challenges remain.
The first challenge is to identify the best algae strain for biofuel production. What kind should we use? Mutant vs. conventional? Carbon dioxide uptake of the conventional strain is highest at low light and level off as it gets brighter during the day. However, Christoph Benning , a Michigan State University professor of biochemistry, discovers that the mutant ingests carbon dioxide regardless of the light intensity, thus doubling the rate of carbon sequestration. But, what if those mutants leak out- a mutant algae boom? To avoid that, David Bayless, a professor of mechanical engineering at Ohio University, instead uses heat-resistant algae that naturally thrive in the hot springs. Bayless indicates that these algae, placed vertically on screens due to limited space, are efficient at absorbing CO2 from the power plant.
The second challenge - space. Like solarand wind energy, algae-derived biofuel also have a problem with scale production. Vast desert/ocean vs. domestic, low cost ponds. How can we reduce high-energy inputs for turning deserts into algae ponds, which require loads of temperature controlling and water management? Will the large-scale algae farm eventually compete for land and water resources as much as other biofuel alternatives? The household-scale production or NASA’s ocean scheme might do a better job here, but the scientific advances are still being tested.
The third challenge is to get every single bit of hydrocarbons out with cheap price. So far, separating oxygen and water from hydrocarbons, harvesting, and converting hydrocarbons into gasoline and diesel fuel have proven difficult. It’s a long way down to make it economically feasible. The technologies for those processes are under investigation at the University of Minnesota’s BioTechnology Institute and Institute on the Environment’s IREE - The Initiative for Renewable Energy and the Environment.
Despite pros and cons of algae-derived biofuel, one message is clear. People are making efforts to replace fossil-based energy with sustainable alternatives by using organisms as tiny as the algae. It might be the time for us to realize the real potential of algae, echoing “Algae, I see you,” which means I understand, “I see into you” in the Na’vi language.
Kites over Lake HarrietCourtesy Mark RyanOver the centuries, kites have been used for ceremonial purposes, military tactics, scientific experiments, and of course just for fun. The actual origin of kites is sketchy. Some historians claim the islanders of the South Seas first used them to catch fish. But others say kites were first invented in China nearly 2500 years ago. 
Steady as she goes.: Kids love flying kites.Courtesy Mark Ryan
Some fanciful kitesCourtesy Mark RyanWhatever the case, kites are fun to fly. Yesterday, the 10th Annual Lake Harriet Winter Kite Festival took place on Lake Harriet in Minneapolis. Despite the frigid temperatures, it was a beautiful day for the event. A big crowd was present when I was there, and there were some colorful as well as unusual kites in the air. And it’s not just a matter of slapping a sheet of old newspaper to a couple slats of balsawood and adding a tail and some string, kite-flying involves a lot of science.
It ain't rocket science: But keeping a kite aloft takes more than just a good breeze.Courtesy Mark RyanAnyway, the event was sponsored by several organizations, including the Minneapolis Parks and Recreation Board, and the Minnesota Kite Society. 
Successful kite launch: Up, up, and away!Courtesy Mark Ryan
If you want to get involved in kite-flying yourself, there’s a ton of information on the Internet to get you started. I’ve linked to a few of the better ones I found including the site for National Kite Month, which runs this spring from March 27th to May 2nd.
Come on now; get off that couch, join in the fun, and go fly a kite.
Using Kites to Study Aerodynamics
World’s largest kite plan archive
PBS Challenge: How does a kite fly?
The Kite Society (UK)
Kite Study for Children (includes some history)
National Kite Month
Off we go!!: A bundled kite-flyer gives her aircraft a good boost at launchCourtesy Mark Ryan
All sorts of kitesCourtesy Mark Ryan
Giant bear kite dominates the skyCourtesy Mark Ryan
Lake Harriet Winter Kite Festival: Minneapolis, MNCourtesy Mark Ryan
