Micro Hydro Power From the Flipwing

A Seattle-based company called Hydrovolts has been winning awards for its miniature turbine that you can drop into streams, canals, and pretty much any place that has a steady flow of water.

The turbine, brand named Flipwing, will be produced in three sizes. The smallest will be about the size of a 2-drawer filing cabinet and the largest will be about 2 x 2 x 6 meters. It can be installed in the water stream vertically or horizontally.

The Flipwing's blades swing open on the reverse upstream stroke, presenting their edge to the current. Thus the kinetic energy of the water flow is used almost entirely in turning the blades in the downstream direction.

Hydrovolt's website is a bit opaque about the amount of electricity the Flipwing produces. Using an average market price of electricity of $0.11 per kWh, the site says the turbine can generate, in a 2m/sec current, $1,400 worth of electricity per year. By my calculations, that means it can make 12.7 MWh of electricity annually.

Here's a video of a small Flipwing unit in operation in a stream. Hydrovolt has several more videos on its YouTube channel:

Coal Fly Ash Spill in TVA Greater Than Waste Released in All U.S. Rivers

The coal fly ash spilled at the Tennessee Valley Authority's Kingston power plant on Dec. 22, 2008, carried toxic metals like arsenic, mercury and barium.

According to data from the EPA, the amount of metal in that one spill exceeded what was released into rivers by power plants throughout the country during the entire year.

The EPA estimated that 2.66 million lbs. (1.2 million kg) of 10 toxic metals flowed into the Emory River.

Meanwhile, area residents filed hundreds of lawsuits against the TVA before the 1-year deadline expired for personal injury claims.

Large Dams Lead to More Rainfall

Photo: ClaudioT.

From the Things You Never Thought Of dept.: Dams lead to higher rainfall and more floods.

Scientists from the Tennessee Technological University and the University of Colorado, Boulder, explain why large dams bring more rain.

First, the reservoir behind the dam produces excessive evaporation that falls to the earth as rain. This seems obvious.

But what's more, says the Newsweek article that reported on the finding, "dams increase atmospheric instabilities in the vertical profile of temperature and humidity."

The increased instability "enhances the amount of convective energy in the air above the reservoir." That means more thunderstorms of greater intensity than before. That, in turn, means higher and more frequent floods than engineers had calculated when they built the dam.

And that, say the scientists, "...raises concerns about dam safety."

Quality of Drinking Water in Large Cities Ranked

If the quality of your municipal drinking water is important to you, move to Arlington, Texas. The Environmental Working Group has rated its water the best among large cities in the U.S.

On the other hand, if you'd rather live in the Northeast because you love its winters, despair not. Providence, R.I., came in 2nd.

The Environmental Working Group rated the water utilities of cities with populations of 250,000 or more on three factors:

...the total number of chemicals detected since 2004; the percentage of chemicals found of those tested; and the highest average level for an individual pollutant, relative to legal limits or national average amounts, including for the most common pollutants (disinfection byproducts, nitrate and arsenic). [From the Group's website.]

The top 10 cities were:

1. Arlington, TX
2. Providence, RI
3. Fort Worth, TX
4. Charleston, SC
5. Boston, MA
6. Honolulu, HI
7. Austin, TX
8. Fairfax County, VA
9. St. Louis, MO
10. Minneapolis, MN

And the bottom 10 were:

91. Jacksonville, FL
92. San Diego, CA
93. North Las Vegas, NV
94. Omaha, NE
95. Houston, TX
96. Reno, NV
97. Riverside County, CA
98. Las Vegas, NV
99. Riverside, CA
100. Pensacola, FL

Connecticut residents: the highest-ranked utility in our state was Bridgeport-based Aquarion, at No. 21. Hartford's Metropolitan District Commission ranked 23rd, and New Haven stood 37th.

See the entire list of cities here.

Washing Machines to Be Subject to Energy-Efficiency Standards in California

Photo credit: celila.

Given that clothes washing machines use several resources, like water, electricity and (sometimes) natural gas, it's kind of surprising that no government agency has tried to set standards for their energy efficiency.

Until now.

The Los Angeles Times reports that the California Energy Commission has prevailed in a lengthy lawsuit against the U.S. Department of Energy enabling the commission to set efficiency standards for washing machines. The new standard could go into effect in 2013.

According to the L.A. Times, the average washing machine uses 39.2 gallons of water per wash. The proposed standard would reduce that average to 21.1 gallons per wash.

The California Energy Commission estimates that 12 to 15 years after the new standard takes effect, the state could save 66.7 billion gallons of water. That's enough water to supply a city the size of San Diego every year, the L.A. Times says.

Energy savings would follow, too. California would need 50 million fewer therms of natural gas and 500 fewer gigawatt-hours of electricity to heat and move water around in the new clothes washers.

9 Threats to Earth's Environmental Stability

The Earth's environment has been unusually stable for the past 10,000 years, but human actions now threaten that stability, say Johan Rockström and 28 colleagues in a recent article published in Nature.

This statement, by itself, is hardly shocking. Scientists began sounding alarms about climate change years ago. But Rockstrom et al present a new approach to the question of human sustainability. They list 9 boundaries that we are crossing and endangering Earth's ability to maintain the environment that enabled human development. Giving teeth to their thesis, they quantify 7 of these environmental boundaries.

The boundaries are:

• Climate change
• Rate of biodiversity loss (terrestrial and marine)
• Interference with the nitrogen and phosphorus cycles
• Stratospheric ozone depletion
• Ocean acidification
• Global freshwater use
• Change in land use
• Chemical pollution
• Atmospheric aerosol loading

The boundaries are interrelated, the authors say. For example, land-use changes in the Amazon could influence water resources in Tibet. And "transgressing the nitrogen–phosphorus boundary can erode the resilience of some marine ecosystems, potentially reducing their capacity to absorb CO₂ and thus affecting the climate boundary."

All boundaries must be addressed, according to the authors. We no longer have the luxury of concentrating on one at the expense of others.

The Nature article summarizes the full paper, "Tipping towards the unknown," available at the Stockholm Resilience Centre (where Professor Rockström is executive director). The paper's web page includes abundant complementary material, such as videos of some of the paper's contributors, the full 36-page scientific article and information for the press.

Kill Weeds in Your Driveway With Vinegar

A couple of days ago I used ordinary store-brand vinegar to kill weeds in my driveway. Just sprayed the vinegar directly onto the weeds, and by the next morning the weeds had started wilting.

I found applying vinegar to be much more economical and environmentally friendly than using herbicides. A 2-gallon bottle of 5% white vinegar cost around 2 dollars. Compare that to the price of your favorite (and much-advertised) herbicide.

You can pour the vinegar on the weed straight from the bottle, or load some vinegar in a spray bottle and squirt it on the offender (like I did).

I sprayed the vinegar in the morning, on a day when there was no chance of rain. (Vinegar degrades in water.) I think I'll spritz some weeds in my lawn next -- see what happens.

Tidal Power Projects Advance in Maine

Boats at low tide at a dock on the Bay of Fundy. Photo © Arun Sinha.

What better place to build a tidal power project than the Bay of Fundy?

The bay is home to the highest tides in the world, which generate fast, massive currents. Wolfville, Nova Scotia, located on an inlet near the apex of the bay, boasts tides of 52 feet (16 meters) every 12 hours 25 minutes! A 5-story house on the beach would be completely under water twice a day at high tide.

Tides in the U.S. portion of the Bay of Fundy aren't as dramatic, but they're not too shabby either. The swing from high to low tide at Passamaquoddy Bay, an inlet of the Bay of Fundy on the eastern tip of Maine along the U.S.-Canadian border, averages about 18 feet (5.5 meters).

That's more than enough to make the region extremely attractive to tidal power producers. Ocean Renewable Power, a Maine-based company that generates electricity from tidal power, holds a permit to produce electricity from Passamaquoddy Bay's tides.

The lure of plentiful tidal power has drawn several development projects to Maine. In addition to its high suitability for the waterways of the state, tidal power is clean, requires fewer turbines than wind to create the same amount of electricity, and poses no threats to boats.

Now, the Federal Energy Regulatory Commission and the state of Maine have agreed to cooperate to bring more tidal power projects to the state. More turbines in the water will mean more opportunities to study their environmental impact, which could lead to faster regulatory decisions.

Maine is just about my favorite state to visit. And having enjoyed a couple of boat rides on the Passamaquoddy Bay many years ago, I can't think of a better body of water in which to place the tidal turbines.

Wringing Water out of Desert Air

The desert, by definition, has little no moisture. You would expect desert air to be as dry as... well, desert air. Why bother trying to squeeze water from it?

Turns out, desert air isn't that arid after all. Israel's Negev desert, for example, is humid enough to hold 11.5 milliliters (ml) of water in every cubic meter of air. Granted, 11.5 ml is a little more than 2 teaspoons, and 2 teaspoons of water don't go far toward slaking a thirst or boiling an egg.

But think of all the cubic meters of air piled above the 17.4 billion-square-meter (6,700 square miles) area of the Negev. The amount of water trapped in the air within 1 meter of the ground alone shoots to 17.4 billion times 11.5 ml, or 200 million liters, or about 53 million gallons.

Got your attention, did I?

Now, the point: Two German organizations have found a way to extract the moisture from desert air and convert it to potable water using only renewable energy.

Scientists at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB in Stuttgart and at Logos Innovationen developed the process.

In their method, hygroscopic brine runs down a tower-shaped unit, where it absorbs moisture from the surroundings. This diluted brine is then sucked into a tank by a vacuuming process. Solar collectors heat the tank.

Because the brine is in a vacuum, it boils at a temperature considerably lower than 100 degrees C. Thus the solar collector doesn't need to work as hard as it would have under normal atmospheric pressure.

The heat from the solar collector boils the water. The evaporated water -- minus the brine -- is condensed and poured down a tube, ready for human use. The weight of the water column helps create the vacuum in the tank, negating the need for a powered vacuum pump.

The leftover brine, freed of the atmospheric water it had absorbed, runs down the tower again, gathering more moisture from the air.

Any electrical power needed by the system is supplied by photovoltaic cells. Which, like the solar collectors, get their power from sunlight.

Which, by definition, is something else the desert has an abundance of.

The scientists have tested prototypes of this system in the lab. Next step: a live demonstration.

Cleaning Up the Air at Seaports

Imagine you're standing on the sea shore, gazing at the horizon. The sun washes over you from a cloudless sky, warming your skin. An occasional seagull caws overhead. You lean into the wind, take a deep breath.

Ahh, smell the salt air, clean and pure.

And the diesel fumes with their particulate matter.

Hold it, hold it. Diesel fumes? Particulate matter?

Yes. Because you're standing in a busy U.S. seaport, surrounded by large ships spewing exhaust smoke into the air.

According to this news report by the Voice of America, air pollution from large ships is expected to grow rapidly as port traffic increases. The EPA is therefore proposing stricter engine and fuel standards for U.S. ships that would significantly improve air quality throughout the U.S.

Thousands of miles of U.S. and Canadian coastline would be named an Emissions Control Area. The standards would apply to all ships operating within 200 nautical miles of the coasts.

From the news report:

By 2030, the domestic and international strategy is expected to reduce annual emissions of nitrogen oxides from large marine diesel engines by about 1.09 million metric tons and particulate matter emissions by about 130,000 metric tons. When fully implemented, the coordinated effort would reduce nitrogen oxide emissions by 80 percent and particulate matter emissions by 85 percent compared with current emissions.

And then the salt air you inhale really will be clean and pure.

Plants Save Water by Telling Farmers When to Irrigate

Ever receive a cell phone call from a plant? Next year, some people may.

AgriHouse, an agri-biotechnology company in Colorado, will start marketing sensors that attach to leaves, measure their turgidity, figure out how much moisture they hold and place cellular calls to farmers when the leaves need water.

The sensors bring scientific precision to bear on answering the age-old questions: Is it time to water the crops? And how much should I douse them with?

Farmers tend to water their fields on a set schedule that they arrive at through measurement and experience. Lacking exact moisture readings at the leaf level, they end up over-watering the soil rather than risk letting the plants dry up.

AgriHouse's sensors tell them when and how much to irrigate. About 129 billion liters (34 million gallons) of fresh water are used daily in commercial agriculture the United States, according to the U.S. Geological Survey. A savings of just 10% would be dramatic, says the president of AgriHouse.

And it's not only water that's saved, but also the energy used to pump the water.

We know that talking to plants can be good for them. It turns out that plants can talk back -- and what they say can be good for us and the environment.

Atrazine -- and TNT -- Cleaned Up by Native Grasses

Native grasses like switchgrass and gammagrass have been known to break up the herbicide atrazine, converting it into carbon dioxide.

Atrazine is a popular weed killer used to treat corn and myriad other crops. Unfortunately, because of its extensive usage, it is a common contaminant in the nation's surface water. Degrading it through natural means like grasses is an appealing, inexpensive and environmentally sound solution.

The scientists who had first studied the effects of the grasses on atrazine recently extended their research to include other soil-bound substances with structures similar to atrazine.

They looked into how the grasses interacted with TNT and RDX. TNT is a suspected carcinogen and leads to immune disorders, allergic reactions and birth defects. RDX can cause seizures if inhaled or eaten in large quantities (pdf).

According to the Department of Defense, the two explosives have contaminated 538 sites in the U.S. between them. Twenty of these are Superfund sites.

In lab tests, the grasses rendered the explosives harmless. All that was left of them was carbon dioxide and water.

The next step is to test the grasses outdoors in actual contaminated sites. Sometimes Nature provides the best solutions.

(Photo of native grasses by Chung-Ho Lin, assistant professor of forestry, University of Missouri.)

Aerogels Super-Efficient at Absorbing Oil

Every year, Americans pour 200 million gallons of used oil down sewers, streams and backyards, according to a story in Science Daily. This results in wastewater contaminated with oil that is hard to remove.

The same story reports that scientists in Arizona and New Jersey have found that minuscule beads of hydrophobic silica aerogel make excellent oil sponges. Aerogels are a porous, super-lightweight solid sometimes called "frozen smoke." They are 99.8% air.

In an experiment, a column of aerogel beads placed in flowing water that contained soybean oil absorbed seven times its weight. It extracted the oil from the water at a "high efficiency."

Expected uses for the aerogel beads: to pluck out oil from wastewater and clean up oil spills in the environment.

(Photo of aerogel in hand, courtesy NASA.)

"Ghost" Nets Entrap Fish

Fishing gear lost or abandoned at sea may be gone and forgotten, but fish continue to fall prey to it. As do turtles, birds and other marine mammals like whales, seals and sea lions.

Not only that, but the gear alters the seafloor and poses a hazard to ships.

According to a report jointly produced by the UN Food and Agriculture Organization (FAO) and UN Environment Programme (UNEP), the problem is getting worse. Global fishing operations have increased in scale and reach, and fishing gear made of synthetic materials lives seemingly forever.

The study estimates that 10% of all marine litter consists of lost or abandoned fishing gear.

To be sure, most of the fishing gear is not deliberately abandoned. It is lost in storms or in "gear conflicts" that occur when fishing nets get entangled in bottom-traps. Whatever the reason, they continue to ensnare fish, a phenomenon known as "ghost fishing."

The problem must be addressed through "prevention, mitigation, and curative measures," says Ichiro Nomura, FAO Assistant Director-General for Fisheries and Aquaculture. The report makes several recommendations:

Financial incentives to encourage fishers to report lost gear or bring to port old and damaged gear.

Marks on fishing gear to help better understand the reasons for gear loss and identify appropriate preventive measures.

New technologies like reporting and retrieval systems, seabed imaging and GPS systems that aid in recovering lost fishing gear, and improvements in weather monitoring technology that can help skippers avoid deploying nets when dangerous weather is imminent.

New fishing materials that incorporate biodegradable elements.

Improved collection, disposal and recycling programs, like putting disposal bins on docks and providing boats with oversized, high-strength disposal bags for old fishing gear. According to the report, most ports do not have such facilities.

Better reporting of lost fishing gear. A key recommendation of the report is that vessels should be required to log fishing gear losses as a routine matter, without apportioning of blame.

Inventing "smarter" fishing gear. Examples include: Gear with passive acoustic pingers that remain active if gear is lost and can help prevent cetacean entanglement, nets incorporating pieces of cord that break when trapped animals begin to thrash, and magnets attached to fishing gear, which can deter sharks from approaching too closely.

(Photo: Loggerhead turtle entangled in pound net leader. Mike Tork, National Oceanic and Atmospheric Administration.)

Most endangered rivers in America

It's the largest watershed in California. Its rivers collect water from 45% of the state's surface area. Nearly 25 million residents depend on the rivers for drinking water, farming, and commercial fishing.

It's the Sacramento-San Joaquin River Delta System. And in the 2009 edition of America's Most Endangered Rivers (TM) -- the annual listing of the nation's 10 most threatened rivers from American Rivers -- it ranks number one.

The top 10 endangered rivers are located, paradoxically, in some of the nation's most rugged and scenic regions. You don't expect to find imperiled rivers in places like Alaska, Idaho, Montana and Minnesota -- lands usually associated with empty spaces, small populations and sparse commercial development.

According to American Rivers, endangered doesn't mean polluted. An endangered river is one that is under serious threat in the coming year, but can be saved through community action.

Is there an endangered river in your neighborhood?

8 Non-carbon energy sources

Two ways to reduce carbon dioxide emissions from power plants:

1. Use existing technologies and better carbon-management practices to cut CO2 releases. Scientific American magazine calls this Plan A.
2. Generate energy through new technologies that bring emissions down to zero -- Plan B.

The Scientific American story linked above is a recent repost of September 2006 story that focuses on Plan B. It describes 8 potential energy sources that discharge no CO2.

Some of the technologies the story mentions have advanced somewhat, while other new ones have emerged. It's an interesting analysis of what's out there. I found myself generally agreeing with the author's predictions.

The 8 energy sources are:

1. Nuclear fusion. Considerable progress has been made in this field since the Scientific American story ran.
2. High-altitude wind. Some serious winds blow at 33,000 feet, where, at certain latitudes, they pack 5,000 to 10,000 watts of power per square meter.
3. Sci-fi solutions, such as cold fusion, bubble fusion, and matter-antimatter reactions. Unrealistic, says the story's author.
4. Space-based solar power. In space, the sun never sets.
5. Nanotech solar cells. Because it's going to be a long time before silicon-based solar cells can compete with grid power on price.
6. A global supergrid. A worldwide network of supercooled, superconducting wires. Not so much a source of energy as a means of efficiently distributing it.
7. Waves and tides. These sources are already being tapped in several places around the world. A proposed project in the UK's Severn River will be the world's largest.
8. Designer microbes. Bespoke cells that could, for example, convert cellulose to fuel, or turn the carbon dioxide from a smokestack into natural gas.

(Photo: Carbon dioxide crystals. Credit: USDA Beltsville Agricultural Research Center.)

7 simple products that cut your energy usage

Saving is a loaded word. It usually involves sacrifice of time, money, or style.

But if you can save without giving up any of these, then saving becomes an agreeable activity.

Yahoo! has published an agreeable list of 7 simple products that save energy -- hence money -- but don't require you to alter your lifestyle in any major way. Not even for the indoor clothes drying racks (#2), which you might think would look odd in your laundry room. You'll get used to them in no time.

The 7 products are:

1. Power strip, which you can turn off so your devices don't consume vampire energy
2. Indoor clothes drying rack, to give your dryer a rest from guzzling all that power
3. Efficient showerheads and faucets, which drench you just as much and as fast as conventional ones
4. Compact fluorescent light bulbs, which will serve you well if you buy and use them as recommended by the Environmental Defense Fund
5. Programmable thermostat, so you can turn the heat on before you wake up in the morning
6. Water heater blanket, because without it, you're just heating your utility closet
7. Sealant for those tiny leaks around the house, because just like you don't want to heat the utility closet, you don't want to heat the outdoors.

Niagara River ice boom degrades environment, says amateur scientist

Ice floes need to flow again on the Niagara River, says Joseph Barrett.

Barrett is a serious fisherman and amateur scientist who has spent a decade trying to prove that the backup of ice caused by the river's ice boom has seriously harmed the environment.

The ice boom is an 8,800-foot long pontoon stretched across Lake Erie, near its outlet to the Niagara River (see live pictures of the ice boom here). The boom blocks winter ice from flowing down the river and over the world-famous falls.

Were the ice left free to flow, it would clog the intakes of the massive turbines of the Niagara Power Project, about 4.5 miles downstream of the falls.

In fact, such an event occurred just last year. On Jan. 30, 2008, a storm broke two spans on the ice boom, releasing ice floes down the Niagara River. Sure enough, the floes wound up blocking the water intakes at the hydroelectric plant down the river, causing electrical generation to drop occasionally to 25% of normal output.

While the ice boom has helped the power plant's electricity roll smoothly, Barrett says it has also prevented the nutrient-rich ice from crossing over to Lake Ontario and feeding thousands of tiny ecosystems along the way.

River ice also pushes sediment up against banks and islands. The lack of ice, Barrett says, is partly responsible for Strawberry Island's erosion from about 100 acres to 3 acres over the past few decades. (For a photo of the island, click here, then scroll down.)

Barrett also provides other examples of the damage wrought by the effects of the ice boom.

What do you think? Should the New York Power Authority and Ontario Power Generation let loose some or all of the ice, and find some other way to divert the floes from the intakes?

Fish ingesting pharmaceuticals

Residues of many medicines, including those used to treat high cholesterol, allergies, high blood pressure, bipolar disorder and depression, were found in fish caught near wastewater plants serving 5 major US cities.

Researchers reported this finding on March 25, the Associated Press said.

The results of the research are not surprising. A year ago, the Associated Press had found that trace amounts of pharmaceuticals were floating around in the nation's water supply. Of course some of it was going to end up in fish.

Medicines get into the water after they pass through our bodies and are not fully neutralized in wastewater treatment plants, and when we simply flush them down the toilet.

In either case, fish suffer.

The EPA provides some advice on discarding needles, syringes and lancets, but I could not find any information on its site about how to get rid of medicines. A pharmacist told me to just toss them in the trash.

At least then they won't be eaten by the fishies.

Environmentalists object to some renewable energy projects

Renewable doesn't automatically mean environmentally friendly. For example:

Three solar power plants have been proposed for the Carrisa Plains in eastern San Luis Obispo County, California. The plants would provide enough electricity to power nearly 100,000 homes.

But in doing so, the plants would cover 16 square miles of the plains with solar panels, reflectors and industrial equipment. Just what the local residents wanted to escape when they moved to the area, long before solar power companies began looking at the unspoiled -- and sunny -- land.

A resident of the plains, Robin Bell, has started the Carrisa Alliance for Responsible Energy. Her goal is to stop the projects in their tracks.

It's not only residents who are concerned by the impact of the plants. Local government officials are, too. They haven't had much experience with evaluating the environmental and biological impact of large solar plants, and they have their own list of issues with the projects.

Besides, I'm sure the law of unintended consequences looms large in their minds.

The controversy at Carrisa Plains portends more tussles in the Golden State. The Bureau of Land Management is reviewing 130 applications for solar and wind projects that threaten to blanket more than 1 million acres of desert land. Sen. Dianne Feinstein, Democrat of California, is preparing legislation that would designate hundreds of thousands of acres of California desert a national monument. If passed, the legislation would put the area out of the reach of energy development companies.

Meanwhile, in the UK, objections swirl around a proposed $28-billion, 10-mile dam across the Severn River, the estuary that separates England and Wales. The dam would tap the energy of the river's massive tide, known as the Severn Bore, which in some places rises 3 to 6 feet.

The dam would swamp about 50,000 acres. Environmentalists fear it will damage the area's mudflats and salt marshes, and disturb the river's flow that brings food to migrating birds.

Distributed power, wherefort art thou?