Micro Hydropower : Turbulent Turbines

One-Third of Scotland Could Soon Be Powered by the World's Biggest Underwater "Windmill" Tidal Plant

http://inhabitat.com/one-third-of-scotland-could-soon-be-powered-by-the-worlds-biggest-underwater-windmill-tidal-plant/

One-Third of Scotland Could Soon Be Powered by the World's Biggest Underwater "Windmill" Tidal Plant




In between the Scottish mainland and the Orkney Islands lies the Pentland Firth, a turbulent sound with tides that can reach up to a startling 18 miles per hour. That’s a lot of untapped power. MeyGen is taking advantage of all that renewable energy with the installation of the world’s largest tidal power plant, and if everything goes as expected, the underwater windmills could eventually power a full third of Scotland.

Read more: One-Third of Scotland Could Soon Be Powered by the World's Biggest Underwater "Windmill" Tidal Plant | Inhabitat - Sustainable Design Innovation, Eco Architecture, Green Building

Daily tides in the Pentland Firth are about 11 miles per hour, which is ideal for a tidal power plant, but that same tidal activity makes installing massive turbines difficult. Nonetheless, the new power station is expected to produce 398 megawatts of electricity every year. That would make it the biggest tidal power plant, passing South Korea’s Sihwa Lake, which generates 254 megawatts each year.
Related: Scotland Approves Europe’s Largest Tidal Energy Project
The plan for building the plant involves dropping 61 turbines onto the floor of the sea, where each one will be weighed in place by concrete legs. Each turbine has rotary blades like a windmill, so to sea life and any wayward divers, the plant will look like a giant undersea wind farm. Though it isn’t the first time someone has used this technology to generate power – there is, among others, one installation in New York City – it is the first time anyone has attempted it at this scale. If it all works, it could set the standard for arrays like this one.

Read more: One-Third of Scotland Could Soon Be Powered by the World's Biggest Underwater "Windmill" Tidal Plant | Inhabitat - Sustainable Design Innovation, Eco Architecture, Green Building

Water used by power plants

Continent’s Tallest Approved Structure to Produce Solar-Wind Energy Hybrid at U.S.-Mexican Border

http://ecowatch.com/2014/05/02/tallest-structure-solar-wind-u-s-mexican-border

This thing is almost designed to discredit green energy.  Spraying fresh clean water in a dessert state where clean water is at a premium is just stupid.

This project will burn 1.5 billion dollars of public money building a massive building only to create water shortages.

Just where is this water going to come from?  Green projects need to generate water and power, not consume them.

If they could do this with sea water, great, but this is not the case.


“A series of pumps deliver water to the Tower’s injection system at the top where a fine mist is cast across the entire opening. The water introduced by the injection system then evaporates and is absorbed by hot dry air which has been heated by the solar rays of the sun. As a result, the air becomes cooler, denser and heavier than the outside warmer air, and falls through the cylinder at speeds up to and in excess of 50 mph. This air is then diverted into wind tunnels surrounding the base of the Tower where turbines inside the tunnels power generators to produce electricity.

http://www.sciencedaily.com/releases/2014/05/140501142227.htm

Breaking up water: Controlling molecular vibrations to produce hydrogen

Date:

May 1, 2014

Source:

Ecole Polytechnique Fédérale de Lausanne

Summary:

Converting methane into hydrogen is crucial for clean energy and agriculture. This reaction requires water and a catalyst. Scientists have now used a novel laser approach to control specific vibrations of a water molecule, which can affect the efficiency of the reaction.

Natural gas (methane) can be converted into hydrogen (H2), which is used in clean energy, synthetic fertilizers, and many other chemicals. The reaction requires water and a nickel catalyst. Methane and water molecules attach on the catalyst's surface, where they dissociate into their atomic components. These then recombine to form different compounds like H₂ and CO. Previous research has focused mainly on understanding how methane dissociates, but experimental constraints have limited research into water dissociation. Publishing inScience, EPFL scientists have used lasers to determine for the first time how specific vibrations in a water molecule affect its ability to dissociate. The experimental results were used to optimize theoretical models for water dissociation (University of New Mexico), which can impact the design of future catalysts.

Methane is widely used on an industrial scale to produce hydrogen, which is used as a clean fuel and as raw material to produce ammonia used for synthetic fertilizers. The process used is referred to as 'steam-reforming' because it involves methane gas reacting with water steam. This reaction requires a metal catalyst that allows the molecules to dissociate and recombine efficiently. But while the details of methane dissociation have been studied for over a decade, the way water molecules separate has remained elusive.

Fine-tuning vibrations with lasers

The team of Rainer Beck at EPFL, have shown that water dissociation depends strongly on the internal vibrations between its hydrogen and oxygen atoms. In a molecule, the atoms are not static but instead may vibrate in different ways. In a water molecule, the two oxygen atoms can vibrate like a scissor ("scissoring"), or can stretch back and forth either together ("symmetrical stretching") or in turns ("asymmetrical stretching"). "These 'stretches' between the oxygen and the hydrogen atoms play a big role in how well or poorly the water molecule can dissociate on a catalyst," says Beck.

Controlling different types of vibrations is the key to understanding a water molecule's ability to dissociate under mild conditions. Employing nickel as a catalyst -- commonly used in steam reformation -- the team used lasers to precisely control how water molecules are being excited. "If you heat up the system with e.g. a flame, you excite all the degrees of freedom at the same time," explains Beck. "You also increase its kinetic energy, so all the water molecules hit the nickel surface at higher speeds, but you have no control over the individual vibrations of the atoms. With a laser, we can selectively excite one type of vibration, which allows us to measure one energy state at a time."

The data showed that the degree of stretching vibrations between the hydrogen and oxygen atoms in a water molecule determines its ability to dissociate react on the catalyst. This happens because the laser adds energy to the water molecules, increasing vibrations to the point where they break up on the catalyst's surface. This point is called a 'transition state', where the water molecules are ready to react. "Ideally, we want to deform the molecules before the hit the surface, in a way that we have biased the structure towards the transition state," says Beck. "This is why laser-selected vibrations are more efficient that just heating up the entire system: we are putting the energy where it needs to be to break the water molecule's bonds."

From experiment to theory

The unprecedented ability to excite specific types of vibrations allowed theoreticians at the University of New Mexico to calculate all the forces between the atoms and the nickel catalyst surface, and simulate what happens when the water molecule hits the catalyst surface with each type of vibration. Without these experimental measurements, such calculations would lack accuracy.

"With our data, the theoreticians can directly compare their model to the experimental data one vibration type at a time, which is far more accurate," says Beck. "This allows for the optimization of dissociation models that can then better predict how other molecules than water or methane will react on a given surface. Our state-resolved experiments are meant to guide the development of predictive theory."

This optimization of theoretical models can also lead to the faster and more efficient development of catalysts for a range of industrial and commercial chemical reactions. As Beck explains: "You can use a computer model to e.g. vary the spacing of the atoms of the catalyst or change the structure of its surface. This is a cheaper or more efficient way to find a good catalyst, rather than having to do trial-and-error experiments. But in order to trust theoretical model, we need this data to test them against."

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Story Source:

The above story is based on materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Materials may be edited for content and length.

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Journal Reference:

1. P. M. Hundt, B. Jiang, M. E. van Reijzen, H. Guo, R. D. Beck. Vibrationally Promoted Dissociation of Water on Ni(111). Science, 2014; 344 (6183): 504 DOI:10.1126/science.1251277

Solar panel systems can strain water resources.

Here's an angle I bet no one even considered.

A friend of mine is on the right track with automatic washing of the panels, but maybe at night.

And to cool the panels something probable needs to be done from the underside.  Like heat sinks or water/fluid cooling in a sealed system.

It looks like evaporation is not going to scale unless we are using sea water or gray water.
It's a complete waste to produce clean drinking water only to use for non-drinking purposes.


http://greeninc.blogs.nytimes.com/2009/09/30/solar-stirs-water-wars-in-the-west/

Solar Stirs Water Wars in the West

By Todd Woody

Isaac Brekken for The New York Times An irrigation riser at Ponderosa Dairies farm in Amargosa Valley, Nev.

As I write in an article in Wednesday’s Times, a water war is breaking out in the desert Southwest over the dozens of large-scale solar power plants planned for the region.
Depending on the technology used, some solar farms can consume more than a billion gallons of water a year in regions that receive three or four inches of rain annually.
It’s a truism that all water politics are local and that’s proving to be the case as solar power becomes the latest fight in the West’s long history of internecine water wars. For solar developers that means dealing with an often-bewildering array of regulations, stakeholders and politics.
In Arizona, for instance, plans for big solar farms have revived old fears that the desert state’s scarce water resources will be exported to energy-hungry California in the form of electricity.
“That has been an issue in the past and it will be come a political issue in the future,” said Kristin K. Mayes, chairman of the Arizona Corporation Commission, the state’s utility regulator. “I don’t think it will be an obstacle to the development of solar energy, but we have to pay attention and deploy solar technologies that use appropriate amounts of water.”
Across the border in Nevada, water politics are even more Byzantine. Individuals and companies own water rights separate from their property. If farmers and ranchers in California worry about big solar projects draining local aquifers, their counterparts across the state line are often eager to sell or lease their water rights to companies like Solar Millennium.

The German solar developer wants to build a 500-megawatt solar power plant complex in the arid Amargosa Valley west of Las Vegas. Its preferred method of cooling the twin solar farms would consume 1.3 billion gallons of water a year, about 20 percent of the desert valley’s water. To obtain rights to that water the company will have to negotiate with scores of local alfalfa farmers and companies.
At a public hearing in Las Vegas in August, environmentalists voiced concern about the impact of the Solar Millennium project on the endangered pupfish, a tiny blue-gray fish that survives only in few aquamarine desert pools fed by Amargosa Valley’s aquifer.
Then a weather-beaten gentleman dressed in blue jeans rose to fret about his future if he could not sell his water rights to Solar Millennium. Jim Marsh was not a down-and-out local alfalfa farmer, however, but the proprietor of a Las Vegas auto dealership. He also owns a casino in the Amargosa Valley and the associated water rights.
The Longstreet Inn and Casino sits off a desolate stretch of Highway 373. On an August afternoon, as temperatures approached 100 degrees, the slot machines sat silent in an empty gaming room while sprinklers arrayed on the perimeter of the property shot jets of water into the surrounding desert scrub.
Under Nevada law, property owners must use their water at least one year out of every five. “I’m pumping water out into the desert to keep my water rights,” said Mr. Marsh. “It’s absolutely ridiculous.”
Bill DeWitt is what you might call a fair-weather alfalfa farmer. He’s a Los Angeles real estate investor who bought up water rights in the Amargosa Valley years ago in anticipation of cashing in on the long-delayed nuclear waste repository at nearby Yucca Mountain.
Now he is considering leasing water rights to Solar Millennium. “We have a significant block of water rights we’ve been using in agricultural — growing alfalfa and hay and other things,” said Mr. DeWitt. “If it pencils out better for making megawatts, maybe that’s the direction to go.”