Thursday, September 8, 2011

Latest from: CleanTechnica

Latest from: CleanTechnica

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The Power of Blimps Rise Again

Posted: 08 Sep 2011 01:18 PM PDT

It is not your typical cigar but, in its decidedly feminine form (complete with a double helium bag, flat bottom and skirts), this hybrid dirigible is buoyed by both military and civilian contracts. There are hybrid structural designs that cross a rigid frame and an inflated blimp but this Hybrid Air Vehicle also combines properties of an aircraft and a hovercraft.

Hybrid Air Vehicles: A new form of Airship

Why We Like Airships…

Aside from the tremendous potential for adult puns, large objects floating in the sky have a certain appeal to the kid in us. Growing up in NJ, I remember calling to others to come and watch the blimps traveling a few hundred feet above our heads. The Lakehurst Naval-Air Station was not far and we didn’t yet have Snooki or the Sopranos to show us what was “really” interesting in rural NJ. They are huge, yet they float. It is like magic and their slow movement suggests the gentle giant. Perhaps there is also something from our first memories when huge beings seemed to float around and take care of us.

history graph of airship development

What is the History of Lighter than Air Ships?

The history of lighter than air craft started with the first hot air balloon built in 1783. Only two weeks later, the first hydrogen gas balloon was flown. We had to wait until 1852 for a “lighter than air craft that could be steered,” which is the definition for the words “dirigible” and “airship.” By 1899, Ferdinand Zeppelin had designs for the ridged framed dirigible that bears his name. In 1925, the US was the sole supplier of the world’s helium and established a reserve which was only recently liquidated. A helium embargo caused other nations to use hydrogen for their airships, including Germany. The Hindenburg was designed to use helium, but was forced to use hydrogen by the embargo. Hydrogen provides only 8% more lift than helium. After Hindenburg was dropped in flames at Lakehurst, NJ, smaller, cheaper, non-rigid airships known as (b-)limps became the diminishing standard. They were used during WWII to spot the shallow operating submarines of the age.

What “Power” of Blimps? Isn’t that a Dirigible?

All airships, rigid and limp, use the power of buoyancy for lift. This is in contrast to air planes and helicopters which use fuel and wing movement to stay in the air. But airships present a larger frontal area to wind resistance so that the

drag on an airship rises as the square of its speed, while the power required to propel it increases as the cube of the speed. In airplanes, lift and drag increase together with speed, so that for a given lift the drag is effectually constant at any speed, and so the power required only increases linearly with speed until close to the speed of sound.

The bottom line is that a large payload dirigible will use less fuel and move more tonnage per hour producing fewer greenhouse gases for a longer period of time than a cargo jet and the overall cost of the vehicle is cheaper.

A blimp has a gas pressure only up to 2psi higher than the surrounding atmosphere. So, bullet holes tend not to do very much. (The Goodyear blimps get them all the time.) But, at higher speeds (max 80-100mph), the vehicle shape tends to deform. A rigid dirigible can go slightly faster while the hybrid structure (rigid keel only) is a good option between cost and performance. The Zeppelin NT pictured above is a blimp with a rigid keel: a structural hybrid.

All airships use their shape to provide some lift under power (10%+). This helps them to come back to Earth. Hybrid Air Vehicles increase this to about 40% with the remaining 60% from buoyancy. The vehicles also have the potential to add up to 25% vectored thrust for unassisted take-offs and landings. This is where the blimp meets the hovercraft — the reason for the skirts — and is a tremendous advantage over the relatively large ground crew required for a conventional airship. Once landed, the hovercraft capacity is reversed to “suck down” the vehicle to the ground. Paul Bouchard president of Discovery Air Innovations (DAI) based in Canada said, “HAV’s heavy lift and cargo capacity of 50 tonnes at speeds up to 100 knots (185 km/h)… will enable economic development of remote, stranded resources with a low environmental impact… without the need for a runway…”

Military Uses

The HAV can stay on site for up to 21 days and be manned or remotely operated. At altitude, it makes an ideal eye in the sky platform:

A radar mounted on a 30 meter high vessel platform has radio horizon at 19.5 kilometers range, while a radar mounted on an 18000m altitude HAA has radio horizon at 478.1 kilometers range.

It is for this reason the HAV won a $517 million contract with Northrop Grumman to develop the Long-Endurance Multi-intelligence Vehicle (LEMV) for deployment by the U.S. Army to Afghanistan in early 2012. This is part of a long standing DARPA program to develop a Radar Airship with a huge antenna.

It appears as if Professor Sir David King’s prediction cargo and military use for airships is becoming a reality sooner than the 10 years he suggested. Perhaps what was really needed was for an airship to look good rather than overstuffed or a bit lean.

Additional information and sources:

Photo Credits: Main photo of NT Zeppelin ben.fitzgerald via flickr ; all other photo’s HAV

DOE Announces $43 Million Program to Jumpstart Offshore Wind

Posted: 08 Sep 2011 01:14 PM PDT

Photo credit:

The Dept. of Energy (DoE) announced a clean energy stimulus package Thursday morning in advance of President Obama’s speech to a joint session of Congress Thursday evening in which he is expected to announce a $300 billion-$400 billion jobs creation program.

The DoE will spend $43 million over the next five years “to advance wind turbine research and development to speed technical innovations, lower costs, and shorten the timeline for deploying offshore wind energy systems,” according to a news release.

With offshore wind farms already established and growing in Europe, the US has yet to build one offshore wind farm. Providing financing and support for 41 projects in 20 US states “will advance wind turbine design tools and hardware, improve information about U.S. offshore wind resources, and accelerate the deployment of offshore wind by reducing market barriers such as supply chain development, transmission and infrastructure,” the DoE explained.

The awards should “help the US compete in the fast-growing offshore wind energy manufacturing sector, promote economic development and job creation, and support the development of an emerging industry that will provide clean electricity to American families,” Secretary Chu stated while announcing the program.

Nineteen offshore wind technology development projects will receive $26.5 million to address technical challenges and provide a foundation for the US offshore wind industry to compete globally.

Twenty-two projects aimed at removing market barriers by researching factors constraining offshore wind deployment along US coasts and the Great Lakes regions will receive $16.5 million.

Follow this link or a full list of award winners.

"The U.S. has an abundant offshore wind resource that remains untapped," Secretary Chu said. "Through these awards, the Department of Energy is developing the critical technology and knowledge base necessary to responsibly develop this resource, enhance our energy security, and create new clean energy jobs."


The Political and Technical Advantages of Distributed Renewable Power

Posted: 08 Sep 2011 12:47 PM PDT

A serialized version of ILSR's new report, Democratizing the Electricity System, Part 3 of 5. Click for Part 1 or Part 2.

The Political and Technical Advantages of Distributed Generation


While technology has helped change the economics of electricity production (in favor of renewables and distributed generation), this new dynamic can as easily be controlled by the incumbent utilities as the old paradigm of centralized fossil fuel power generation.

The cornerstone of the distributed generation revolution is its potential democratizing influence on the electric grid, the opportunity unlocked for local ownership and the coincident political support for more renewable energy. In no place is that clearer than in the public support for renewable energy.

An increasing number of renewable energy projects (primarily wind, but also large-scale solar) have met with resistance from local residents or environmentalists. Centralized, remote generation might seem to avoid NIMBY issues by placing wind turbines or solar power plants far from population centers; but in practice, there have been opponents to these projects as well. Large power plants raise questions about environmental impact from creature habitat to water consumption. Power from distant plants must be transmitted over high-voltage transmission lines to get to load centers without significant losses, and such lines are built only at great ratepayer expense, over many years, and with the taking of land with eminent domain. Some folks just hate the look of power plants, regardless of their sustainable nature.

Resistance has been organized enough to win restrictive state siting policies (e.g. wind policy in Wisconsin) or to coordinate environmental advocacy organizations to oppose solar power plants on undeveloped desert lands. In some cases, resistance takes on the strange aspect of "wind turbine syndrome," or other mysterious illnesses.

At the heart of the matter, citizens rightly see renewable energy as different, and find it frustrating to see new, widely available resources like sun and wind developed under the old, centralized paradigm and owned by the usual suspects. In a recent study by the ever-methodical Europeans, they found that opponents to new wind and solar power have two key desires: "people want to avoid environmental and personal harm" and they also want to "share in the economic benefits of their local renewable energy resources."

It's not that people are made physically ill by new renewable energy projects. Rather, they are sick and tired of seeing the economic benefits of their local wind and sun leaving their community.

Local Ownership Boosts Economic Benefit of Renewables:

Such opposition is perfectly rational, since investments in renewable energy can be quite lucrative (private developers and their equity partners routinely seek 10% return on investment or higher). And the economic benefits of local ownership far outweigh the economic colonialism of absentee owners profiting from local renewable energy resources.

Additionally, when projects are absentee owned, local residents see little to no economic advantage to offset their concerns about health or the environment.

It's not just centralized renewable energy projects facing opposition; distributed generation (DG) can also face resistance. While DG projects are of a more modest scale than centralized power generation, they also reside closer to actual electricity demand; thus, they are closer to population centers. For solar, this is largely a non-issue, because it can be easily installed on rooftops or other existing structures. Similarly, other technologies like geothermal or even natural gas generate little hostility from locals. On the other hand, for wind power there's little distinction between a 30 MW and 300 MW project, because all the turbines are the same size. A distributed wind project will place very large turbines close to population centers and wind projects of all sizes have met with stiffer resistance.

For both centralized and distributed generation, local ownership becomes the key to unlocking local support. For example, the following chart illustrates the local support for wind power in two German towns, Nossen and Zschadraß.

Local Ownership Boosts Public Support for Wind (study link):

 With local ownership of the wind project, 45% of residents had a positive view toward more wind energy (Zschadraß). In the town with an absentee-owned project (Nossen), only 16% of residents had a positive view of expanding wind power; a majority had a negative view.

By unlocking economic opportunity, distributed generation and local ownership of renewable energy create a positive feedback loop for more investment in renewable energy.

Avoiding Eminent Domain

Distributed generation also avoids one of the major drawbacks to centralized generation: the need for new transmission infrastructure, commonly constructed by seizing land with the power of eminent domain. According to the Federal Energy Regulatory Commission (FERC), there are nearly 15,000 miles of new, high-voltage transmission lines planned to be in service by 2013. With most transmission lines requiring significant right-of-way (200 feet), this is equivalent to 363,500 acres of property needed. A substantial portion that will be taken with eminent domain or negotiated with landowners under the threat of eminent domain.

One issue for many landowners is that their land is taken or easement granted for a one-time payment, while the utility continues to draw revenue from selling access to the transmission line for decades. In Wyoming, landowners have organized to try to change the law to require an annual payment, in part because the transmission lines are being constructed to ferry wind power from Wyoming to places out-of-state.

There are few solutions to the eminent domain challenge, although a bill introduced during the 2009 Minnesota state legislative session would have tried to make the process fairer in that state. Currently, Minnesota utilities are exempt from many of the rules restricting how local government entities can use eminent domain. Utilities, unlike governments, do not have to negotiate in good faith, are not required to show landowners any appraisals of their property and do not have to compensate businesses for losses stemming from a forced change of location. The proposed legislation (which failed) would have harmonized the rules for utilities and local governments, and made eminent domain for transmission fairer.

Page 2 –>> Distributed Generation & the Grid

With DoE, DoD Backing SolarStrong Aims to Double US Residential Solar Power Installations

Posted: 08 Sep 2011 07:15 AM PDT

Photo credit: SolarCity

SolarCity’s SolarStrong project, which the company says could double the number of US residential solar photovoltaic (PV) installations, moved a step closer to becoming reality yesterday when Energy Secretary Stephen Chu approved a conditional commitment to partially guarantee a $344 million loan.

Part of the SolarStrong project entails SolarCity working with leading US military housing privatization developers to install, own and operate as many as 160,000 rooftop solar power installations on as many as 124 military housing developments across 33 states, according to a SolarCity news release.

The project is expected to result in over $1 billion worth of solar projects and 371 megawatts (MW) of residential solar power capacity being installed. USRG Renewable Finance, a subsidiary of the US Renewables Group, and BoA Merrill Lynch will serve as lead lender partners for the project.

"We're extremely grateful to the Department of Energy's Loan Programs Office, in addition to our partners, U.S. Renewables Group and BofA Merrill Lynch. Without this group, we would not have been able to make the economics of this project work," said Lyndon Rive, SolarCity's CEO. "Now the solar industry has a debt model that can make distributed generation affordable on a massive scale."

The US Dept. of Energy’s National Renewable Energy Lab’s (NREL) Jobs and Economic Development Impact model estimates that the SolarStrong installations can be expected to create some 6,000 direct job-years of work related to the installation and ongoing maintenance of the residential solar power systems.

The first SolarStrong project, at Hickam Communities at the Joint Base Pearl Harbor-Hickam in Hawaii, is already underway. There, SolarCity is working with real estate developer Lend Lease to install residential solar power systems on more than 2,000 military family homes.

"Thanks to the Energy Department's leadership and resolve, we can now bring an unprecedented opportunity to privatized military housing across the U.S.," said Aaron Gillmore, SolarCity's vice president of solar development.

"We believe the SolarStrong model will deliver the most affordable solar option available to military housing, and provide a template for financing large-scale residential solar projects well into the future."

The US Dept. of Defense is the single largest energy consumer in the US. The SolarStrong project will help the DoD enhance its energy security and meet a stated goal of renewable energy supplying more than 25% of its energy needs by 2025.


Making Cheaper and More Efficient Solar Cells with Copper

Posted: 08 Sep 2011 05:10 AM PDT

There are two ways to lower the cost of producing energy through photovoltaics – more efficient solar cells (more power per square foot) and lower production costs (lower cost per square foot). The ETAlab of the Fraunhofer ISE has devised a way to do both simultaneously. The research team in the laboratory for new solar cell structures and processing steps has not only made the solar cell contacts out of 100% cost-effective materials (replacing expensive silver with cheaper copper and nickel), but the process also increases the efficiency of the solar cell to a very respectable 21.4%.

In order to achieve a high level of efficiency, the front contacts in the solar cell not only have to exhibit a low level of loss with light-generated current but also cover the least amount of the cell surface possible. Technologically speaking, materials with high conductivity work best. Traditionally speaking, silver has been the metal of choice. In the current industry standard, the relatively wide and porous contacts are produced by screen-printing silver pastes. The ETAlab team's switch from silver to copper reduced the cost by around 10%, due to the significant difference in price. The electro-plating processes necessary to generate the contacts with copper were also comparatively inexpensive.

Of course, copper and silver have different chemical characteristics despite conducting about the same amount of electricity, so the contacts aren't quite built the same way. The challenge in constructing a copper contact was that the copper tended to leak into the semiconductor (which then means the solar cell slowly stops working altogether!). To stop the leakage, the ETAlab research team bound the copper to a silicon layer with nickel – which also conducts electricity and can be cheaply electro-plated, so double win there.

While the nickel/silicon/copper combination can be used with the silver screen-print, it can also be used without it. The anti-reflective coating (ACR) can be locally removed from the combination with processes like laser ablation, so that the line width is no more than 20 microns. A narrower line width means that less of the solar panel is shaded by its own contact. The opened range of the ARC nickel (reinforced with copper and tin or silver so that it can be soldered) is then selectively deposited.

The new process had one more advantage – one that the team wasn't necessarily expecting. The copper-using cells not were not only as efficient as the more expensive standard cells, but they were more stable in the heat – the research team put it under a thermic load of 1600 hours at 392°F and the copper cells still worked just as well as they had in the beginning.

The next challenge is adapting the process for a larger solar array, as the prototype nickel/silicon/copper solar cell was smaller than 1"x1". The Fraunhofer ISE will introduce the theme of long-term stable copper metallization and its results so far at the 26th European Photovoltaic Solar Energy Conference and Exhibition this week in Hamburg.

Source | Picture:


MSU Researchers Discover How Bacteria Can Clean Up Nuclear Waste & Generate Electricity

Posted: 08 Sep 2011 04:08 AM PDT

Photo Credit: Michigan State University

A team of researchers at Michigan State University has solved the mystery of how Geobacter bacteria found in soils manage to clean up nuclear waste and generate electricity at the same time. Going a step further, the team genetically engineered a Geobacter strain that does an even better job of it.

MSU microbiologist Gemma Reguera has filed patents to build on her research, “which could lead to the development of microbial fuel cells capable of generating electricity while cleaning up environmental disasters,” according to an MSU news release.

"Geobacter bacteria are tiny micro-organisms that can play a major role in cleaning up polluted sites around the world," said Reguera, an MSU AgBioResearch scientist. "Uranium contamination can be produced at any step in the production of nuclear fuel, and this process safely prevents its mobility and the hazard for exposure."

The ability of Geobacter to clean up and neutralize uranium was proven when they were recruited to clean-up uranium mill tailings at a site in Rifle, Colorado. Researchers stimulated reproduction and activity of Geobacter already in the soil by injecting acetate, which they feed on, into contaminated groundwater. This gave the microbes energy sufficient for them to remove the uranium.

Exactly how Geobacter accomplished this feat wasn’t known until Reguera and her team made their discovery. It turns out conductive, hair-like appendages, called pilli or nanowires, are doing most of the work and managing electrical activity as the Geobacter bacteria essentially electroplate uranium, thereby neutralizing it and preventing it from leaching into groundwater. Their nanowires also protect the Geobacter, enabling them to live in a toxic environment.

Reguera and her team then went on to genetically engineer a Geobacter strain that enhanced the cells’ nanowire production. “The modified version improved the efficiency of the bacteria's ability to immobilize uranium proportionally to the number of nanowires while subsequently improving its viability as a catalytic cell,” according to MSU’s news release.


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