Saturday, September 24, 2011

Latest from: CleanTechnica

Latest from: CleanTechnica

Link to CleanTechnica

40% Efficient UV Nanotech PV Cells for Space Receive $1 Million Funding

Posted: 24 Sep 2011 10:47 AM PDT

The University of Arkansas has announced that researchers there and at Arkansas State University are getting over $1 million in new funding to further their work on creating better solar cells for spacecraft. NASA is providing the bulk of that — $735,000 — but matching funds also come from the two universities — $237,000 from the University of Arkansas and $86,000 from Arkansas State.


The theoretical maximum efficiency of silicon solar cells is around 29%. To get around this limit, cells are made with different materials and designed to capture energy not only from visible light but from the infrared and ultraviolet spectrum as well: triple junction cells. The highest quality cells are costly and reserved for use in space and concentrating solar collectors, where fewer of them need to be used. NASA has been using solar cells with an efficiency of around 23% while the industry maximum in the lab is around 44% using triple junction cells.

This new research is using alternative materials to silicone and is trying to get the conversion efficiency in space to over 40%. Here’s more from the University of Arkansas:

The funding will allow researchers in Manasreh's Optoelectronics Research Lab to continue growing and functionalizing semiconductor and metallic nanoparticles to be used in solar cells. He said this work could eventually lead to the start of a private company based in Arkansas. In 2010, Manasreh received a five-year $1.13 million grant from the U.S. Air Force Office of Scientific Research, which included cost sharing from the University of Arkansas, to pursue similar and complementary work….

Manasreh employs two approaches to fabricate solar cells. Instead of silicon, the first approach involves a combination of copper, indium, gallium and selenium (CuInSe2and CuInGaSe2) as the semiconductor material to grow nanocrystals. The researchers make the nanocrystals functional by generating volatile ligands, which are molecules that bind to a central atom. The nanocrystals are then either converted into thin films or combined with titanium dioxide or zinc oxide nanotubes to create the desired solar cells. After fabrication of the cells, the researchers will test and evaluate their performance.

The second approach uses molecular beam epitaxy, a method of depositing nanocrystals, to create quantum dots made of indium arsenide (InAs). Quantum dots are nanosized particles of semiconductor material.

To enhance the performance of the solar cells, the researchers will use short ligands to couple metallic nanoparticles to the nanocrystals and quantum dots. They will then investigate the plasmonic effect of trapping sun light, which in turn increases the energy conversion efficiency. Just as a photon is the quantum of the electromagnetic waves, a plasmon is the quantum of charge waves generated by light.

Photo Credit: Bernt Rostad


Solar Growth vs Fossil Fuel Demise

Posted: 24 Sep 2011 10:00 AM PDT

Following up on our two posts this week on the 2011 Solar Census conducted by The Solar Foundation, The Solar Foundation sent along the following fun graphic. Thought it was cool enough to share as a weekend quickie :D

Here it is (CLICK TO ENLARGE):

Failing industry? I think not.

Should we stop giving billions to fossil fuels and use that money for solar and other clean energy? I think so. (And, apparently, so does the World Bank.)

DOE Guarantees Loans Up to $624MM for Wind, Geothermal, Cellulosic Ethanol

Posted: 24 Sep 2011 05:38 AM PDT

The US Dept. of Energy (DOE) issued partial loan guarantees for renewable energy projects in three states totaling as much as $624 million Friday. Energy Secretary Chu announced partial loan guarantees of $168.9 million for Granite Reliable Power’s 99-megawatt (MW) wind farm, New Hampshire’s largest; up to $350 million for Ormat Nevada’s 113MW geothermal power plants; and $105 million for POET’s ‘first-of-its-kind’ cellulosic ethanol bio-refinery in Iowa.

New Hampshire Wind Power

Granite Reliable Power’s 99MW wind farm located in northern New Hampshire’s Coos County would be the state’s largest, creating nearly 200 construction jobs. Thirty-three Vestas V90 3.0MW wind turbines will be erected on the site, generating enough clean, renewable electrical power for nearly 20,000 homes while avoiding more than 124,000 metric tons of CO2 emissions annually.

Most of the Granite wind farm’s electricity will be sold to Central Vermont Public Service and Green Mountain Power. Project lead lender WestLB bank filed for a partial DOE loan guarantee under the Financial Institution Partnership Program (FIPP), in which the DOE provides a partial guarantee for up to 80% of a loan.

"Today's investment brings new jobs to New Hampshire and supports the commercial-scale deployment of clean energy technologies in the U.S.," Secretary Chu said while announcing the award.

"America's wind energy resources are abundant, clean and mostly untapped. Continued investments in this source of emissions-free energy will strengthen the economy, create good American jobs and help the nation compete with other countries that are quickly scaling up wind power generation."

Nevada Geothermal Power

Ormat Nevada was awarded a partial loan guarantee for as much as $350 million to build three geothermal power plants in Nevada with a total generating capacity of 113MW of clean, renewable, baseload electrical power. Upon completion, the plants would boost Nevada’s geothermal power production by almost 25%. An estimated 332 jobs will be created during construction and another 64 for operating the plants.

The Ormat geothermal plants will produce enough electricity to power some 88,000 homes while avoiding nearly 580,000 metric tons of CO2 emissions.

All of the geothermal power plants’ output will be sold to the Nevada Power Co. under separate long-term power purchase agreements (PPAs). John Hancock Life Insurance Co. (USA) submitted the DOE application under the FIPP.

"We are investing in geothermal projects that will further develop the nation's clean energy resources, create skilled jobs for American workers and ensure the U.S. remains a global leader in geothermal energy development," Secretary Chu said. “The project announced today will produce virtually no greenhouse gas emissions and will create hundreds of new jobs in Nevada."

Cellulosic Ethanol in Iowa

Secretary Chu also announced a $105 million loan guarantee to support construction of one of the nation’s first commercial-scale cellulosic ethanol biorefineries in Emmetsburg, Iowa. Sponsored by POET, Project LIBERTY is expected to produce as much as 25 million gallons of ethanol per year.

Projected to generate some $14 million in new revenue to area farmers providing the corn crop residue that will serve as feedstock for the ethanol plants, approximately 200 construction jobs and 40 permanent jobs are expected to be created. Equipment made in the USA will make up an estimated 85% of all the equipment used.

Project LIBERTY will use enzymes to convert cellulose from corncobs, corn leaves and corn husks into ethanol, producing enough bio-gas to power its operations and most of POET’s adjacent grain-based ethanol plant. POET intends to use the same design and process across all its 27 grain ethanol plants for a combined annual capacity of 1 billion gallons of cellulosic ethanol per year.

"This project represents a pioneering effort to make broad scale deployment of cellulose ethanol a reality," Secretary Chu stated. "Producing the next generation of biofuels can not only reduce America's oil dependency, it can also create vast new economic opportunities for rural Americans."


25% of Single Family American Homes Are Now Energy Star Qualified

Posted: 24 Sep 2011 05:32 AM PDT

Argon-filled Double-paned Window.

The Environmental Protection Agency announced this week that 25% of all single family homes in the U.S in 2010 were energy star certified.

The EPA and it’s stakeholders help home purchasers to maximize the energy efficiency of their homes overall by funding the setup of energy-saving devices and techniques such as insulation, insulated glazing (see below), leak and draft prevention, and more.

Since 1995, approximately 1.2 million homes have earned the Energy Star rating, resulting in savings approaching $350 million off electric bills and also avoiding the greenhouse gas emissions equivalent to that of roughly 450,000 vehicles.

Insulated glazing involves the use of two or three glass panes in each window (two is “doubled-paned” and 3 is “triple-paned”) with a small space between each pane to achieve an insulation efficiency that allows especially visible light (which turns into heat) in through each window into the room, but at the same time  helps to trap heat in rooms, because it is difficult for it to pass through them. The space between the windows is usually filled with a gas, such as argon. This is actually a use of the greenhouse effect that is positive for the environment.

Heat passes through traditional single-paned windows easily, and because windows need to be transparent, alternative insulation such as foam and fiberglass are not suitable.

"New homes that earn EPA's Energy Star seal of approval rise above the competition by offering a better quality and value, while allowing homeowners to do their part to keep our communities clean," said EPA Assistant Administrator for Air and Radiation, Gina McCarthy.

"With Energy Star’s energy-efficient homes, homeowners will cut down on electric bills and emissions to keep our air cleaner and our communities healthier. Reaching this impressive market share milestone for Energy Star qualified homes is an accomplishment for American home buyers and builders and a step in the right direction to better protecting the environment through sustainable living.”

Photo Credit: Skvidal
Source: EPA


Solar-powered Delivery System Eases Congestion and Pollution in Dutch City

Posted: 24 Sep 2011 05:10 AM PDT

Duke Energy to Construct Its Fifth Wind Farm in Texas

Posted: 24 Sep 2011 04:57 AM PDT

Scroby Sands Wind Farm

For the second time this month, Duke Energy announced that it will construct a large-scale wind farm in Texas, United States.

Duke Energy Renewables will build, own, and operate the wind farm, which is to have an electricity generation capacity (nameplate capacity) of 202 MW (202,000 kW). This is titled the Los Vientos II Wind Power project and it is to sell its electricity and renewable energy credits to Austin Energy.

The nameplate capacity of a wind farm is the maximum amount of electricity that it can generate. This is not to be confused with the average amount of electricity that it generates.  The average amount of electricity generated is the most important figure because the cost of electricity from power plants is partially and heavily dependent on that.

The average amount of electricity that a wind farm generates is dependent on the average wind speed of the location that the wind farm is situated. In other words, the average amount of electricity generated by a wind farm is completely dependent on the geographic location of the farm. Whenever someone describes a wind farm as 300 MW for example, then that means it generates up to 300 MW, but it is not actually 300.

The company intends to commence construction of the wind farm in December. It intends to complete it and start operating it in 2012. This effort is part of a much larger one to add 770 MW (770 million watts) of wind farms by 2012.

As was the first Los Vientos project, this wind farm will be situated in Willacy County, which is 120 miles south of Corpus Christi, 20 miles inland from the Gulf of Mexico.

CPS Energy is to buy all of the electricity from the first phase of the project under the terms of a 25-year power purchase agreement.

Photo Credit: Leo Reynolds
Source: Wind Today


MIT Research Could Lead to Improved Hydrogen Storage

Posted: 24 Sep 2011 04:46 AM PDT

Sow-Hsin Chen, left, and Yun Liu SM '03, PhD '05, right.

Hydrogen has, for a long time, been considered by many a potential alternative to fossil fuels such as gasoline for cars, but it has to be stored as a liquid under extremely high pressures ranging from 5,000 to 10,000 psi (pounds per square inch), and in a very expensive container which has to be insulated to keep as much outside heat as possible away from the hydrogen it contains.

The alternative to high-pressure storage is the hydrogen has to be cooled to and permanently kept at -423° Fahrenheit by a very energy-intensive refrigerator. This also requires very heavy insulation.

The more heat the hydrogen is exposed to, the more it expands, and as hydrogen and gases, in general, expand, their pressure increases too, and this increases the likelihood of the storage tank exploding or leaking.

The higher the pressure, the stronger the tank has to be to withstand that pressure. Hydrogen atoms are so small that they escape from many types of containers very easily by slipping out through tiny holes in them, and a consequence of that is even tiny inconspicuous leaks are a major problem.

In general, when storing any liquid or gas under pressure, leaks are much harder to contain because the high pressure inside the storage container forces particles through small holes that something under low pressure would not leak through.

MIT researchers say that they may have found a way to store it using charcoal (activated carbon) with an incorporated platinum catalyst (which suggests that there could be a potential sustainability and cost problem, although this is still a step closer to something potentially better that does not need platinum).

Hydrogen atoms will actually bond to the sponge-like charcoal material, making it possible to store it at ambient pressure and room temperature in tanks. Normally, the problem with this concept is bonding the hydrogen atoms to the charcoal tightly enough that they don’t leak away, but at the same time, not too tightly because they will need to be released for use later.

This is an unusual technological advancement and a sign of out-of-the-box thinking. I will keep an eye out for future advancements of this idea.

Photo Credit: MIT News Office


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