Solar cells are picky. If an incoming photon has too little energy, the cell won’t absorb it. If a photon has too much, the excess is wasted as heat. No matter what, a silicon solar cell can never generate more than one electron from a single photon. Such harsh quantum realities severely limit the conversion efficiency of photovoltaic cells, and scientists have spent decades looking for work-arounds. Now, researchers at the Massachusetts Institute of Technology’s Center for Excitonics have published a compelling case that the key to greater solar efficiency might be an organic dye called pentacene. In today’s issue of Science Daniel Congreve, Jiye Lee, Nicholas Thompson, Marc Baldo and six others show that a photovoltaic cell based on pentacene can generate two electrons from a single photon—more electricity from the same amount of sun. Scientists have suspected for some time that this might work; today’s paper is proof of concept. The key is a phenomenon called singlet-exciton fission, in which an arriving photon generates two “excitons” (excited states) that can be made to yield two electrons. Previous researchers had accomplished similar tricks using quantum dots (tiny pieces of matter that behave like atoms) and deep-ultraviolet light. “What we showed here,” Baldo says, in addition to using visible light, “is that [this process] works very, very effectively in organic materials.” Full Article:
Peel-and-stick, or water-assisted transfer printing (WTP), technologies were developed by a group at Stanford and have been used before for nanowire based electronics. A new partnership between Stanford University and the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) has conducted the first successful demonstration using actual thin film solar cells, NREL principal scientist Qi Wang said. The university and NREL showed that thin-film solar cells less than one-micron thick can be removed from a silicon substrate used for fabrication by dipping them in water at room temperature. Then, after exposure to heat of about 90°C for a few seconds, they can attach to almost any surface. Wang met Stanford's Xiaolin Zheng at a conference last year where Wang gave a talk about solar cells and Zheng talked about her peel-and-stick technology. Zheng realized that NREL had the type of solar cells needed for her peel-and-stick project. Full Article:
Carbon Dioxide Capture and Storage is a transitional technology mitigating climate change as we implement proven alternative energy technologies.
Fuel cells help reduce grid dependency and mitigate financial losses from power outages while keeping critical infrastructure up and running. No longer an environmentalist's pipe dream, fuel cells' reliability, scalability and wide range of fuel sources are saving money for companies in a variety of industries, and making dependable access to emissions-free power a reality.
Energy storage systems, like any energy or power system, carry some degree of risk. With today's technology, these risks are largely understood and can be effectively reduced or mitigated.
According to the study 'Security & Safety in a Smart Energy World', presented by TÜV SÜD at the opening of the 2013 Hannover Messe, the energy and manufacturing sectors are underestimating the potential risks involved in modernising power grids; awareness of the vulnerability of smart grids is negligible and protective action is rare.
Awareness is growing in the wind industry about the severe impact that blade leading edge erosion can have on wind turbine output. Recent research shows that erosion can lead to a loss in annual energy production (AEP) of up to 20 percent, costing thousands of dollars.
The 420 megawatt Macarthur wind farm was opened in the state of Victoria on Friday. It is the largest wind farm in the southern hemisphere and its 3 megawatt Vestas turbines are the largest in Australia. The Mcarthur Wind Farm is actually the first project to use Vestas’ V112-3.0 MW wind turbines. The project’s expected operating capacity is 35% and its cost was almost exactly one billion dollars. One billion dollars may sound like a lot of money, probably because it is, but that doesn’t mean it’s not a good deal. The wind farm has an operating life of 25 years and if a 5% discount rate is used for the cost of money, it will generate electricity at about 6 cents a kilowatt-hour. While this is slightly higher than the average price of electricity generated from coal in Australia, it does have the very large advantage of being non-fatal on both the personal and planetary scales. It’s also cheaper than electricity from new coal plants and is a major reason why Australia is extremely unlikely to ever build any new coal capacity.
First Solar is buying an under-the-radar startup called TetraSun to add expertise around silicon solar cell manufacturing to its technology portfolio, which until now has focused on using the material cadmium telluride to make solar cells. The Arizona-based thin film solar giant announced the pending acquisition on Tuesday during its analyst day — its first since 2009 — in which it laid out a persuasive technology and business development plan for the next five years. Investors liked what they heard and pushed the company’s stock up by nearly 50 percent during trading. So why TetraSun? Apparently Silicon Valley-based TetraSun has some disruptive silicon cell designs that set it apart from the rest of the silicon solar companies. Its designs require fewer manufacturing steps to produce conventional silicon cells, and eliminates the need for silver and transparent conductive oxide. Silver is used to transport electricity produced by the cells, while the oxide is a coating that protects the cells and helps the semiconductor material (such as silicon or cadmium telluride) to grab the light more effectively to produce electricity. First Solar claims that TetraSun’s cells also can perform better in hot climates than conventional silicon cells. That feature will make solar panels with TetraSun’s cells more desirable in places like the Middle East and India, two markets with a lot of potentials for growth. First Solar says it plans to start making TetraSun’s cells in the second half of 2014.
The Folsom-based California Independent System Operator, which operates the state's wholesale electricity transmission grid, said today that wind power turbines on the grid set a new record of 4,196 megawatts on Sunday. The record came at 6:44 p.m. That mark came on the heels of Friday's passing of the 4,000-megawatt threshold. Previously, the ISO's all-time record peak output for wind energy was 3,944 megawatts on March 3. "With these impressive wind-production levels, California is well positioned to meet the 33 percent by 2020 green power goal," said ISO President and CEO Steve Berberich. "Our control center operators are tracking a steady increase in renewable energy ... " Currently, ISO said there is a total of 5,899 megawatts of wind plant capacity installed within the California grid. California is the nation's second largest producer of wind power, trailing only Texas. ISO said that Texas, which has a current wind-generation peak capacity of 10,407 megawatts, reached a record peak of 9,481 megawatts on February 9.
Helical Robotics, HR-MP20 Magnetic Platform Lifting Vehicle Lightweight and portable design for easy deployment, use, and transport. Mecanum wheel drive system offers best in class maneuverability. Magnetic adhesion system does not contact the work surface.
BrightSource Energy on Wednesday shelved a major solar power project in California for the second time this year. In a document filed with the California Energy Commission, BrightSource said it "has determined there is a need to suspend" its application to permit the 500 megawatt Hidden Hills solar thermal power project until further notice. The company did not give a reason for the suspension, and company officials were not immediately available for comment. BrightSource, based in Oakland, said it will continue to evaluate the project, which was to be located in Inyo County near the Nevada border. In January, BrightSource suspended its 500 MW Rio Mesa project in Riverside County, California after multiple delays in the permitting process. Late last year, CEC staff said the Hidden Hills project would have "significant" impact on the environment, adding that the use of photovoltaic solar panels "would be environmentally superior" to BrightSource's solar thermal technology. BrightSource disputed those claims at recent hearings, and the CEC was expected to issue a final decision on the project later this year.
Saudi Arabia wants to spend over $100 billion to build vast solar arrays and reduce its dependency on oil to generate electricity. But desert sandstorms pose a major challenge to keeping solar panels clean and efficient. Japanese startup Miraikikai is developing a solution to getting rid of this pesky dust and grit: a cleaning robot that doesn't need water. The firm has produced the Wall Walker wall and ceiling robot, and recently unveiled a prototype solar panel cleaner built with researchers at Kagawa University. It weighs about 24 pounds -- light enough to be carried by one person -- and measures about 22 inches across. It cleans with a rotating brush and can operate for up to two hours on a battery charge. The robot's efficacy has been demonstrated in arid regions, Miraikikai said in a release, and the machine can clean panels as well as human workers. Making optimal use of the device would result in low-cost cleaning even in areas with relatively cheap labor costs.
It takes more than perfunctory "safety moment" sharing and hard hat stickers to ensure employees and contractors make safety their top priority. In creating a viable safety culture, site leaders first identified the unique strengths of each company and exchanged lessons learned at other power generation facilities.
Series of reforms being explored as China seeks to expand clean tech investment
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