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  • richardmitnick 9:18 am on January 25, 2017 Permalink | Reply
    Tags: , Clean Energy, Electron holes, How solar cells turn sunlight into electricity, Negative and positive silicon or n- and p-type silicon,   

    From COSMOS: “How solar cells turn sunlight into electricity” 

    Cosmos Magazine bloc


    25 January 2017
    Andrew Stapleton

    Some solar power plants contain more than a million panels. But how do they convert the sun’s energy to electricity? Rolfo Brenner / EyeEm / Getty Images

    Renewables have overtaken coal as the world’s largest source of electricity generation capacity. And about 30% of that capacity is due to silicon solar cells. But how do silicon cells work?

    A silicon cell is like a four-part sandwich. The bread on either side consists of thin strips of metallic electrodes. They extract the power generated within the solar cell and conduct it to an external circuit.

    Just like a sandwich, it’s the filling which is the most interesting part – this is where photons from the sun are converted into usable electricity. The filling of a solar cell consists of two different layers of silicon: negative and positive silicon, or n- and p-type silicon.


    Creating positive or negative types of silicon is relatively easy. The silicon is impregnated with elements known as dopants. Dopants replace some of the silicon atoms in the crystal structure, allowing the number of electrons present in each layer to be manipulated.

    For instance, phosphorus is used to create n-type silicon while boron is used to create p-type silicon. Phosphorus has one more electron than silicon. When substituted into the silicon structure, the electron is so weakly bound to the phosphorus that it can move freely within the crystal, creating a negative charge.

    On the other hand, boron has fewer electrons than silicon and sucks up silicon’s electrons. This creates “electron holes” – regions of mobile positive charge in the crystal structure.

    At the interface of the p- and n- type silicon, the positive electron holes and the electrons combine. It’s not a simple electrostatic interaction, but the upshot is that you get a slightly positive charge in the n-type silicon and a slightly negative charge in the p-type silicon at the interface of the n- and p- type silicon – the opposite of what you might expect.

    Photons from the sun pass between the strips of the top electrode and strike silicon atoms in the crystal structure. Like the strike of a cue ball, the colliding photon gives some of the silicon electrons enough energy to escape from their parent silicon atom.

    The “free” electrons move to and accumulate within the n-type silicon.

    Once free electrons have accumulated in the n-type silicon, it’s time to put all the free electrons to work. In order to use their energy, the electrodes must be connected via an external circuit. Electrons flow through the electrodes and the external electric circuit from the n-type to the p-type. The p-type silicon acts as an electron sink. Without it, the electron flow would clog up.

    It is this flow of electrons that creates the electrical current we can use to power appliances or charge batteries for when the sun isn’t shining.

    See the full article here .

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  • richardmitnick 8:58 am on December 15, 2016 Permalink | Reply
    Tags: America’s First Offshore Wind Farm Spins to Life, , Clean Energy,   

    From NYT: “America’s First Offshore Wind Farm Spins to Life” 

    New York Times

    The New York Times

    DEC. 14, 2016

    The Block Island Wind Farm’s turbines off the coast of Rhode Island in August. They began spinning on Monday and will deliver electricity to Block Island, a community nearby. Credit Kayana Szymczak for The New York Times

    Until this week, all of the wind power generated in the United States was landlocked.

    But in a first for America, the ocean breeze is now generating clean, renewable power offshore — electricity that will supply a small island community off the coast of Rhode Island. Renewable energy, including from offshore wind, is crucial to the effort to avoid some of the worst effects of climate change, according to environmentalists and some elected officials.

    On Monday, the country’s first offshore wind farm, developed by a company called Deepwater Wind and helped along by the state’s political leadership, started spinning its turbines to bring electricity to Block Island, a vacation destination with few year-round residents that had previously relied on diesel-fueled generators for power.

    “This is a historic milestone for reducing our nation’s dependence on fossil fuels, and I couldn’t be more thrilled that it’s happening here in the Ocean State,” Senator Sheldon Whitehouse, Democrat of Rhode Island and co-founder of the Senate Climate Action Task Force, said in a statement from Deepwater Wind.

    Though the Block Island Wind Farm is small — made up of five turbines, which were built by a division of General Electric, and capable of powering about 17,000 homes — it is the first successful offshore wind development in the United States, and it sets up the possibility for offshore wind projects elsewhere along the coast.

    According to a spokeswoman for Deepwater Wind, about 90 percent of the island’s needs will be met by the wind-generated power, and more will go back to the grid. Current estimates are that the wind farm will supply 1 percent of the state’s electricity, the spokeswoman said.

    Despite its modest size, the wind farm, which cost about $300 million to build, still represents a significant reduction in carbon dioxide emissions — about 40,000 tons per year.

    Deepwater Wind will receive a federal tax credit for the project, and first-year rates for Rhode Island customers of National Grid, the utility company laying one of the cables to the wind farm, may be higher than what customers currently pay.

    Environmentalists, members of the Obama administration and government officials in several states see significant potential for offshore wind energy, given that winds over the ocean usually blow stronger and more steadily than those on land.

    Earlier this year, the Obama administration announced a lease for a wind farm off the coast of Long Island, and the Department of Energy has said that if wind farms were built in all of the suitable areas, including in the Great Lakes, they could provide up to twice as much electricity as the country now uses.

    In the past, offshore wind farms have faced significant opposition in the United States for a few reasons: high costs, complicated rules about who gets to build on the seafloor and what they build, and complaints from people who do not want their ocean view obstructed.

    In Europe, however, thousands of wind turbines have sprouted up along the coast, and an additional 3,000 megawatts of wind power were added last year (about 100 times the amount of power provided by the Block Island Wind Farm).

    There has been some opposition to offshore wind projects in Europe, including from President-elect Donald J. Trump, who unsuccessfully fought to block construction of a wind farm off the coast of Scotland near one of his golf courses.

    Mr. Trump has expressed skepticism of wind power, saying in an interview with The New York Times that “the wind is a very deceiving thing.” And an email written by Thomas J. Pyle, who is running the Department of Energy transition for the president-elect, said that the Trump administration might be looking to get rid of all energy subsidies.

    Mr. Trump has also been accused of exaggerating the harmful effects of wind turbines on bird populations, which Mr. Pyle also addressed in the email, writing, “Unlike before, wind energy will rightfully face increasing scrutiny from the federal government.”

    See the full article here .

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  • richardmitnick 1:31 pm on December 3, 2016 Permalink | Reply
    Tags: California Energy Commission, Clean Energy, Massive US Solar Farms Will Deliver Power to Millions,   

    From Seeker: “Massive US Solar Farms Will Deliver Power to Millions” 

    Seeker bloc


    California Energy Commission Blog

    A recent report by the U.S. Department of Energy finding that U.S. solar power capacity will have nearly tripled in less than three years by 2017 is a milestone not only as a technology whose time has come but also as a major shift where the embrace of solar power is a result not just of environmental principle but of practical necessity.

    Ten percent of total U.S. energy consumption comes from renewables, and solar currently makes up 6 percent of that segment, according to the U.S. Energy Information Administration, and is among the fastest-growing sources of energy.

    Once a cottage industry of small-scale producers, the solar energy landscape has grown and seen a number of major projects go online in recent years. Based on the recent Major Solar Projects List by the Solar Energy Industries Association, last updated in September, combined solar capacity for the more than 4,000 projects currently operating, under construction or under development stands above 72 gigawatts. To put that number in perspective, a single gigawatt, the equivalent output of two coal-fired power plants, can power 750,000 homes.

    “Consumers are now starting to demand more from their energy providers and are beginning to play a more active role in their interaction with the grid, which is ultimately changing the way utilities are serving them,” John Berger, CEO of Sunnova, told Seeker. “As a result, we are currently witnessing the beginning of the greatest shift in the electricity industry that we’ve seen during its 100-plus year existence. It’s also the biggest shift we’ve seen in the energy industry since oil started to be used in transportation 100 years ago.”

    States like California provide solar energy companies the political and geographic advantages to operate and expand. Last year, the Solar Star project (in Los Angeles and Kern counties) was completed, bringing online a 579-megawatt solar plant. The Desert Sunlight Solar Farm, a 550-megawatt solar power station in the Sonoran Desert, was also finished in 2015. The year prior, the Topaz Solar Farm, a 550-megawatt solar plant San Luis Obispo Count, became fully operational.

    The solar energy market in Hawaii, a state that generates more solar electricity per capita than any other state in 2015, is “one of the shining lighthouses of what’s possible on a state-level basis,” Alan Russo, senior vice president at REC Solar, tells Seeker. Solar energy adoption rates in Hawaii are among the highest in the nation, Russo adds, in large part because the utility costs are so high. Hawaii traditionally has had to import most of its energy and is the first state to legally commit itself to generating 100 percent of its energy from renewables in 2045.

    But solar is even growing in states with competing energy interests from traditional sources. Take Texas, for example. “Texas, a traditionally oil and gas state and subsequently a wind state, is leading the way in new utility-scale solar projects,” Berger notes of the Lone Star state, where Sunnova is based. “Texas is currently the fastest growing utility-scale solar market in the country, and by the end of 2016, the state’s total installed solar capacity is expected to more than double.”

    The reason for the growth of solar isn’t simply one of environmental conscience but also cost. “Solar costs just a small fraction of what it did even a few years ago,” notes Eli Hinckley, head of the energy group at Sullivan & Worester. “In addition to the absolute price drop, the cost is certain, basically just the price of installation.”

    As the spread between the price of renewables like solar closes with that of traditional energy sources like oil and coal, the decision to move to solar power becomes more enticing to both consumers and businesses, the latter of whom have the added benefit of touting their green credentials to the former.

    “Kind of like the IT transformation back in the ’90s versus where it is today, solar is going from — or renewables in general are going from kind of an esoteric, technology-driven decision to a mainstream provider of business value,” Russo said. “With that, it’s becoming less a matter of ‘Do I do it?’ vs. ‘How much do I do it?’ ‘When do I do it?’ and ‘How do I do it?'”

    And it’s not just in the United States where the cost of renewables is becoming more competitive. Take the example of Abu Dhabi, whose government just received bids for the construction of a large solar farm. “Prices were as low as 2.42 cents per kWh,” Hinckley said. “That is less than it costs to generate power from some coal and gas plants that are already built and is a fraction of what it would cost to build and operate a new fossil fuel plant.”

    The move by Abu Dhabi, a major player in energy markets, has chosen solar over natural gas, of which it controls nearly 5 percent of global reserves, represents “an enormous shift in the perception of solar as the future of energy,” Hinckley said.

    See the full article here .

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  • richardmitnick 10:20 am on October 22, 2016 Permalink | Reply
    Tags: , , Clean Energy, From greenhouse gas to usable ethanol, ,   

    From Science Node: “From greenhouse gas to usable ethanol” 

    Science Node bloc
    Science Node

    19 Oct, 2016
    Morgan McCorkle

    ORNL scientists find a way to use nano-spike catalysts to convert carbon dioxide directly into ethanol.

    In a new twist to waste-to-fuel technology, scientists at the Department of Energy’s Oak Ridge National Laboratory (ORNL) have developed an electrochemical process that uses tiny spikes of carbon and copper to turn carbon dioxide, a greenhouse gas, into ethanol. Their finding, which involves nanofabrication and catalysis science, was serendipitous.

    Access mp4 video here .
    Serendipitous science. Looking to understand a chemical reaction, scientists accidentally discovered a method for converting combustion waste products into ethanol. The chance discovery may revolutionize the ability to use variable energy sources. Courtesy ORNL.

    “We discovered somewhat by accident that this material worked,” said ORNL’s Adam Rondinone, lead author of the team’s study published in ChemistrySelect. “We were trying to study the first step of a proposed reaction when we realized that the catalyst was doing the entire reaction on its own.”

    The team used a catalyst made of carbon, copper and nitrogen and applied voltage to trigger a complicated chemical reaction that essentially reverses the combustion process. With the help of the nanotechnology-based catalyst which contains multiple reaction sites, the solution of carbon dioxide dissolved in water turned into ethanol with a yield of 63 percent. Typically, this type of electrochemical reaction results in a mix of several different products in small amounts.

    “We’re taking carbon dioxide, a waste product of combustion, and we’re pushing that combustion reaction backwards with very high selectivity to a useful fuel,” Rondinone said. “Ethanol was a surprise — it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”

    The catalyst’s novelty lies in its nanoscale structure, consisting of copper nanoparticles embedded in carbon spikes. This nano-texturing approach avoids the use of expensive or rare metals such as platinum that limit the economic viability of many catalysts.

    “By using common materials, but arranging them with nanotechnology, we figured out how to limit the side reactions and end up with the one thing that we want,” Rondinone said.

    The researchers’ initial analysis suggests that the spiky textured surface of the catalysts provides ample reactive sites to facilitate the carbon dioxide-to-ethanol conversion.

    “They are like 50-nanometer lightning rods that concentrate electrochemical reactivity at the tip of the spike,” Rondinone said.

    Given the technique’s reliance on low-cost materials and an ability to operate at room temperature in water, the researchers believe the approach could be scaled up for industrially relevant applications. For instance, the process could be used to store excess electricity generated from variable power sources such as wind and solar.

    “A process like this would allow you to consume extra electricity when it’s available to make and store as ethanol,” Rondinone said. “This could help to balance a grid supplied by intermittent renewable sources.”

    The researchers plan to refine their approach to improve the overall production rate and further study the catalyst’s properties and behavior.

    ORNL’s Yang Song, Rui Peng, Dale Hensley, Peter Bonnesen, Liangbo Liang, Zili Wu, Harry Meyer III, Miaofang Chi, Cheng Ma, Bobby Sumpter and Adam Rondinone are coauthors on the study.

    The work was supported by DOE’s Office of Science and used resources at the ORNL’s Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.

    See the full article here .

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    Science Node is an international weekly online publication that covers distributed computing and the research it enables.

    “We report on all aspects of distributed computing technology, such as grids and clouds. We also regularly feature articles on distributed computing-enabled research in a large variety of disciplines, including physics, biology, sociology, earth sciences, archaeology, medicine, disaster management, crime, and art. (Note that we do not cover stories that are purely about commercial technology.)

    In its current incarnation, Science Node is also an online destination where you can host a profile and blog, and find and disseminate announcements and information about events, deadlines, and jobs. In the near future it will also be a place where you can network with colleagues.

    You can read Science Node via our homepage, RSS, or email. For the complete iSGTW experience, sign up for an account or log in with OpenID and manage your email subscription from your account preferences. If you do not wish to access the website’s features, you can just subscribe to the weekly email.”

  • richardmitnick 7:53 am on October 6, 2016 Permalink | Reply
    Tags: "Energy and Climate: Vision for the Future", , Clean Energy, , Michael McElroy   

    From Harvard: “A way forward on climate” 

    Harvard University

    Harvard University

    October 5, 2016
    Alvin Powell

    Atop the roof of the Science Center with solar panels in the background, SEAS/EPS Professor Michael McElroy talks about his new book, Energy and Climate: Vision for the Future, on the global energy challenge with climate change.

    Headlines focus on international agreements, sea levels, melting ice, and superstorms, but climate change is most of all an energy problem. Burning fossil fuels to power our cars and heat our homes produces carbon dioxide that transforms the atmosphere into a greenhouse, trapping heat that otherwise would radiate into space.

    While the fundamentals are solid, everything else about climate change is evolving. Climate science is advancing and economic pressures have dramatically altered the national fuel mix — for the better, most agree, though we still have miles to go. Even the political landscape that determines national climate action — or inaction — is in flux.

    Michael McElroy, Gilbert Butler Professor of Environmental Studies, has long helped explain the complexities of climate to students, scholars, and government leaders. His most recent book, Energy and Climate: Vision for the Future, published in August by Oxford University Press, is a continuation of that work. He discussed the book in a recent interview with the Gazette.


    GAZETTE: In Energy and Climate, you talk about the U.S. energy picture being transformed over the last five years in ways that may make needed changes regarding climate tougher to accomplish. How has the U.S. energy scene changed into the one we’re in now?

    McELROY: The big change is that we no longer have the previous driving concern about national energy security. What has made the difference was the shale revolution. Ten years ago we were projecting that the U.S. would not only be dependent on imports for oil but also for natural gas. We now have a surplus of both. The U.S. is presently a net exporter of petroleum products. Prices for both natural gas and oil have plummeted. I had a student who wrote a beautiful senior thesis four or five years ago, in which he tried to analyze the break-even price for production of natural gas from shale. His conclusion was it would be about $5 per million BTU at a time when natural gas prices — wholesale prices — were $7, $8, $9. Now they’re below $3. So it’s a different world. Oil prices were $168 a barrel in 2008 just before the economic crisis. They are now below $50.

    The U.S. also has abundant sources of coal. Were it not for the climate issue, we could contemplate taking advantage of this resource also, doing so as efficiently as possible to eliminate conventional sources of pollution such as sulfur and nitrogen oxides and particulates. Emissions of CO2 could go through the roof under these scenarios. There is no cost-effective means to capture CO2. Concerning the potentially expanded emphasis [that] coal — not to mention oil and natural gas — could have on our energy system, this would be a disaster for climate. Bottom line is that we can no longer rely on policies that could be adopted to address concerns about energy security, looking to climate policy as a silent secondary beneficiary. We must now confront the climate issue directly. Clearly many in the body politic are reluctant to do so.

    GAZETTE: And the electricity supply has gotten cleaner, hasn’t it? But not because of climate change efforts?

    McELROY: Not because of climate change, but for economic reasons, largely. If you’re a utility and you’re able to vary the mix of generation options you can tap to produce electricity, your primary choice is likely to be between coal and natural gas. Old coal-fired power plants are very inefficient compared to new gas-fired power plants. The efficiency to turn the energy of coal into electricity in some of the older plants is as low as 20 percent. If you’re just worrying about efficiency, if you have the opportunity to turn off that inefficient coal plant and switch to a gas system and additionally save money [since gas is cheaper than coal], you’re going to do it. The choice is economically driven and the consumers are actually benefiting.

    GAZETTE: In your vision for the future, you emphasize that more electricity usage could be part of the solution. Clearly, electricity is already a big part of our energy picture; why should it be even larger?

    McELROY: Dealing with CO2 emissions from the transportation sector is extremely difficult if the transportation sector is fueled with liquid fossil fuels. You can’t capture CO2 from the tailpipe of every vehicle on the road — 260 million cars in the U.S. At the same time, there’s another a good reason to want to use electricity more in this application. If you drive your car with gasoline, the fraction of the energy in the gasoline that turns the wheels of your car may be as low as about 20 percent. If you drive your car with electricity, the fraction of electricity that turns the wheels could be as high as 95 percent. So, on an efficiency basis, electricity is better. As I discussed in the book, if I had to pay the retail price for electricity here in Cambridge, 19.8 cents a kilowatt hour when I was writing the relevant chapter, the equivalent gasoline price would be as low as $1.46 a gallon, as low as 67 cents a gallon in Washington state where electricity prices average about 9 cents per kilowatt-hour. So on a cost basis, it’s a good thing to do. Then, in addition, air quality would improve if we switched to driving electrically, so long as the electricity was produced from a nonpolluting source. The climate issue would be the obvious beneficiary.

    GAZETTE: You go chapter by chapter on possible fuels, and settle on wind and solar as the cleanest and most likely sources to power a future clean electricity grid. What are their drawbacks and can those be addressed?

    McELROY: The economics of wind in the United States is actually quite favorable. You can produce electricity for about 5 cents a kilowatt-hour with wind at present. So it’s competitive. The really serious drawback is that the wind is strongest in winter and our demand for electricity is highest in summer. The wind is also generally stronger at night than it is during the day and our big demand is during the day. And wind doesn’t blow all the time. So we need to find some way to deal with that particular issue.

    There are a number of possible strategies. You could integrate the electrical system over a large part of the country — so if wind is blowing in one place and not in another, by combining outputs you could reduce the net variability. If you had the opportunity to store electricity, that could minimize the problem also. So putting an emphasis on storage systems is a good thing to do. There’s important work going on here at Harvard by Mike Aziz and Roy Gordon on the flow battery idea. It’s something that might actually scale up as a utility scale opportunity to store electricity.

    I am enthusiastic also about the idea of taking advantage of the distributed storage available potentially in the batteries of large numbers of electrically propelled vehicles. I discuss this idea at some length in the book. You could imagine charging your car at night when prices of electricity are low and then selling power back to the grid during the day when prices are high, assuming you don’t need to drive at that time. This could represent a win-win strategy.

    You would still have the issue of summer demand for electricity when wind conditions will be less favorable. That’s where solar comes in. Solar, however, to this point, is still more expensive than wind. Despite this, solar is doing quite well in the U.S. We have a house on Cape Cod and five years ago or so we installed PV cells on the roof. We did this by making a deal with a particular company, Solar City, one in which they actually own the solar cells. They sized the solar cells to meet our projected historical annual demand for electricity. They gave us a deal where we have a fixed price for electricity for 20 years at half of what we were paying previously. How do they manage to do that? Turns out the retail cost for electricity on Cape Cod is very high. It’s very high because the delivery cost is high. The retail price is about 26 cents a kilowatt-hour, more than half of which is for delivery. So they’re giving us a deal at 13 cents per kilowatt-hour.

    There are requirements in almost all of the states now that some fraction of the electricity has to be renewable. If the utilities are not able to meet that requirement from their own resources, which generally they’re not, then they have to buy it. So the Solar Cities of the world are auctioning their renewable energy for incorporation in the grid. If New England Electric is looking for a certain amount of electricity from a renewable source, then Solar City can supply this by packaging sources from large numbers of houses under their control.

    The other thing that’s happening in the U.S. is that meters in many states are allowed to run in reverse. We’re not typically present on Cape Cod in winter. The sun is still shining most of the time and the house continues to produce electricity. Solar City is selling this electricity to the grid at the retail price. Our meter is running in reverse. So, for a lot of reasons, solar has done very well.

    GAZETTE: You say that one of the top priorities for this country should be upgrading the transmission grid. I think a lot of people, when thinking about climate change, think wind farm, solar farm, but not transmission grid. Why do we need that?

    McELROY: Think of the role played more than 100 years ago by Thomas Alva Edison. Edison was an incredible inventor. He was also a very smart guy and he built the first electricity-generating system in Manhattan. Then Westinghouse came along and suddenly we began to see electricity generated in central facilities and distributed more widely to local customers. We’ve built our electrical system in a piecemeal way. We didn’t say, “What’s the best national electricity system?” If we had done that, we would have had an interconnected national electricity system.

    The U.S. has three electricity systems: East Coast grid, West Coast grid, and Texas. It’s very difficult to move electricity across those boundaries. At a minimum, we should invest to interconnect the boundaries. That’s a no-brainer and it would not be very expensive. I like to think about being able to move electricity efficiently over several thousand miles, coast to coast, border to border. We have wonderful wind resources in the middle of the country. The key location to produce electricity from the sun is in the southwest, where we have great solar conditions. The ideal would be to bring both those sources to where the markets are, on the East Coast and West Coast and in major cities like Chicago. But if you’re going to serve those markets you have to be able to deliver.

    In addition, the demand for electricity peaks in the morning and peaks in the evening: when people get up and when they come back from work. If we had a system that was interconnected from California to Massachusetts, at a minimum we’d take advantage of the three-hour time shift to smooth out the peaks in demand.

    What are the obstacles? The obstacles are largely political — the fact that you have to bring power across state boundaries, and you may have to go across individuals’ property. The federal government has the authority to overrule objections if it’s declared to be in the national interest or if it’s in effect a matter of national security. That’s largely why we have a reasonably efficient natural gas distribution system. It could be done for electricity also if we had the will to do it.

    If you really make a commitment to developing this electrical infrastructure, you’re going to have to employ lots of people. So this would be good for the economy. My vision would be one in which we invest in community colleges that train people for those jobs. These are going to be good-paying jobs that can’t be exported.

    See the full article here .

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    Harvard University campus

    Harvard is the oldest institution of higher education in the United States, established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was named after the College’s first benefactor, the young minister John Harvard of Charlestown, who upon his death in 1638 left his library and half his estate to the institution. A statue of John Harvard stands today in front of University Hall in Harvard Yard, and is perhaps the University’s best known landmark.

    Harvard University has 12 degree-granting Schools in addition to the Radcliffe Institute for Advanced Study. The University has grown from nine students with a single master to an enrollment of more than 20,000 degree candidates including undergraduate, graduate, and professional students. There are more than 360,000 living alumni in the U.S. and over 190 other countries.

  • richardmitnick 11:09 am on October 1, 2016 Permalink | Reply
    Tags: , Clean Energy, MeyGen, , Tidal arrays   

    From Smithsonian: “Inside the World’s First Large-Scale Effort to Harness Tidal Energy” 


    September 29, 2016
    Maya Wei-Haas


    Next month, the UK-based company MeyGen will install four underwater turbines off the coast of Scotland

    Tidal arrays are like the younger sibling of windmills—a bit smaller and slower spinning than their wind-loving brethren. But unlike windmills, they operate under many feet of water, spinning in the predictable movement of the ocean’s tides.

    Over the course of the last decade, a handful of companies have taken individual tidal turbines for a successful spin. But the next wave of tidal energy is about to break. Recently, the UK-based tidal energy company MeyGen unveiled its plans for the world’s first multi-turbine tidal energy field.

    The company is starting with a test of four turbines that will soon be deployed in the churning waters of the Inner Sound in Pentland Firth, Scotland. If the test goes swimmingly, they plan to deploy well over a hundred more over the next decade that would generate up to 398 megawatts of electricity—powering roughly 175,000 homes in Scotland.

    One of the four turbines comes from Atlantis, a tidal power technology company headquartered in Edinburgh, Scotland, and the three others were developed by Glasgow-based Andritz Hydro Hammerfest. The devices stand some 85 feet tall, about the height of a five story house, and sport three blades that spin with a diameter spanning nearly 60 feet. While smaller than windmills, the turbines are still quite heavy, each weighing in at 65 tons—roughly the same as six African bush elephants.

    The array will likely hit the water this October, says Cameron Smith, project development director of Atlantis Resources. The turbines have already been shipped to the site and undergone testing on shore. “All we need now is an appropriate tidal window and weather window and we’ll be installing,” he says. Engineers assemble the turbine bases on land, and then, with a crane, lift them from a barge and lower them to the sea floor. Once submerged, each will have at least 26 feet of clearance at the lowest tides.

    The turbine stands some 85 feet tall (MeyGen)

    Tidal turbines have many advantages over other renewables, explains Andreas Uihlein, scientific project officer at the European Commission. First, the turbines are submerged underwater, completely out of sight.

    Though some people revel in the beauty of solar or windmill farms, many consider them eyesores. The Block Island offshore windmill farm, the first of its kind in the United States, met largely broad appeal when it was installed this summer, because of its small size and promise to replace the island’s diesel generators. But the distaste for wind farms was abundantly clear with the uproar surrounding the 130-turbine Cape Wind project off of Martha’s Vineyard. So the positioning of the giant turbines well below the cresting waves is considered a plus.

    The tidal turbines also generate a predictable supply of power. Unlike wind or solar that rely on the whims of the weather, researchers can actually calculate the tidal pull and the amount of energy these systems will generate. Though the power isn’t a constant supply, ebbing and flowing through the day, its predictability lessens the need to store large energy reserves.

    The systems will also help with local employment. “There’s the potential to generate 5,300 full-time equivalent jobs over the next three or four years,” says Smith. “I’m hugely proud that 43 percent of this first phase was manufactured using local supply chain.” Many of these new jobs require the same skills as the oil and gas industry, which means that this fledgling industry provides a new home for talented labor.

    Pentland Firth’s Inner Sound and the individually deployed turbines have undergone extensive monitoring, showing few environmental impacts. Noise levels for turbines already churning away are well below a level that would cause damage, according to MeyGen’s environmental impact analysis. The biggest concern would be collisions with the marine mammals—particularly the harbor seal, whose populations have plummeted in recent years. But no collisions have yet been observed for the single turbine installations, according to a recent report from Annex IV, the body established by the International Energy Association Ocean Energy Systems to examine the environmental impacts of marine renewable energy.

    It seems almost too good to be true.

    That is because, of course, the story doesn’t end there. “There’s always trade offs in energy generation. You could take every one of those statements and put an asterisk next to it,” says Brian Polagye, co-director of the Northwest National Marine Renewable Energy Center, a collaboration between the University of Washington, Oregon State University and the University of Alaska Fairbanks with the goal of advancing the commercialization of marine energy technology.

    Though initial tests showed no environmental impact, even minor influences will become magnified as the company increases the number of turbines in the field. And, as the Annex IV report notes, most of the research has been focused on measuring the amount of noise the turbines generate, but few have identified how this level of noise could actually affect the behavior of marine animals. Though the noise levels are low, the sound could still interfere with animal communication, navigation or detection of prey.

    There is also much still unknown about the durability of the turbines. Their placement underwater keeps them out of sight, but the corrosive marine environment could slowly eat away at the devices. They also suffer constant mechanical stress, buffeted about in the currents.

    Though many companies have deployed individual units, none have been in the ocean for very long. Marine Current Turbines installed the first tidal turbine in Northern Ireland’s Strangford Lough in 2008. Now in its eighth year, this 1.2 MW spinner, composed of two separate turbines attached to a center platform, has been feeding the grid since its installation.

    “The big challenge for almost every company is going to be, how are you going to do this at a cost that competes with other sources of energy?” says Polagye.

    As a new industry, tidal energy has had its fair share of setbacks, with several companies, including the Ireland-based Wavebob Ltd., folding after failing to secure funding. But with improved designs, MeyGen and others are spinning their way back up to the top. Their long-term success relies in part on the government support for development and installation, explains Polagye.

    The United Kingdom government works on what’s known as “market-pull mechanisms,” explains Polagye. In this system, the government pays the difference between the cost of the renewable energy and that of standard electricity. This system pulls the new companies into the market, allowing them to compete with the big dogs of energy. The United States government, however, uses push mechanisms, supplying grants for development but little help competing with other energy sources. In order for these systems to have a future in the U.S. market, says Polagye, the government needs to develop similar pull mechanisms for energy.

    Though tidal currents aren’t strong enough along every coast to host one of these spinners, there are still many spots around the world with potential. In order for a site to be worthwhile, they must have some type of geographic restriction, like straits and fjords. This narrowing of the flowpath increases the speed of the water movement in the retreating or advancing tides, and therefore increases the energy recovered from the site.

    “If you look at a map of the world and show all the [potential turbine] sites to scale, they’d look really tiny—you probably would have trouble seeing them,” says Polagye. “But if you were to aggregate them all together, you’d probably end up with a few hundred gigawatts of energy.” And though the world will likely never run completely on tidal energy, a few hundred gigawatts is nothing to shake your iPhone at. To put that amount in perspective, since 400 MW is expected to power 175,000 homes, one gigawatt could power roughly 500,000 homes.

    A 2015 report from the European Commission’s Joint Research Center suggests that by 2018, there will be about 40 MW of tidal and 26 MW of wave energy undergoing installation. While tidal energy takes advantage of the tides, wave energy harnesses the energy from churning waves. Still in its early days of development, researchers are exploring different ways to do this—from long floating structures that “ride” the waves to massive bobbing buoys. Though wave energy lags behind tidal, according to the report, it has a global potential 30 times that of tidal energy, due to the large number of potential sites for deployment around the globe.

    Where the field of tidal turbines will go in the next couple decades is a bit of a mystery.

    “A lot of that depends on MeyGen,” says Polagye. “The turbine has to operate well and it has to not kill seals. If they do that, they’re definitely on a good trajectory.”

    See the full article here .

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    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

  • richardmitnick 7:42 am on September 8, 2016 Permalink | Reply
    Tags: Clean Energy, Offshore wind research,   

    From UMASS Amherst: “UMass Amherst Researchers to Study Offshore Wind Industry” 

    U Mass Amherst

    University of Massachusetts

    September 7, 2016
    No writer credit

    UMass Amherst researchers are developing a multi-disciplinary framework for offshore wind research, focusing on increasing innovation within projects and reducing costs by examining risks, finances and regulations associated with the industry.

    The Massachusetts Research Partnership in Offshore Wind, funded with $300,000 from the Massachusetts Clean Energy Center’s Renewable Energy Trust, includes six Massachusetts academic and research institutions – UMass Amherst, Northeastern University, Tufts University, UMass Dartmouth, UMass Lowell and Woods Hole Oceanographic Institution.

    The funding was announced by the Baker-Polito administration as part of $700,000 for nine academic and research institutions across Massachusetts to advance studies relating to offshore wind development.

    For the 18-month project, James F. Manwell, director of the Wind Energy Center in the UMass Amherst College of Engineering, will serve as team leader. Other faculty members are professors Matthew A. Lackner, Sanjay R. Arwade, Don J. DeGroot, Jon G. McGowan and Erin D. Baker. Collectively, this team has extensive experience in a wide range of offshore wind energy research areas and a long history of engagement in wind energy technology, policy, education and development.

    The research team will concentrate on three areas. These include design standards. Having suitable design standards is crucial the development of the offshore wind energy industry. Design standards help to ensure that turbines and their support structures are adequate to the environmental and operating conditions they will experience but also are not inordinately expensive. They provide the framework for the designers and they also offer confidence to the lending institutions and the insurers.

    In addition, the researchers will focus on wind turbine system modeling. Wind turbine technology continues to evolve, with larger rotors, taller towers and deeper‐water installations. It is critical to have accurate and efficient models of the wind turbine system behavior, especially when they are located offshore and subjected to wind, waves and currents, including hurricanes and other extreme events. UMass Amherst has significant expertise in the modeling, simulation, analysis and validation of offshore wind turbine system behavior and has collaborated with experts in Europe, industry and national labs in this area.

    There will also be work on geotechnical issues. The geotechnical engineering site characterization phase of an offshore wind project provides information on seabed stratigraphic soil units and soil engineering properties for design of turbine support structures. It generally requires the use of specialized vessels/drilling platforms and, coupled with the large size of project areas, makes it a significant part of a project’s initial capital investment. This is especially the case in regions with complex geologic histories that created significant spatial variations in soil units and properties, such as the glaciated New England coastal area.

    See the full article here .

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    U Mass Amherst campus

    UMass Amherst, the Commonwealth’s flagship campus, is a nationally ranked public research university offering a full range of undergraduate, graduate and professional degrees.

    As the flagship campus of America’s education state, the University of Massachusetts Amherst is the leader of the public higher education system of the Commonwealth, making a profound, transformative impact to the common good. Founded in 1863, we are the largest public research university in New England, distinguished by the excellence and breadth of our academic, research and community outreach programs. We rank 29th among the nation’s top public universities, moving up 11 spots in the past two years in the U.S. News & World Report’s annual college guide.

  • richardmitnick 7:35 am on September 8, 2016 Permalink | Reply
    Tags: , Clean Energy, , Energy pick n’ mix: are hybrid systems the next big thing   

    From CSIRO: “Energy pick n’ mix: are hybrid systems the next big thing?” 

    CSIRO bloc

    Commonwealth Scientific and Industrial Research Organisation

    8th September 2016
    Claire Ginn

    Solar and wind power side by side. No image credit.

    What’s powering your home? Are you connected to the electricity grid? Do you have solar panels? A fuel cell? Perhaps a backyard wind turbine? It’s totally feasible to check all of these boxes: this is what’s called a ‘hybrid energy system’.

    Hybrid energy systems combine two or more forms of energy generation, storage or end-use technologies, and they can deliver a boatload of benefits compared with single source systems.

    Variety is the spice of life, so why limit ourselves to just one energy source or storage option? In these cases, hybrid energy systems are an ideal solution since they can offer substantial improvements in performance and cost reduction, and can be tailored to varying end user requirements.

    Configurations could include renewable or non-renewable energy sources, electrical and chemical energy storage and fuel cells, often connected via a smart grid.

    They have the potential to dramatically reduce cost and emissions from energy generation and distribution for households, but can be held back by the limitations of individual power generation or storage technologies – this may include cost, inconsistent supply (like interrupted solar on a cloudy day), etc.

    This means there is substantial demand for hybrid energy solutions to lower cost and improve efficiency, while still meeting performance requirements.

    So to meet this demand, we’ve established a Centre for Hybrid Energy Systems at our Clayton site in Victoria. It’s a state-of-the-art facility showcasing our substantial expertise and capability in integrating energy storage, renewable energy, hydrogen and fuel cell technologies, fuel processing, systems design and construction.

    According to our research Fellow Dr Sukhvinder Badwal, there’s now an increased availability of renewable and modular power generation and storage technologies such as batteries, fuel cells, and household solar.

    “These technologies are becoming cost competitive, but the key to greater use is to combine them in connected hybrid systems,” Dr Badwal said.

    “By doing this, we can offer substantial improvements in performance and cost.”

    We’re keen to put our heads together with industry partners, and the collaborative space will be used to share the benefits of emerging hybrid energy systems with industry and government to maximise the value of local energy sources.

    The Centre is underpinned by our research across low-emission energy technologies that create value for industry and households and provide the knowledge which will help guide Australia towards a smart, secure energy future.

    See the full article here .

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    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

  • richardmitnick 8:30 am on September 7, 2016 Permalink | Reply
    Tags: , Clean Energy, , ,   

    From MIT: “Sponge creates steam using ambient sunlight” 

    MIT News
    MIT News
    MIT Widget

    August 22, 2016
    Jennifer Chu | MIT News Office

    MIT graduate student George Ni holds a bubble-wrapped, sponge-like device that soaks up natural sunlight and heats water to boiling temperatures, generating steam through its pores.
    Photo: Jeremy Cho

    Bubble wrap, combined with a selective absorber, keeps heat from escaping the surface of the sponge. Photo: George Ni

    How do you boil water? Eschewing the traditional kettle and flame, MIT engineers have invented a bubble-wrapped, sponge-like device that soaks up natural sunlight and heats water to boiling temperatures, generating steam through its pores.

    The design, which the researchers call a “solar vapor generator,” requires no expensive mirrors or lenses to concentrate the sunlight, but instead relies on a combination of relatively low-tech materials to capture ambient sunlight and concentrate it as heat. The heat is then directed toward the pores of the sponge, which draw water up and release it as steam.

    From their experiments — including one in which they simply placed the solar sponge on the roof of MIT’s Building 3 — the researchers found the structure heated water to its boiling temperature of 100 degrees Celsius, even on relatively cool, overcast days. The sponge also converted 20 percent of the incoming sunlight to steam.

    The low-tech design may provide inexpensive alternatives for applications ranging from desalination and residential water heating, to wastewater treatment and medical tool sterilization.

    The team has published its results today in the journal Nature Energy. The research was led by George Ni, an MIT graduate student; and Gang Chen, the Carl Richard Soderberg Professor in Power Engineering and the head of the Department of Mechanical Engineering; in collaboration with TieJun Zhang and his group members Hongxia Li and Weilin Yang from the Department of Mechanical and Materials Engineering at the Masdar Institute of Science and Technology, in the United Arab Emirates.

    Building up the sun

    The researchers’ current design builds on a solar-absorbing structure they developed in 2014 — a similar floating, sponge-like material made of graphite and carbon foam, that was able to boil water to 100 C and convert 85 percent of the incoming sunlight to steam.

    To generate steam at such efficient levels, the researchers had to expose the structure to simulated sunlight that was 10 times the intensity of sunlight in normal, ambient conditions.

    “It was relatively low optical concentration,” Chen says. “But I kept asking myself, ‘Can we basically boil water on a rooftop, in normal conditions, without optically concentrating the sunlight? That was the basic premise.”

    In ambient sunlight, the researchers found that, while the black graphite structure absorbed sunlight well, it also tended to radiate heat back out into the environment. To minimize the amount of heat lost, the team looked for materials that would better trap solar energy.

    A bubbly solution

    In their new design, the researchers settled on a spectrally-selective absorber — a thin, blue, metallic-like film that is commonly used in solar water heaters and possesses unique absorptive properties. The material absorbs radiation in the visible range of the electromagnetic spectrum, but it does not radiate in the infrared range, meaning that it both absorbs sunlight and traps heat, minimizing heat loss.

    The researchers obtained a thin sheet of copper, chosen for its heat-conducting abilities and coated with the spectrally-selective absorber. They then mounted the structure on a thermally-insulating piece of floating foam. However, they found that even though the structure did not radiate much heat back out to the environment, heat was still escaping through convection, in which moving air molecules such as wind would naturally cool the surface.

    A solution to this problem came from an unlikely source: Chen’s 16-year-old daughter, who at the time was working on a science fair project in which she constructed a makeshift greenhouse from simple materials, including bubble wrap.

    “She was able to heat it to 160 degrees Fahrenheit, in winter!” Chen says. “It was very effective.”

    Chen proposed the packing material to Ni, as a cost-effective way to prevent heat loss by convection. This approach would let sunlight in through the material’s transparent wrapping, while trapping air in its insulating bubbles.

    “I was very skeptical of the idea at first,” Ni recalls. “I thought it was not a high-performance material. But we tried the clearer bubble wrap with bigger bubbles for more air trapping effect, and it turns out, it works. Now because of this bubble wrap, we don’t need mirrors to concentrate the sun.”

    The bubble wrap, combined with the selective absorber, kept heat from escaping the surface of the sponge. Once the heat was trapped, the copper layer conducted the heat toward a single hole, or channel, that the researchers had drilled through the structure. When they placed the sponge in water, they found that water crept up the channel, where it was heated to 100 C, then turned to steam.

    Tao Deng, professor of material sciences and engineering at Shanghai Jiao Tong University, says the group’s use of low-cost materials will make the device more affordable for a wide range of applications.

    “This device offers a totally new design paradigm for solar steam generation,” says Deng, who was not involved in the study. “It eliminates the need of the expensive optical concentrator, which is a key advantage in bringing down the cost of the solar steam generation system. Certainly the clever use of bubble wrap and commercially available selective absorber also helps suppress the convection and radiation heat loss, both of which not only improve the solar harvesting efficiency but also further lower the system cost. “

    Chen and Ni say that solar absorbers based on this general design could be used as large sheets to desalinate small bodies of water, or to treat wastewater. Ni says other solar-based technologies that rely on optical-concentrating technologies typically are designed to last 10 to 20 years, though they require expensive parts and maintenance. This new, low-tech design, he says, could operate for one to two years before needing to be replaced.

    “Even so, the cost is pretty competitive,” Ni says. “It’s kind of a different approach, where before, people were doing high-tech and long-term [solar absorbers]. We’re doing low-tech and short-term.”

    “What fascinates us is the innovative idea behind this inexpensive device, where we have creatively designed this device based on basic understanding of capillarity and solar thermal radiation,” says Zhang. “Meanwhile, we are excited to continue probing the complicated physics of solar vapor generation and to discover new knowledge for the scientific community.”

    This research was funded, in part, by a cooperative agreement between the Masdar Institute of Science and Technology and MIT; and by the Solid-State Solar Thermal Energy Conversion Center, an Energy Frontier Research Center funded by U.S. Department of Energy.

    See the full article here .

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    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 5:48 am on August 13, 2016 Permalink | Reply
    Tags: , Clean Energy, , Scotland just generated more power than it needs from wind turbines alone, Wind power   

    From Science Alert: “Scotland just generated more power than it needs from wind turbines alone” 


    Science Alert

    12 AUG 2016

    Master Wen/Unsplash


    Last Sunday, Scotland achieved something great – for the first time on record, wind power alone generated 106 percent of Scotland’s electricity needs in a single day.

    Environmental group WWF Scotland has just confirmed that on 7 August 2016, wind turbines in Scotland pumped 39,545 megawatt-hours (MWh) of electricity into the National Grid, while the nation’s homes, businesses, and industry needed just 37,202 MWh.

    “While it’s not impossible that this has happened in the past, it’s certainly the first time since we began monitoring the data in 2015 that we’ve had all the relevant information to be able to confirm it,” WWF Scotland director Lang Banks told the Associated Press.

    “However, on the path to a fully renewable future, this certainly marks a significant milestone.”

    Before we get into the details, there are a couple of caveats that we should get out there first.

    To say this was a particularly windy day is an understatement. It was chaos. Wind speeds reached an incredible 185 km/h (115mph) in some parts of the country, forcing bridges to close, trains to be delayed, and ferries cancelled.

    Power was cut in parts of Dundee, Scotland’s fourth biggest city, and a 17,000 tonne oil rig was ripped from its tug and floated to shore.

    It was also a Sunday, which means businesses and industry facilities would have required a whole lot less energy than they would on a weekday, so just bear that in mind.

    But the fact that the country was able to achieve this feat at all goes to show that renewables are more viable than ever as a replacement for fossil fuel.

    Despite having the largest oil reserves in the European Union – accounting for nearly 60 percent of total EU reserves – Scotland has been going all in on renewables over the past few years.

    Back in April, it announced that it had generated 57.7 percent of its electricity consumption from renewable sources in 2015, which put it squarely at the halfway mark of powering itself on 100 percent renewable electricity by 2030.

    It’s also planning on building the world’s largest floating wind farm off the coast of Peterhead – a town at the easternmost point on mainland Scotland. If they get this thing off the ground (so to speak), it could be supplying power to nearly 20,000 homes by the end of 2017.

    “Scotland’s abundant energy resources play a vital role in delivering security of electricity supply across the UK. The Scottish Government is committed to supporting onshore wind, which is one of our most cost-effective low-carbon energy technologies,” a government spokesperson told the AP.

    With the cost of wind energy now on par with natural gas, Germany achieving 95 percent of its daily energy needs via renewables recently, and Portugal clocking four straight days powered entirely by renewable energy, the future of energy is here.

    I, for one, welcome our new turbine overlords.

    See the full article here .

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