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Dear Subscriber |
On January 14, 2009, the US Energy Association held its 5th Annual State of the Energy Industry event addressing energy efficiency, electric power supply, renewable energy, and petroleum and natural gas in panel discussions consisting of company CEOs. Some surprises included the fact that Denmark now gets 50% of its energy production from CHP (combined heat and power) which is 80% efficient onsite and the solar industry experienced a 100% growth in 2008 in the US. Questions from the suit and tie crowd included "How much will electric vehicles impact the grid in 2030?" Visit www.usea.org for more information. Also you can dowload IRI comprehensive energy policy recommendations to the new administration.
Sincerely,
President |
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A Design For Cheaper Wind Power |
Kevin Bullis, Technology Review, Monday, December 01, 2008 http://www.technologyreview.com/energy/21737/?nlid=1549&a=f
FloDesign Wind Turbine, a spin-off from the aerospace company FloDesign based in Wilbraham, MA, has developed a wind turbine that could generate electricity at half the cost of conventional turbines. The company recently raised $6 million in its first round of venture financing and has announced partnerships with wind-farm developers.
The company's design, which draws on technology developed for jet engines, circumvents a fundamental limit to conventional wind turbines. Typically, as wind approaches a turbine, almost half of the air is forced around the blades rather than through them, and the energy in that deflected wind is lost. At best, traditional wind turbines capture only 59.3 percent of the energy in wind, a value called the Betz limit.
FloDesign surrounds its wind-turbine blades with a shroud that directs air through the blades and speeds it up, which increases power production. The new design generates as much power as a conventional wind turbine with blades twice as big in diameter. The smaller blade size and other factors allow the new turbines to be packed closer together than conventional turbines, increasing the amount of power that can be generated per acre of land.
The idea of enshrouding wind-turbine blades isn't new. But earlier designs were too big to be practical, or they didn't perform well, in part because the blades had to be very closely aligned to the direction of the wind--within three or four degrees, says Stanley Kowalski, FloDesign's CEO. The new blades are smaller and can work at angles of up to 15 to 20 degrees away from the direction of the wind.
From the front, the wind turbine looks something like the air intake of a jet engine. As air approaches, it first encounters a set of fixed blades, called the stator, which redirect it onto a set of movable blades--the rotor. The air turns the rotor and emerges on the other side, moving more slowly now than the air flowing outside the turbine. The shroud is shaped so that it guides this relatively fast-moving outside air into the area just behind the rotors. The fast-moving air speeds up the slow-moving air, creating an area of low pressure behind the turbine blades that sucks more air through them.
It's plausible that such a design could double or triple a turbine's power output, says Paul Sclavounos, a professor of mechanical engineering at MIT. Part of the increase comes simply from guiding the air to the turbine with the shroud. But Sclavounos notes that it also helps to use the wind surrounding the turbine to speed up the airflow, because the power produced by a wind turbine increases with the cube of the wind speed. The key question is whether the new turbines can be built and maintained at a low-enough cost, Sclavounos says.
FloDesign has already built a small prototype for wind-tunnel tests. Its next step is to build a 12-foot diameter, 10-kilowatt system for field tests. The prototype will be finished by the end of next year or early in 2010, with commercial wind turbines to follow. (The company is not yet taking orders.) Eventually the company plans to make turbines as large as one megawatt.
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Wind Power at $1 Per Watt |
Broadstar Wind Systems, a company based in Dallas Texas, has provided the public with not one, but two lofty promises: that their wind turbines can 1) be integrated into almost any location, including cities and 2) are inexpensive, at a cost of $1 per watt. Older, more traditional wind turbine systems has its drawbacks. They had to be big and tall. You needed at least one acre of clear land. And they couldn't handle winds from all directions. Broadstar aims to take care of most of these weaknesses with their new turbines.
According to BroadStar, the AeroCam is short, compact and easy-to-install, with parallel rotor blades located much closer to the ground than conventional propeller-based turbines.That low-ground proximity allows the machines to capture surface-wind energy at low rotational speeds. And it qualifies AeroCam to "infill" existing rural wind farms. Meaning: the small turbines can be stuck between taller and larger propeller-based ones for better power generation. In urban areas, they can be installed on commercial and residential rooftops, picking up wind drafts that strike buildings, and then moving upwards, catching currents from four to 80 mph.
The kicker? BroadStar is convinced that its machines will be "manufactured, transported, installed and maintained at lower costs" than any other wind turbine on the planet. And most - if not all - rooftop solar panels. - solveclimate.org. They've certainly got their work cut out for them. Their 250,000 kWh machine is priced at $250k. Not exactly cheap, but that's a boatload of power right there. Enough to power almost 100 homes. Could there be some sort of collective group that sets up this power system and have 100 homes or businesses chip in towards the cost? I don't see why not. After all, it's an investment towards energy for a long, long time - unlike regular power which you'd have to pay monthly for. Sometimes we don't need the government's help. We just need to use our minds and our wills to make things happen.
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How much does it cost to install solar on an average US house? |
By Lee Devlin on January 30, 2008, Solar Power Authority, http://www.solarpowerauthority.com/archives/2008/01/how-much-does-it-cost-to-install-solar-on-an-average-us-house.html
Because of my engineering background and my interest in the topic of renewable energy, people sometimes ask me how much it would cost to install enough photovoltaic (PV) solar panels to generate all of one's own electrical energy. There are websites to help with this, but they can sometimes be confusing unless you're a technologist so I've developed some simple guidelines that will help to put a PV solar system's cost in perspective.
In the U.S., a rule-of-thumb is that an average house consumes electricity at the rate of 1 kW. Since there are about 730 hours in each month and the average price of a kW-hour of electricity is about $.10, an average monthly electric bill should be around $73 for 730 kWh of electricity. I will say that this can vary considerably if you have some non-standard items like a hot-tub or some electrical appliances running continuously. It will also increase significantly in months when you run an air conditioning unit. The cost of electricity varies widely across the U.S. as well from a low of $.07/kWh in West Virginia to a high of $.24/kWh in Hawaii, so you'd need to adjust my guidelines accordingly because what I'm writing about here applies to an average home with average electricity costs.
A conservative value to use for a solar panel's generating capacity is 10 watts/sq. ft. This represents a panel conversion efficiency of about 12% which is typical. That means that for every kW you need to generate, you'd need about 100 sq. ft. of solar panels. If the sun would shine 24 hours a day, you could put up 100 sq. ft. of panels and you'd have enough to power an average home. But as we all know, the sun doesn't shine all the time. The sun is only available during the day and the amount of sunshine per day is very dependent on cloud cover. Also, the length of each day is dependent on the season. Fortunately, there are resources on the web to help you figure out how many hours per day on average you can count on the sun to shine based on where you live. The numbers across the U.S. vary from an average of around 3 hours per day in places like Seattle, Chicago, and Pittsburgh to 5 or 6 hours per day in states like Colorado and California to a high of 7 hours a day in Arizona. What that means is that the size of your solar panel array can vary from around 400 to 800 sq. ft. (i.e., 4 kW to 8 kW) respectively, depending on where you live. You'll need more panels if you live in a location that gets less average sunshine per day and fewer if you live in a location that gets higher amounts of average sunshine.
If your utility company allows you to have net metering, that is, they supply you with a special meter that will spin backwards when you generate more electricity than you use, your annual bill can average out to be zero. Because of the change in the length of the day in the winter months, you'll likely be a net purchaser of electricity in those months and in the summer months, you may be a net producer. A grid-tied system like I'm describing is different than off-grid systems, such as those used in remote locations with no electrical service, since those require batteries and that can significantly increase the overall system cost.
At the time of this writing, the installed cost of solar panels runs between $7 to $9 per watt, so a 5 kW system would cost on the order of $35,000-$45,000 and an 8 kW system would be anywhere from $56,000 to $72,000. Many utility companies are offering incentives with some subsidizing as much as 50% of the cost of the system. Even so, a system that generates an average of $73 of electricity per month would take a long time to pay for itself even if you could get it at half cost. For example, a system that cost $18,000 would have a payback period on the order of 20 years. The panel cost today is around $4 per watt and the extra cost that brings it up to $7 to $9 installed is to cover the installation labor and the electronics needed to tie it into your existing electrical system.
The good news is that the installed cost of PV solar panels is expected to continue to drop as thin film panels from companies like First Solar, Nanosolar, and AVA Solar become available to the residential market. Right now, First Solar is only selling to commercial customers. Nanosolar and AVA Solar have yet to ramp up their production facilities. It will be interesting to see where this all goes in a year or two since these companies are talking about very aggressive price targets and volumes, on the order of $1-2 per watt and volumes that are several times today's total output. Assuming that the installation and auxiliary equipment costs can be reduced to around $1 per watt, then a 5 kW system may cost as little as $10,000 and the payback would be on the order of 10 years even without subsidies, which begins to make PV solar much more attractive. Of course, all this assumes that electric rates stay constant. However, if anything, electric rates are likely to continue to rise as fuel and other infrastructure costs increase so payback periods for solar panels are likely to become even shorter in the future. I expect we will begin to see many more of them being installed on roofs, especially in areas with favorable solar conditions or higher than average electricity rates.
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The Year in Energy |
Technical advances jump-start electric cars, wind turbines, and solar power. When oil prices shot to $145 per barrel this year, supporters of alternative-energy technologies of all kinds cheered. Spirits fell, however, especially at some advanced biofuels companies, after oil prices plummeted to $40, a contingency considered at the beginning of this year in our realistic assessment of biofuels.Yet the year has seen some remarkable advances in energy technology, and many of the innovators in this area remain hopeful that the coming decade won't be like the 1980s, when a drop in oil prices snuffed out interest in alternative energy. A number of improvements to wind turbines could increase the amount of power that they produce and make wind power cheaper. Among the improvements were new blade designs inspired by whales, as well as better generators and a new enclosed design that could double power output.
Electric vehicles and plug-ins also took steps forward with better batteries, as well as with an ambitious plan by a company called Better Place to develop a vehicle-charging and battery-swapping network that will begin in Israel and Denmark. More recently, the same company has announced projects in Australia, California, and Hawaii. One of the cars that could be a part of this system was announced by Renault--indeed, all of the major automakers have confirmed projects for plug-in hybrids or electric cars. Solar panels continue to improve. Experimental solar concentrators could make solar power as cheap as electricity from coal. Modifications to conventional solar cells could lower prices even sooner. A basic research finding could lead to a cheap way to store solar power--and, for that matter, any other source of electricity. That could be a boon to the power grid and allow renewable sources to supply much more of our electricity. (See David Talbot's "Lifeline for Renewable Power.")
Meanwhile, as the United States lurches along without an energy policy, oil-rich sheikhs in the Middle East are pressing forward with the construction of a car-free, zero-emissions city in the desert. While predictions of a deep recession, as well as continuing low oil prices and credit woes, during the upcoming year remain worrisome, the United States has a new administration that, going by its rhetoric and cabinet appointees, will strongly support alternative energy. And already, technological advances have made renewable-power prices competitive with prices for conventional power in many places worldwide, allowing sources such as wind and solar to thrive even without government support.
Ed. note: Note that nuclear energy has been omitted. No mention of the thorium fuel cycle being revived (THPW) - TV. Honda Solar Cell Learn about Honda's next-generation solar cells and see what we see. www.honda.com
Solar Power Generation Share & Learn Leading Ideas On Power Generation Efficiency Today! Communities.Bentley.com
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Measured Long-Range Repulsive Casimir-Lifshitz forces |
Nature 457, 170-173 (8 January 2009) | doi:10.1038/nature07610;
Received 6 August 2008; Accepted 30 October 2008
J. N. Munday, Federico Capasso & V. Adrian Parsegian Department of Physics, School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA National Institutes of Health, Bethesda, Maryland 20892, USA
Correspondence to: Federico Capasso2 Correspondence and requests for materials should be addressed to F.C. (Email: capasso@seas.harvard.edu).
Abstract Quantum fluctuations create intermolecular forces that pervade macroscopic bodies 1, 2, 3. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces4. However, as recognized in the theories of Casimir, Polder and Lifshitz 5, 6, 7, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies 8, 9, 10, 11. Here we show experimentally that, in accord with theoretical prediction 12, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir-Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction 13, 14, 15.
Department of Physics, School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA National Institutes of Health, Bethesda, Maryland 20892, USA Correspondence to: Federico Capasso2 Correspondence and requests for materials should be addressed to F.C. (Email: capasso@seas.harvard.edu).
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