vaticanOnly a few days after Roman Catholic Easter, the tradition’s faith leaders announced a plan to care for God’s Creation by harvesting energy from sunlight. Solar photovoltaic (PV) power exists in a small scale all over the world, from arrays less than 1 kW to a couple dozen MW. But the Holy See just announced that they intend to build what would today be the world’s biggest solar PV system at 100 MW.
Exporting Green Power
An installation of this size is estimated to provide all the power needs of the small nation-state and even allow them to export electricity to their neighbors in Italy. The Vatican already has a sizable solar installation that powers the 6,300 seat dome where weekly mass is held. That system was made possible by a donation of $1.5 million of panels from German solar producer, Solarworld. This time around, Italy’s supportive renewable energy policy (a generous feed-in tariff) helped to make the project economical.
The 100 MW solar farm is slated to be built ground-mounted on 740 acres that the Vatican owns north of Rome. Such a large installation is equal to almost half the size of Italy’s whole solar market in 2008. Initial cost estimates run as low as $450 million which, if realized, would be a leap forward in solar cost reduction to below $5 per watt including installation costs (making the source much more competitive with new fossil fuel-fired power plants).
It Doesn’t Stop with PV
The Vatican also plans to utilize solar thermal systems to heat and cool the staff cafeteria. And they are looking into projects to process their waste and even their horses waste into usable energy as well.
Will Other Religious Institutions Lead as Well?
Caring for God’s Creation is a value spoken by practitioners across the world’s faiths. I hope these visible efforts by the Vatican help to inspire similar progress in the Sustainable Energy Transition at churches, mosques, and synagogues — and in the homes and schools of their practitioners. Thank you for your leadership on environmental stewardship, Pope Benedict XVI.
Wednesday, April 29, 2009
Tuesday, March 17, 2009
Monday, March 16, 2009
Solar Space Heating and Cooling
Solar Space Heating and Cooling
This prototype home in Tucson, Arizona, employs active and passive solar technologies, including a hidden, roof-top solar water heater, reflective window coverings, and overhangs.
Just as solar energy can heat the water for a building, it can also heat and cool the air.
Space Heating
A solar space-heating system can consist of a passive system, an active system, or a combination of both. Passive systems are typically less costly and less complex than active systems. However, when retrofitting a building, active systems might be the only option for obtaining solar energy.
Passive Solar Space Heating
Passive solar space heating takes advantage of warmth from the sun through design features, such as large south-facing windows, and materials in the floors or walls that absorb warmth during the day and release that warmth at night when it is needed most. A sunspace or greenhouse is a good example of a passive system for solar space heating.
Passive solar design systems usually have one of three designs:
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Direct gain (the simplest system) stores and slowly releases heat energy collected from the sun shining directly into the building and warming materials such as tile or concrete. Care must be taken to avoid overheating the space.
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Indirect gain (similar to direct gain) uses materials that hold, store, and release heat; the material is located between the sun and living space (typically the wall).
- Isolated gain collects solar energy remote from the location of the primary living area. For example, a sunroom attached to a house collects warmer air that flows naturally to the rest of the house.
For more information about passive solar space heating, visit the EERE Passive Solar Heating, Cooling, and Daylighting page.
Active Solar Space Heating
Active solar space-heating systems consist of collectors that collect and absorb solar radiation combined with electric fans or pumps to transfer and distribute that solar heat. Active systems also generally have an energy-storage system to provide heat when the sun is not shining. The two basic types of active solar space-heating systems use either liquid or air as the heat-transfer medium in their solar energy collectors.
Liquid-based systems heat water or an antifreeze solution in a hydronic collector. Air-based systems heat air in an air collector. Air-based solar heating systems usually employ an air-to-water heat exchanger to supply heat to the domestic hot water system, making the system useful in the summertime. Both of these systems collect and absorb solar radiation, then transfer the solar heat directly to the interior space or to a storage system, from which the heat is distributed. An auxiliary or backup system provides heat when storage is discharged. Liquid systems are more often used when storage is included.
Here is a summary of the many different types of active solar space-heating systems:
Medium-temperature solar collectors are generally used for solar space heating. Solar space heating systems operate in much the same way as indirect solar water-heating systems, but they have a larger collector area, larger storage units, and more complex control systems. They are also usually configured to provide solar water heating and typically provide 30% to 70% of the residential heating, or combined heating and hot water, requirements. Active solar space-heating systems require more sophisticated design, installation, and maintenance techniques.
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A very economical, but specialized space heating system is based upon use of transpired air collectors, mounted as an exterior cladding on a south-facing wall. These systems are used for ventilation preheating. This system heats only outdoor air. These collectors are unglazed, and a blower or fan is used to draw air through perforations in the wall to deliver ventilation air into the building. Solar ventilation air preheating systems are generally used in commercial and industrial applications that require large quantities of ventilation air, including: a) buildings that require much outdoor ventilation, such as warehouses, large manufacturing plants, and airplane maintenance hangars; b) crop drying; and c) pre-heatingof boiler combustion air.
Space Cooling
Cooling and refrigeration can be accomplished using thermally activated cooling systems (TACS) driven by solar energy. These systems can provide year-round utilization of collected solar heat, thereby significantly increasing the cost effectiveness and energy contribution of solar installations. These systems are sized to provide 30% to 60% of building cooling requirements using solar, with the remainder usually dependent on TACS fueled by natural gas. The TACS available for solar-driven cooling include absorption systems and desiccant systems. Generally, solar cooling is not used because of the high initial costs of TACS and the solar fields needed to drive them.
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Solar absorption systems use the thermal energy from a solar collector to separate a binary mixture of an absorbent and a refrigerant fluid. The refrigerant is condensed, throttled, and evaporated to yield a cooling effect, which is then re-absorbed to continue the cycle. Double-effect absorption systems (which use the heat twice in series) are about twice as efficient as single-effect systems, but require significantly higher input temperatures. Because of the high temperature requirements of absorption cooling systems, evacuated-tube or concentrating collectors are typically used.
- Solar desiccant systems use thermal energy from the solar collector to regenerate dessicants that dry ambient air; they then use that dry air in indirect and/or direct evaporative stages to provide cooled air to the load. The solar heat is used to regenerate the desiccant, driving off the absorbed water. Some systems use flat-plate collectors at intermediate temperatures.
Photovoltaic Mileage
New Life-Cycle Assessment Reveals Your Photovoltaic Mileage May Vary
by Jeremy Elton Jacquot, Los Angeles on 02. 9.08
Science & TechnologyNot all photovoltaic technologies are created equal; some, in fact, incur quite heavy environmental footprints - producing silicon, for example, consumes a lot of water and energy while refining zinc produces a sizeable chunk of emissions. Environmental Science & Technology's Naomi Lubick reports that Vasilis Fthenakis, a scientist at Columbia University and the Brookhaven National Laboratory, just finished a LCA of some of the leading technologies which determined that new thin-film cadmium-telluride (CdTe) materials - such as the ones we covered here - come out on top.
Benefiting from its highly efficient energy conversion, CdTe photovoltaic systems consumed less energy and produced fewer emissions; in addition, when compared to its multicrystal and ribbon silicon competitors, the CdTe technology had the lowest cost. In order to obtain these results, Fthenakis and his colleagues compared data from more than a dozen solar companies, taking into account the manufacturing process, energy conversion and various components.
Unfortunately, the assessment failed to shed light on the technologies' total environmental impact - "not telling you exactly what your impact is if you were to buy them," as Corinne Reich-Weiser, a graduate student at UC Berkeley, explained. For instance, she notes that the emissions produced during the transportation of components before production and assembly are only partly taken into consideration; moreover, the assessment is based on idealized European and U.S. grids even though most components are built in China. Publish Post
Still, it provides an effective means of "easily comparing" all of the available technologies, she says, deeming it "incredibly useful." New and future solar technologies should be able to bridge that emissions gap within the coming years as companies continue innovating and expanding their operations. Fthenakis notes that the one missing element from his assessment he hopes to amend soon is the end-of-life and recycling data; he believes this should help make the technologies' emissions profiles even better.
Friday, March 6, 2009
Powershift09 Conference Brings Thousands of Activists to DC Demanding Clean Energy
I was there for the conference,too bad couldn't make to the lobby day...
by Bonnie Hulkower, New York, New York on 03. 4.0
by Bonnie Hulkower, New York, New York on 03. 4.0
Powershift 09 Rally on Lawn of the Capitol photo from Fritz Meyr's flickr page
Powershift 2009 was an energetic and informative conference that culminated with a march of 3,000 plus young (and young at heart) people demanding clean energy and green jobs. The inclement weather only made the march more inspiring. Other Powershift 2009 highlights included: Protestors visiting their representatives in Congress and the Senate; Four young leaders giving testimony to the House Select Committee for Energy Independence and Global Warming; and an anti-coal protest at the Capitol Power Plant.
When I arrived, I scanned the cavernous conference center for the registration area and asked a woman wearing a green t-shirt and badge that said LEADER for directions. As I walked to the table she had pointed to, the brilliance of the conference organizers dawned on me—every participant was wearing a tag that proclaimed them a LEADER!
Powershift09 conference badge photo by Bonnie H.
The event felt like the first day of school with people rushing off in small groups to various standing room only workshops and panels. Some of the content is available online on YouTube, including videos of speeches from EPA Administrator Lisa Jackson, Secretary of the Interior Ken Salazar, and Congressman Ed Markey. Beyond those speakers, many illustrious green stars that we’ve highlighted on TreeHugger.com, such as Gus Speth, Bill McKibben, and Tim De Christopher, were hanging out, mingling and chatting with the conference attendees.
Gus Speth and young leader at Powershift09 conference photo by Bonnie H.
One of the other most impressive features of the conference was the hyper articulateness of some of the youngest “leaders”, with a presentation by a 12-year old from Seeds of Green, while a program called DoRIght Leadership Corps had two high school sophomores presenting. These weren’t novelty acts; these teens and tweens eloquently delivered.
Another event highlight was the impromptu Saturday night march. My friend Antuan Cannon of Envirolution related the story to me. After the Roots concert, a spontaneous rally broke out in the convention center corridors. After being pushed by security on to the streets, the police arrived to clearing people out of the road to let cars pass. Rather than disassemble, fifty plus students began marching toward the White House.
This small group leading the way forward merged with other small groups that had the same idea. It reminded Antuan of the scene in Braveheart, when all the reinforcements appear over the horizon. As the merged group made its way to the White House, cars honked to show support, when these activists sang the National Anthem with pride. You can have high tech presentations, Van Jones speaking, the Roots rocking, but it doesn’t get anymore democratic and inspiring than that.
Saturday night Spontaneous March to White House photo via UOPowershift09's flickr page
Monday, February 2, 2009
SunPower Signs German Supply Deal,from Green2tech
California’s SunPower announced its second supply contract in as many months today, an agreement to ship 100 megawatts of solar panels to German solar power plant integrator City Solar Kraftwerke. Under the 3-year deal, SunPower will also provide City Solar with commercial rooftop and ground-mounted systems.
Last month, SunPower signed a deal to supply its solar panels to Italy’s Ecoware, another solar power plant integrator. That contract is a 4-year deal for SunPower to supply at least 130 MW of its solar panels to Ecoware, starting in the first quarter of 2009. SunPower didn’t disclose the financial terms of the City Solar or Ecoware contracts.
This latest contract with City Solar includes SunPower’s solar roof tiles for commercial rooftop installations and trackers for utility-scale, ground-mounted systems. City Solar, founded in 2002, has at least 20 solar projects under its belt, according to its web site. Most of its projects are turn-key solar power plants, including ground-level and rooftop projects, in Germany, but the company has also ventured into Spain with its five largest solar power plant installations.
City Solar’s biggest project is in Beneixama, Spain, generating 20 MW. The company said that ground project involved 200 solar panels, with work starting in August 2006 and finalized in the late summer of 2007.
SunPower has also done some work in Spain, last week announcing the completion of the 18 MW Olivenza solar power plant in Badajoz, Spain. SunPower, which has an office in Madrid, said it has completed construction of more than 165 MW of solar power plants in Spain, and more than 400 MW worldwide.
T. Boone, Sen. Reid Team Up for Clean Energy Summit Redux
The three came together to plug the second annual National Clean Energy Summit due to take place in Las Vegas on Feb. 23. The gathering is meant to serve as a forum for politicians, scientists, executives, academics, and advocates to hash out energy policy just as the government is gearing up to dole out billions in stimulus for, among other things, renewables R&D, energy efficiency and conservation projects, and infrastructure upgrades.
The first summit, put together by Reid and the Center for American Progress Action Fund, produced several policy recommendations likely to be revisited at this year’s event. More ambitious goals that have come to the fore in recent months may raise the bar for proposals at the summit.http://earth2tech.com/category/nyt/
Saturday, December 6, 2008
Fastest solar-powered car goes on tour
Space age vehicle to travel 1,550 miles through Scandinavia | Nuna 2, the world's fastest solar-powered car at 105 mph, is touring Scandinavia this week and next. The car is seen here after racing in Athens, Greece, last May. |
The Associated Press
updated 11:51 a.m. ET, Mon., Aug. 16, 2004
STOCKHOLM, Sweden - Drivers in Scandinavia are doing double takes this week after a vehicle that looks like something straight out of "Star Wars" hit the road on a tour of Norway and Sweden.
Nuna 2, the world's fastest solar-powered car with a top speed of 105 mph, started a nine-day drive through the two countries Sunday to promote solar energy and space technology. The trip follows a tour through 15 other European nations last May through June.
The shiny, black vehicle — just large enough for one person — was built by a team of Dutch university students. It is powered by solar panels like those on European Space Agency spacecraft.
Down-to-earth technology
"We're trying to show that space technology can be used in other areas as well," said Johan Marcopoulos from the Swedish National Space Board, one of the organizers of the trip. "Hopefully, more people will become interested in the possibilities."
The 1,550-mile tour is scheduled to end in Andenes, northern Norway, on Aug. 22.
The three-wheeled car, 16 feet long and 6 feet wide, has an aerodynamic chassis that resembles an airplane wing. The driver lies inside the vehicle head up, and looks through a small Plexiglas bubble. With no room for a steering wheel, he uses two rods to turn the vehicle's three wheels.
Enthusiasts, though, should not get too excited. With a price tag of $500,000 for the Nuna II, solar-powered cars won't be in stores anytime soon.
"It'll be a while before we see solar cells on regular cars," said Rosita Suenson, ESA project manager for the journey. "There's a lot of other technology that must fall into place before that."
In October 2003, the Nuna II won a solar-powered race across the Australian Outback, setting a new record time for the grueling coast-to-coast challenge. It traveled the 1,870 miles at the World Solar Challenge in 31 hours, five minutes — first to the finish line at the world's biggest race for cars driven solely by solar energy.
'Odd bird on the roads'
Marcopoulos said the car likely will travel at an average speed of 40-55 mph on its Scandinavian tour. It will stop regularly en route to give people a better look.
A team of Dutch students will take turns driving the vehicle, which will have an escort of two ordinary cars.
"It's sure to catch the attention of other drivers," Marcopoulos said. "It's a bit of an odd bird on the roads."
Background on Nuna 2 is online at http://www.adiante2004.com/page.php
Copyright 2004 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Thursday, November 27, 2008
Friday, November 21, 2008
The Southwest desert's real estate boom
From California to Arizona, demand for sites for solar power projects has ignited a land grab
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| Solar energy properties are scrambling to lock up desert land like the Mormon Mesa in Nevada. |
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| An FPL solar power plant in the Californian Mojave. Laws requiring renewable-energy development will mean that many more are built, but environmentalists concerned about protecting the habitats of endangered species are torn. |
(Fortune Magazine) -- Doug Buchanan grins with relief when he sees the carcasses. He has just driven up a steep dirt road onto a vast, sunbaked mesa overlooking the Mojave Desert in western Nevada. There, a few feet from the trail, lie the corpses of two steers. A raven perches on one, the only object more than three feet above the ground on this pancake-flat plateau. Cattle, dead or alive, qualify as good news in Buchanan's line of work. If cattle are present, that means grazing is permitted, and that in turn means that this land is most likely not protected habitat for the desert tortoise.
Buchanan, 53, is scouting sites for a solar power company called BrightSource Energy, an Oakland-based startup backed by Google (GOOG, Fortune 500) and Morgan Stanley (MS, Fortune 500). The blunt, fifth-generation Californian, who used to survey the same area for natural-gas power sites, knows that the presence of an endangered species such as the tortoise could derail BrightSource's plans to build a multibillion-dollar solar energy plant on the mesa.
BrightSource badly wants these 20 square miles of federal land on what is called Mormon Mesa. The company was in such a hurry to stake its claim with the U.S. Bureau of Land Management that it applied for a lease sight unseen. That's an expensive gamble for a startup, given that application fees alone run in the six figures. "I usually like to go out and kick the tires before filing a claim," Buchanan says, "but there's a lot of competitive pressure these days to move fast."
That's putting it mildly. A solar land rush is rolling across the desert Southwest. Goldman Sachs, utilities PG&E and FPL, Silicon Valley startups, Israeli and German solar firms, Chevron, speculators - all are scrambling to lock up hundreds of thousands of acres of long-worthless land now coveted as sites for solar power plants.
The race has barely begun - finished plants are years away - but it's blazing fastest in the Mojave, where the federal government controls immense stretches of some of the world's best solar real estate right next to the nation's biggest electricity markets. Just 20 months ago only five applications for solar sites had been filed with the BLM in the California Mojave. Today 104 claims have been received for nearly a million acres of land, representing a theoretical 60 gigawatts of electricity. (The entire state of California currently consumes 33 gigawatts annually.)
It's not just a federal-land grab either. Buyers are also vying for private property. Some are paying upwards of $10,000 an acre for desert dirt that a few years ago would have sold for $500.
No doubt the prospect of potential riches is overheating expectations. But California and surrounding states have mandated massive increases in renewable energy in the next few years. That has led some experts at Emerging Energy Research of Cambridge, Mass., to predict that Big Solar could be a $45 billion market by 2020.
Meanwhile, the land rush is setting the stage for a showdown between solar investors and those who want to protect a fragile environment that is home to the desert tortoise and other rare critters. The Southwest is on the cusp of what could be a green revolution. And the biggest obstacle of all may be ... environmentalists.
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Over the past year a parade of executives bearing land claims have made the trek to a stucco BLM office just off the interstate in the dusty city of Needles, Calif., a 110-mile drive south from Las Vegas. (It's the town where the late "Peanuts" cartoonist, Charles M. Schulz, briefly lived as a boy; in the comic strip, Snoopy's brother Spike is a resident.) The Bush administration has instructed the BLM to facilitate renewable-energy projects (along with nonrenewable ones). But Sterling White, the BLM's earnest Needles field manager, is also concerned about what could happen if they transform the Mojave into a collection of giant power stations. "One of our biggest challenges is the cumulative impact of these projects," he says.
Nearly 80% of the land that White's office oversees is federally protected wilderness or endangered-species habitat. That leaves about 700,000 acres for solar power plants, only some of which are near transmission lines. Land leases are handed out on a first-come, first-served basis, but White is also supposed to weed out speculators from genuine solar developers based on loose criteria such as who is negotiating with utilities and who is applying for state power licenses. White has yet to approve a single lease, but he has summarily rejected four because they lie in protected-species habitat.
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Solar prospectors tend to be as secretive about their land as forty-niners were about the veins of gold they discovered. Most bids are placed by limited-liability corporations with opaque names that conceal their ownership. And no one has been as quick to move into the Mojave - or as tightlipped about it - as Solar Investments.
That entity, it turns out, is Goldman Sachs's (GS, Fortune 500) solar subsidiary. The investment bank's designs on the desert are a topic of intense interest and speculation. Goldman declined to comment. But here's what we know:
Solar Investments filed its first land claim in December 2006 and within a month had applied for more than 125,000 acres for power plants that would produce ten gigawatts of electricity. Many of the sites lie close to the transmission lines that connect the desert to coastal cities. (Goldman has also staked claims on 40,000 acres of the Nevada desert.) **
Nobody expects Goldman to begin operating solar plants. It will probably either partner with another developer or sell its limited-liability company (and its leases) outright. The firm has been making the rounds of solar developers. "The conversation's been pretty wide-ranging, primarily as an investor interested in financing deals," says one solar energy executive approached by Goldman. "But there's clearly an element of interest in our technology." Goldman has requested permission to install meteorological equipment on its sites and is evaluating "competing technologies, including solar dish systems, power towers, and large-scale photovoltaic arrays," according to a letter Goldman sent to the BLM in August 2007.
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