On the University of Arizona campus, researchers with the school’s optical science department are developing a new solar array that could make solar energy cheaper than its competition.
Led by Dr. Roger Angel, in a partnership with REhnu (renew) energy the team is designing a solar collector array using techniques developed by the school’s optical science department. Their goal: getting below a cost of $1 per watt, a target that makes solar energy competitive with nonrenewable energy sources like coal, oil, and gas.
There are several ways to do this, but the team has settled on a design that uses a hemisphere of concentrated photovoltaic cells that sits at the focus of light reflected by a large mirror that’s nearly ten feet across.
The system is fixed to a structure that can follow the sun throughout the day using tracking systems developed by the optical science department for telescopes, including sensors to seek the sun, a GPS system to help the tracker orient to the sun, and motors to shift and tilt the assembly as the sun crosses the sky.
Unlike rooftop systems, which remain in fixed angle to the sun, and therefore lose efficiency in the early morning and late afternoon, following the sun allows the system to collect energy from dawn to dusk.
The system uses a lightweight steel structure, assembled in open cube frames, allowing the system to hold up to eight collectors in each. The structure has the advantage of being relatively stiff, but uses less steel, fulfilling one of the overall goals of the project: shrinking costs by reducing the number of materials.
Blake Coughenour is a research associate and graduate student with the optical sciences department and helped develop the collector.
“I think it’s important because solar is a great resource that we’re not ever taking advantage of, especially in the American southwest we’re protecting ourselves from so much light that we’re wasting,” he said. “If we can find a way to efficiently use that light, we can really solve the world’s energy problems.”
Whittling down the cost and complexity of the device has been a major goal. In the lab at Steward Observatory, the team went through several prototypes for testing, learning as they went even while keeping on eye on an commonly-used efficiency goal of 30 percent. Older solar systems are about 10 percent efficient, meaning that the system captures 10 percent of the energy that's available. Tripling that number makes solar economically feasible.
The energy coming from the mirror is intense, creating several design challenges that the team had to overcome.
“This is a quarter inch piece of steel,” he said. “If we put this at the focus of our mirror, we can burn a hole through it in about five seconds.”
They solved this in two ways, first at the focus on the mirror is a glass sphere, like a fortune teller’s crystal ball. However, the glass ball is made of specialized and expensive fuzed glass.
Properties of the glass make it transparent to nearly all light wavelengths, which means it doesn’t block light from the mirror and it won’t heat up like other glasses. As Coughenour notes, it’s one of the few glasses that crack or “blow up” from the mirror’s energy.
As Coughenour said, “It’s safe, but you’re putting a lot of light into one little place.”
The glass ball also creates a lensing effect, allowing it to keep light on the cPV cells even as the structure moves. This allows the collector to keep pumping out energy under windy conditions. For a solar array sitting in the desert, this is a nice advantage.
They also added a reflective coating to the glass mount, allowing the metal to survive moments when the system is “off sun” and the ray of reflected light hits it rather than the glass sphere. In earlier tests, cables and struts that were in the glare sometimes melted or smoldered.
Behind the glass, a copper bowl holds the cPV cells, allowing each one to get as much light as possible through small funnels that are focused on each cell. This means more energy, but it also means more heat, which requires a closed-loop cooling system similar to the one in a car and a pattern of metal fins at the back they copied from high-end personal computers.
“If we didn’t have a cooing system, the cells would heat up to a couple hundred degrees and they would melt,” said Coughenour. While a cooling system adds complexity, he said, it also allows for a denser system of solar cells, dropping the cost and making it easier to pack many more arrays on a chunk of land.
High-efficiency fans cool the water in an assembly above the collector.
The team is still learning. The current system will move from its home behind Bear Down gym to the University of Arizona’s tech park in the next few months, adding the the UA’s “solar zone.” There, the team will work to make future versions more efficient, using easily to manufacture parts, while producing even more energy.
Their ultimate goal is to deploy these systems at large scale. According to the REhnu website, the corporate partner of the work, a system deployed over six acres could produce 2.5 billion kilowatts a year, enough to power 220,000 homes.
“If we show that we can build this thing, we can take it to manufacturing scale and start rolling out huge megawatt-sized plants,” said Coughenour.
July 25th 2012 at 12:34
Gov. Jan Brewer is endorsing Jonathan Paton for U.S. House in Congressional District 1.
While Paton is familiar to Southern Arizonans from his run for congress in district 8 in 2010, he's got three other Republicans to beat before he would move on to the general election to face the winner of the Democratic primary.
She made the endorsement this week, writing, "As a State Senator, Jonathan was a leader in the fight for smaller government, less regulation and lower taxes. He provided a key vote in support of SB 1070, and he stands with Arizona in our fight for a safe and secure border. Like me, he is committed to a strong economy, quality job growth and better schools for our children."
Paton faces Republicans Patrick Gatti, Gaither Martin and Douglas Wade, and the latest campaign finance reports show he has out-fundraised all of them.
On the Democratic side, Ann Kirkpatrick seeks to win the seat back after losing it in the 2010 cycle, she faces Wenona Benally Baldenegro.
Wenona Benally Baldenegro
July 19th 2012 at 9:39
Tired of the two-party system? Don't want to see your property taxes continue to climb? Want more of a say in who populate the benches of state courtrooms? How about overriding legislative cuts to education?
If any or all of the above appeal to you, you've come to the right place, that being the November general election in Arizona.
The ballot may well have something for nearly everyone, and that's not even counting the hundreds of folks who will seek elective office from county supervisors and sheriffs to U.S. Senate and president.
Ten or more propositions could make the ballot in the fall. Seven constitutional amendments already will be offered for certain, placed there by the Legislature in action over the last two sessions.
If it gets on the ballot, the measure with the potential to cause the most impact is the "Open Government Act," being pushed by those who want to end what they call the two-party stranglehold on elective office.
Petitions will be filed on Tuesday, according to group members. If it qualifies, the measure would replace the party primary election system in Arizona with an open primary, one in which all candidates run on one ballot, and the top two vote getters move on to face one another in the general election.
California and the state of Washington have implemented the system, both through voter initiative.
Legislative-proposed constitutional amendments headed for the ballot would:
-- Modify how Superior Court and Court of Appeals selections are made.
-- Protect crime victims from having to pay for causing death or injury.
-- Give property tax breaks to businesses for newly acquired equipment.
-- Give the state sovereignty over its natural resources.
-- Limit annual distributions from the state permanent fund.
-- Authorize the Legislature to set up a process for exchanging trust land to protect military installations.
-- Limit annual growth in limited property value of locally assessed properties.
On Friday's Arizona Week, we plan to explore the measures proposed for the ballot and how voters should prepare.
arizona open primary
July 3rd 2012 at 9:42
posted to Cue Sheet by James Reel
There's a grave-robber on the loose, raiding tombs and stealing the teeth of famous composers, apparently in preparation for opening some sort of dental museum, according to this report from an Austrian newspaper. This sort of thing is not new (aside from the perpetrator's boasting online); the body parts of historical celebrities often have an afterlife of their own. In the 1980s I saw in an English museum what looked like a little scrap of black leather that purported to be Napoleon's penis; this could not have been true, for the emperor's pride is apparently held elsewhere. More reliable are the storied adventures of certain composers' partial remains, including Chopin's heart and Haydn's head. One composer himself was notoriously fond of fondling relics of great men; Anton Bruckner, a very strange man to begin with, had tendencies that stopped a few steps short of necrophilia.
July 3rd 2012 at 6:54
July, along with the official start of the monsoon season, brings us a new fiscal year and a summer program schedule featuring award-winning news and entertainment programs.
The Your Vote 2012 campaign continues with in-depth local, state, and national election coverage in addition to get-out-the-vote public service announcements. Over the next several months, AZPM will host a multitude of in-studio debates and forums with candidates running in statewide, Congressional and the U.S. Senate races. Visit here to see the most up-to-date information. On June 29th, we streamed live on our web site the Washington Week “Town Hall Forum on SB1070” a collaboration of WETA/Washington, KPBS/San Diego, and PBS 6/Tucson. On Sunday July 1st at 4 p.m., we will rebroadcast the program in its entirety on PBS World (Channel 27-3, Cox 83, Comcast 203). Then, on Monday July 2nd at 6:30 p.m., we will broadcast highlights from this program within Arizona Illustrated on PBS 6. You can also watch the town hall on line anytime at azpm.org/yourvote.
AZPM kicks off July with one of our biggest television programs of the year, A Capitol Fourth. This live national broadcast of America’s favorite Independence Day tradition features unrivaled performances from some of the country’s best-known musical names topped off by the greatest display of fireworks anywhere in the nation. Tom Bergeron takes the helm as the new host of this star-spangled affair, live from the West Lawn of the U.S. Capitol on Wednesday, July 4th at 5 p.m. (live from D.C.) with encore presentations at 8 p.m. and 9:30 p.m. on PBS 6. More details can be found here.
On radio, NPR 89.1 FM will broadcast The Capitol Steps: Politics Takes a Holiday on July 4th at 7 p.m., pre-empting Jazz at Lincoln Center. For thirty years The Capitol Steps have been putting politics and scandal to music. Tune in to this radio special full of political satire with song parodies and skits, created and delivered by many former Congressional and Senate staffers!
Starting on July 7th, NPR 89.1 FM will freshen up its weekend lineup with several new programs!
• Snap Judgment from NPR tells intriguing stories about extraordinary and defining events in people’s lives. The program’s raw, intimate, and musical brand of storytelling dares listeners to see a sliver of the world through another's eye. Snap Judgment host Glynn Washington, takes listeners on a narrative journey - leaping from one person's frying pan into another person's fire. Deejay-driven musical delivery, paired with lush sound design, drops listeners into the very heart of what matters. Snap Judgment's fast-paced (sometimes dark, sometimes playful) narrative highlights people from across the globe that put everything on the line. More here.
• Living on Earth, hosted by Steve Curwood, is an award-winning, environmental news program which delves into the leading issues affecting the world we inhabit. As the population continues to rise and the management of the earth's resources becomes even more critical, Living on Earth examines the issues facing our increasingly inter-dependent world. More here.
• RadioLab is an experiential investigation that explores themes and ideas through a patchwork of people, sounds, and stories. In each episode, RadioLab experiments with sound and style allowing science to fuse with culture, and information to sound like music. Hosted by Jad Abumrad with co-host Robert Krulwich, RadioLab is designed for listeners who demand skepticism but appreciate wonder. More here.
On Classical 90.5 FM over the next 13 weeks, Music Mountain will replace Santa Fe Chamber Music Festival, on Thursday evenings at 8 p.m. starting July 5th. The Milwaukee Symphony Orchestra replaces Deutche Welle Festival Concerts Sunday evenings at 8 p.m. starting July 1st. While Community Concerts take a siesta for the summer, they will be replaced with Fiesta! on Sunday afternoons at 3 p.m. starting July 1st. Fiesta! is a new production devoted to Latino concert music and presents artistically significant compositions from Latin America, Spain, and Portugal. The acclaimed composer, musician, performer, and professor, Elbio Barilari, is the host and creative force behind this series. He invites listeners to enjoy and learn about the lively and compelling sounds of Latin American classical music. More here.
I encourage you to give these new radio programs a listen, and let us know what you think.
PBS 6 offers something for everyone this summer. With the 2012 Olympics coming to London in August, Michael Wood’s Story of England, a four-part series hosted by historian Michael Wood, explores the 2,000-year-old history of the village of Kibworth in Leicestershire, England. A new Masterpiece Mystery: Inspector Lewis series starts Sunday, July 8th at 8 p.m. with the first of four new episodes, “The Soul of Genius.” “Generation Vipers” follows on the 15th, “Fearful Symmetry” on the 22nd, and “The Indelible Stain” on the 29th. The new series Market Warriors premieres on Monday nights at 8 p.m. starting July 16th. From the producers of Antiques Roadshow, Market Warriors features 4 expert shoppers competitively scouring flea markets across the country for vintage valuables. This three-part series is followed each Monday by the original Antiques Roadshow at 9 p.m.
Our efforts for the benefit of Southern Arizona would simply not be possible without you. On behalf of all of us at AZPM, please accept my sincere thanks for your continued support and best wishes for the summer.
July 2nd 2012 at 8:53
"Show me your papers."
That's the line that politicians boasted was the underlying theme to SB1070, the phrase a takeoff on the misquoted line from the bandido in Treasure of Sierra Madre -- "We don't need no stinkin' badges."
The media picked up "show me your papers" quickly and ubiquitously, even in the aftermath of Monday's Supreme Court ruling on the issue.
That's the phrase used by both sides in the debate over the Affordable Care Act, with one side saying it is good to make everyone take responsibility for health insurance, the opponents saying such a mandate is a breach of individual freedom.
And again, the media glommed onto it and have driven it into the linguistic ground.
The problem with both phrases -- "show me your papers" and "individual mandate" -- is that they are no longer true based on the Supreme Court rulings of this week.
The court struck down the "show me your papers" part of Arizona's immigration law. Immigrants cannot be compelled to carry proof of legal residency with them, the court said. Thus, if stopped by an Arizona law-enforcement officer suspecting someone is in the country illegally, no "showing of papers" is needed.
Yet the media continued using the phrase in the hours and days after the ruling.
Same with "individual mandate," which the Supreme Court truck down. It goes to the heart of explaining the court's decision. The mandate was claimed under the Constitution's commerce clause, but the court said no. Rather, it ruled, an individual is not "mandated" to carry health insurance; he or she can pay a tax instead.
All in all some rather fine points of word usage. Nevertheless, accuracy must prevail, most especially when our striving to explain ends up oversimplifying to the point of fictionalizing.
Affordable Care Act
show me your papers
June 29th 2012 at 12:47