The U.S. Department of Energy aims to make electricity from the sun cheaper than that from burning coal or natural gas.
NATIONAL HARBOR, Md.—Silicon translates sunshine into electricity—and Earth receives enough sunshine in a daylight hour to supply all of humanity’s energy needs for a year. But despite being as common as sand, photovoltaic panels made from silicon—or any of a host of other semiconducting materials—are not cheap, especially when compared with the cost of electricity produced by burning coal or natural gas. The U.S. Department of Energy (DoE) aims to change that by bringing down the cost of solar electricity via a new program dubbed “SunShot,” an homage to President John Kennedy’s “moon shot” pledge in 1961.

The U.S. Department of Energy aims to make electricity from the sun as cheap as that from burning coal or natural gas – by 2017.
Image: Dennis Schroeder, NREL Staff Photographer.

“If you can get solar electricity down at [$1 per watt], and it scales without subsidies, gosh, I think that’s pretty good for the climate,” notes Arun Majumdar, director of the Advanced Research Projects Agency–Energy (ARPA–e), the DoE’s high-risk research effort. “With SunShot, the goal is to reduce the cost of solar to [$1 per watt] in the next six years.”

As it stands, melting silicon or depositing thin layers of copper indium gallium selenide, then manufacturing photovoltaic modules and installing them on rooftops or in large arrays in the desert, can cost as much as $10 per watt. And whereas some technologies can deliver modules for roughly $1 per watt, installation at least doubles that.

“We are making solar for the masses…to get to [a] cost point that is viable,” said Bruce Sohn, president of Columbus, Ohio–based First Solar, the world’s largest thin-film photovoltaic manufacturer, which claims it can produce its modules for less than $1 per watt, on a panel at ARPA–e’s second annual summit on March 1. “We are looking to make something that can compete head to head with fossil fuels over the long term.”

As part of the new SunShot initiative, DoE committed some $27 million to fund novel methods for producing solar cells and their components—like 1366 Technology’s effort to grow pure silicon wafers directly rather than hewing them from long ingots of the material or Solexant’s effort to build thin-film solar cells from semiconducting materials that are neither toxic nor rare. The goal is to produce solar modules at roughly 50 cents per watt with attendant hardware and installation costing the same amount. To reach that target the photovoltaic cells will have to convert at least 20 percent of the sunlight that shines on it into electricity and cost only 25 cents per watt by 2017. “The future of the U.S. depends on three securities: national, economic and environmental. The foundation of all of this is innovations in energy technology,” Majumdar said in his own speech to the summit. “The future is still up for grabs. How do we win the future? Invent affordable clean technology. Make them locally, sell them globally.”

Of course, harvesting the sun’s power is not limited to photovoltaic panels. The DoE push also will incorporate efforts to create solar-thermal power plants that can store the heat of the sun for 12 to 17 hours by 2020, along with attempting to address some of the issues surrounding permitting, inspection and connection of solar systems to the electricity grid. “We want change, we want innovation, we want to overthrow the old energy order,” said former California governor Arnold Schwarzenegger in a summit keynote address. “We want a new era of energy and a new era of American competitiveness.”

Former California Governor Arnold Schwarzenegger addresses the 2011 APRA-E Technology and Innovation Summit on California’s role in clean energy.

Already, electricity from the sun costs roughly the same as that generated from burning fossil fuels in places like Hawaii, which remains the only state to rely on imported oil for the bulk of its power. And solar power represents the fastest-growing sector of electricity generation. U.S. solar production in 2010 increased by nearly one gigawatt (billion watts), although that represents roughly the amount of electricity one nuclear power plant can produce. But even at that pace of adoption—spurred by both federal and state government largesse—solar still produces less than 1 percent of all U.S. electricity. And in 2035, by which time the DoE’s Energy Information Administration (EIA) predicts that solar will have grown fastest among all energy resources (increasing sevenfold), all renewables put together, solar included, will only provide 14 percent of U.S. electricity.

The EIA has often been wrong in such long-term forecasts, but competing with natural gas—newly cheap thanks to the vast resources tapped by fracking in the eastern U.S.’s Marcellus Shale Formation—may prove difficult, even with SunShot. “Natural gas has low capital cost, higher fuel cost but overall lowest costs,” noted EIA Administrator Richard Newell at the ARPA–e conference. “There are significantly higher costs for other power sources.”

Yet, even at a higher price, solar can offer benefits, which is why Duke Energy has invested $50 million putting solar arrays on the roofs of grocery stores and some of its other large customers. “Distributed solar can be thought of as a distributed resource, a multiple value resource,” Duke Chief Technology Officer David Mohler told ARPA–e attendees. “The proper comparison for that is not the cost of a bulk power system, it’s the cost and benefit of having an embedded resource.”

And flexible solar cells in sheets have already found novel applications powering the telecommunications and other electronic equipment of U.S. Marine units deployed in Afghanistan. Small-scale solar is also booming in places such as Kenya that do not have an electricity grid for charging cell phones or batteries that power lights at night. “We will need every energy resource we can lay our hands on,” said Kurt Yeager, executive director of the Galvin Electricity Initiative, an effort to develop the smart grid in the U.S. “There are two billion people in the world without access to electricity. Security means giving them energy.”

Of course, the DoE has already invested some $1 billion in solar energy research since the turn of the century, funding efforts to develop “black” silicon or cells employing quantum dots. “If renewables are cost-competitive with fossil fuels then it’s a very, very different world,” Secretary of Energy Steven Chu said at the ARPA–e summit.

Secretary for the US Department of Energy, Steven Chu, discusses the big picture of how the United States uses Energy and why innovation in clean technology is the key to Winning the Future.

Yet, despite inventing the technology in the 1950s and more than 30 years of government support, the U.S. share of the global market for photovoltaic modules is down from more than 40 percent in 1995 to just 6 percent in 2011. China’s Jiangsu Province alone—home to Suntech Power, the world’s largest maker of photovoltaic panels—has begun investing more than $152 million a year in solar technology since 2009.

“Just because we lost the lead doesn’t mean we can’t get it back,” Chu said. “We still have the opportunity to lead the world in clean energy…but time is running out.”

Article by By David Biello.
Source: scientificamerican.com.

You may have recently moved to a new house and decided to add some twinkle to your garden, back yard, lawn or patio. Or maybe it is a place where you have spent all your life and now you’d like to do a few subtle or dramatic changes with outdoor lighting. It could be that you just want to add a bit of creative touch to your apartment balcony where you catch a breath of fresh air after a long day. Your neighbors across the yard have some nice string lights on their balcony and you are starting to think about doing something similar.
Where do you start?

Solar Path Lights. Image by Your Solar Link.

It can be a challenging and at the same time a fun process when looking into creating outdoor lighting for your home, yard or garden. The fun part of the process is that you are in control of creating a unique outdoor environment, inspired by your own imagination. You can create a comforting, welcoming mood with unique and eye-catching outdoor lighting.
However two challenges come to mind – finding a good bargain on the lights themselves, and the cost of hiring a licensed electrician to do the installation.

This is where solar powered outdoor lights step in. Solar lighting has become an increasingly popular alternative to the conventional and costly electric lights that currently illuminate our homes and living spaces.
Solar lights are affordably priced, simple and safe to install yourself (no digging ditches, laying the wire and attaching it to a junction box), and solar lights can be relocated easily, and above all else, you also save on electricity costs.

Solar lights use photovoltaic cells that absorb sunlight during the day and turn it into energy. Rechargeable batteries store the energy, making it available at night when it is needed. LED (light emitting diode) bulbs, which require little power and last 10 times longer than incandescent bulbs, provide the illumination. There is no wiring necessary to connect the lights to each other or to the electric grid.
Until recently, most solar lights emitted only muted light and were not all that reliable. With the latest developments in the solar lighting industry, this has changed and super-bright LEDs have replaced more conventional filament bulbs.
Light-emitting diodes (LEDs) create light without producing the waste heat of regular bulbs, are very bright, and yet require a minimal amount of electricity to function. The result is a reliable, long-lasting light source that will typically work for the life of the solar light product.
Other progress in solar lighting technology has been made in the development of more efficient, affordably-priced photovoltaic cells, improved circuitry, and more efficient batteries.

When shopping for solar lights, it’s important to match the light to the function you want it to perform. Consider these three primary categories of solar lights for use in the landscape: decorative accent lights, path lights and spotlights.

Decorative Solar Accent Lights.

Solar Butterfly Lights with Amber LEDs. Image by Your Solar Link.

Solar accent lights create an enjoyable and inviting glow for your landscape. They are designed to mark a place. Solar accent lights can be used to mark landscape hazards, such as a step or a rock that could be a hazard in the dark. They also can be used as garden features themselves, such as decorative solar figurines.
This type of solar light is not used to intensely illuminate an object or light up a pathway. But they would be a good choice to softly illuminate shrubbery and low hedges. Due to their low light output, accent lights usually stay lit longer than other types of solar lights. A quality accent solar light can run many nights on just a single day of sunlight charge.

Accent solar lights typically use efficient multi-crystalline solar cells that allow them to charge even on a cloudy day or in partially shaded areas.
Some accent lights utilize amber LEDs to create a softer ambience. Some of them can change colors, blink or flicker to simulate candle light.

Color Changing Solar Accent Lights. Image by Your Solar Link.

Amber LEDs use less electricity than the white LEDs, meaning they are going to stay on even longer after a short sun charge.
Compared to the other types of solar lights, accent lights have the lowest light output and are among the most affordably priced.

Solar Butterfly Lights with Amber LEDs. Image by Your Solar Link.

Path Solar Lights.
Path solar lights are good for lighting paths, walkways, driveway perimeters or other regions around your home and in your landscape. They are often used in multiples to guide the way along a set of stairs or a dark walk.

Path solar lights. Image by Your Solar Link.

Path lights usually come with a choice of ground stakes, flange mounts and hanging hooks. This gives the user a wide choice of placing options.
They also have on-off switches, a feature that allows the homeowner to store the electrical charge for a special event and ensure the longest potential run time. Some models may offer options such as high-low power, colored lenses, or timers. Solar path lights are in the mid-range choice in terms of price and light output.

Motion Sensor Path Solar Lights. These Path Lights increase in brightness as people pass by.
Image by Your Solar Link.

Task Solar Lights (Solar Security Lights, Solar Flood Lights and Solar Spotlights).
These solar lights are the brightest group of solar lights and usually carry the highest price tag. They are designed to direct a bright beam of light on plants, statuary or entryways.

Solar Spot Light. Image by Your Solar Link.

Solar task lights and spotlights are usually designed so they can be mounted in a number of ways and can be adjusted to shine in any direction. Most often, the solar panel can be mounted independently from the light (the two connected by a wire), which allows you to place the panel in a position where it will get the sun, and the light where you need it to shine at night.

What to consider when choosing solar lights for your exterior lighting needs.

Step 1.
Decide if you need decorative accent, path or task solar lights.

Step 2.
Find out whether the battery needs full sunlight to charge. Some lights charge with partial sun and work great under trees or in areas with low sunlight. This type of solar light can also be charged on a cloudy day.

Step 3.
Consider the operating time. Usually solar lights perform year round and even charge the battery to provide operation during long winter nights. Some solar lights shine for several days before needing to recharge.

Step 4.
Check the type of light bulb the solar light uses. LED lights offer the brightest and most efficient light when it comes to efficiency, size, price and energy usage. Some accent solar lights use amber LED lights to create a softer glow.

Step 5.
Compare extra items like timers or an on-off switch to the cost. Colored lenses change the look of the solar lights without compromising the brightness. Some solar lights mount to your house, hang from trees or can be mounted to your patio rail.

Step 6.
Match the lighting to your landscape theme. Decorative solar lights (figurines) can create an interesting theme for a landscape or lawn, or while positioned next to shrubbery trimmed to your taste. Country style solar lanterns will add that special countryside charm to your garden. Hanging Japanese Soji lanterns on your trees or patio will bring an Asian flare to your outdoors. Modern stainless steel solar accent lights complement contemporary landscapes. An ultra bright stainless steel solar light will be a great choice to light up your flag pole.

The possibilities are unlimited!

Cityscapes of glass-clad buildings gleaming in the sun make Anna Dyson think about wasted energy. Dyson heads the Center for Architecture Science and Ecology, or CASE, a research consortium that wants to turn office windows into multifaceted solar power generators.

Image by William Conway/Progress Photography.

Researchers at the Center for Architecture Science and Ecology are testing a new “diamond” technology that would be installed on glazing to generate power.

Their “integrated concentrating dynamic solar facade” consists of grids of clear pyramids that help focus the sun’s rays to generate energy. It would essentially make buildings look as if they were draped in giant jeweled curtains.

Image by Kevin Rivoli, AP.

RPI research assistants pose for a portrait with the Helioptix window units installed at the Syracuse Centre of Excellence in Environmental & Energy Systems building.

A prototype gets a real-world tryout after the opening this week of an eco-friendly research building in Syracuse. Researchers at CASE — a collaborative research group involving Rensselaer Polytechnic Institute in Troy and the international architecture firm Skidmore, Owings & Merrill — call it a step toward exploiting the huge but largely untapped “green” resource of building exteriors.

“The reason we’re interested in windows is because they have the largest surface areas, typically, in buildings, especially in tall, urban buildings,” said Dyson, a professor of architecture at RPI. “We have a lot of vertical surface area to work with to really generate a lot of power.”

Image by Kevin Rivoli / AP.

RPI research assistants perform maintenance on the Helioptix window units installed in Syracuse, N.Y.

In contrast to typical flat solar panels, CASE’s system is designed to do several things.

Each clear pyramid, with facets less than a foot square, has a lens to focus sunlight onto a tiny solar cell. The concentrated cells are designed to be more efficient in generating energy than traditional cells. And the pyramid modules rotate to track the sun. Pumped water keeps the solar cells cool to maximize efficiency. The cooling water also “captures” that waste heat for other uses, such as hot water or radiant heat for the building.

The pattern of pyramids also would deflect and diffuse the sun’s rays, meaning office workers with eastern exposures could work in natural light all morning instead of drawing the blinds against the glare. Windows will still provide a view, albeit one obstructed a bit where the patterns of pyramids are placed.

The technology behind concentrating the sun’s energy through a lens is not new, nor is the concept of placing solar cells on the side of a building. But the integration of all these ideas to perform multiple tasks is novel.

Dyson notes that a building’s biggest energy suckers are usually cooling, heating and lighting. This system would tackle all three, whether it’s extracting maximum solar power in New York City or deflecting and diffusing sunlight in Phoenix. Jason Vollen, an RPI architecture professor at CASE, said their integrated system squeezes every bit of usability out of the system.

The system has already been tested on an RPI rooftop. Now, a prototype has been built into the facade of the Syracuse headquarters of the Center of Excellence in Environmental & Energy Systems, a public-private research partnership devoted to sustainability research.

The prototype, one of many green features of the state-of-the-art building, is an 8-by-8-foot panel and will become fully operational soon. A second, portable prototype will be generating energy earlier.

Syracuse, where the winters can be long, snowy and gray, might not seem the best place to try out a new system to generate solar power, but Vollen said it will be a good test in “less than optimal solar climates.”

Vollen believes the system can catch on in the fast-growing market for “green building” and energy efficiency systems. He said the system would be especially suitable for older buildings undergoing retrofits, which is expected to be a growth market.

The solar system is included in construction documents for a high-profile construction project being planned for the Fashion Institute of Technology in New York City, according to Jonathan Maille, a director of HeliOptix, which is licensed to market the system.

Dyson did not provide a price, though the complex system will cost more than planting some photovoltaic cells on the roof. But she claims the payback time is sooner.

Still, one veteran solar energy consultant not involved in the project said that while he likes the concept, users should be ready for the potential for costs down the road. Peter Talmage, now a professor of renewable energy at Greenfield Community College in Massachusetts, said whatever the limits of traditional solar panels, they require only minimal maintenance needs.

He noted that this system is far more complicated.

“You have to throw in a good chunk for operation and maintenance costs,” Talmage said.

Source: dcnonl.com