• How to make solar cells from grass clippings

    Grass clippings could be turned into solar cells using inexpensive chemicals and materials, according to new research.

    By John Roach, Contributing Writer, NBC News

    Within a few years, a special powder sold in little plastic baggies could turn your grass clippings into an electricity-generating solar cell, scientists reported Thursday.

    "That's the dream," Andreas Mershin, a researcher at the Massachusetts Institute of Technology and co-author of a paper describing the process, told me.

    The powder in the bag is an inexpensive chemical cocktail that stabilizes the molecules in green plants that carry out photosynthesis known as photosystem-I so that they can be used to generate electricity.

    Instructions on how to build the rest of the so-called biophotovoltaic would be printed on a cartoon included with the baggie.

    One step is to extract and concentrate photosystem-I from yard waste, for example, with a membrane such as cheesecloth and spinach. "It is not that hard," Mershin promised. "The green stuff is easy."

    In addition, these do-it-yourselfers will need to roughen up a piece of glass or metal, which increases the surface area, to stick the stabilized green goo onto.

    Wires connected to this plate would deliver the trickle of electricity to a battery, cell phone or a light.

    Mershin and his colleagues explain their process for building one of these biophotovoltaics in the open access journal Scientific Reports. 

    The research improves on previous work by Mershin's MIT colleague Shuguang Zhang, who coated photosystem-I on a flat glass surface. 

    This produced an electric current, but such a small amount that it was practically useless. In addition, the stabilizing chemicals used were expensive and assembling it all involved expensive lab equipment.

    Mershin looked to nature for inspiration and found a potentially better design in forests of pine trees that allow "for more light to be absorbed," he said.

    He mimicked this forest effect with zinc oxide nanowires and a sponge-like titanium-dioxide nanostructure. 

    When this chip is coated with the light-harvesting material extracted from plants, it creates a solar cell with 0.1 percent efficiency.

    "At 0.1 percent, you can only do this as a proof-of-principle," Mershin said. "Nobody is going to be doing this in real life until we get to about 1 or 2 percent efficiency and about 12 months of lifetime."

    The hope is that researchers around the world will replicate the results — which can be done with inexpensive materials and equipment — and improve on the design to reach that milestone.

    If so, this technology could be a way to bring electricity to the 1.2 billion people in the world who live without it today.

    Ideally, he said, not even the plastic baggie with the powder will be required. "We'll just send out fliers that have the information."

    MIT researcher Andreas Mershin has a vision that within a few years, people in remote villages in the developing world may be able to make their own solar panels, at low cost, using otherwise worthless agricultural waste as their raw material.

    More on solar energy technology:

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

    Next-gen nuclear plants could provide carbon-free energy, but the painfully slow process of approving better, safer reactors — not to mention real anxiety over meltdowns and waste — threaten to derail projects before they can be built.

     

  • Ocean motion could produce 9 percent of U.S. electricity

    Georgia Institute of Technology / DOE

    A map generated by Georgia Tech's tidal energy resource database shows mean current speed of tidal streams.

    By John Roach, Contributing Writer, NBC News

    Next-generation technologies that harvest electricity from ocean waves and tides sloshing along the U.S. coasts could provide about 9 percent of the nation's demand by 2030, according to a pair of recent studies.

    The findings, which include maps of these ocean energy resources, should help guide companies looking to develop them.

    "We have believed for a long time that the resource was significant and these assessments add a tremendous level of confidence to what that potential is," Mike Reed, water power team lead with the U.S. Department of Energy's Wind and Water Program told me Monday. 

    Today, about 6 percent of the nation's electricity comes from traditional hydropower projects, such as the Grand Coulee Dam, that direct the flow of the river through turbines to generate power.

    Since such dams plug up rivers and make it difficult for migrating fish species such as salmon to reach their spawning grounds, they have lost favor in recent years. 

    Looking forward, energy developers see promise in technologies that capture the energy in waves and tides off the coasts. 

    Designs to do this range from buoys that harness the up-and-down motion of passing waves to turbines on the ocean floor that are spun by the ebb and flow of the tides.

    The studies released earlier this month from the U.S. Department of Energy could help nudge along the development and deployment of these technologies by showing the resource is there to be captured.

    Motion of the ocean
    The U.S. uses about 4,000 terawatt hours of electricity per year. The maximum theoretical electric generation that could be produced from waves and tides is approximately 1,420 terawatt hours per year, the assessments found.

    "We are never suggesting that all of that would be captured," Hoyt Battey, team lead for water power market acceleration and deployment with the DOE Wind and Water Program, told me. 

    But based on the resource assessments and current understanding of what it will take to scale up and deploy the technology, wave and tidal power could be upwards of 9 percent by 2030.

    The DOE has set a goal that water power, including traditional hydroelectricity, total 15 percent of the nation's supply by 2030.

    To measure the wave resource, the DOE worked with the Electric Power Research Institute and Virginia Tech to develop a model that accurately predicted past wave regimes and used it to predict future wave climate.

    Those predictions are converted into wave power densities. As surfers know, waves from one day to the next are not the same, but they know what beaches tend to have the best waves when conditions are right, Reed noted.

    Like surfers trying to figure out where and when to vacation, utility owners and operators can use the new resource data to figure out where the best reliable waves are to put their converters.

    This knowledge, combined with reliable forecasts out several days on wave heights, will allow utilities to balance their loads with other sources such as a natural gas fired power plant.

    "Wave energy is predictable and forecastable," he said. "If you are a utility operator or utility owner, that predictability adds value."

    Tides are even more predictable, noted Battey. "You know down to the second years ahead of time what the tidal regime will be," he said.

    The tidal resource maps were created by researchers at Georgia Tech and are available online.

    Realizing the potential
    Resource assessments such as these, as well as others mapping potential geothermal, solar and wind resources, can nudge development of green energy technologies.

    But a key word in such assessments is "potential." As long as generating electricity from coal, oil, and natural gas remains cheap and politically salable, wave and tidal resources will struggle to compete.

    Reed takes the long view. Although wave and tidal energy projects today are expensive, he said, their costs should fall as the technology is improved and scaled up over the next few decades.

    "A good comparison would be to go back 15 to 20 years in the wind and solar industry and see how their costs have dramatically come down," he said.

    While wind and solar still struggle to compete with traditional sources today, the falling prices of the technologies and abundance of the resources are beginning to make them attractive.

    Given the size of the wave and tidal resource identified, Reed said there's plenty of room for wave and tidal energy developers to get their feet wet and begin to drive down costs.

    More on wave and tidal energy:

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

     

     

    Next-gen nuclear plants could provide carbon-free energy, but the painfully slow process of approving better, safer reactors — not to mention real anxiety over meltdowns and waste — threaten to derail projects before they can be built.

     

  • New Year's Resolution: Get fit, make electricity

    SportsArt Fitness

    A new system of fitness machines turns the watts you generate while working out into electrticity to power the gym.

    By John Roach, Contributing Writer, NBC News

    A new generation of workout machines that generate electricity as you work up a sweat are poised to invade fitness centers and help you keep your New Year's resolution to trim down your waistline.

    The electricity generated by the machines is fed back into the grid, helping the gym save on its utility bills.

    The so-called Green System from Woodinville, Wash.,-based SportsArt Fitness, represents a novel way to harness "human power," Ken Carpenter, director of sales for the company, told me.

    It joins a growing list of similar concepts, including PaveGen's pavers that generate electricity as people walk (and boogie) on them and devices such as shoes and a backpack that charge batteries as you go for a jog or hike in the woods.

    Sweaty watts
    The Green System consists of recumbent and upright bikes as well as elliptical trainers, each with a box that captures 75 percent of the watts you generate during a workout. 

    Boxes in several machines are hooked together and routed through an inverter that can handle up to 2,000 watts. Assuming an average of 133 watts per person, a pod might have 15 machines on it, Carpenter said.

    "Most facilities are going to be drawing so many watts and amperage, you'd have to have a lot of inverters to really reverse that meter, because of light bulbs, air conditioning, and all the other things being powered," he said.

    Nevertheless, 2,000 watt hours are enough to power a clothes washer for 6 hours, a microwave oven for 2.5 hours, or a 27-inch flat screen TV for 17 hours, according to SportsArt Fitness.

    This is enough electricity that the system will pay for itself in about three years, according to Carpenter. The company has an online calculator where you can figure out your potential savings.

    The system includes an inverter and the exercise machines. The inverter runs about $3,000, while the the machines could cost about $3,500 to $7,000.

    Generating award points
    The system is also hooked up with Victoria, Canada,-based EcoFit, which produces digital technology to calculate the number of watts an individual generates during a workout, put it on a graphical display and keep track of watts over time on a card.

    In the future, the companies hope to turn these "eco-points" generated at the gym into currency accepted at coffee shops and other retail outlets. 

    Back at the gym, the display technology also allows individuals to compete. For example, if you see your buddy is generating 115 watts, you might ramp it up so you can generate 130 watts.

    Right now, most people measure their performance at the gym in terms of workout time, or distance biked, or calories burned, but Carpenter said he thinks this paradigm will shift to watts "the more eco-conscious people get."

    So, eat, drink, and be merry this weekend. But come the New Year, hit the gym and generate some watts.

    More on harnessing human power:

     

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

     

    Next-gen nuclear plants could provide carbon-free energy, but the painfully slow process of approving better, safer reactors — not to mention real anxiety over meltdowns and waste — threaten to derail projects before they can be built.

  • Map shows when solar power is a bargain

    California's investments in renewable energy help make San Diego one of the hottest markets for green jobs in the U.S.

    By John Roach, Contributing Writer, NBC News

    In 2013, the cost of solar power in San Diego will be cheaper than electricity from the local utility grid, according the predictions of an energy policy analyst who created a handy graphic to illustrate when so-called grid parity will be achieved.

    Sam Mircovich / Reuters

    A prototype sun tracking solar panel made by Concentrix Solar collects energy from its location at the University of California San Diego in this file photo.

    The interactive graphic posted on the Energy Self Reliant States website shows when this moment will be reached in major U.S. cities between now and 2027. 

    Parity is a "tipping point, when democratization of the electricity system not only makes political and economic sense, but becomes more competitive than using utility-delivered electricity," writes analyst John Farrell.

    His calculations assume that the cost of solar will continue to fall by 7 percent a year and grid electricity will rise at 2 percent a year. 

    If true, then San Diego will be the first to reach the parity milestone, followed by New York in 2015. From there, parity is progressively reached across the southern tier of the U.S. with my cloudy, rainy, northern hometown of Seattle not reaching parity until 2027.

    More on solar power:

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

     

    Next-gen nuclear plants could provide carbon-free energy, but the painfully slow process of approving better, safer reactors — not to mention real anxiety over meltdowns and waste — threaten to derail projects before they can be built.

  • Electrified cages jolt coral reef survival

    YouTube

    Metallic structures with a low level electric current provoke limestone formations that attract coral growth. The technology is proving effective at restoring reefs around the world, including Bali.

    By John Roach, Contributing Writer, NBC News

    A low-level electric current running through domed-shaped metallic structures in the waters off Bali is giving a jolt to coral reef survival there, according to news reports.

    The Biorock technology is seen by some conservationists as a means to repair coral reefs damaged by years of destructive cyanide and dynamite fishing practices, as well as steadily warming oceans.

    Warming oceans are a threat to the reefs since they result in more frequent episodes of coral bleaching, a phenomenon when higher temperatures cause photosynthetic algae that provide corals with food and color to leave, turning the corals white.

    Without food for a sustained period of time, the corals will die. A coral bleaching event in 1998 killed one sixth of the world's tropical reefs. 

    Biorock technology builds from the late German marine architect Wolf Hibertz's discovery in the 1970s that electrified metallic structures cause dissolved minerals in the water to crystallize on them.

    This grows "into a white limestone similar to that which naturally makes up coral reefs and tropical white sand beaches," the Global Coral Reef Alliance explains.  

    Marine life including corals and oysters colonize this limestone.

    "Corals grow two to six times faster. We are able to grow back reefs in a few years," Thomas J. Goreau, a marine biologist who is leading the development of the technology, told AFP.

    Goreau is president of the Global Coral Reef Alliance, a U.S.-based non-profit dedicated to the protection, preservation, and sustainable management of coral reefs. 

    Bali success
    The alliance today works with organizations around the world to implement the Biorock technology, including a 20-year-long project in Pemuteran Bay off the north coast of Bali.

    Today there are about 60 of the electrified metallic cages in the bay, creating a coral reef there that is "flourishing better than ever before," AFP reports.

    What's more, researchers overseeing the project say that the Biorock technology makes the corals more resistant to global warming.

    "Biorock is the only method known that protects corals from dying from high temperatures. We get from 16 to 50 times higher survival of corals from severe bleaching," Goreau told AFP.

    These restored reefs in turn attract fish and tourists.

    Technology limits?
    While the technology is useful for small areas, the scale of coral bleaching is just too large for it to be a cost-effective solution, Rod Salm, a coral reef specialist with The Nature Conservancy, told the Associated Press in a 2007 story about Biorock technology.

    A more effective method of saving reefs from mass coral bleaching may be large marine protected areas that offer plenty of shade and cooler waters for the reefs, Salm noted in a 2010 blog post for Nature.

    But at the small scale, at least, Goreau argues that Biorock is more cost-effective than other solutions. For example, the National Oceanic and Atmospheric Administration recently touted the successful recovery of 376 square feet of coral in Florida that was damaged when a boat ran aground in 2002. 

    With $56,671 in settlement funds, the government agency attached corals to a special cement that hardens underwater. By 2010, the restored reef was healthier than an adjacent undamaged section.

    Goreau issued a press release countering the agency's success story saying that his Biorock technology is more cost effective. Based on the settlement funds used for the restoration, the government project cost $1,622 per square foot. Biorock technology can be used to grow six foot tall reef structures for $13 to $20 per square foot, he claims.

    The technology will be featured in One Day on Earth, a television program sponsored by the United Nations, in early 2012. You can check it out in the video below.

    11/11/11 ONE DAY IN PEMUTERAN BAY BALI from Rani E. Morrow-Wuigk on Vimeo.

    More on coral reef damage and restoration:

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

    A five-thousand-year-old material gets new life and super strength thanks to new technology. From the 103rd story of the Willis Tower in Chicago to Apple's future headquarters to a Corning research lab, we see how tough glass can get while maintaining its timeless beauty.

     

  • 'Greenhouse effect' used to generate electricity

    MIT

    Researchers are working on a device that traps the sun's energy using a greenhouse-like effect and converts it into electricity.

    By John Roach, Contributing Writer, NBC News

    A device that gets scorching hot as it captures and traps much of the sun's energy using a greenhouse-like approach could usher in an era of inexpensive electricity from the sun.

    The breakthrough comes from a sunlight-absorbing material made of photonic crystals that are arranged to prevent the escape of most of the energy it captures from direct sunlight.

    The concept is similar to the way carbon dioxide molecules in the atmosphere trap the sun's energy, which keep the planet warmer than it would be if all the energy escaped to space.

    In this case, infrared radiation from the sun enters the device through holes in the surface, but the reflected rays are blocked when they try to escape, explains Peter Bermel, an electronics researcher working on the device at the Massachusetts Institute of Technology. 

    This blockage is achieved by a geometry that limits re-radiation of the sun's rays to a narrow range of angles — the solar disk and region right around the sun. The rest of the rays stay in the device and heat it up.

    All this concentrated heat is focused on the production of high-energy photons, which are used to generate electricity via a thermophotovoltaic device.

    Conventional photovoltaic cells are limited in their ability to convert sunlight into electricity due to the inefficient conversion of the broad spectrum of sunlight that hits the cells. 

    This limit, known as Shockley-Queisser, is 31 percent. 

    "What we're doing is a way around that limit … we are taking a very broad spectrum and then we are squeezing it, in some sense," Bermel told me.

    Peter Bermel / MIT

    This is a diagram of the angle-selective thermophotovoltaic system. In theory, such devices could produce electricity more efficiently than conventional photovoltaic cells.

    That's because heat is absorbed across a broad range of wavelengths and then tailored to generate the high-energy photons needed to generate electricity. The approach, Bermel said, could reach efficiencies of 35 to 36 percent, which is higher than the Shockley-Queisser limit.

    Thermophotovoltaic devices have existed since the 1950s, but the concentration of sunlight is traditionally done with giant and expensive arrays of mirrors. Bermel's approach, by contrast, can be made with inexpensive chip-manufacturing technology, he said.

    A major expense, though, will come in the equipment needed to track the sun so that the device is always getting direct sunlight to take advantage of the selective-angle approach.

    Other solar concentrators, such as the luminescent solar concentrators we reported on in November, get around the outlay for tracking technology by absorbing diffuse sunlight and pumping it to conventional solar cells.

    However, some sunlight is still reabsorbed in the LSC technology and control of the wavelengths is difficult, Bermel noted.

    "The nice thing about our angle-selective approach is that it can keep losses to extremely low levels, relatively speaking," he said.

    What's more, the higher efficiencies of the thermophotovoltaics, in theory, could make up for the added costs of the tracking, he added.

    To get there, though, will require more work on optimizing the angular selectivity of their material to reach the theoretical efficiencies.

    "I don't want to oversell the research and say we've already figured it all out and it is going to be in your home in the next year or two," Bermel said. "That's not realistic."

    Nevertheless, finding new ways to concentrate sunlight to generate electricity is welcome news as global concentrations of carbon dioxide reach new highs, raising worries about that other greenhouse effect.

    More on solar energy breakthroughs:

    Bermel and colleagues describe their work in the journal Nanoscale Research Letters. 

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

    Kids' play has moved to tablets and PCs. In this new age, toy makers and researchers alike are sorting out the benefits — and detriments — of playful educational interaction in virtual space.

  • How driving can light up cities

    New Energy Technologies

    Cars can help generate electricity to light up city streets by rolling over these rumble strip-like speed bumps as the come to a stop. The technology was recently demonstrated in Roanoke, Va.

    By John Roach, Contributing Writer, NBC News

    The roads of the future may be lined with speed bumps if a Maryland company succeeds in wide-scale deployment of a technology that harvests kinetic energy from cars and trucks and converts it to electricity.

    The technology essentially helps slow vehicles down as they roll over rumble strip-like treadles that capture energy that is otherwise lost as heat when drivers step on the brakes. 

    This harvested energy is used to generate electricity that can power streetlights, nearby buildings and keep emergency communications equipment charged up, for example.

     

    The MotionPower strip is being developed by Maryland-based New Energy Technologies. They recently demonstrated it at an event center in Roanoke, Virginia, where stopping cars lit up a series of lights.

    A total of 580 cars drove over the strip in a 6-hour period, generating enough electricity to power an average U.S. home for a day, according to the company.

    The concept of harvesting energy from people as they move around is nothing new. We've seen an energy harvesting backpack, pair of shoes, and a knee brace, for example, as well as pavers that light up when people step on them a la the late Michael Jackson in his "Billie Jean" video.

    New Energy Technologies envisions their system as a way to generate clean and green energy for cities and, at the same time, help them shave costs off their electricity bills.

    Assuming the technology works as advertised, there's the question of economics. How much does the system cost to install and maintain and what's the payback in terms of a city's savings on utility bills? A spokesman said hard numbers aren't yet available.

    More on energy harvesting technologies:

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

     

     

    Disposable computers for hurling into infernos, underwater robots that team up for search and rescue, and other new tools are coming to the aid of emergency responders during calamities.

     

  • Ant frying tech could make solar cheap

    Chris Giebink, Penn State

    An LSC is illuminated by a laser beam (central spot) resulting in luminescence that is emitted from the edges and projected onto a white business card. The faintly visible concentric rings and different colors of light on the business card result from microcavity effects.

    By John Roach, Contributing Writer, NBC News

    Admit it. You fried an ant under a magnifying glass. It's OK. We did it too. Now scientists are reporting a breakthrough in a similar technology that could bring down the cost of solar power.

    About 50 percent of the cost of solar power is due to the materials and manufacturing of solar cells, essentially pieces of silicon that convert sunlight into electricity. By concentrating the sunlight, you can get the same amount of power with fewer cells.

    One way to do this is with a magnifying glass, like we do when we fry ants. But this is a bit tricky when we want to concentrate sunlight all day long because we have to make sure the glass is directly aligned with the sun. 

    "In order to do that, you have to track the sun … and that drives up the cost of your concentrating system," Chris Giebink, an assistant professor of electrical engineering at Pennsylvania State University, told me today.

    Luminescent solar concentrators
    The approach he and his colleagues are improving upon is a decades old technology called luminescent solar concentrators. These contraptions concentrate light by absorbing it with special dyes that re-emit about 75 percent of the light within the confines of a transparent slab of material.

    The trapping effect is similar to the way optical fibers use light to transmit data. "It is trapped so it is guided towards the edges and that's where you stick your solar cells," Giebink explained.

    The bigger you make the LSC, the more concentrated the light that's fed to the solar cells on the edges. In theory, these things can concentrate the light to the power of 100 suns — all without tracking the sun since they work at any angle and even concentrate diffuse light on cloudy days.

    "On paper, it sounds really good," Giebink said. "In practice, the reason you don't see these things is because they don't work very well."

    The biggest problem is that much of the sunlight that is absorbed by the dye and reemitted into the glass either bounces off the glass and gets reabsorbed by the dye and lost or reemitted in a direction where it is no longer trapped, which has about a 25 percent chance of occurring.

    "Since we are bouncing through this thing hundreds of times, that adds up to a big problem. It has prevented these things from getting anywhere close to their theoretical potential," Giebink said.

    Preventing re-absorption
    He and his colleagues have now found a way to prevent the light from being reabsorbed by the dye en route to the edge of the glass.

    To do this, they made an LSC with two very thin films stacked on a layer of glass. 

    The first film — about 100 nanometers thick — is a luminescent layer containing the dye that absorbs and reemits sunlight. This layer sits on top of a low refractive index layer, "which essentially means from the standpoint of light it looks a lot like air," Giebink explained.

    This combination creates what is called a microcavity. The researchers found if they changed the thickness of the luminescent layer, the microcavity would change in a way that prevents the light reemitted by the dye from being reabsorbed when it bounces off the bottom of the glass.

    "We've changed the thickness of one of the films such that light essentially can't fit in that thin film anymore and as a result it is reflected back with very high efficiency, close to 100 percent," Giebink said.

    Their experimental results suggest this approach allows them to get to about 25 suns for a window pane sized collector, which is 2.5 times greater than a conventional LCS.

    Going forward, the researchers need to optimize the design so that it is both cheap to manufacture and has the desired effect. After all, it won't bring down the cost of solar power if the concentrator cost as much as the solar cells it's meant to replace.

    "We've shown the general idea works, but how exactly to build one of these things is not entirely clear," Giebink said.

    Complementary approach
    The breakthough is compatible with another approach to this problem reported by researchers at the Massachusetts Institute of Technology in 2008 that focused on creating dyes that are less susceptible to reabsorbing the light they reemit.

    "We took any dye that you want and decreased the probability of re-absorption a lot just by how we structure the concentrator itself," Giebink explained. "We ought to be able to combine the two approaches. That's the direction we are going now."

    If it all works out, the researchers estimate it could reduce the cost of solar power systems by about a factor of two, he added, which could help make solar energy more price competitive with coal and oil, easing the transition away from fossil fuel energy.

    More on solar power technologies:

    The researchers, who included Giebink and Gary Widerrecht and Michael Wasielewski with Argonne-Northwestern Solar Energy Research Center and Northwestern University, published their findings in current issue of Nature Photonics.

    John Roach is a contributing writer for msnbc.com. To learn more about him, check out his website. For more of our Future of Technology series, watch the featured video below.

    Disposable computers for hurling into infernos, underwater robots that team up for search and rescue, and other new tools are coming to the aid of emergency responders during calamities.