Solar power is radiant energy that's produced by the sun. Every single day the sun radiates, or sends out, a huge quantity of energy. The sun radiates more energy in one second than people have used since the beginning of time!
The energy of the Sun derives from within the sun itself. Like other stars, the sun is really a big ball of gases––mostly hydrogen and helium atoms.
The hydrogen atoms in the sun’s core combine to form helium and generate energy in a process called nuclear fusion.
During nuclear fusion, the sun’s extremely high pressure and temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. But the helium atom contains less mass than the four hydrogen atoms that fused. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.
It requires countless years for the energy in the sun’s core to make its way to the solar surface, after which somewhat over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the speed of light.
Only a small portion of the power radiated by the sun into space strikes our planet, one part in two billion. Yet this amount of energy is enormous. On a daily basis enough energy strikes the usa to supply the nation’s energy needs for one and a half years!
Where does all of this energy go?
About 15 percent of the sun’s energy that hits the earth is reflected back to space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produces rainfall. Solar energy is also absorbed by plants, the land, and the oceans. The rest could be employed to supply our energy needs.
Who invented solar energy ?
Humans have harnessed solar power for centuries. As early as the 7th century B.C., people used simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire. More than a century ago in France, a scientist used heat from a solar collector to make steam to drive a steam engine. In the beginning of this century, scientists and engineers began researching ways to use solar energy in earnest. One important development was a remarkably efficient solar boiler introduced by Charles Greeley Abbott, an american astrophysicist, in 1936.
The solar hot water heater gained popularity at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing prior to The second world war. This growth lasted prior to the mid-1950s when low-cost gas had become the primary fuel for heating American homes.
The public and world governments remained largely indifferent to the possibilities of solar power prior to the oil shortages of the1970s. Today, people use solar technology to heat buildings and water and also to generate electricity.
How we use solar power today ?
Solar power is employed in a number of different ways, of course. There are 2 simple forms of solar energy:
* Solar thermal energy collects the sun's warmth through 1 of 2 means: in water or in an anti-freeze (glycol) mixture.
* Solar photovoltaic energy converts the sun's radiation to usable electricity.
Let us discuss the five most practical and popular techniques solar power can be used:
1. Small portable solar photovoltaic systems. We see these used everywhere, from calculators to solar garden tools. Portable units can be utilized for everything from RV appliances while single panel systems can be used traffic signs and remote monitoring stations.
2. Solar pool heating. Running water in direct circulation systems via a solar collector is a very practical solution to heat water for your pool or hot tub.
3. Thermal glycol energy to heat water. In this method (indirect circulation), glycol is heated by sunshine and the heat is then transferred to water in a warm water tank. This technique of collecting the sun's energy is more practical now than ever before. In areas as far north as Edmonton, Alberta, solar thermal to heat water is economically sound. It can pay for itself in 3 years or less.
4. Integrating solar photovoltaic energy into your home or business power. In many parts of the world, solar photovoltaics is an economically feasible solution to supplement the power of your home. In Japan, photovoltaics are competitive with other types of power. In america alone, new incentive programs make this form of solar technology ever more viable in many states. An increasingly popular and practical method of integrating solar energy into the power of your home or business is through the use of building integrated solar photovoltaics.
5. Large independent photovoltaic systems. For those who have enough sun power at your site, you might be able to go off grid. It's also possible to integrate or hybridize your solar energy system with wind power or other kinds of sustainable energy to stay 'off the grid.'
How do Photovoltaic panels work ?
Silicon is mounted beneath non-reflective glass to create photovoltaic panels. These panels collect photons from the sun, converting them into DC electric power. The power created then flows into an inverter. The inverter transforms the energy into basic voltage and AC electric power.
Solar cells are prepared with particular materials called semiconductors like silicon, which is presently the most generally used. When light hits the Photovoltaic cell, a specific share of it is absorbed inside the semiconductor material. This means that the energy of the absorbed light is given to the semiconductor.
The energy unfastens the electrons, permitting them to run freely. Pv cells also have one or more electric fields that act to compel electrons unfastened by light absorption to flow in a specific direction. This flow of electrons is a current, and by introducing metal links on the top and bottom of the -Photovoltaic cell, the current can be drawn to use it externally.
What are the positives and negatives of solar energy ?
Solar Pro Arguments
- Heating our homes with oil or propane or using electricity from power plants running with fossil fuels is a reason behind climatic change and climate disruption. Solar power, on the other hand, is clean and environmentally-friendly.
- Solar hot-water heaters require little maintenance, and their initial investment can be recovered within a relatively small amount of time.
- Solar hot-water heaters can work in almost any climate, even just in very cold ones. Simply choose the right system for your climate: drainback, thermosyphon, batch-ICS, etc.
- Maintenance costs of solar powered systems are minimal and the warranties large.
- Financial incentives (USA, Canada, European states…) can reduce the cost of the initial investment in solar technologies. The U.S. government, for example, offers tax credits for solar systems certified by by the SRCC (Solar Rating and Certification Corporation), which amount to 30 percent of the investment (2009-2016 period).
Solar Cons Arguments
- The initial investment in Solar Water heaters or in Photovoltaic Electric Systems is greater than that required by conventional electric and gas heaters systems.
- The payback period of solar PV-electric systems is high, as well as those of solar space heating or solar cooling (only the solar domestic hot water heating payback is short or relatively short).
- Solar water heating do not support a direct in conjunction with radiators (including baseboard ones).
- Some air cooling (solar space heating and the solar cooling systems) are very pricey, and rather untested technologies: solar air-con isn't, till now, a truly economical option.
- The efficiency of solar powered systems is rather dependent on sunlight resources. It's in colder climates, where heating or electricity needs are higher, that the efficiency is smaller.
Who am i ? - Barbara Young writes on solar RV panels in her personal hobby website 12voltsolarpanels.net. Her efforts are dedicated to helping people save energy using solar power to lower CO2 emissions and energy dependency.
Showing posts with label Energy. Show all posts
Showing posts with label Energy. Show all posts
Thursday, June 17, 2010
Tuesday, October 6, 2009
Conflicted Conservation
Saving the earth might mean trampling indigenous rights BY MADHUSREE MUKERJEE
Even as industrial civilization reaches into the farthest corners of the globe to extract resources such as oil, timber and fish, environmentalists are striving to mitigate its deleterious effects on the biosphere. Projects to reduce pollution, prevent climate change and protect biodiversity, however, are drawing criticism that they could drive indigenous people off their lands and destroy their livelihoods.
Conservationists have historically been at odds with the people who inhabit wildernesses. During the last half of the 20th century, millions of indigenous people in Africa, South America and Asia were ousted from their homelands to establish nature sanctuaries free of humans. Most succumbed to malnutrition, disease and exploitation, recounts anthropologist Michael Cernea of George Washington University. Such outcomes—coupled with the realization that indigenous groups usually help to stabilize ecosystems by, for instance, keeping fire or invasive weeds at bay— have convinced major conservation groups to take local human concerns into account. The World Wildlife Fund (WWF) now describes indigenous peoples as “natural allies,” and the Nature Conservancy pledges to seek their “free, informed and prior” consent to projects impacting their territories.
Recent incidents, however, have made some observers wonder. “They’re talking the talk, but are they walking the walk?” asks Jim Wickens of the advocacy group Forest Peoples Program, based in Moreton-in-Marsh, England. Wickens cites a “huge cry of concern” by 71 grassroots groups protesting a WWF effort to set up a certification scheme for shrimp aquaculture. Shrimp farms have often been established along tropical coastlines by cutting down mangroves, and their effluents have damaged neighboring fisheries and farmlands. The Mangrove Action Project, an advocacy group based in Port Angeles, Wash., considers intensive shrimp aquaculture impossible to make sustainable. The WWF counters that less than one third of shrimp manufacturers worldwide are currently achieving the standards that it hopes to set. As such, certification should “certainly make shrimp farming cleaner,” says Jason Clay, WWF’s vice president of markets. Geographer Peter Vandergeest of York University in Toronto worries, however, that the endeavor will falter unless the communities that are affected by shrimp farms have a say in setting standards and enforcement. Given the remoteness of many shrimp farms, he explains, auditors’ checks will be rare, and “you can easily put on a show.”
Perhaps more worrisome to advocates for indigenous peoples, however, are so-called carbon-offset schemes that seek to protect standing forests. Several of the large environmental organizations hold that the carbon saved by preventing deforestation could be sold as offsets, thereby generating funds for conservation and communities. A scheme referred to as REDD (reducing emissions from deforestation and degradation) may be introduced this December into the United Nations Climate Change Convention, and it could be partly financed by offsets. The Nature Conservancy hopes that three billion tons of such credits, valued at $45 billion, can be generated by 2020.
But Marcus Colchester of Forest Peoples Program comments: “We see a risk that the prospect of getting a lot of money for biodiversity could lead to indigenous peoples’ concerns falling by the wayside.” In particular, increasing the financial value of forests could lead to “the biggest land grab of all time,” claims Tom B. K. Goldtooth of the Indigenous Environmental Network, based in Bemidji, Minn. Interpol has warned that unscrupulous entities plan to profit from REDD: their methods could include expelling an indigenous people from their forest to acquire legal title over it. The Nature Conservancy, which supports indigenous peoples’ efforts to acquire legal rights to their territories, counters that “increasing the value of forests through REDD can only provide them benefi ts.”
Concerns of displacement are particularly acute in Indonesia, where villagers opposing logging operations and paper, pulp and palm oil plantations on their territories have experienced violent attacks. Some 20 carbon forestry projects are already in the works there. Colchester warns that the government’s regulations on REDD do not adequately protect indigenous peoples. In the Kampar Peninsula, for instance, a forestry company proposes to clear-cut a ring of swamp forest and plant it with acacia—so as to protect the forest in the core area and thereby earn REDD credits. The project would limit the access of the Melayu people to their traditional fishing creeks and hunting grounds; they have protested by preventing company staff from entering the area.
Similar fears of dispossession color attempts to protect coral reefs. In May six nations in Southeast Asia, with technical support from the Nature Conservancy, WWF and Conservation International, committed to the Coral Triangle Initiative, which will protect 75,000 square kilometers of coastline, coral reefs and ocean. M. Riza Damanik of KIARA, the Fisheries Justice Coalition of Indonesia, worries that the richest fishing grounds will be zoned off as protected areas.
Environmental psychologist Lea Scherl of James Cook University in Australia, who has studied the region’s marine protected areas, believes that such concerns are justified. In the largest conservation organizations, she explains, scientists design projects on the macro level—as if the map contained only natural features— and factor in culture afterward. “The people rarely have a meaningful voice at the very outset,” she says. Furthermore, efforts to mitigate a project’s impacts on local communities are underfunded and often unsystematic, compared with the scientific aspects.
In the end, it is those who have intimate details of the land and the seas, accumulated over generations, who hold key insights to conservation. As Scherl puts it: “You lose that knowledge when you take the people away.”
Source of Information : Scientific American September 2009
Even as industrial civilization reaches into the farthest corners of the globe to extract resources such as oil, timber and fish, environmentalists are striving to mitigate its deleterious effects on the biosphere. Projects to reduce pollution, prevent climate change and protect biodiversity, however, are drawing criticism that they could drive indigenous people off their lands and destroy their livelihoods.
Conservationists have historically been at odds with the people who inhabit wildernesses. During the last half of the 20th century, millions of indigenous people in Africa, South America and Asia were ousted from their homelands to establish nature sanctuaries free of humans. Most succumbed to malnutrition, disease and exploitation, recounts anthropologist Michael Cernea of George Washington University. Such outcomes—coupled with the realization that indigenous groups usually help to stabilize ecosystems by, for instance, keeping fire or invasive weeds at bay— have convinced major conservation groups to take local human concerns into account. The World Wildlife Fund (WWF) now describes indigenous peoples as “natural allies,” and the Nature Conservancy pledges to seek their “free, informed and prior” consent to projects impacting their territories.
Recent incidents, however, have made some observers wonder. “They’re talking the talk, but are they walking the walk?” asks Jim Wickens of the advocacy group Forest Peoples Program, based in Moreton-in-Marsh, England. Wickens cites a “huge cry of concern” by 71 grassroots groups protesting a WWF effort to set up a certification scheme for shrimp aquaculture. Shrimp farms have often been established along tropical coastlines by cutting down mangroves, and their effluents have damaged neighboring fisheries and farmlands. The Mangrove Action Project, an advocacy group based in Port Angeles, Wash., considers intensive shrimp aquaculture impossible to make sustainable. The WWF counters that less than one third of shrimp manufacturers worldwide are currently achieving the standards that it hopes to set. As such, certification should “certainly make shrimp farming cleaner,” says Jason Clay, WWF’s vice president of markets. Geographer Peter Vandergeest of York University in Toronto worries, however, that the endeavor will falter unless the communities that are affected by shrimp farms have a say in setting standards and enforcement. Given the remoteness of many shrimp farms, he explains, auditors’ checks will be rare, and “you can easily put on a show.”
Perhaps more worrisome to advocates for indigenous peoples, however, are so-called carbon-offset schemes that seek to protect standing forests. Several of the large environmental organizations hold that the carbon saved by preventing deforestation could be sold as offsets, thereby generating funds for conservation and communities. A scheme referred to as REDD (reducing emissions from deforestation and degradation) may be introduced this December into the United Nations Climate Change Convention, and it could be partly financed by offsets. The Nature Conservancy hopes that three billion tons of such credits, valued at $45 billion, can be generated by 2020.
But Marcus Colchester of Forest Peoples Program comments: “We see a risk that the prospect of getting a lot of money for biodiversity could lead to indigenous peoples’ concerns falling by the wayside.” In particular, increasing the financial value of forests could lead to “the biggest land grab of all time,” claims Tom B. K. Goldtooth of the Indigenous Environmental Network, based in Bemidji, Minn. Interpol has warned that unscrupulous entities plan to profit from REDD: their methods could include expelling an indigenous people from their forest to acquire legal title over it. The Nature Conservancy, which supports indigenous peoples’ efforts to acquire legal rights to their territories, counters that “increasing the value of forests through REDD can only provide them benefi ts.”
Concerns of displacement are particularly acute in Indonesia, where villagers opposing logging operations and paper, pulp and palm oil plantations on their territories have experienced violent attacks. Some 20 carbon forestry projects are already in the works there. Colchester warns that the government’s regulations on REDD do not adequately protect indigenous peoples. In the Kampar Peninsula, for instance, a forestry company proposes to clear-cut a ring of swamp forest and plant it with acacia—so as to protect the forest in the core area and thereby earn REDD credits. The project would limit the access of the Melayu people to their traditional fishing creeks and hunting grounds; they have protested by preventing company staff from entering the area.
Similar fears of dispossession color attempts to protect coral reefs. In May six nations in Southeast Asia, with technical support from the Nature Conservancy, WWF and Conservation International, committed to the Coral Triangle Initiative, which will protect 75,000 square kilometers of coastline, coral reefs and ocean. M. Riza Damanik of KIARA, the Fisheries Justice Coalition of Indonesia, worries that the richest fishing grounds will be zoned off as protected areas.
Environmental psychologist Lea Scherl of James Cook University in Australia, who has studied the region’s marine protected areas, believes that such concerns are justified. In the largest conservation organizations, she explains, scientists design projects on the macro level—as if the map contained only natural features— and factor in culture afterward. “The people rarely have a meaningful voice at the very outset,” she says. Furthermore, efforts to mitigate a project’s impacts on local communities are underfunded and often unsystematic, compared with the scientific aspects.
In the end, it is those who have intimate details of the land and the seas, accumulated over generations, who hold key insights to conservation. As Scherl puts it: “You lose that knowledge when you take the people away.”
Source of Information : Scientific American September 2009
Thursday, July 23, 2009
A SOLAR-POWERED BOILER
HEATING YOUR HOME’S WATER SUPPLY WITHOUT USING GAS OR OILWhy use natural gas or oil to heat your home’s water supply when the sun can do it for free? The big boiler in the sky lays down 100 watts of power across a single square foot. The simple solar-powered hotwater system that I’ve built from scratch will put these free watts to work on the rooftop of my new eco-conscious home. Once I get it installed, it will generate about 450 gallons of hot water a day, plenty for my family of four, while consuming half the amount of energy of a conventional hot-water system. Plus, it will fuel my home’s radiant heating system, a series of polyethylene pipes built into the floor that use hot water to warm the house. The first step is to build two 150- square-foot solar collectors—tidy sandwiches of glass, copper tubes, aluminum sheets and foam insulation held together by a pair of aluminum frames. I’ll position the panels at 65 degrees to the plane of the roof, facing south, like my house, to catch as much sun as possible to heat up the fluid (the antifreeze glycol) flowing through the copper tubes. Next I’ll install a pair of insulated 158-gallon storage tanks in the basement to hold my supply of municipal water. To heat it up, a pump will circulate hot glycol from the collectors through a heat exchanger inside each tank. When sensors in the roof-mounted panels hit about 60°F, a controller automatically turns a valve to start circulating the glycol. One tank distributes water for showers and dishes while the other services the radiant floors. What happens during the winter when the sun’s intensity wanes? That’s where heat from my newly drilled geothermal well comes in. More on that project next month.—JOHN B. CARNETT
Source of Information : Popular Science July 2009
Wednesday, July 22, 2009
Cleaner fossil fuels
Carbon-restricting legislation, if enacted, will discourage the use of coal, the dirtiest of all fossil fuels. Natural gas is cleaner but still emits carbon dioxide when burned. Both will be used for decades, but carbon-capture technology could clean them up until they can be replaced completely.
where we are now: 1,460 GW
what we NEED by 2050: 3,830 GW (all of it clean)
CAPTURE THE CARBON
The Dynegy power plant in
Moss Landing, California, could
be the first to use Calera’s
carbon-to-cement emissionsscrubbing
technology.
Tech to watch: Carbon-to-cement
Electricity generation accounts for 35 percent of human-generated carbon dioxide emissions globally, and almost all of that comes from burning coal or natural gas. Production of cement— 2.9 billion tons of it worldwide every year—contributes another 5 percent of carbon dioxide every year. For the Silicon Valley start-up Calera, those are convenient facts. The company has found a way to slash emissions from two of the biggest greenhouse-gas sources simultaneously by turning carbon dioxide into the raw material for buildings and highways. The basics are simple. Take the smokestack exhaust from a coal- or gas-fired power plant and run it through seawater. The carbon dioxide and other pollutants in the flue gases combine with magnesium and calcium in the seawater to form a kind of synthetic limestone. That material can then be processed into either cement or aggregate, the main ingredients in concrete and asphalt. The seawater, which is clean but depleted of magnesium and calcium, is sent back to the ocean. The technology is obviously best suited to the coasts, but inland, briny water drawn from overtapped aquifers could replace seawater. Calera’s process has a side benefit that could make it particularly attractive to the owners of existing coal- and gas-fired power plants: It traps the socalled criteria pollutants—sulfur dioxide, nitrogen oxides, particulates, heavy metals—that the Clean Air Act requires power plants to “scrub” from their smokestacks by 2012. Roughly half the plants in the U.S. haven’t complied with the law, because of the expense and the fact that 20 percent of the electricity a plant produces would have to be used for scrubbing. Add a scrubber to separate out carbon—the most conventional route to clean coal—and you eat up another 20 percent. Total cost: $1.7 billion for a 500-megawatt plant. “If you own an old coal plant that’s already at 35 percent efficiency, you’re pretty much out of business,” says Calera CEO Brent Constantz. In contrast, he estimates, it would cost $400 million for a 500-megawatt plant to install his company’s technology.—H.R.
Source of Information : Popular Science July 2009
where we are now: 1,460 GW
what we NEED by 2050: 3,830 GW (all of it clean)
CAPTURE THE CARBONThe Dynegy power plant in
Moss Landing, California, could
be the first to use Calera’s
carbon-to-cement emissionsscrubbing
technology.
Tech to watch: Carbon-to-cement
Electricity generation accounts for 35 percent of human-generated carbon dioxide emissions globally, and almost all of that comes from burning coal or natural gas. Production of cement— 2.9 billion tons of it worldwide every year—contributes another 5 percent of carbon dioxide every year. For the Silicon Valley start-up Calera, those are convenient facts. The company has found a way to slash emissions from two of the biggest greenhouse-gas sources simultaneously by turning carbon dioxide into the raw material for buildings and highways. The basics are simple. Take the smokestack exhaust from a coal- or gas-fired power plant and run it through seawater. The carbon dioxide and other pollutants in the flue gases combine with magnesium and calcium in the seawater to form a kind of synthetic limestone. That material can then be processed into either cement or aggregate, the main ingredients in concrete and asphalt. The seawater, which is clean but depleted of magnesium and calcium, is sent back to the ocean. The technology is obviously best suited to the coasts, but inland, briny water drawn from overtapped aquifers could replace seawater. Calera’s process has a side benefit that could make it particularly attractive to the owners of existing coal- and gas-fired power plants: It traps the socalled criteria pollutants—sulfur dioxide, nitrogen oxides, particulates, heavy metals—that the Clean Air Act requires power plants to “scrub” from their smokestacks by 2012. Roughly half the plants in the U.S. haven’t complied with the law, because of the expense and the fact that 20 percent of the electricity a plant produces would have to be used for scrubbing. Add a scrubber to separate out carbon—the most conventional route to clean coal—and you eat up another 20 percent. Total cost: $1.7 billion for a 500-megawatt plant. “If you own an old coal plant that’s already at 35 percent efficiency, you’re pretty much out of business,” says Calera CEO Brent Constantz. In contrast, he estimates, it would cost $400 million for a 500-megawatt plant to install his company’s technology.—H.R.
Source of Information : Popular Science July 2009
Tuesday, July 21, 2009
Safer Nuclear
It’s nearly impossible to imagine making meaningful carbon dioxide reductions without designing safer, cleaner reactors and rolling them out immediately—because no one wants to build more of the reactors we have today.where we are now: 372 GW
what we need by 2050: 700 GW
Tech to watch: Next generation nuclear
Of all carbon-free energy sources, nuclear power is the only one that’s already working on a large scale, generating 21 percent of America’s electricity. It’s also the one that freaks people out the most. Memories of Chernobyl, fears of terrorists getting nuclear material, and unease over waste that stays radioactive for tens of thousands of years all mean that before nuclear power can be expanded on an order needed to meet greenhouse-gas-reduction targets, engineers will need to build new reactors that help mitigate the unique dangers of nuclear fission. In the short term, we’ll have to settle for so-called Generation III+ reactors—simpler, safer and cheaper versions of the water-cooled behemoths that dot the landscape today. But 20 to 30 years down the line, things start to get much more interesting. Here’s a look at the next few decades of nuclear power.—SEÁN CAPTAIN
Generation III+
DESIGN Pressurized water
HOW IT WORKS. Like today’s reactors, these bathe enriched uranium fuel in water that absorbs heat to make steam.
PROMISE. Gen III+ pressurized-water reactors add “passive” safety mechanisms that cool the reactor if the plant loses power. For example, in an emergency, water flows from an extra tank above the reactor, driven by gravity.
PROBLEMS. Radioactive waste takes years to cool before it can be stored in underground repositories, which still don’t exist.
STATUS. Mitsubishi-Westinghouse, which developed the design, has received approval from the U.S. Nuclear Regulatory Commission and has signed contracts to build six reactors in the U.S. and four in China.
Generation IV
DESIGN. Pebble bed
HOW IT WORKS. Tennis-ball-size graphite spheres (pebbles) filled with uranium dioxide fuel capsules are stacked in the reactor like gumballs, where they start a nuclear reaction. A pump sends helium into the reactor, where it flows around the pebbles, absorbs heat, and then drives a turbine.
PROMISE. If the coolant is lost, the graphite pebbles absorb enough heat to prevent the fuel from melting down.
PROBLEMS. A single reactor requires billions of perfectly manufactured fuel capsules. If oxygen seeps in, the fuel can catch fire. The reactor uses enriched uranium (also good for making bombs) and produces radioactive waste.
STATUS. Researchers have built and run small test reactors, but the design hasn’t been commercialized.
Generation V
DESIGN. Traveling wave
HOW IT WORKS. Enriched uranium starts the process, releasing neutrons that help convert scrap depleted uranium (left over from enrichment plants) into plutonium. The plutonium releases yet more neutrons that convert more depleted uranium into usable fuel.
PROMISE. Very little enriched uranium is required, and there is already enough to last for centuries using this technology.
PROBLEMS. Cooling the reactor could require molten sodium, which catches fire if it comes into contact with oxygen or water. No one has built even an experimental traveling-wave reactor.
STATUS. A think tank called Intellectual Ventures wants to build a plant by 2020, but outside experts are skeptical, saying it could take decades.
Source of Information : Popular Science July 2009
Sunday, July 19, 2009
Wind power
Wind power is all about location—getting turbines where the breeze blows steady and strong. One of the best places for that is far out at sea. And because one of the biggest obstacles to expanding wind power is overcoming the objections of residents who don’t want wind farms blocking their views, deepwater wind, which is invisible from shore, has dual appeal.
where we are: 94 GW what we need by 2050: 2,000 GW
Tech to watch: Deepwater wind
According to the U.S. Department of the Interior, seabound wind farms off the Pacific coast could generate 900 gigawatts of electricity every year. Unfortunately, the water there is far too deep for even the tallest windmills to touch bottom. An experiment under way off the coast of Norway, however, could help put them anywhere. The project, called Hywind, is the world’s first large-scale deepwater wind turbine. Although it uses a fairly
standard 152-ton, 2.3-megawatt turbine, Hywind represents “totally new technology,” says Walter Musial, the principal engineer for ocean renewable energy at the National Renewable Energy Laboratory of the U.S. Department of Energy. The turbine will be mounted 213 feet above the water on a floating platform, or spar—a technology Hywind’s creator, the Norwegian company StatoilHydro, draws from its experience as Scandinavia’s largest gas and oil company. The steel spar, which is filled with ballast and extends 328 feet below the sea surface, will be tethered to the ocean floor by three cables; these will stabilize the platform and prevent the turbine from bobbing excessively in the waves. Hywind’s stability in the turbulent, wintry Scandinavian sea would prove that even the deepest corners of the ocean are suitable for wind power. If all goes according to plan, the turbine will start generating electricity six miles off the coast of southwestern Norway as early as September. To produce electricity on a large scale, a commercial wind farm will have to use bigger turbines than Hywind does, but it’s difficult enough to balance such a large turbine so high on a floating pole in the middle of the ocean. To make that turbine heavier, the whole rig’s center of gravity must be moved much closer to the ocean’s surface. To do that, StatoilHydro plans to engineer a new kind of wind turbine, one whose gearbox (the mechanism that transfers power between the rotor and the generator) sits at sea level rather than behind the blades. Hywind is a test run, but the payoff for perfecting floating wind-farm technology could be enormous. Out at sea, the wind is often stronger and steadier than close to shore, where all existing offshore windmills are planted. Deep-sea farms are invisible from land, which helps overcome the windmill-as-eyesore objection that has derailed wind farms in the past. If the technology catches on, it will open up vast swaths of the planet’s surface to one of the best low carbon power sources available.—H.R.
Source of Information : Popular Science July 2009
where we are: 94 GW what we need by 2050: 2,000 GW
Tech to watch: Deepwater wind
According to the U.S. Department of the Interior, seabound wind farms off the Pacific coast could generate 900 gigawatts of electricity every year. Unfortunately, the water there is far too deep for even the tallest windmills to touch bottom. An experiment under way off the coast of Norway, however, could help put them anywhere. The project, called Hywind, is the world’s first large-scale deepwater wind turbine. Although it uses a fairly
standard 152-ton, 2.3-megawatt turbine, Hywind represents “totally new technology,” says Walter Musial, the principal engineer for ocean renewable energy at the National Renewable Energy Laboratory of the U.S. Department of Energy. The turbine will be mounted 213 feet above the water on a floating platform, or spar—a technology Hywind’s creator, the Norwegian company StatoilHydro, draws from its experience as Scandinavia’s largest gas and oil company. The steel spar, which is filled with ballast and extends 328 feet below the sea surface, will be tethered to the ocean floor by three cables; these will stabilize the platform and prevent the turbine from bobbing excessively in the waves. Hywind’s stability in the turbulent, wintry Scandinavian sea would prove that even the deepest corners of the ocean are suitable for wind power. If all goes according to plan, the turbine will start generating electricity six miles off the coast of southwestern Norway as early as September. To produce electricity on a large scale, a commercial wind farm will have to use bigger turbines than Hywind does, but it’s difficult enough to balance such a large turbine so high on a floating pole in the middle of the ocean. To make that turbine heavier, the whole rig’s center of gravity must be moved much closer to the ocean’s surface. To do that, StatoilHydro plans to engineer a new kind of wind turbine, one whose gearbox (the mechanism that transfers power between the rotor and the generator) sits at sea level rather than behind the blades. Hywind is a test run, but the payoff for perfecting floating wind-farm technology could be enormous. Out at sea, the wind is often stronger and steadier than close to shore, where all existing offshore windmills are planted. Deep-sea farms are invisible from land, which helps overcome the windmill-as-eyesore objection that has derailed wind farms in the past. If the technology catches on, it will open up vast swaths of the planet’s surface to one of the best low carbon power sources available.—H.R.
Source of Information : Popular Science July 2009
Saturday, July 18, 2009
Biofuels
Ethanol is the most widely used biofuel today, but it’s hardly a panacea to our energy woes. Researchers are scrambling to transform moreefficient organic materials switchgrass, sugarcane, algae, sewage and even medical waste—into low-emission fuel for both transportation and electricity generation.
where we are: 643,000 barrels per day
what we need by 2050: 34 million per day
TECH TO WATCH: algae
The canals of Venice, Italy, may soon provide a green power source for the city’s seaport and prove that algae-derived energy can meet commercial electricity demand. A $272.6-million plant is awaiting authorization to generate electricity by burning biodiesel fuel made from canal algae. To get the fuel for the plant, algae harvested from the canal will be cultivated in 26-foot plastic bioreactors (and fertilized with carbon dioxide from the plant itself), dried, expellerpressed to squeeze oil-like lipids from the dried biomass, and turned into biodiesel through the addition of lye. By 2011, the plant could generate 40 megawatts, which would be used to power the city’s seaport and channel the excess electricity—33 megawatts—to docked tankers and cruise ships, all with zero net carbon emissions. The Venice project won’t be costeffective; it’s designed as a technology demonstrator and to give the city a jump on expected stricter cap-and-trade legislation. In the meantime, however, other innovations promise to finally make algal power affordable. While centrifuges account for 34 percent of the total investment costs, there is now a cheaper way to separate the algae from the water they grow in. In March, AlgaeVenture Systems in Ohio announced a new method to “dewater” algae using capillary action: A superabsorbent polymer pulls water molecules through a membrane and leaves the algae dry. The company claims that the process reduces biofuel production costs from $875 per ton to just $1.92. Advances in algal oil extraction and the conversion to biodiesel should bring expenses down even further. Although there are currently no plans for a commercial plant in the U.S., companies like BioProcess Algae are hoping to change that. BioProcess recently received a grant to build a pilot plant in Shenandoah, Iowa. If successful, prototype plants like this one could eventually help make domestic algae power more than a curiosity. —AMBER SASSE
The perfect biofuel?
THE TECHNOLOGY is still experimental, but late last year researchers at Penn State University discovered how to make methane—a main ingredient in natural gas—from the very thing driving climate change: carbon dioxide. The key is microorganisms called methanogens. Engineer Bruce Logan discovered that the organisms produced methane with nothing but water and carbon dioxide when zapped with an electric current. Build a fuel cell around the microbes, and as long as the electricity that feeds into the device comes from a renewable source like wind or solar, the process can provide a carbon-neutral source of combustible fuel.—CATHERINE PRICE
Source of Information : Popular Science July 2009
where we are: 643,000 barrels per day
what we need by 2050: 34 million per day
TECH TO WATCH: algae
The canals of Venice, Italy, may soon provide a green power source for the city’s seaport and prove that algae-derived energy can meet commercial electricity demand. A $272.6-million plant is awaiting authorization to generate electricity by burning biodiesel fuel made from canal algae. To get the fuel for the plant, algae harvested from the canal will be cultivated in 26-foot plastic bioreactors (and fertilized with carbon dioxide from the plant itself), dried, expellerpressed to squeeze oil-like lipids from the dried biomass, and turned into biodiesel through the addition of lye. By 2011, the plant could generate 40 megawatts, which would be used to power the city’s seaport and channel the excess electricity—33 megawatts—to docked tankers and cruise ships, all with zero net carbon emissions. The Venice project won’t be costeffective; it’s designed as a technology demonstrator and to give the city a jump on expected stricter cap-and-trade legislation. In the meantime, however, other innovations promise to finally make algal power affordable. While centrifuges account for 34 percent of the total investment costs, there is now a cheaper way to separate the algae from the water they grow in. In March, AlgaeVenture Systems in Ohio announced a new method to “dewater” algae using capillary action: A superabsorbent polymer pulls water molecules through a membrane and leaves the algae dry. The company claims that the process reduces biofuel production costs from $875 per ton to just $1.92. Advances in algal oil extraction and the conversion to biodiesel should bring expenses down even further. Although there are currently no plans for a commercial plant in the U.S., companies like BioProcess Algae are hoping to change that. BioProcess recently received a grant to build a pilot plant in Shenandoah, Iowa. If successful, prototype plants like this one could eventually help make domestic algae power more than a curiosity. —AMBER SASSE
The perfect biofuel?
THE TECHNOLOGY is still experimental, but late last year researchers at Penn State University discovered how to make methane—a main ingredient in natural gas—from the very thing driving climate change: carbon dioxide. The key is microorganisms called methanogens. Engineer Bruce Logan discovered that the organisms produced methane with nothing but water and carbon dioxide when zapped with an electric current. Build a fuel cell around the microbes, and as long as the electricity that feeds into the device comes from a renewable source like wind or solar, the process can provide a carbon-neutral source of combustible fuel.—CATHERINE PRICE
Source of Information : Popular Science July 2009
Friday, July 17, 2009
TECH TO WATCH: hydrokinetic power
Conventional hydroelectric power (think of the Hoover Dam) provides 7 percent of the electricity in the U.S. But the only way to increase that number without damming more rivers—which causes widespread ecological damage both above and below the dam—is to use nonconventional hydropower sources that capture energy from the movement of waves, rivers and tides.
where we are: 31 GW what we need by 2025: 67 GW
The future of hydropower is taking shape just downstream from a standard hydroelectric dam in Hastings, Minnesota. The power isn’t hydroelectric, though; it’s hydrokinetic, generated from the motion of free-flowing water. Installed this winter in –30° weather and switched on in January, the Houston-based Hydro Green Energy’s pilot plant is the first federally licensed hydrokinetic project in the U.S. Like an underwater wind turbine, it will produce electricity by using the high-velocity current gushing out of an existing hydroelectric dam to turn a 12-foot, three-blade fan. Known as “run-of-river” hydrokinetic, Hydro Green’s technology is similar to turbines that are being used to tap tidal power in Europe, except it’s optimized to work in water flowing in just one direction (tidal turbines use water flowing both in and out). To generate utility-scale power, turbines would be combined into arrays. They could be used in free-flowing rivers too, but coupling them with existing hydroelectric dams eases the Federal Energy Regulatory Commission’s licensing process and offers close access to the electricity grid. Hydro Green says that its technology can create power much more cheaply than a windmill can (4 to 7 cents per kilowatt-hour, compared with 10 cents per kilowatt-hour for wind). The main goal of the plant, which is rated for 100 kilowatts—enough to power 40 homes—is to answer some essential, basic questions: How do you build blades strong enough to withstand the constant flow of water? (Another company, Verdant, installed an experimental hydrokinetic project in New York City’s East River in 2007, only to have the rotors snap days later). How do you balance the presence of a turbine with the local ecosystem— for example, how does a hydrokinetic plant affect the river’s fish population? This spring, Hydro Green embarked on a $500,000 study to determine the impact of the turbines on six species of river fish, and a second, 150-kilowatt turbine will soon be up and running.—HILLARY ROSNER
RIVER RUNNING
Workers attach a walkway
to the nation’s first
commercial hydrokinetic
power turbine, on the
Mississippi River in
Hastings, Minnesota.
Source of Information : Popular Science July 2009
where we are: 31 GW what we need by 2025: 67 GW
The future of hydropower is taking shape just downstream from a standard hydroelectric dam in Hastings, Minnesota. The power isn’t hydroelectric, though; it’s hydrokinetic, generated from the motion of free-flowing water. Installed this winter in –30° weather and switched on in January, the Houston-based Hydro Green Energy’s pilot plant is the first federally licensed hydrokinetic project in the U.S. Like an underwater wind turbine, it will produce electricity by using the high-velocity current gushing out of an existing hydroelectric dam to turn a 12-foot, three-blade fan. Known as “run-of-river” hydrokinetic, Hydro Green’s technology is similar to turbines that are being used to tap tidal power in Europe, except it’s optimized to work in water flowing in just one direction (tidal turbines use water flowing both in and out). To generate utility-scale power, turbines would be combined into arrays. They could be used in free-flowing rivers too, but coupling them with existing hydroelectric dams eases the Federal Energy Regulatory Commission’s licensing process and offers close access to the electricity grid. Hydro Green says that its technology can create power much more cheaply than a windmill can (4 to 7 cents per kilowatt-hour, compared with 10 cents per kilowatt-hour for wind). The main goal of the plant, which is rated for 100 kilowatts—enough to power 40 homes—is to answer some essential, basic questions: How do you build blades strong enough to withstand the constant flow of water? (Another company, Verdant, installed an experimental hydrokinetic project in New York City’s East River in 2007, only to have the rotors snap days later). How do you balance the presence of a turbine with the local ecosystem— for example, how does a hydrokinetic plant affect the river’s fish population? This spring, Hydro Green embarked on a $500,000 study to determine the impact of the turbines on six species of river fish, and a second, 150-kilowatt turbine will soon be up and running.—HILLARY ROSNER
RIVER RUNNINGWorkers attach a walkway
to the nation’s first
commercial hydrokinetic
power turbine, on the
Mississippi River in
Hastings, Minnesota.
Source of Information : Popular Science July 2009
Wednesday, July 15, 2009
Solar Power
“Solar power” no longer refers just to chunky photovoltaic panels. A variety of tools for turning sunlight into usable energy—thin-film solar, solar thermal, solar heating, and more—are undergoing a burst of technological acceleration. Whether it’s powering an entire housing development or simply heating your house, taken together, their potential is huge.
where we are : 12.4 GW what we need by 2050: 2,000 GW
A shortage of low-carbon power sources seems absurd when you consider that a nearby star bathes the planet in 85,000 terawatts of energy every year. We just have to capture it.
The Google-funded start-up eSolar has devised a relatively cheap and efficient form of solar power by refining concentrating solar thermal (CST), in which large mirror arrays focus light to create heat and ultimately electricity. Proponents say CST can make solar cost-competitive with coal within a decade. It is “probably the only thing that can be done at a big enough scale to produce terawatts,” says Bill Gross, eSolar’s CEO. At the first eSolar power plant, a five-megawatt facility called Sierra situated northeast of Los Angeles, 24,000 mirrors gather the sunlight falling on 20 acres of land and train it on water-filled boiler units perched on top of towers. This creates temperatures of approximately 850°F, producing steam that turns an onsite turbine to generate electricity.
CST has been around since 1980, but in the 1990s a lack of public interest sent it into hibernation. Now public interest is back in a big way, and CST has awoken with a vengeance. One new megawatt of CST hardware was installed worldwide in 2006; in 2007 there were 100. The Earth Policy Institute projects that the installation of CST worldwide will double every 16 months, from 457 megawatts in 2007 to 6,400 megawatts by 2012. At least 13 plants are in advanced planning stages in the U.S. ESolar’s approach is comparatively cheap because, unlike most of its competitors, which use large, custom-built parabolic mirrors to capture sunlight from all angles, eSolar uses small, flat mirrors, each about the size of a big-screen television. Computerized tracking keeps each mirror focused at the optimal angle throughout the day. The mirrors are easy to manufacture, and it takes just two workers to attach them to relatively light scaffolding on-site. ESolar’s standard 46-megawatt array, which makes enough juice to power about 30,000 homes, occupies only a quarter of a square mile, which will allow the company to avoid the land-use fights that have ensnared other solar companies. Sierra is a demonstration project, but in February eSolar signed a deal to build 11 46-megawatt plants in the Southwest, and it is set to build a full gigawatt’s worth of plants in India. “Efficiency wins in every industry,” Gross says, “and it’s going to win in solar as well.”—DAVID ROBERTS
ELECTRICAL FIELD The Google-funded start-up eSolar uses computer tracking to keep thousands of mirrors like the ones in this illustration focused on boilers sitting atop towers. The light heats the water to 850°F, creating steam that turns a turbine and generates electricity.
Source of Information : Popular Science July 2009
where we are : 12.4 GW what we need by 2050: 2,000 GW
A shortage of low-carbon power sources seems absurd when you consider that a nearby star bathes the planet in 85,000 terawatts of energy every year. We just have to capture it.
The Google-funded start-up eSolar has devised a relatively cheap and efficient form of solar power by refining concentrating solar thermal (CST), in which large mirror arrays focus light to create heat and ultimately electricity. Proponents say CST can make solar cost-competitive with coal within a decade. It is “probably the only thing that can be done at a big enough scale to produce terawatts,” says Bill Gross, eSolar’s CEO. At the first eSolar power plant, a five-megawatt facility called Sierra situated northeast of Los Angeles, 24,000 mirrors gather the sunlight falling on 20 acres of land and train it on water-filled boiler units perched on top of towers. This creates temperatures of approximately 850°F, producing steam that turns an onsite turbine to generate electricity.
CST has been around since 1980, but in the 1990s a lack of public interest sent it into hibernation. Now public interest is back in a big way, and CST has awoken with a vengeance. One new megawatt of CST hardware was installed worldwide in 2006; in 2007 there were 100. The Earth Policy Institute projects that the installation of CST worldwide will double every 16 months, from 457 megawatts in 2007 to 6,400 megawatts by 2012. At least 13 plants are in advanced planning stages in the U.S. ESolar’s approach is comparatively cheap because, unlike most of its competitors, which use large, custom-built parabolic mirrors to capture sunlight from all angles, eSolar uses small, flat mirrors, each about the size of a big-screen television. Computerized tracking keeps each mirror focused at the optimal angle throughout the day. The mirrors are easy to manufacture, and it takes just two workers to attach them to relatively light scaffolding on-site. ESolar’s standard 46-megawatt array, which makes enough juice to power about 30,000 homes, occupies only a quarter of a square mile, which will allow the company to avoid the land-use fights that have ensnared other solar companies. Sierra is a demonstration project, but in February eSolar signed a deal to build 11 46-megawatt plants in the Southwest, and it is set to build a full gigawatt’s worth of plants in India. “Efficiency wins in every industry,” Gross says, “and it’s going to win in solar as well.”—DAVID ROBERTS
ELECTRICAL FIELD The Google-funded start-up eSolar uses computer tracking to keep thousands of mirrors like the ones in this illustration focused on boilers sitting atop towers. The light heats the water to 850°F, creating steam that turns a turbine and generates electricity.
Source of Information : Popular Science July 2009
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