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7 October 2013 Last updated at 17:25 ET By Paul Rincon Science Editor, BBC News website
Researchers at a US lab have passed a crucial milestone on the way to their ultimate goal of achieving self-sustaining nuclear fusion.
Harnessing fusion - the process that powers the Sun - could provide an unlimited and cheap source of energy.
But to be viable, fusion power plants would have to produce more energy than they consume, which has proven elusive.
Now, a breakthrough by scientists at the National Ignition Facility (NIF) could boost hopes of scaling up fusion.
NIF, based at Livermore in California, uses 192 beams from the world's most powerful laser to heat and compress a small pellet of hydrogen fuel to the point where nuclear fusion reactions take place.
The BBC understands that during an experiment in late September, the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel - the first time this had been achieved at any fusion facility in the world.
This is a step short of the lab's stated goal of "ignition", where nuclear fusion generates as much energy as the lasers supply. This is because known "inefficiencies" in different parts of the system mean not all the energy supplied through the laser is delivered to the fuel.
But the latest achievement has been described as the single most meaningful step for fusion in recent years, and demonstrates NIF is well on its way towards the coveted target of ignition and self-sustaining fusion. For half a century, researchers have strived for controlled nuclear fusion and been disappointed. It was hoped that NIF would provide the breakthrough fusion research needed.
In 2009, NIF officials announced an aim to demonstrate nuclear fusion producing net energy by 30 September 2012. But unexpected technical problems ensured the deadline came and went; the fusion output was less than had originally been predicted by mathematical models.
Soon after, the $3.5bn facility shifted focus, cutting the amount of time spent on fusion versus nuclear weapons research - which was part of the lab's original mission.
However, the latest experiments agree well with predictions of energy output, which will provide a welcome boost to ignition research at NIF, as well as encouragement to advocates of fusion energy in general.
It is markedly different from current nuclear power, which operates through splitting atoms - fission - rather than squashing them together in fusion.
NIF, based at the Lawrence Livermore National Laboratory, is one of several projects around the world aimed at harnessing fusion. They include the multi-billion-euro ITER facility, currently under construction in Cadarache, France.
However, ITER will take a different approach to the laser-driven fusion at NIF; the Cadarache facility will use magnetic fields to contain the hot fusion fuel - a concept known as magnetic confinement.
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Most people would agree that fossil fuels simply need to go. They’re the cause of pollution, wars and climate change. Thankfully, scientists have been researching alternative energy solutions like wind and solar power for years.
But wind and solar are still more expensive than oil and coal, and may not be the best solution for all places or uses. For example, some medical devices that are implanted in a human body could benefit from super tiny batteries that last decades.
So, scientists are continuing the quest for abundant, cheap and efficient energy by investigating lesser-known sources, ones that may seem a little unusual, even ridiculous, unrealistic, and in some cases, morbid.
“I think in order to solve the impending energy needs we might have to go a bit beyond,” said Bobby Sumpter, a senior research scientist of computational theoretical chemistry at Oak Ridge National Laboratory.
Here are 11 of the more unusual sources that go above and beyond the norm. Who knows. One day, you may use sugar to power your laptop, bacteria to run your car or dead bodies to heat a building.
- 1 Body Heat
The next time you’re standing in a crowded subway in the middle of summer, don’t sweat it. The heat your body produces can warm an entire building, complete with offices, apartments and shops. At least that’s what is happening in Stockholm, Sweden and Paris, France. Jernhuset, a state owned property administration company, is putting together a plan to capture body heat from train commuters traveling through Stockholm’s Central Station. The heat will warm water running through pipes, which will then be pumped through the building’s ventilation system.
Paris Habitat, owner of a low-income housing project in Paris, will also use body heat to warm 17 apartments in a building, which is directly above a metro station near Pompidou Center. On a more morbid and less sweaty note, a crematorium in the United Kingdom is using gasses released from the cremation process to heat a crematorium. The energy in cremated bodies is already being captured when it has to pas through filters to remove the mercury in the deceased’s fillings. Instead of letting the energy escape, pipes are used to pump it through the building.
- 2 Sugar
Traditionally, putting sugar into a gas tank is a prank that can ruin a car’s engine. But some day, it could be a great way to fuel a vehicle.
“We should not dismiss ideas, we should let people pursue ideas of unusual things,” Diego del Castillo Negrete, a senior research scientist in the Fusion Energy Division at the Oak Ridge National Laboratory said.
Researchers and chemists at Virginia Tech are developing a way to convert sugar into hydrogen, which can be used in a fuel cell, providing a cheaper, cleaner, pollutant-free and odorless drive. The scientists combine plant sugars, water and 13 powerful enzymes in a reactor, converting the concoction into hydrogen and trace amounts of carbon dioxide.
The hydrogen could be captured and pumped through a fuel cell to produce energy. Their process delivers three times more hydrogen than traditional methods, which translates into cost savings.
Unfortunately, it might be another 10 years before consumers can actually dump sugar into their gas tanks. What seems more realistic in the short term is using the same technology to create long-lasting sugar-based batteries for laptops, cell phones and other electronics.
- 3 Solar Wind
One hundred billion times more power than humanity currently needs is available right now, out in space. It comes through solar wind, a stream of energized, charged particles flowing outward from the sun. Brooks Harrop, a physicist at Washington State University in Pullman and Dirk Schulze-Makuch of Washington State’s School of Earth and Environmental Science, think they can capture these particles with a satellite that orbits the sun the same distance Earth does.
Their so-called Dyson-Harrop satellite would have a long copper wire charged by onboard batteries in order to produce a magnetic field perfect for snagging the electrons in the solar wind. The energy from the electrons would be beamed from the satellite via a infrared laser to Earth, since the infrared spectrum would not be affected by the planet’s atmosphere.
This Dyson-Harrop satellite holds a few technical problems that researchers are currently trying to fix. It has no protection from space debris, and some of the power could be lost as it’s beamed through Earth’s atmosphere. Plus, finding a way to aim the laser beam across millions of miles of space is no small task.
What seems more realistic is to use this satellite in order to power nearby space missions.
- 4 Feces and Urine
Most people think that feces and urine should be disposed of immediately. But feces contains methane, a colorless, odorless gas that could be used in the same way as natural gas.
At least two solutions -- one in Cambridge, Mass., called Park Spark and one in San Francisco run by Norcal Waste -- is focused on converting dog poo into methane.
In both solutions, dog walkers are provided biodegradable bags, which after they’re filled, are placed into a large container called a digester. Inside, microorganisms process the poo, giving off methane as a byproduct. The methane can be used to power lights
In Pennsylvania, a dairy farm is looking to cow manure for energy. Six hundred cows that produce 18,000 gallons of manure daily are helping the farm save $60,000 a year. The waste is used to produce electricity, bedding, fertilizer and heating fuel. And Hewlett-Packard recently released a study explaining how a dairy farmer could make money by leasing land to Internet server companies, who could power computers with the methane.
Human waste is just as good. In Bristol, Australia a VW Beetle car is powered by methane captured from a raw sewage treatment plant. Engineers from Wessex Water estimate the waste from 70 homes can generate enough gas to make the car run for 10,000 miles.
And let’s not forget urine. At the Heriot-Watt University's School of Engineering and Physical Sciences in Edinburgh, scientists are looking for a way to make world's first urine-powered fuel cells. It could be a viable way for astronauts or military personnel, for instance, to produce power on the go. Urea is an accessible, non-toxic, organic chemical compound rich in nitrogen. So yes, humans are constantly carrying around a chemical compound that can produce electricity.
- 5 Vibrations
Go out and party, it may help the environment. Club Watt in Rotterdam, Netherlands is using floor vibrations from people walking and dancing to power its light show. The vibrations are captured by “piezoelectric” materials that produce an electric change when put under stress.
The U.S. Army is also looking at piezoelectric technology for energy. They put the material in soldier’s boots in order to charge radios and other portable devices. Although this is an interesting renewable energy with great potential, it’s not cheap.
Club Watt spent $257,000 on this first generation 270-square-foot floor, more money than it can recoup. But the floor will be reprogrammed to improve output in the future. Your dance moves really can be electric.
- 6 Sludge
California municipalities alone produce 700,000 metric tons of dried sludge annually, which has the potential to generate 10 million kilowatt-hours of electricity per day. The University of Nevada, Reno, is drying sludge to make it burnable for a gasification process, which turns it into electricity.
A team of researchers at the university built the processing machine as a way of producing low cost and energy efficient technology. The machine turns gooey sludge into powder by using relatively low temperatures in a fluidized bed of sand and salts to produce the biomass fuel.
The waste-to-energy technology is designed to be on site which means companies can save on trucking costs, disposal fees, and electricity. Although the research is still on going, estimates show that a full-scale system can potentially generate 25,000 kilowatt-hours per day to help power reclamation facilities.
- 7 Jellyfish
Jellyfish that glow in the dark contain the raw ingredients for a new kind of fuel cell. Their glow is produced by green fluorescent protein, referred to as GFP. A team at The Chalmers University of Technology in Gothenburg, Sweden placed a drop of GFP onto aluminum electrodes and then exposed that to ultraviolet light. The protein released electrons, which travel a circuit to produce electricity.
The same proteins have been used to make a biological fuel cell, which makes electricity without an external light source. Instead of an external light source, a mixture of chemicals such as magnesium and luciferase enzymes, which are found in fireflies, were used to produce electricity from the device.
These fuel cells can be used on small, nano devices such as those that could be implanted in a person to diagnose or treat disease.
- 8 Exploding Lakes
There are three known "exploding lakes," in the world, called such because they contain huge reservoirs of methane and carbon dioxide trapped in the depths by differences in water temperature and density.
If temperatures should change and the lake turns, these gases would immediately fizz to the surface like a shaken bottle of soda, killing the millions of people and animals living nearby. In fact, such an event happened on August 15, 1984, when Cameroon's Lake Nyos unleashed a huge cloud of concentrated carbon dioxide, instantly suffocating hundreds of people and animals.
In Rwanda, Lake Kivu is such a foreboding place. But the government has built a power plant that sucks up the noxious gases from the lake to power three large generators, which produce 3.6 megawatts of electricity. The government hopes that in the next couple of years, the plant could be producing enough power for one-third of the country.
- 9 Bacteria CDC.
Billions of bacteria live out in the wild, and like any living organism, they have a survival strategy for when there is a limited food supply. E. coli bacteria store fuel in the form of fatty acids that resembles polyester. That same fatty acid is needed for the production of biodiesel fuel. So, researchers are looking to genetically modify E. coli microorganisms to overproduce those polyester-like acids.
The scientists removed enzymes from the bacteria to boost fatty acid production, and then dehydrated the fatty acid to get rid of the oxygen, which made turned it into a type of diesel fuel. The same bacteria that can make us sick can also help save people money and the environment, by providing fuel for transportation.
- 10 Carbon Nanotubes Carbon Nanotubes are hollow tubes of carbon atoms that have a range of potential uses, from armor-like fabrics to elevators that could lift cargo between Earth and the Moon. Recently, scientists from MIT have a found a way to use carbon nanotubes to collect 100 times more solar energy than a regular photovoltaic cell.
The nanotubes could work as antenna to capture and funnel sunlight onto solar arrays. This means that instead of having an entire rooftop covered in solar panels, a person may need just a small space.
- 11 Trains
Stretching the imagination when it comes to energy could get us closer to generating energy the way nature does: free and efficient.
In London Mayor Boris Johnson announced Friday that excess heat from the subway tunnels and an electric substation will be funneled into British homes.
Decade after decade politicians and scientists have promised us that we will soon be breaking our dependence on foreign oil based fuels and energy. Unfortunately, fossil fuels continue to dry up and the big switch to renewable energy stills feels quite a ways away. As the United States (and much of the world) continues to suck oil from Canada, the Middle East, and other fertile sources, the need for alternative energy is still ever present and will soon need serious consideration. Further research and development of several emerging alternative energy sources could break our addiction to oil, but not until they are given the funding and attention they need to become feasible on the consumer market. Following are several alternative energy sources not currently in widespread use and the needs they are purported to fill.
Cold fusion energy is a renewable energy source derived from the nuclear fusing of atoms. Cold fusion is so-called because it happens at near room temperature, whereas regular fusion reactions occur at intensely hot temperatures, such as the center of a star. Scientists have been researching the technology since the 1980's with the hope of one day constructing a cold fusion power plant, but thus far no such facility has been built. One of the most promising attempts thus far has come from the U.S. Navy's Space and Naval Warfare Systems Center (SPAWAR) who spoke at a 2004 American Chemical Society conference, claiming to have found evidence for nuclear fusion within a cold fusion cell design. The evidence was controversial however, and cold fusion technology is still a ways off from being commercially feasible.
Arguably the most cutting edge research into alternative energy involves generating power from gravity and space. Zero-point energy, as it is called, is theoretically available for the taking, provided that scientists can develop an efficient way to extract it from the vacuum flux of space. While the specifics of this technology are far too abstruse for the layman to grasp, there are several quantum physicists currently working on harnessing this energy for commercial use. NASA has reached some limitations in rocket-propulsion and has thus been looking into the possibility of using magnetic energy to power their spacecraft. Other possible uses of zero-point energy could lead to the production of automobile engines that harness this sort of energy to power themselves. Leading the way in this line of research is Thomas Bearden, President of the Association of Distinguished American Scientists. In a videotaped interview, (quoted from AltEnergy.org) Bearden states that "there is no doubt [these] engines exist and their release for public use will revolutionize society."
Energy scientists have begun investigating the possibility of extracting power from the lunar pull of the Earth's oceans. In order to generate power from the seas, turbine dams would have to be placed in strategic locations where the pull of the changing tide is strongest. Such technology would consume no fuel and, so long as there was water in the ocean, would provide clean, renewable energy for our consumption needs. Energy-Consumers-Edge.com points out several current obstacles facing the use of this kind of power, chief among them the intermittent changing of the tides. Since the tides only change twice a day, slowing down and speeding up as they come and go, the power generated by a tidal dam would be inconsistant. Additionally, the U.S Department of Energy (DOE) reports that America does not currently operate any tidal power plants because cost of building a them is higher than the expected energy yield justifies. The DOE remains optimistic about the future of tidal power however, predicting that "Newly developed tidal turbines may prove ultimately to be the least environmentally damaging of the tidal power technologies because they don't block migratory paths [of sea-life]."
Biomass fuels are a slowly emerging alternative energy source that has several important uses including heating and electricity generation. Biomass fuels are harvested from decomposing garbage, corn, and other vegetation. As these substances break down they produce methane gas, which can be captured through pipes and burned to produce heat and energy. Currently, biomass stoves are sold at the consumer level as a replacement for traditional gas and electric stoves (which still rely on fossil fuels to run), but have not caught on at a significant level. These units burn biomass pellets which are made from corn husk and various other plant matter. In order to encourage the use of biomass stoves, Energy Star is now offering a significant tax rebate to any consumer willing to make the switch.
Vegetable oil is natural energy source produced by plants. The common kitchen ingredient has been found to be a much safer, cleaner fuel source than gasoline or diesel, and has actually been shown to run in some diesel engines. With the right adjustments and modifications, anyone with a diesel car or truck could in fact drive on straight vegetable oil instead of fossil fuel. Despite the fact that this practice is currently illegal, some drivers have decided to make the switch anyway. TreeHugger.com quotes one happy veggie-driver boasting about her vegetable oil powered Jetta. "After more than 2,000 miles on veggie oil, there seem to be few disadvantages to the transformation," she says. "My car seems to get slightly better mileage, it seems to run a little more quietly and it has just as much zip as it does on diesel." It may seem impractical to drive this way in current times, but there may come a day where gas pumps serve up vegetable oil, and cars come off the line equipped to drive on this renewable alternative fuel.
Hydrogen power is a newly emerging alternative energy source that possesses the ability to power cars and generate electricity. Hydrogen is formed by the electrolysis of water and can be harnessed for energy purposes by the hydrogen fuel cell. This technology combines hydrogen and oxygen to make water, and in the process electricity is formed which can be extracted from the cell and put to use. The fuel cell is being developed for use in high-end consumer cars, such as the BMW Hydrogen-7. Aside from the fuel cell, hydrogen fuel can also be burned to produce power. In 2009, Italy opened the world's first hydrogen power plant. The facility outputs 12 megawatts of power without producing any dangerous green house gases.