The mammoth 800-plus meter (2625 ft) tall tower will instantly become one of the world's tallest buildings. Its 200-megawatt power generation capacity will reliably feed the grid with enough power for 150,000 US homes, and once it's built, it can be expected to more or less sit there producing clean, renewable power with virtually no maintenance until it's more than 80 years old. In the video after the jump, EnviroMission CEO Roger Davey explains the solar tower technology, the Arizona project and why he couldn't get it built at home in Australia.
How Solar Towers Work
Enviromission's solar tower is a simple idea taken to gigantic proportions. The sun beats down on a large covered greenhouse area at the bottom, warming the air underneath it. Hot air wants to rise, so there's a central point for it to rush towards and escape; the tower in the middle. And there's a bunch of turbines at the base of the tower that generate electricity from that natural updraft.
It's hard to envisage that sort of system working effectively until you tweak the temperature variables and scale the whole thing up. Put this tower in a hot desert area, where the daytime surface temperature sits at around 40 degrees Celsius (104 F), and add in the greenhouse effect and you've got a temperature under your collector somewhere around 80-90 degrees (176-194 F). Scale your collector greenhouse out to a several hundred-meter radius around the tower, and you're generating a substantial volume of hot air.
Then, raise that tower up so that it's hundreds of meters in the air - because for every hundred metres you go up from the surface, the ambient temperature drops by about 1 degree. The greater the temperature differential, the harder the tower sucks up that hot air at the bottom - and the more energy you can generate through the turbines.
The advantages of this kind of power source are clear:
Because it works on temperature differential, not absolute temperature, it works in any weather;
Because the heat of the day warms the ground up so much, it continues working at night;
Because you want large tracts of hot, dry land for best results, you can build it on more or less useless land in the desert;
It requires virtually no maintenance - apart from a bit of turbine servicing now and then, the tower "just works" once it's going, and lasts as long as its structure stays standing;
It uses no 'feed stock' - no coal, no uranium, nothing but air and sunlight;
It emits absolutely no pollution - the only emission is warm air at the top of the tower. In fact, because you're creating a greenhouse underneath, it actually turns out to be remarkably good for growing vegetation under there.
Although not as efficient as their sailboat, the fourth upgrade to this 1960s hexagonal building in the Netherlands (hence its name Villa 4.0) does ensure that the building's heating, cooling, and lighting will be achieved with the lowest possible energy consumption while also re-establishing its intimacy with the surrounding green plot. More details about the numerous adaptations applied to this naturally illuminated family home after the jump.
The architects stuck to the existing materials as much as possible though certain interventions, such as upgrading the outer walls and roofs, were necessary, as was insulating the building to improve its thermal efficiency. Some windows were also replaced, and inner walls were gutted to set the gaping living room free. The bedroom floors were replaced with bamboo, and skylights filter throughout the house.
Water is heated by the sun and the home via underfloor heating, as well as a very efficient wood-fired stove that is also used for cooking. All of the incandescent lamps were replaced with LED lighting that uses 90% less energy, punching a serious hole in the home’s overall carbon footprint. And for a final unique touch, a pump was installed to extract water from a nearby brook that is then splashed onto Villa 4.0?s roof, cooling the house down before the water loops back to the brook. We haven’t said much about the garden upgrades, but suffice to say this last renovation is certain to last a very long time.
When Rick Simpson first announced he had cured cancer by using his home-grown cannabis oil, it would have been fair to expect fanfares and Nobel prizes at the very least.
Rick Simpson and his home grown cancer treatment
With Cancer expected to directly impact on 1 in 3 of our lives at some stage, it is in its self a huge proportion of the entire healthcare spend. So to suggest here was a substance which could reduce tumors for just a few pence/cents a dose, was big news. Or so you would have thought.
What actually happened beggars belief. Rick Simpson was arrested, branded a snake oil peddlar and cast off from his native Canadian homeland, forced to live in the US under the threat of re-arrest should he return to Canada.
Today however its been announced the cannabis extract marketed by UK based biotech GW Pharmaceuticals is expected to achieve universal approval in the treatment of (wait for it) cancer. Sativex was initially brought to market as a treatment for the spasticity associated with Multiple Sclerosis. But as more evidence becomes available its becoming apparent Rick Simpson was onto something with his cancer treatment.
And with sales for the treatment of cancer expected to double the £150 million pounds it made as a MS treatment when licensing is completed, that would be a fair assumption.
So are the cannabis laws really in place to 'save our children'? Or is there another, entirely more sinister agenda in play?
Read the entire Rick Simpson story, including step-by-step instructions on how to make your own cancer medicine at http://phoenixtears.ca/
It's no wonder that the judges of the Building to Building Pedestrian Bridge International Challenge awarded this mind-blowing, shape-shifting helix bridge by Sanzpont first place. Featuring a tensile fabric that allows the bridge to move as visitors walk across it, it also captures energy from the sun. If that's not enough goodness for our strictest technophiles, check this out: the bridge also lights up at night with linear LED technology, and purifies the air in its immediate environment.
How does a moving bridge produce energy? With foldable photovoltaic panels of course; but Sanzpont, which has been featured on Inhabitat several times in the past, is never satisfied with the bare minimum, so they raised this design’s artistic appeal and sustainbability a few notches.
A bridge with many personalities, the daytime energy-generator acts as a night time art exhibit when linear LED lights illuminate the bridge, giving it a low-energy, futuristic glow. And then, just in case we become too techy and alienated from nature, Sanzpont has incorporated plants into the design to ensure that the bridge would also purify the air in its surrounding environment. This final touch rounds off the design’s low environmental impact, albeit at what must be a staggering financial cost. Even so, Sanzpont has knocked our socks off once again with their incredible vision.
Ultraviolet semiconductor diode lasers are widely used in data processing, information storage and biology. Their applications have been limited, however, by size, cost and power. The current generation of ultraviolet lasers is based on a material called gallium nitride, but Jianlin Liu, a professor of electrical engineering, and his colleagues have made a breakthrough in zinc oxide nanowire waveguide lasers, which can offer smaller sizes, lower costs, higher powers and shorter wavelengths.
Until now, zinc oxide nanowires couldn't be used in real world light emission applications because of the lack of p-type, or positive type, material needed by all semiconductors. Liu solved that problem by doping the zinc oxide nanowires with antimony, a metalloid element, to create the p-type material.
The p-type zinc oxide nanowires were connected with n-type, or negative type, zinc oxide material to form a device called p-n junction diode. Powered by a battery, highly directional laser light emits only from the ends of the nanowires.
"People in the zinc oxide research community throughout the world have been trying hard to achieve this for the past decade," Liu said. "This discovery is likely to stimulate the whole field to push the technology further."
Liu's findings have been published in the July issue of Nature Nanotechnology. Co-authors are: Sheng Chu, Guoping Wang, Jieying Kong, Lin Li and Jingjian Ren, all graduate students at UC Riverside; Weihang Zhou, a student at Fudan University in China; Leonid Chernyak, a professor of physics at the University of Central Florida; Yuqing Lin, a graduate student at the University of Central Florida; and Jianze Zhao, a visiting student from Dalian University of Technology in China.
The discovery could have a wide-range of impacts.
For information storage, the zinc oxide nanowire lasers could be used to read and process much denser data on storage media such as DVDs because the ultraviolet has shorter wavelength than other lights, such as red. For example, a DVD that would store two hours of music could store four or six hours using the new type of laser.
For biology and medical therapeutics, the ultra-small laser light beam from a nanowire laser can penetrate a living cell, or excite or change its function from a bad cell to a good cell. The light could also be used to purify drinking water.
For photonics, the ultraviolet light could provide superfast data processing and transmission. Reliable small ultraviolet semiconductor diode lasers may help develop ultraviolet wireless communication technology, which is potentially better than state-of-the-art infrared communication technologies used in various electronic information systems.
While Liu and the students in his laboratory have demonstrated the p-type doping of zinc oxide and electrically powered nanowire waveguide lasing in the ultraviolet range, he said more work still needs to be done with the stability and reliability of the p-type material.
In the long term the technology could be used by customers to design many different products themselves -- tailor-made to their needs and preferences.
Using new digital technology the printer allows you to create your own designs on a computer and reproduce them physically in three dimensional form in chocolate.
The project is funded as part of the Research Council UK Cross-Research Council Programme -- Digital Economy and is managed by the Engineering and Physical Sciences Research Council (EPSRC) on behalf of ESRC, AHRC and MRC. It is being led by the University of Exeter in collaboration with the University of Brunel and software developer Delcam.
3-D printing is a technology where a three dimensional object is created by building up successive layers of material. The technology is already used in industry to produce plastic and metal products but this is the first time the principles have been applied to chocolate.
The research has presented many challenges. Chocolate is not an easy material to work with because it requires accurate heating and cooling cycles. These variables then have to be integrated with the correct flow rates for the 3-D printing process. Researchers overcame these difficulties with the development of new temperature and heating control systems.
Research leader Dr Liang Hao, at the University of Exeter, said: "What makes this technology special is that users will be able to design and make their own products. In the long term it could be developed to help consumers custom- design many products from different materials but we've started with chocolate as it is readily available, low cost and non-hazardous. There is also no wastage as any unused or spoiled material can be eaten of course! From reproducing the shape of a child's favourite toy to a friend's face, the possibilities are endless and only limited by our creativity."
A consumer- friendly interface to design the chocolate objects is also in development. Researchers hope that an online retail business will host a website for users to upload their chocolate designs for 3-D printing and delivery.
Designs need not start from scratch, the web- based utility will also allow users to see designs created by others to modify for their own use.
Dr Hao added: "In future this kind of technology will allow people to produce and design many other products such as jewellery or household goods. Eventually we may see many mass produced products replaced by unique designs created by the customer."
EPSRC Chief Executive Professor Dave Delpy said: "This is an imaginative application of two developing technologies and a good example of how creative research can be applied to create new manufacturing and retail ideas. By combining developments in engineering with the commercial potential of the digital economy we can see a glimpse into the future of new markets -- creating new jobs and, in this case, sweet business opportunities."
The batteries in a standard pacemaker, for instance, are said to last for about eight years - after that, surgery is required to access the device. Implants such as heart pumps are often powered by batteries that can be recharged from outside the body, but these require a power cord that protrudes through the patient's skin, and that keeps them from being able to swim or bathe. Now, however, scientists at Germany's University of Freiburg are developing biological fuel cells, that could draw power for implants from the patient's own blood sugar.
The research team is being led by Dr. Sven Kerzenmacher, of Freiburg's Department of Microsystems Engineering. They are looking into the use noble metal catalysts, such as platinum, to trigger a continuous electrochemical reaction between glucose in the blood and oxygen from the surrounding tissue fluid. The use of platinum (or a similar metal) would be ideal, as the material exhibits long-term stability, it can be sterilized, and electrodes made from it wouldn't be sensitive to unwanted chemical reactions, including hydrolysis and oxidation.
The Freiburg scientists are ultimately hoping that the surfaces of implants could be covered with a thin coating of the fuel cells, which would then power the devices indefinitely.
Geologists have used temperature measurements from more than 20,000 boreholes around the world to estimate that some 44 terawatts (44 trillion watts) of heat continually flow from Earth's interior into space. Where does it come from?
Radioactive decay of uranium, thorium, and potassium in Earth's crust and mantle is a principal source, and in 2005 scientists in the KamLAND collaboration, based in Japan, first showed that there was a way to measure the contribution directly. The trick was to catch what Kamioka Liquid-scintillator Antineutrino Detector (KamLAND) dubbed geoneutrinos – more precisely, geo-antineutrinos – emitted when radioactive isotopes decay.
"As a detector of geoneutrinos, KamLAND has distinct advantages," says Stuart Freedman of the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), which is a major contributor to KamLAND. Freedman, a member of Berkeley Lab's Nuclear Science Division and a professor in the Department of Physics at the University of California at Berkeley, leads U.S. participation. "KamLAND was specifically designed to study antineutrinos. We are able to discriminate them from background noise and detect them with very high sensitivity."
KamLAND scientists have now published new figures for heat energy from radioactive decay in the journal Nature Geoscience. Based on the improved sensitivity of the KamLAND detector, plus several years' worth of additional data, the new estimate is not merely "consistent" with the predictions of accepted geophysical models but is precise enough to aid in refining those models.
One thing that's at least 97-percent certain is that radioactive decay supplies only about half the Earth's heat. Other sources – primordial heat left over from the planet's formation, and possibly others as well – must account for the rest.
Hunting for neutrinos from deep in the Earth
Antineutrinos are produced not only in the decay of uranium, thorium, and potassium isotopes but in a variety of others, including fission products in nuclear power reactors. In fact, reactor-produced antineutrinos were the first neutrinos to be directly detected (neutrinos and antineutrinos are distinguished from each other by the interactions in which they appear).
The KamLAND anti-neutrino detector is a vessel filled with scintillating mineral oil and lined with photomultiplier tubes (inset), the largest scintillation detector ever constructed, buried deep underground near Toyama, Japan. Credit: KamLAND Collaboration
Because neutrinos interact only by way of the weak force – and gravity, insignificant except on the scale of the cosmos – they stream through the Earth as if it were transparent. This makes them hard to spot, but on the very rare occasions when an antineutrino collides with a proton inside the KamLAND detector – a sphere filled with a thousand metric tons of scintillating mineral oil – it produces an unmistakable double signal.
The first signal comes when the antineutrino converts the proton to a neutron plus a positron (an anti-electron), which quickly annihilates when it hits an ordinary electron – a process called inverse beta decay. The faint flash of light from the ionizing positron and the annihilation process is picked up by the more than 1,800 photomultiplier tubes within the KamLAND vessel. A couple of hundred millionths of a second later the neutron from the decay is captured by a proton in the hydrogen-rich fluid and emits a gamma ray, the second signal. This "delayed coincidence" allows antineutrino interactions to be distinguished from background events such as hits from cosmic rays penetrating the kilometer of rock that overlies the detector.
Says Freedman, "It's like looking for a spy in a crowd of people on the street. You can't pick out one spy, but if there's a second spy following the first one around, the signal is still small but it's easy to spot."
KamLAND was originally designed to detect antineutrinos from more than 50 reactors in Japan, some close and some far away, in order to study the phenomenon of neutrino oscillation. Reactors produce electron neutrinos, but as they travel they oscillate into muon neutrinos and tau neutrinos; the three "flavors" are associated with the electron and its heavier cousins.
Being surrounded by nuclear reactors means KamLAND's background events from reactor antineutrinos must also be accounted for in identifying geoneutrino events. This is done by identifying the nuclear-plant antineutrinos by their characteristic energies and other factors, such as their varying rates of production versus the steady arrival of geoneutrinos. Reactor antineutrinos are calculated and subtracted from the total. What's left are the geoneutrinos.
Tracking the heat
All models of the inner Earth depend on indirect evidence. Leading models of the kind known as bulk silicate Earth (BSE) assume that the mantle and crust contain only lithophiles ("rock-loving" elements) and the core contains only siderophiles (elements that "like to be with iron"). Thus all the heat from radioactive decay comes from the crust and mantle – about eight terawatts from uranium 238 (238U), another eight terawatts from thorium 232 (232Th), and four terawatts from potassium 40 (40K).
KamLAND's double-coincidence detection method is insensitive to the low-energy part of the geoneutrino signal from 238U and 232Th and completely insensitive to 40K antineutrinos. Other kinds of radioactive decay are also missed by the detector, but compared to uranium, thorium, and potassium are negligible contributors to Earth's heat.
Additional factors that have to be taken into account include how the radioactive elements are distributed (whether uniformly or concentrated in a "sunken layer" at the core-mantle boundary), variations due to radioactive elements in the local geology (in KamLAND's case, less than 10 percent of the expected flux), antineutrinos from fission products, and how neutrinos oscillate as they travel through the crust and mantle. Alternate theories were also considered, including the speculative idea that there may be a natural nuclear reactor somewhere deep inside the Earth, where fissile elements have accumulated and initiated a sustained fission reaction.
KamLAND detected 841 candidate antineutrino events between March of 2002 and November of 2009, of which about 730 were reactor events or other background. The rest, about 111, were from radioactive decays of uranium and thorium in the Earth. These results were combined with data from the Borexino experiment at Gran Sasso in Italy to calculate the contribution of uranium and thorium to Earth's heat production. The answer was about 20 terawatts; based on models, another three terawatts were estimated to come from other isotope decays.
This is more heat energy than the most popular BSE model suggests, but still far less than Earth's total. Says Freedman, "One thing we can say with near certainty is that radioactive decay alone is not enough to account for Earth's heat energy. Whether the rest is primordial heat or comes from some other source is an unanswered question."
Better models are likely to result when many more geoneutrino detectors are located in different places around the globe, including midocean islands where the crust is thin and local concentrations of radioactivity (not to mention nuclear reactors) are at a minimum.
Says Freedman, "This is what's called an inverse problem, where you have a lot of information but also a lot of complicated inputs and variables. Sorting those out to arrive at the best explanation among many requires multiple sources of data."
Jan Kleissl, a professor of environmental engineering at the UC San Diego Jacobs School of Engineering.
In a study in an upcoming issue of the journal Solar Energy, Kleissl and his team published what they believe are the first peer-reviewed measurements of the cooling benefits provided by solar photovoltaic panels. Using thermal imaging, researchers determined that during the day, a building’s ceiling was 5 degrees Fahrenheit cooler under solar panels than under an exposed roof. At night, the panels help hold heat in, reducing heating costs in the winter.
“Talk about positive side-effects,” said Kleissl.
As solar panels sprout on an increasing number of residential and commercial roofs, it becomes more important to consider their impact on buildings’ total energy costs, Kleissl said. His team determined that the amount saved on cooling the building amounted to getting a 5 percent discount on the solar panels’ price, over the panels’ lifetime. Or to put it another way, savings in cooling costs amounted to selling 5 percent more solar energy to the grid than the panels are actually producing— for the building researchers studied.
Data for the study was gathered over three days in April on the roof of the Powell Structural Systems Laboratory at the Jacobs School of Engineering with a thermal infrared camera. The building is equipped with tilted solar panels and solar panels that are flush with the roof. Some portions of the roof are not covered by panels.
The panels essentially act as roof shades, said Anthony Dominguez, the graduate student lead on the project. Rather than the sun beating down onto the roof, which causes heat to be pushed through the roof and inside the ceiling of the building, photovoltaic panels take the solar beating. Then much of the heat is removed by wind blowing between the panels and the roof. The benefits are greater if there is an open gap where air can circulate between the building and the solar panel, so tilted panels provide more cooling. Also, the more efficient the solar panels, the bigger the cooling effect, said Kleissl. For the building researchers analyzed, the panels reduced the amount of heat reaching the roof by about 38 percent.
Although the measurements took place over a limited period of time, Kleissl said he is confident his team developed a model that allows them to extrapolate their findings to predict cooling effects throughout the year.
For example, in winter, the panels would keep the sun from heating up the building. But at night, they would also keep in whatever heat accumulated inside. For an area like San Diego, the two effects essentially cancel each other out, Kleissl said.
The idea for the study came about when Kleissl, Dominguez and a group of undergraduate students were preparing for an upcoming conference. They decided the undergraduates should take pictures of Powell’s roof with a thermal infrared camera. The data confirmed the team’s suspicion that the solar panels were indeed cooling the roof, and the building’s ceiling as well.
“There are more efficient ways to passively cool buildings, such as reflective roof membranes,” said Kleissl. “But, if you are considering installing solar photovoltaic, depending on your roof thermal properties, you can expect a large reduction in the amount of energy you use to cool your residence or business.”
The study was funded by a NASA Graduate Student Research Program fellowship. Kleissl’s research is funded by the National Science Foundation, California Public Utilities Commission, the Department of Energy and the California Energy Commission. The authors thank the staff of the Powell Structural Lab, especially Andrew Gunthardt, for making the building available for the study.If additional funding became available, Kleissl said his team could develop a calculator that people could use to predict the cooling effect on their own roof and in their own climate-specific area. To further increase the accuracy of their models, researchers also could compare two climate-controlled, identical buildings in the same neighborhood, one with solar panels, the other without.