Tag: space-based solar power (SBSP)

Powered by the Sun: Breakthrough Solar Cells

solar1In addition to becoming cheaper, and increasing in efficiency and yields, solar cell technology is also growing in terms of innovative design. By going beyond the conventional design of silicon panels and electrical cables, researchers are ensuring that solar technology can go farther. And the latest advances in design are especially far-sighted, aiming to merge solar technology with just about any surface, and even sending it into space.

In the former case, researchers at Michigan State University have created a fully transparent solar concentrator, which could turn any window or sheet of glass – from highrise buildings to the screens on smartphones and tablets – into a photovoltaic solar cell. And whereas other “transparent” solar panels have been designed in the past, this one is the first that truly lives up to the word.

transparent-solar-cellScientifically, a transparent solar panel is something of an oxymoron. Solar cells, specifically the photovoltaic kind, make energy by absorbing photons and converting them into electrons. If a material is transparent, by definition it means that all of the light passes through the medium. This is why previous transparent solar cells have actually only been partially transparent, and usually cast a colorful shadow.

To get around this limitation, the Michigan State researchers use a slightly different technique for gathering sunlight. Instead of trying to create a transparent photovoltaic cell, they used a transparent luminescent solar concentrator (TLSC), which consists of organic salts that absorb specific non-visible wavelengths of ultraviolet and infrared light, which they then luminesce (glow) as another wavelength of infrared light (also non-visible).

https://i0.wp.com/www.extremetech.com/wp-content/uploads/2014/08/transparent-luminescent-solar-concentrator-colorful.jpgThis emitted infrared light is guided to the edge of plastic, where thin strips of conventional photovoltaic solar cell convert it into electricity. Currently, the Michigan TLSC has an efficiency of around 1%, but they think 5% should be possible. On their own, these aren’t huge figures, but on a larger scale — every window in a house or office block — the numbers quickly add up to a significant electrical yield.

Moreover, the researchers are confident that the technology can be scaled all the way from large industrial and commercial applications, down to consumer devices, while remaining “affordable.” So far, one of the larger barriers to large-scale adoption of solar power is the intrusive and ugly nature of solar panels. But if large amounts of solar power can be produced from sheets of glass and plastic, it would go a long way to making the scaling process feasible.

solar_panel_origamiAnother major innovation comes from Brigham Young University, where researchers have been working with NASA’s Jet Propulsion Laboratory to address the challenge of Space-Based Solar Power. For some time, scientists have understood that a solar array in orbit of Earth would be ideally suited for solar power collection, since it would be immune to weather, cloud cover or diurnal cycles (aka. nighttime).

Unfortunately, getting solar cells into space is a bit of a problem. In order to be effective, solar panels need to be thin have a large surface area to soak up more rays. This makes it difficult to transport them into orbit, and requires that they be broken down,and flown up piece by piece, and then assembled once in orbit. Given the cost of mounting a sending a single rocket into orbit, this prospect becomes very costly very fast.

solar_panel_origami1However, the Brigham team came up with a simple and elegant solution to this problem, and found it in the form of origami. By working with complex origami folds, they were able to design a solar array that can shrink down to one-tenth of its original size. Folded up, the device is 2.7 meters (8.9 feet) across and can easily wrap around a spacecraft. Once it reaches space, the array would then unfold to become as wide as 25 meters (82 feet).

Given that solar panels deal with large, flat, thin structures, the origami concept seems like a natural fit. And this is not the first time that it has been used in space equipment design – in the 1990’s, Japanese astrophysicist Koryo Miura created a prototype for another folding solar panel. However, that project was abandoned for various reasons, not the least of which was lack of funding.

space-solar-headTo make the concept work and renew interest in the application, he Brigham team worked with Robert Lang, a world-renowned origami expert who also happens to be a mathematician and engineer and once worked at JPL himself. As Brian Trease, a mechanical engineer at the Jet Propulsion Laboratory, said:

He was trained as a physicist, used to work at JPL, and then got tired of the formal bureaucracy and left to start folding paper. Now he’s a world expert… We see value in going directly to any artist, even if they don’t have his credentials, because they have the thousands of hours or folding and tinkering to realize what can and can’t be done. Anytime you can bring in other disciplines, they just visualize things differently and bring in different solutions to your problems.

The new solar panels could be used to power spacecraft and potentially also on orbiting power stations that could wirelessly send energy to Earth via microwaves. A similar design could also be used on Earth to provide new options for portable solar power in remote locations. The same type of design might also be used in architecture or product design because of its unusual looks and function.

NASA_suntowerAccording to Trease, the Department of Defense has already been in touch with them regarding applications for soldiers in the field:

Soldiers right now might carry around 100 pounds, 15 of those pounds are batteries and fuel. If you can eliminate that, you’ve dramatically reduced their load… It’s different from opening an umbrella, because it can accommodate rigid material. You could do something like a deployable glass chandelier or a table. When it’s deployed, it looks like a flower blooming–it’s got a nice aesthetic to it.

In the next few weeks, Trease will also meet with other experts to consider different potential applications for space equipment, like antennas and reflectors, that could also deploy using origami. And given the rapidly-dropping prices associated with placing objects into orbit, this could prove to be the basis for the dream of Space-Based Solar Power – where all our energy needs are met by solar arrays in orbit that then beam them to Earth.

 

Source: extremetech.com, fastcoexist.com

The Future of Solar: The Space-Based Solar Farm

space-solar-headThe nation of Japan has long been regarded as being at the forefront of emerging technology. And when it comes to solar energy, they are nothing if not far-sighted and innovative. Whereas most nations are looking at building ground-based solar farms in the next few years, the Japanese are looking at the construction of vast Lunar and space-based solar projects that would take place over the course of the next few decades.

The latest proposal comes from the Japan Aerospace Exploration Agency (JAXA), which recently unveiled a series of pilot projects which, if successful, should culminate in a 1-gigawatt space-based solar power generator within just 25 years. Relying on two massive orbital mirrors that are articulated to dynamically bounce sunlight onto a solar panel-studded satellite, the energy harvested would then be beamed wirelessly to Earth using microwaves, collected Earth-side by rectifying antennas at sea, and then passed on to land.

lunaringJAXA has long been the world’s biggest booster of space-based solar power technology, making significant investments in research and rallying international support for early test projects. And in this respect, they are joined by private industries such as the Shimizu Corporation, a Japanese construction firm that recently proposed building a massive array of solar cells on the moon – aka. the “Lunar Ring” – that could beam up to 13,000 terawatts (roughly two-thirds of global power consumption) to Earth around the clock.

Considering that Japan has over 120 million residents packed onto an island that is roughly the size of Montana, this far-sighted tendency should not come as a surprise.  And even before the Fukushima disaster took place, Japan knew it needed to look to alternative sources of electricity if it was going to meet future demands. And considering the possibilities offered by space-based solar power, it should also come as no surprise that Japan – which has very few natural resources – would look skyward for the answer.

solar_array1Beyond Japan, solar power is considered the of front runner of alternative energy, at least until s fusion power comes of age. But Until such time as a fusion reaction can be triggered that produces substantially more energy than is required to initiate it, solar will remain the only green technology that could even theoretically provide for our global power demands. And in this respect, going into space is seen as the only way of circumventing the problems associated with it.

Despite solar power being in incredible abundance – the Earth’s deserts absorb more energy in a day than the human race uses in an entire year – the issue of harnessing that power and getting it to where it is needed remain as stumbling blocks. Setting up vast arrays in the Earth’s deserts would certainly deal with the former, but transmitting it to the urban centers of the world (which are far removed from it’s deserts) would be both expensive and impractical.

space-based-solarpowerLuckily, putting arrays into orbit solves both of these issues. Above the Earth’s atmosphere, they would avoid most forms of wear, the ground-based day/night cycle, and all occluding weather formations. And assuming the mirrors themselves are able to reorient to be perpetually aimed at the sun (or have mirrors to reflect the light onto them), the more optimistic estimates say that a well-designed space array could bring in more than 40 times the energy of a conventional one.

The only remaining issue lies in beaming all that energy back to Earth. Though space-based arrays can easily collect more power above the atmosphere than below it, that fact becomes meaningless if the gain is immediately lost to inefficiency during transmission. For some time, lasers were assumed to be the best solution, but more recent studies point to microwaves as the most viable solution. While lasers can be effectively aimed, they quickly lose focus when traveling through atmosphere.

spaceX_solararrayHowever, this and other plans involving space-based solar arrays (and a Space Elevator, for that matter) assume that certain advances over the next 20 years or so – ranging from light-weight materials to increased solar efficiency. By far the biggest challenge though, or the one that looks to be giving the least ground to researchers, is power transmission. With an estimated final mass of 10,000 tonnes, a gigawatt space solar array will require significant work from other scientists to improve things like the cost-per-kilogram of launch to orbit.

It currently costs around $20,000 to place a kilogram (2.2lbs) into geostationary orbit (GSO), and about half that for low-Earth orbit (LEO). Luckily, a number of recent developments have been encouraging, such as SpaceX’s most recent tests of their Falcon 9R reusable rocket system or NASA’s proposed Reusable Launch Vehicle (RLV). These and similar proposals are due to bring the costs of sending materials into orbit down significantly – Elon Musk hopes to bring it down to $1100 per kilogram.

So while much still needs to happen to make SBSP and other major undertakings a reality, the trends are encouraging, and few of their estimates for research timelines seem all that pie-eyed or optimistic anymore.

Sources: extremetech.com, (2)

Towards a Cleaner Future: Solar and Wind Drones

solar_cell_galliumWith supplies of easily accessible fossil fuels diminishing, pushing us towards dirtier sources of oil and natural gas (such as tar sands and frakking), researchers are looking for ways to make renewable energy more efficient and accessible. Towards this end, they are pushing the boundaries of solar cells and wind turbines are capable of, but the constraints of land and weather limit where vast solar or wind farms can be set up.

Luckily, a UK-based company known as New Wave Energy has spent the last few years developing the technology to produce an army of power-generating drone aircraft to overcome these very problems. Basically, each craft is a 20x20m (65ft) flat surface fitted with solar panels and turbines to generate power from the sun and wind, and four small propellers that keep it aloft.

solar_dronesThe drones would be capable of flying at altitudes of up to 15,240 meters (50,000 feet), putting them far above the clouds that can obscure the sun. The propellers would allow the craft to track the course of the sun to remain in optimal position for as long as possible. At these altitudes, the wind is also more consistent and powerful, which means smaller turbines can be used in place of the giant towers necessary down near the ground.

In terms of transmitting that power, the key is in the use of microwaves. In essence, power from the drones would be beamed down as a low-energy microwave and collected by antenna arrays on the ground. These antennas can then be used to turn the electromagnetic radiation into usable DC power and then send it to where it is needed.

solar_drones1One of the benefits of this design is that the proposed drone power plants wouldn’t need to land to refuel themselves. Supposedly, they will be able to power themselves entirely with the energy generated on-board, and still produce 50kW of power. This that means several thousand drones would be needed to power a large city of 205,000 homes.

However, these swarms of robotic power plants aren’t just a way to replace the power infrastructure we already have. They could be used to augment our current power supplies as demand increases, removing the need to expand on large, expensive power plants. Also, they bring power to remote areas with poor service, or to restore power in regions affected by natural disasters.

solar_panelThus, the cost of building and deploying the drones will determine whether or not that’s feasible. At present, the company plans to raise about $500,000 on Kickstarter to fund the construction of a prototype for testing and marketing. If this campaign does turn out to be successful, the first flying power plant could be aloft within six months.

Combined with other improvements that are making wind and solar power more efficient and affordable, and future prospects for space-based solar power (SBSP) that are being made possible thanks to space startups like Google X, we could be looking at a near-future where solar and wind meet the lion’s share of our energy requirements.

Source: extremetech.com

Climate Crisis: Illustrative Video of Impending Disaster

IPCC2012_vid3Recently, the United Nation’s Intergovernmental Panel on Climate Change released its 2012 report, which contained some rather stark observations and conclusions. In addition to reconfirming what the 2007 report said about the anthropogenic effects of CO2 emissions, the report also tackled speculation about the role of Solar Forcing and Cosmic Rays in Global Warming, as well as why warming has been proceeding slower than previously expected.

In the end, the report concluded that certain natural factors, such as the influence of the Sun and Cosmic Rays in “seeding clouds”, were diminishing, and thus have a negative effect on the overall warming situation. In spite of that, global temperatures continue to increase, due to the fact that humanity’s output of greenhouse gases (particularly CO2) has not slowed down one bit in recent years.

IPCC2012_vidThe report also goes on to explain detailed scenarios of what we can expect in the coming decades, in extreme and extensive detail. However, for those who have neither the time, patience, or technical knowledge that wade through the report, a helpful video has been provided. Courtesy of Globaia,this four minute video sums up the facts about Climate Change and how it is likely to impact Earth’s many inhabitants, human and otherwise.

Needless to say, the facts are grim. By 2050, if humans remain on their current path, global temperatures will rise more than two degrees Celsius above what it’s been for most of human history. By 2100, it might even climb four degrees. The IPCC report, and this video, confirm what we’ve been hearing everywhere. Arctic sea ice is disappearing, sea levels are rising, storms are getting more destructive, and the full extent of change is not even fully known.

IPCC2012_vid6As the organization that put together this data visualization along with other scientists, Globaia says that it created this video as a call to action for policymakers. Felix Pharand-Deschenes, who founded the Canadian nonprofit company and animated the video, claims that:

If we are convinced of the seriousness of the situation, then political actions and technological fixes will result,” says  “But we have to change our minds first. This is the reason why we try to translate our terrestrial presence and impacts into images–along with the physical limits of our collective actions.

But of course, there’s still hope. As Pharand-Deschenes went on to say, if we can summon up a “war effort,” and work together the way World War II-era citizens did, we could still manage to the social systems that are largely responsible for the problem. This includes everything from transportation and energy to how we grow our food, enough to stay below a two degree rise.

IPCC2012_vid5Of course, this is no small task. But as I love to remind all my readers, research and efforts are happening every day that is making this a reality. Not only is solar, wind and tidal power moving along by leaps and bounds, becoming profitable as well as affordable, we are making great strides in terms of Carbon Capture technology, alternative fuels, and eco-friendly living that are expected to play a huge role in the coming decades.

And though it is often not considered, the progress being made in space flight and exploration also play a role in saving the planet. By looking to make the process of sending ships and satellites into space cheaper, concepts like Space-Based Solar Power (SBSP) can become a reality, one which will meet humanity’s immense power demands in a way that is never marred by weather or locality.

IPCC2012_vid4Combined with sintering and 3-D printing, asteroid prospecting and mining could become a reality too in a few decades time. Currently, it is estimated that just a few of the larger rocks beyond the orbit of Mars would be enough to meet Earth’s mineral needs indefinitely. By shifting our manufacturing and mining efforts offworld with the help of automated robot spacecraft and factories, we would be generating far less in the way of a carbon footprint here on Earth.

But of course, the question of “will it be enough” is a burning one. Some scientists say that an increase of even two degrees Celsius is more than Earth’s creatures can actually handle. But most agree that we need to act immediately to prepare for the future, and that one of the things standing in the way of action is the fact that the problem seems so abstract. Luckily, informational videos like this one present the problem is clear and concise terms.

ipcc2012_vid1The IPCC reports that we only have 125 billion tons of CO2 left to burn before reaching the tipping point, and at current rates, that could happen in just over two decades. Will we have a fully renewable-powered, zero-carbon world by then? Who knows? The point is, if we can get such a task underway by then, things may get worse before they get better, but they will improve in the end. Compared to the prospect of extinction, that seems like a bargain!

In the meantime, check out the video – courtesy of Globaia and the International Geosphere-Biosphere Programme (IGBP) – and try to enjoy it despite its gloomy predictions. I assure you, it is well worth it!


Source: fastcoexist.com

 

Powered by the Sun: Nanotech Solar Cells

???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????With every passing year, interest in solar power has been growing by leaps and bounds. Given the impacts of Climate Change, widespread droughts, tropical storms, wildfires and increasing global temperatures, this should not come as a surprise. But an equally important factor in the adoption of clean energy alternatives has to do with improvements that are being made which will make it more efficient, accessible, and appealing to power companies and consumers.

Three such recent developments come to us from Standford, MIT, and the Neils Bohr Institute, respectively; where researchers have announced new ways using nanoprocesses to boost the yield of individual solar cells. In addition to cutting costs associated with production, installation, and storage, increasing the overall electrical yield of solar cells is a major step towards their full-scale implementation.

solar_nanoFirst, there’s MIT’s new concept for a solar cell, which uses nanowires to massively boost the efficiency of quantum dot photovoltaic cells. Quantum dots – which are basically nano-sized crystals of a semiconducting material – are already being considered as an alternative to conventional silicon cells, since they are cheaper and easier to produce.

However, until recently they have been a letdown in the efficiency department, lagging significantly behind their silicon counterparts. By merging zinc oxide nanowires into the design of their quantum dot photovoltaic cells, the MIT researchers were able to boost the current produced by 50%, and overall efficiency by 5%.  Ultimately, their goal is to get that up to 10%, since that is considered to be the threshold for commercial adoption.

gallium-arsenide-nanowire-solar-cellMeanwhile, researchers at the Niels Bohr Institute in Denmark and EPFL in Switzerland announced that they have built solar cells out of single nanowires. In this case, the process involved growing gallium-arsenide (GaAs) wires on a silicon substrate, and then completing the circuit with a transparent indium tin oxide electrode, which are currently employed in the creation of photovoltaic cells and LEDs on the market today.

Prior to these development, nanowires were being researched mainly in conjunction with computer chips as a possible replacement for silicon. But thanks to the combined work of these researchers, we may very well be looking at solar cells which are not only hair-thin (as with the kind being developed by Penn State University) but microscopically thin. And much like the research at the University of Oslo involving the use of microbeads, this too will mean the creation of ultra-thin solar cells that have a massive energy density – 180 mA/cm2, versus ~40 mA/cm2 for crystalline silicon PVs.

solar_boosterAnd last, but not least, there was the announcement from Stanford University of a revolutionary new type of solar cell that has doubled the efficiency of traditional photovoltaic cells. This new device uses a process called photon-enhanced thermionic emission (PETE) that allows for the absorption of not only light, but heat. This combination makes this new type of cell the equivalent of a turbocharged solar panel!

pete-photovoltaic-thermionic-diagram-stanfordIn conventional cells, photons strike a semiconductor (usually silicon), creating electricity by knocking electrons loose from their parent atoms. The PETE process, on the other hand, uses the gallium arsenide wafer on top gather as much sunlight as possible, creating a lot of excited electrons using the photovoltaic effect. The underside, which is composed of nanoantennae, emits these photoexcited electrons across a vacuum to the anode with gathers them and turns them into an electrical current.

Beneath the anode is a of heat pipe that collects any leftover heat which could be used elsewhere. One of the easiest applications of PETE would be in concentrating solar power plants, where thousands of mirrors concentrate light on a central vat of boiling water, which drives a steam turbine. By concentrating the light on PETE devices instead, Stanford estimates that their power output could increase by 50%, bringing the cost of solar power generation down into the range of fossil fuels.

Though there are still kinks in their design – the cell has a very low 2% rate of energy efficient thus far – the researchers at Stanford are making improvements which are increasing its efficiency exponentially. And although their planned upgrades should lead to a solar cell capable of operating in extremely hot environments, they stress that the goal here is to build one that is capable of gathering power in non-desert environments, such as Spaced-Based solar arrays.

Combined with improved production methods, storage capacities, and plans to mount solar arrays in a variety of new places (such as on artificial islands), we could be looking at the wholesale adoption of solar power within a few years time. Every day, it seems, new methods are being unveiled that will allow Solar to supplant fossil fuels as the best, cheapest and most efficient means of energy production. If all goes as planned, all this could be coming just in time to save the planet, fingers crossed!

Sources: Extremetech.com, (2)

Powered by the Sun: The Future of Solar Energy

Magnificent CME Erupts on the Sun - August 31Researchers continue to work steadily to make the dream of abundant solar energy a reality. And in recent years, a number of ideas and projects have begun to bear fruit. Earlier this year, their was the announcement of a new kind of “peel and stick” solar panel which was quite impressive. Little did I know, this was just the tip of the iceberg.

Since that time, I have come across four very interesting stories that talk about the future of solar power, and I feel the need to share them all! But, not wanting to fill your page with a massive post, I’ve decided to break them down and do a week long segment dedicated to emerging solar technology and its wicked-cool applications. So welcome to the first installment of Powered By The Sun!

spaceX_solararrayThe first story comes to us by way of SpaceX, Deep Space Industries, and other commercial space agencies that are looking to make space-based solar power (SBSP) a reality. For those not familiar with the concept, this involves placing a solar farm in orbit that would then harvest energy from the sun and then beam the resulting electricity back to Earth using microwave- or laser-based wireless power transmission.

Originally described by Isaac Asimov in his short story “Reason”, the concept of an actual space-based solar array was first adopted by NASA in 1974. Since that time, they have been investigating the concept alongside the US Department of Energy as a solution to the problem of meeting Earth’s energy demands, and the cost of establishing a reliable network of arrays here on Earth.

Constructing large arrays on the surface is a prohibitively expensive and inefficient way of gathering power, due largely to weather patterns, seasons, and the day-night cycle which would interfere with reliable solar collection. What’s more, the sunniest parts of the world are quite far from the major centers of demand – i.e. Western Europe, North America, India and East Asia – and at the present time, transmitting energy over that long a distance is virtually impossible.

NASA "Suntower" concept
NASA “Suntower” concept

Compared to that, an orbiting installation like the SBSP would have numerous advantages. Orbiting outside of the Earth’s atmosphere, it would be able to receive about 30% more power from the Sun, would be operational for almost 24 hours per day, and if placed directly above the equator, it wouldn’t be affected by the seasons either. But the biggest benefit of all would be the ability to beam the power directly to whoever needed it.

But of course, cost remains an issue, which is the only reason why NASA hasn’t undertaken to do this already. Over the years, many concepts have been considered over at NASA and other space agencies. But due to the high cost of putting anything in orbit, moving up all the materials required to build a large scale installation was simply not cost effective.

spacex-dragon-capsule-grabbed-by-iss-canadarm-640x424However, that is all set to change. Companies like SpaceX, who have already taken part in commercial space flight (such as the first commercial resupply to the ISS in May of 2012, picture above) are working on finding ways to lower the cost of putting materials and supplies into orbit. Currently, it costs about $20,000 to place a kilogram (2.2lbs) into geostationary orbit (GSO), and about half that for low-Earth orbit (LEO). But SpaceX’s CEO, Elon Musk, has said that he wants to bring the price down to $500 per pound, at which point, things become much more feasible.

And when that happens, there will be no shortage of clients looking to put an SBSP array into orbit. In the wake of the Fukushima accident, the Japanese government announced plans to launch a two-kilometer-wide 1-gigawatt SBSP plant into space. The Russian Space Agency already has a a working 100-kilowatt SBSP prototype, but has not yet announced a launch date. And China, the Earth’s fastest-growing consumer of electricity, plans to put a 100kW SBSP into Low-Earth Orbit by 2025.

space-based-solarpowerMost notably, however, is John Mankins, the CTO of Deep Space Industries and a 25-year NASA vet, who has produced an updated report on the viability of SBSP. His conclusion, in short, is that it should be possible to build a small-scale, pilot solar farm dubbed SPS-ALPHA for $5 billion and a large-scale, multi-kilometer wide power plant for $20 billion. NASA’s funding for SPS-ALPHA dried up last year, but presumably Mankins’ work continues at Deep Space Industries.

Cost and the long-term hazards of having an array in space remain, but considering its long-term importance and the shot in the arm space exploration has received in recent years – i.e. the Curiosity Rover, the proposed L2 Moon outpost, manned missions to Mars by 2030 – we could be looking at the full-scale construction of orbital power plants sometime early in the next decade.

And it won’t be a moment too soon! Considering Earth’s growing population, its escalating impact on the surface, the limits of many proposed alternative fuels, and the fact that we are nowhere near to resolving the problem of Climate Change, space-based solar power may be just what the doctor ordered!

Thanks for reading and stay tuned for the next installment in the Powered By The Sun series!

Source: Extremetech.com