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)

Powered by the Sun: Efficiency Records and Future Trends

solar_panelThere have been many new developments in the field of solar technology lately, thanks to new waves of innovation and the ongoing drive to make the technology cheaper and more efficient. At the current rate of growth, solar power is predicted to become cheaper than natural gas by 2025. And with that, so many opportunities for clean energy and clean living will become available.

Though there are many contributing factors to this trend, much of the progress made of late is thanks to the discovery of graphene. This miracle material – which is ultra-thin, strong and light – has the ability to act as a super capacitor, battery, and an amazing superconductor. And its use in the manufacture of solar panels is leading to record breaking efficiency.

graphene-solarBack in 2012, researchers from the University of Florida reported a record efficiency of 8.6 percent for a prototype solar cell consisting of a wafer of silicon coated with a layer of graphene doped with trifluoromethanesulfonyl-amide (TFSA). And now, another team is claiming a new record efficiency of 15.6 percent for a graphene-based solar cell by ditching the silicon all together.

And while 15.6 efficiency might still lag behind certain designs of conventional solar cells (for instance, the Boeing Spectrolabs mass-production design of 2010 achieved upwards of 40 percent), this represents a exponential increase for graphene cells. The reason why it is favored in the production of cells is the fact that compared to silicon, it is far cheaper to produce.

solar_power2Despite the improvements made in manufacturing and installation, silicon is still expensive to process into cells. This new prototype, created by researchers from the Group of Photovoltaic and Optoelectronic Devices (DFO) – located at Spain’s Universitat Jaume I Castelló and the University of Oxford – uses a combination of titanium oxide and graphene as a charge collector and perovskite to absorb sunlight.

As well as the impressive solar efficiency, the team says the device is manufactured at low temperatures, with the several layers that go into making it being processed at under 150° C (302° F) using a solution-based deposition technique. This not only means lower potential production costs, but also makes it possible for the technology to be used on flexible plastics.

twin-creeks-hyperion-wafer-ii-flexibleWhat this means is a drop in costs all around, from production to installation, and the means to adapt the panel design to more surfaces. And considering the rate at which efficiency is being increased, it would not be rash to anticipate a range of graphene-based solar panels hitting the market in the near future – ones that can give conventional cells a run for their money!

However, another major stumbling block with solar power is weather, since it requires clear skies to be effective. For some time, the idea of getting the arrays into space has been proposed as a solution, which may finally be possible thanks to recent drops in the associated costs. In most cases, this consists or orbital arrays, but as noted late last year, there are more ambitious plans as well.

lunaring-3Take the Japanese company Shimizu and it’s proposed “Luna Ring” as an example. As noted earlier this month, Shimizu has proposed creating a solar array some 400 km (250 miles) wide and 11,000 km (6,800 miles) long that would beam solar energy directly to Earth. Being located on the Moon and wrapped around its entirety, this array would be able to take advantage of perennial exposure to sunlight.

Cables underneath the ring would gather power and transfer it to stations that facing Earth, which would then beam the energy our way using microwaves and lasers. Shimizu believes the scheme, which it showed off at a recent exhibition in Japan, would virtually solve our energy crisis, so we never have to think about fossil fuels again.

lunaring-2They predict that the entire array could be built and operational by 2035. Is that too soon to hope for planetary energy independence? And given the progress being made by companies like SpaceX and NASA in bringing the costs of getting into space down, and the way the Moon is factoring into multiple space agencies plans for the coming decades, I would anticipate that such a project is truly feasible, if still speculative.

Combined with increases being made in the fields of wind turbines, tidal harnesses, and other renewable energy sources – i.e. geothermal and piezoelectric – the future of clean energy, clear skies and clean living can’t get here soon enough! And be sure to check out this video of the Luna Ring, courtesy of the Shimizu corporation:


Sources:
gizmodo.com, fastcoexist.com

News From Space: Luna Rings and Spidersuits!

space_cameraSpace is becoming a very interesting place, thanks to numerous innovations that are looking ahead to the next great leap in exploration. With the Moon and Mars firmly fixed as the intended targets for future manned missions, everything from proposed settlements and construction projects are being plotted, and the requisite tools are being fashioned.

For instance, the Shimizu Corporation (the designers of the Shimizu Mega-City Pyramid), a Japanese construction firm, has proposed a radical idea for bringing solar energy to the world. Taking the concept of space-based solar power a step further, Shimizu has proposed the creation of a “Luna Ring” – an array of solar cells around the Moon’s 11000 km (6800 mile) equator to harvest solar energy and beam it back to Earth.

lunaringThe plan involves using materials derived from lunar soil itself, and then using them to build an array that will measure some 400 km (250 miles) thick. Since the Moon’s equator receives a steady amount of exposure to the Sun, the photovoltaic ring would be able to generate a continuous amount of electricity, which it would then beam down to Earth from the near side of the Moon.

It’s an ambitious idea that calls for assembling machinery transported from Earth and using tele-operated robots to do the actual construction on the Moon’s surface, once it all arrives. The project would involve multiple phases, to be spread out over a period of about thirty years, and which relies on multiple strategies to make it happen.

lunaring-1For example, the firm claims that water – a necessary prerequisite for construction – could be produced by reducing lunar soil with hydrogen imported from Earth. The company also proposes extracting local regolith to fashion “lunar concrete”, and utilizing solar-heat treatment processes to fashion it into bricks, ceramics, and glass fibers.

The remotely-controlled robots would also be responsible for other construction tasks, such as excavating the surrounding landscape, leveling the ground, laying out solar panel-studded concrete, and laying embedded cables that would run from the ring to a series of transmission stations located on the Earth-facing side of the Moon.

space-based-solarpowerPower could be beamed to the Earth through microwave power transmission antennas, about 20 m (65 ft) in diameter, and a series of high density lasers, both of which would be guided by radio beacons. Microwave power receiving antennas on Earth, located offshore or in areas with little cloud cover, could convert the received microwave power into DC electricity and send it to where it was needed.

The company claims that it’s system could beam up to 13,000 terawatts of power around-the-clock, which is roughly two-thirds of what is used by the world on average per year. With such an array looming in space, and a few satellites circling the planet to pick up the slack, Earth’s energy needs could be met for the foreseable future, and all without a single drop of oil or brick of coal.

The proposed timeline has actual construction beginning as soon as 2035.

biosuitAnd naturally, when manned missions are again mounted into space, the crews will need the proper equipment to live, thrive and survive. And since much of the space suit technology is several decades old, space agencies and private companies are partnering to find new and innovative gear with which to equip the men and women who will brave the dangers of space and planetary exploration.

Consider the Biosuit, which is a prime example of a next-generation technology designed to tackle the challenges of manned missions to Mars. Created by Dava Newman, an MIT aerospace engineering professor, this Spiderman-like suit is a sleeker, lighter alternative to the standard EVA suits that weigh approximately 135 kilograms (300 pounds).

biosuit_dava_newmanFor over a decade now, Newman has been working on a suit that is specifically designed for Mars exploration. At this year’s TEDWomen event in San Francisco, she showcased her concept and demonstrated how its ergonomic design will allow astronauts to explore the difficult terrain of the Red Planet without tripping over the bulk they carry with the current EVA suits.

The reason the suit is sleek is because it’s pressurized close to the skin, which is possible thanks to tension lines in the suit. These are coincidentally what give it it’s Spiderman-like appearance, contributing to its aesthetic appeal as well. These lines are specifically designed to flex as the astronauts ends their arms or knees, thus replacing hard panels with soft, tensile fabric.

biosuit1Active materials, such as nickel-titanium shape-memory alloys, allow the nylon and spandex suit to be shrink-wrapped around the skin even tighter. This is especially important, in that it gets closer Newman to her goal of designing a suit that can contain 30% of the atmosphere’s pressure – the level necessary to keep someone alive in space.

Another benefit of the BioSuit is its resiliency. If it gets punctured, an astronaut can fix it with a new type of space-grade Ace Bandage. And perhaps most importantly, traditional suits can only be fitted to people 5′ 5″ and taller, essentially eliminating short women and men from the astronaut program. The BioSuit, on the other hand, can be built for smaller people, making things more inclusive in the future.

Mars_simulationNewman is designing the suit for space, but she also has some Earth-bound uses in mind . Thanks to evidence that showcases the benefits of compression to the muscles and cardiovascular system, the technology behind the Biosuit could be used to increase athletic performance or even help boost mobility for people with cerebral palsy. As Newman herself put it:

We’ll probably send a dozen or so people to Mars in my lifetime. I hope I see it. But imagine if we could help kids with CP just move around a little bit better.

With proper funding, Newman believes she could complete the suit design in two to three years. It would be a boon to NASA, as it appears to be significantly cheaper to make than traditional spacesuits. Funding isn’t in place yet, but Newman still hopeful that the BioSuit will be ready for the first human mission to Mars, which are slated for sometime in 2030.

In the meantime, enjoy this video of the TEDWomen talk featuring Newman and her Biosuit demonstration:

Sources: gizmag, fastcoexist, blog.ted

Powered by the Sun: The Artificial Leaf

solar_power1Despite progress made in recent decades, solar power still has some obstacles to overcome before it can be completely adopted. Thanks to several innovations, the price of manufacturing and installing solar panels has dropped substantially, intermittency remains a problem. So long as solar power remains limited by both geography and weather, we can expect to remain limited in terms of use.

And short of building Space-Based Solar Power (SBSP) arrays, or producing super-capacitor batteries with graphene – both of which are being explored – the only other option is to find ways to turn solar power into other forms of usable fuel. When the sun isn’t shining, people will need something else to power their homes, appliances, heating and AC. And given that the point is to reduce pollution, it will also have to be clean.

??????And that’s precisely what Daniel Nocera and his team are doing over at the University of Harvard. Their “artificial leaf” – a piece of silicon (solar cell) coated with two catalysts – is a means of turning sunshine into hydrogen fuel. Basically, when sunlight shines in, the leaf splits the water into bubbles of hydrogen and oxygen on each side, which can then be used in a fuel cell.

Efforts in the past to build similar solar cells have faltered, due largely to the costs involved. However, with the price of solar-related materials dropping in recent years, this latest device may prove commercially viable. And built to a larger scale, the device could provide a super-cheap and storable energy source from which could then be piped off and used in a fuel cell to make electricity. And combined with arrays of solar panels, we could have the energy crisis licked!

artificial-leafNocera and his team first announced the technology back in 2011, back when he was still a chemist at MIT. Since that time, they have published a follow-up paper showing how the team has improved the leaf’s efficiency, laying out future challenges, and how these might be overcome. Foremost amongst these are a field trial, with the eventual aim of building a commercial device for the developing world.

Beyond that, Nocera hopes to commercialize the technology through his company, the Massachusetts-based Sun Catalytix. Once realized, he plans to to put his dream of giving the poor “their first 100 watts of energy” into action. Here’s hoping he succeeds. The poor need power, and the environment needs a break from all our polluting!

Thank you all for reading the latest installment of PBTS! And be sure to check out this video of the artificial leaf in action: