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:, (2)

Powered by the Sun: Mirrored Solar Dishes

sun_magneticfieldIn the race to develop alternative energy sources, solar power is the undeniable top contender. In addition to being infinitely renewable So much sunlight hits the Earth each day that the world’s entire electricity needs could be met by harvesting only 2% of the solar energy in the Sahara Desert. Of course, this goal has remained elusive due to the problem of costs – both in the manufacture of solar panels and the installation therefor.

But researchers at IBM think they’re one step closer to making solar universally accessible with a low-cost system that can concentrate the sunlight by 2,000 times. The system uses a dish covered in mirrors to aim sunlight in a small area, and which follows the sun throughout the day to catch the most light. Other concentrated solar power systems do the same thing, but a typical system only converts around 20% of the incoming light to usable energy, while this one can convert 80%.

Inline_solardishThis not only ensures a much larger yield, but also makes the energy it harvests cheap. Bruno Michel, the manager for advanced thermal packaging at IBM Research, believes the design could be three-times cheaper than “comparable” systems. Officially, the estimate he provides claim that the cost per kilowatt hour will work out to less than 10 cents, which works out to 0.01 cents per watt (significantly cheaper than the $0.74 per watt of standard solar).

But as he explains, using simple materials also helps:

The reflective material we use for the mirror facets are similar to that of potato chip bags. The reinforced concrete is also similar to what is being used to build bridges around the world. So outside of the receiver, which contains the photovoltaic chips, we are using standard materials.

A few small high-tech parts will be built in Switzerland (where the prototype is currently being produced). but the main parts of the equipment could easily be built locally, wherever it’s being used. It’s especially well-suited for sunny areas that happen to be dry. As the system runs, it can use excess heat that would normally be wasted to desalinate water. Hence, a large installation could provide not only abundant electricity, but clean drinking water for an entire town.

inline-i-solar-02A combined system of this kind could be an incredible boon to economies in parts of the world that are surrounded by deserts, such as North Africa or Mongolia. But given the increasing risk of worldwide droughts caused by Climate Change, it may also become a necessity in the developed world. Here, such dishes could not only provide clean energy that would reduce our carbon footprint, but also process water for agricultural use, thus combating the problem on two fronts.

IBM researchers are currently working with partners at Airlight Energy, ETH-Zurich, and Interstate University of Applied Sciences Buchs NTB to finish building a large prototype, which they anticipate will be ready by the end of this summer. After testing, they hope to start production at scale within 18 months. Combined with many, many other plans to make panels cheaper and more effective, we can expect to be seeing countless options for solar appearing in the near future.

And if recent years are any indication, we can expect solar usage to double before the year is out.


Five Technologies for the Developing World

Developed-and-developing-countriesWhen it comes to providing energy in the “developed world”, the challenge is in finding ways to generate electricity, heat, and cooling in a way that will not burden our environment. Whereas providing these things in the past has never been much of a challenge, finding ways to meet future demand in a way that is sustainable and renewable often is. Lucky for us, we have the means to meet this challenge head on.

But in the “developing world”, where the infrastructure does not readily exist, populations continue to grow exponentially, and the concerns about the natural environment are quite grave already, the challenge of providing for people’s basic needs presents a significant challenge. At the same time however, it presents an opportunity for creative solutions.

What follows is just a few examples of what engineers and designers have come up with in recent years. These devices are especially innovative because they are capable of increasing the supply of safe, cheap energy on a user-by-user basis, bypassing the years it takes to extend a power grid to remote places, the resources needed to increase a country’s energy production capacity, or the environmental damage involved.

Voto-Stove1. The Voto: Millions of people around the world use coal or wood-fired stoves to provide for their cooking and heating needs. Developed by the company Point Source Power, the VOTO converts the energy these fires release as heat into electricity, which can power a handheld light, charge a phone or even charge a spare battery. Initially designed for backpackers and campers, the company is also trying to find a way to make it accessible to residents of the developing world, where it will be much more useful.

2. Window Socket: Here we have what is perhaps the simplest solar charger in existence. Simply attach the suction cup to a window or any sun-exposed surface, let sit for 5 to 8 hours, and the solar panels will store enough electricity to power a device for up to ten hours. Created by Kyuho Song and Boa Oh of Yanko Design to resemble a normal wall outlet as closely as possible, the charger can be taken and used anywhere, making it truly versatile.

window_socket33. The Berkeley-Darfur Stove: In recent years, health researchers have come to the conclusion that open-fire stoves lead to millions of deaths in the developing world. Hence this design by Potential Energy, a nonprofit dedicated to adapting and scaling technologies to help improve lives in the developing world. Featuring a tapered wind collar, a small fire box opening, nonaligned air vents that reduce the amount of wind allowed to stoke or snuff the fire, and ridges that ensure the optimal distance between the fire and pot, this stove is safe, fuel-efficient, and requires less wood to power. Over 25,000 units have been distributed to the Darfur region and Ethiopia so far.

gravitylight4. Gravity Light: Along with wood-burning stoves, kerosene-burning lamps are also a major health concern because of the fumes they create. Hence the simple and elegant solution known as the Gravity Light. Developed by the research initiative, the device is powered by attaching a 20 lbs bag or rocks or dirt to a cord and then lifting it into place. The potential energy stored in that lifting motion is then gradually converted to electricity as the the bag descends over the course of about 30 minutes, powering a light or other electrical device in that time.

5. SOCCKET: Soccer is easily the most popular sport in the world, with millions of people playing daily. And in an attempt to turn this daily activity into an efficient form of energy that would replace kerosene lamps, Uncharted Play, a for-profit social enterprise, has created a ball that uses a kinetically-powered pendulum to generate and store electricity. After about 30 minutes of play, the ball stores enough energy to power an attachable LED lamp for 3 hours. Development of the product was funded via Kickstarter, and the first ones will ship in the next few weeks. A percentage of all retail sales will go to providing SOCCKETs to schools in the developing world.

two_SOCCKETsWhen it comes right down to it, these devices are especially innovative because of the way they marry  new technology to basic utility. In the end, what people get are things that are simple to use, effective, clean, and safe. And if history and sociological research have taught us anything, it’s that little things that make life healthier and easier have a profound impact on the lives of people.

Combined with large-scale concept (like 3D-printed structures) simple solutions like these are likely to make a big difference in the lives of millions of people. By ensuring that people have access to lighting and heating that does not compromise their health, is better for their environment, and less-labor intensive and expensive, the daily grind that characterizes far too many people’s existence is sure to get easier and allow for new opportunities.

Though they might seem like minor improvements, incremental changes have a way of adding up and can lead to serious and positive social change. And I for one am eager to see it happen!


Powered by the Sun: The Ion Cannon Solar Panel

solar5Hello and welcome back to my ongoing series of PBTS, dedicated to all the advancements being made in solar power. Today’s entry is an interesting one, and not just because it involves an ion cannon… well sort of! It comes to us courtesy of Twin Creeks, a solar power startup that has come up with a revolutionary way to generate photovoltaic cells that are half the price of those currently found on the market.

For many decades, solar power has been held back due to the fact that the cost has been prohibitive compared to fossil fuels and coal. By offering yet another way of cutting the cost of their production, Twin Creeks is bringing this clean alternative one step closer to realization. Ah, but here’s the real kicker: turns out that this revolutionary process involves a hydrogen ion particle accelerator!

hyperion-particle-accelerator1-640x353As has been mentioned in this series before, conventional solar cells are made from slicing 200-micrometer-thick (0.2mm) sections of silicon wafer from a large block. Then electrodes are added, a sheet of protective glass is placed on top, and they are placed in the sun to generate electricity. But of course, this approach has two serious drawbacks. One, a great deal of silicon is wasted in the production process. Two, the panels would if they were thinner than 200 micrometers, but silicon is brittle and prone to cracking if it’s too thin.

And this is where Twin Creeks ion cannon, aka. Hyperion, comes into play. It’s starts with a series of 3-millimeter-thick silicon wafers being placed around the outside edge of the big, spoked wheel (see above). The particle accelerator then bombards these wafers with hydrogen ions and, with exacting control of the voltage of the accelerator, the hydrogen ions accumulate precisely 20 micrometers from the surface of each wafer.

twin-creeks-hyperion-wafer-ii-flexibleA robotic arm then transports the wafers to a furnace where the ions expand into hydrogen gas, which cause the 20-micrometer-thick layer to shear off. A metal backing is applied to make it less fragile as well as highly flexible (as seen on the right). The remaining silicon wafer is taken back to the particle accelerator for another dose of ions. At a tenth of the thickness and with considerably less wastage, it’s easy to see how Twin Creeks can halve the cost of solar cells.

This process has been considered before, but the cost of a particle accelerator has always been too high. However, Twin Creeks got around this by building their own, one which is apparently “10 times more powerful” (100mA at 1 MeV) than anything on the market today. Because of this, they are able to guarantee a product that is half the cost of solar cells currently coming out of China. At that price, solar power truly begins to encroach on standard, fossil-fuel power.

But, of course, there still needs to be some development made on producing solar cells that can store energy overnight. Weather strictures, such as the ability to generate electricity only when its sunny out, remains another stumbling block that must be overcome. Luckily, it seems that there are some irons in that fire as well, such as research into lithium-ion and nanofabricated batteries. But that’s another story and another post altogether 😉

Stay tuned for more sun-powered hope for the future!