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The Future in a Tiny Sphere: A Conversation with Yoshinobu Tsujikawa
Blaine Brownell, 5 Feb 07

Sphelar® (Photo: Kyosemi Corporation)

Japan leads the world in solar power technology. Japan not only produces half the total solar cells made in the world, it also exports 30% of these cells, with expected demand for 20% increases per year. The Japanese government pushes renewable energy policies that have resulted in the installation of more than 100,000 residential solar power systems by 2004, as well as a projection of 5 GW of solar generation capacity by 2010. Japan even plans to launch a solar satellite by 2040, which will deliver energy to the earth via low-intensity microwaves. The satellite will absorb the sun’s energy 24 hours a day, unobstructed by clouds, and generate one million kilowatts per second – equal to the output of a nuclear power plant.

Now a Kyoto-based company, Kyosemi, is redesigning the future of photovoltaics themselves. Conventional photovoltaic technology is based on harnessing the sun's rays within a flat substrate, typically comprised by single or poly-crystalline silicon material. This arrangement is easy to design and manufacture; the only problem is that the efficacy of this technology relies on its position relative to the sun. Traditional but expensive solutions to this challenge involve motorized frames that follow the sun’s path throughout the day, requiring energy and maintenance in order to work properly.

Kyosemi’s solution is based on an entirely different geometry. Their innovative new Sphelar® is a matrix of tiny, spherical-shaped solar cells. The spheres are designed to absorb sunlight at any angle, and therefore do not require motorization for tracking the sun. Based on their geometry, Sphelar cells even optimize the use of reflected and indirect light, and have been shown to convert energy with close to 20% efficiency – beyond most flat photovoltaic technologies. Its flexible disposition also makes Sphelar appropriate for applications at a variety of scales, including mobile electronic devices.

Comparison with flat solar cell (Illustration: Kyosemi Corporation)

Yoshinobu Tsujikawa, a leading engineer and assistant to the President at Kyosemi Corporation, graciously agreed to answer some of my questions about Sphelar during the recent Semicon Japan conference in Tokyo:

BB: Please tell me about your career history.

YT: Before I joined Kyosemi, I worked at Mitsubishi Chemical Industry, which has a partnership with Monsanto. I actually visited the Monsanto headquarters in St. Louis thirty years ago, and I had much training in gallium arsenide-based semiconductors. Mitsubishi Monsanto Chemical Corporation is located in Tsukuba, and I produced single crystalline gallium arsenide, gallium arsenide phosphide vapor phase technology, and gallium arsenide substrates, which are used to emit light.

BB: When did you join Kyosemi?

YT: In May of 2002. At that time, I transferred to Hokkaido Semiconductor, and in 2003, I returned to Kyosemi Corporation. That same year, Kyoto Semiconductor changed its name to Kyosemi Corporation. I have since been involved in developing solar technologies at Kyosemi Corporation.

BB: What is the relationship with Hokkaido Semiconductor?

YT: It is a subsidiary of Kyoto Semiconductor – a factory located in Kamisuganawa which manufactures LEDs and photodiodes. The microgravity utilization center is in Eniwa city.

BB: How has the solar (and semiconductor) industry changed since the beginning of your career? Has the technology become more efficient?

YT: The efficiency is related to the physical properties of the particular cell used. Depending on whether you are studying single crystalline silicon, amorphous silicon, or polycrystalline silicon, the efficiency of energy conversion is different.

BB: When was Sphelar first developed?

YT: Kyoto Semiconductor was founded in 1980. Founder and CEO Josuke Nakata began developing an idea for a spherical solar cell in 1993 when he was in the Kamisunagawa district in Hokkaido. Sphelar is the first spherical single crystalline semiconductor to be grown under micro-gravity conditions, and it has an energy-conversion efficiency of close to 20% in the laboratory. At the time Nakata was conducting his preliminary experiments with Sphelar, he was invited by the Kamisunagawa governor to discuss this new energy technology in light of the Hokkaido coal plant closures ordered by the Japanese government.

Sphelar die module (Photo: Kyosemi Corporation)

BB: What year was this?

YT: Between 1980 and 1990, Japan decided to curtail coal production because of its nature as a dirty and limited resource. Unfortunately, many coal miners lost their jobs, and they could not easily transition to other work. The local government has been consulting with a variety of experts regarding suitable replacements to coal energy.

BB: The coal workers who lost their jobs – can they work in a new industry?

YT: The fabrication and assembly of our technology is mainly carried out in Eniwa, which is an urban location. Most of the coal mines were located in the countryside. Also, we are planning to transfer the assembly of our products to foreign countries, to be closest to the consumer.

BB: Japan is currently the leading producer of solar technology in the world. Could you speak more about the government’s support for solar energy?

YT: When the coal mines were shut down, NEDO (the New Energy and Industrial technology Development Organization) was born. NEDO is Japan's largest public R&D management organization for promoting the development of advanced industrial, environmental, new energy and energy conservation technologies, and they give generous support in the form of grants to select companies who are developing promising new technologies.

BB: Does the Japanese government continue to support your research & development efforts?

YT: Yes, Kyosemi continues to receive funding from NEDO. They support our exhibitions in various conferences and expositions.

BB: I read recently that China is becoming a more capable player in the solar arena. Would Kyosemi Corporation entertain partnering with a Chinese manufacturer? Perhaps you could decrease your manufacturing costs.

YT: Many people think that is a good idea, and we have considered it. However, Sino-Japanese relations are still tenuous in terms of sharing intellectual property, so we will abstain for now.

BB: I read that Japan wants 10% of its energy to come from solar power in 2030.

YT: According projections by Mizuho Securities, Japan will be able to generate 5 GW from solar power by 2010 based on the current growth rate. That compares favorably with 3 GW projected for Europe.

BB: By 2020, Europe is expected to produce 35 GW, and China 2 GW of solar power. Why is there no projection for Japan according to this study?

YT: It is a matter of national character. China and European countries have many policies based on extrapolating current data.

BB: Do the Japanese think this kind of policy is important?

YT: Yes, but Japan is conservative because we have no idea what 2020 will bring, especially since Japan’s resources are very limited, and it is difficult to predict how the peak oil crisis will affect world energy markets.

BB: Where is Sphelar currently used?

YT: Originally, we wanted to install Sphelar modules on building rooftops, but the assembly of rooftop installations proved to be difficult. Moreover, it was complicated to make such systems, which tend to be large in scale. Therefore, we have shifted our focus to the development of small, low power applications such as portable consumer electronics.

BB: Such as wearable solar-powered devices?

YT: Wearable is a good idea, but the problem there is durability. Clothes move a lot and require washing, so the wiring becomes the weak link.

BB: Then what kind of applications?

YT: SphelarVoiceTM is one example. Laurie Anderson designed a device called the AimuletLA for the Aichi Expo in 2005, and it utilizes SphelarVoice technology. The AimuletLA is a small device, slightly larger than a credit card, which enables visitors to learn information about their environment. While the device delivers a low-volume audio signal to the user, it requires no battery. One may simply point the AimuletLA at an item of interest in an exhibition powered by SphelarVoice technology, and infrared light projected by Sphelar modules carries audio information that is decoded by the card. The AimuletLA is perfect for museum tours, for example, because visitors may hear guided audio information without worrying about bulky devices or batteries. This technology is now commercialized and has become very popular.

SphelarVoice technology (Photo: Blaine Brownell)

BB: The low-power technology is very beautiful. What about jewelry? Until now, jewelry has only been art. If it could also generate energy, it would be very interesting – “functioning body art.? Maybe you could do a Sphelar fashion show and Japanese designers could create jewelry with it.

YT: That is an interesting notion. Kyosemi has been developing the technology for more pragmatic applications thus far. For example, we have produced hearing aids for indigenous people in Africa. The Sphelar-powered hearing devices assist communication by transmitting audio vibrations via bone in the ear canal.

BB: What about larger scales?

YT: Sphelar dome modules may be connected to form a network, and they can communicate to each other via electro-waves. Applications include crop monitoring in agriculture, site security, handicapped access, and visitor way-finding. Like SphelarVoice, visitors can learn information about a particular context, whether at the scale of an exhibition or a city. We call it a Sensornet, or sensor network, which is inherently battery-free. Have you heard of ubiquitous computing? I heard the word “pervasive? is more popular in the West, but we Japanese like “ubiquitous.?

Sphelar dome module (Photo: Kyosemi Corporation)

BB: What about cars? Could they utilize Sphelar technology?

YT: I think so, but we are not currently studying that. There is certainly a possibility, however.

BB: Are you considering integration in buildings again?

YT: Yes, the development of building-integrated photovoltaics (BIPVs) is our final goal, but it requires a large area of the Sphelar modules. We are currently struggling with how to assemble these modules in such a large area. Eventually, we hope to increase the size of the Sphelar arrays up to the scale of utility plants and power stations.

BB: Usually BIPVs are used in windows.

YT: Yes, we have a flexible substrate with integrated solar spheres which we call the Sphelar Window.

Sphelar Window flexible substrate (Photo: Blaine Brownell)

BB: What if, as opposed to glass, Sphelar could be integrated with other building materials, such as concrete or other opaque products? After all, buildings are clad with many other materials which might be utilized to harness solar energy.

YT: This is a good idea. Some researchers from Denmark asked us to collaborate to integrate Sphelar modules in concrete, but we had no idea how to do it at the time. Unfortunately our grant fell through, but if we have the chance again, we would like to try this kind of project. Some architects in Spain are installing dome modules all over buildings, perhaps in the tradition of the flamboyant architect Gaudi.

BB: Looking at your growth projections, the scale gradually increases, doesn’t it? Is Hokkaido the number one fabrication location?

YT: Yes, for Sphelar cells. We are also studying the assembly of Sphelar cells for these applications in Hokkaido, and eventually assembly will move to the consumer end.

BB: Your technology works at a variety of scales. What if you linked them all? Low-power consumer electronics connected to sensornets connected to BIPvs… it could be interesting.

YT: Yes. Currently we are focused on providing energy necessary for life, but eventually we hope to enter the realm of art.

Sphelar bracelets (Photo: Blaine Brownell)

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In order to insure energy and economic independence as well as better economic growth without being blackmailed by foreign countries, our country, the United States of America’s Utilization of Energy sources must change.
"Energy drives our entire economy." We must protect it. "Let's face it, without energy the whole economy and economic society we have set up would come to a halt. So you want to have control over such an important resource that you need for your society and your economy." The American way of life is not negotiable.
Our continued dependence on fossil fuels could and will lead to catastrophic consequences.

The federal, state and local government should implement a mandatory renewable energy installation program for residential and commercial property on new construction and remodeling projects with the use of energy efficient material, mechanical systems, appliances, lighting, etc. The source of energy must by renewable energy such as Solar-Photovoltaic, Geothermal, Wind, Biofuels, Ocean-Tidal, etc. including utilizing water from lakes, rivers and oceans to circulate in cooling towers to produce air conditioning and the utilization of proper landscaping to reduce energy consumption. (Sales tax on renewable energy products should be reduced or eliminated)

The implementation of mandatory renewable energy could be done on a gradual scale over the next 10 years. At the end of the 10 year period all construction and energy use in the structures throughout the United States must be 100% powered by renewable energy. (This can be done by amending building code)

In addition, the governments must impose laws, rules and regulations whereby the utility companies must comply with a fair “NET METERING? (the buying of excess generation from the consumer at market price), including the promotion of research and production of “renewable energy technology? with various long term incentives and grants. The various foundations in existence should be used to contribute to this cause.

A mandatory time table should also be established for the automobile industry to gradually produce an automobile powered by renewable energy. The American automobile industry is surely capable of accomplishing this task. As an inducement to buy hybrid automobiles (sales tax should be reduced or eliminated on American manufactured automobiles).

This is a way to expedite our energy independence and economic growth. (This will also create a substantial amount of new jobs). It will take maximum effort and a relentless pursuit of the private, commercial and industrial government sectors commitment to renewable energy – energy generation (wind, solar, hydro, biofuels, geothermal, energy storage (fuel cells, advance batteries), energy infrastructure (management, transmission) and energy efficiency (lighting, sensors, automation, conservation) (rainwater harvesting, water conservation) (energy and natural resources conservation) in order to achieve our energy independence.

"To succeed, you have to believe in something with such a passion that it becomes a reality."

Jay Draiman, Energy Consultant
Northridge, CA. 91325
Feb. 5, 2007

P.S. I have a very deep belief in America's capabilities. Within the next 10 years we can accomplish our energy independence, if we as a nation truly set our goals to accomplish this.
I happen to believe that we can do it. In another crisis--the one in 1942--President Franklin D. Roosevelt said this country would build 60,000 [50,000] military aircraft. By 1943, production in that program had reached 125,000 aircraft annually. They did it then. We can do it now.
The American people resilience and determination to retain the way of life is unconquerable and we as a nation will succeed in this endeavor of Energy Independence.

Solar energy is the source of all energy on the earth (excepting volcanic geothermal). Wind, wave and fossil fuels all get their energy from the sun. Fossil fuels are only a battery which will eventually run out. The sooner we can exploit all forms of Solar energy (cost effectively or not against dubiously cheap FFs) the better off we will all be. If the battery runs out first, the survivors will all be living like in the 18th century again.

Every new home built should come with a solar package. A 1.5 kW per bedroom is a good rule of thumb. The formula 1.5 X's 5 hrs per day X's 30 days will produce about 225 kWh per bedroom monthly. This peak production period will offset 17 to 2

4 cents per kWh with a potential of $160 per month or about $60,000 over the 30-year mortgage period for a three-bedroom home. It is economically feasible at the current energy price and the interest portion of the loan is deductible. Why not?

Title 24 has been mandated forcing developers to build energy efficient homes. Their bull-headedness put them in that position and now they see that Title 24 works with little added cost. Solar should also be mandated and if the developer designs a home that solar is impossible to do then they should pay an equivalent mitigation fee allowing others to put solar on in place of their negligence. (Installation should be paid “performance based?)

Installation of renewable energy and its performance should be paid to the installer and manufacturer based on "performance based" (that means they are held accountable for the performance of the product - that includes the automobile industry). This will gain the trust and confidence of the end-user to proceed with such a project; it will also prove to the public that it is a viable avenue of energy conservation.

Installing renewable energy system on your home or business increases the value of the property and provides a marketing advantage.

Nations of the world should unite and join together in a cohesive effort to develop and implement MANDATORY RENEWABLE ENERGY for the sake of humankind and future generations.

Jay Draiman
Northridge, CA 91325

Posted by: Jay Draiman on 5 Feb 07

I just wanted to say that this is a fine story about a promising technology. I don't have any big national MANDATORY national policy to demand. I don't even make my home in the States. But I do think Sphelar seems brilliant, and I should be glad to hear what others who are of a more technical inclination than I think of it.

Please continue with the great work, Worldchanging. It is appreciated by those of us who mostly remain silent.

Posted by: a reader on 5 Feb 07

I did a back of an envelope calcuation. Instead of the $300B we put into the Iraq war (my friends call it the qWagmire) we could have put that money into solar cells and provided free electricity to plug in hybrid vehicles. That $300B translates to 200 M Gal of gasoline America does not need; does not pollute; does not import. Instead we have this stupid war and an economy going bancrupt.

Posted by: South Side Sky on 6 Feb 07

I didn't do any calculations at all but it seems to me that if $300B could render free renewable energy, that energy should be used to power efficient buildings and transit systems that would effectively render personal automobiles and the wasteful infrastructure they require a thing of the past.

Posted by: Gil Lopez on 6 Feb 07

I think this is great, but I do have concerns about wearing electronics and having them close to our bodies as we do now with our cell phones, ipods, etc and what kinds of effects this can have on our bodies that are being more and more susceptible to our environments such as chemicals. My mom talks more on the phone than anyone I know and got cancer in her face right where she held up her cell phone.

Posted by: Cindy on 6 Feb 07

"In order to insure energy and economic independence as well as better economic growth without being blackmailed by foreign countries"

You've got it all backwards.

It's us in the good old US of A that are blackmailing the rest of the world.

We TAKE their energy by military force.

Now, I'm all for solar (and hydro and wind), but:

- electricity is not an ultra-dense liquid fuel (like oil is)
- storage of electricity in high J/kg*m3 storage is an unsolved problem (for a few decades already)
- No amount of solar panel manufacturing could even meet the demand of USA if we wanted (and could) go to 30-50% solar dependent. That would require us (again) to take others solar panels through military force and leave the rest of the world hanging

Don't understand me wrong, I'm all for increasing sustainable alternative sources.

BUT they are NOT a quick fix (in the next 15 years) and in the next 15 years oil & natgas will be much more expensive and harder to get.

The question remains: what do we do during that time?

Take the resources from others by military force? Kill hundreds of thousands of people in the process, like in Iraq and soon in Iran?


Scale down?

Something else?

To repeat: nobody is blackmailing us. We take what we want by force, while the rest of the world protests.

Hardly worldchanging, if you ask me....

Posted by: Matt Salonen on 8 Feb 07

I am extremely happy with inventions like these to come to the market. What I am less happy with, is the fact that even basic physics language about these things again go wrong in a text that brings it to us. Sentences like "...generate one million kilowatts per second..." make it look like these people don't know what they are talking about and take away a part of the credibility of the story. So please correct it in future publishing..Thank you.

(It has to be one millioen Joules per second or simply one million kiloWatts)

Posted by: Leenknegt Donald on 9 Feb 07

In response to Mark's comment: "electricity is not an ultra-dense liquid fuel (like oil is)"

and "sustainable alternative sources ...are NOT a quick fix (in the next 15 years) "

The quickest fixes involve plug-in hybrid cars and wind-powered electricity, along with common sense conservation.

Toyota is supposed to have a plug-in hybrid Prius in the 2008 model year. These cars can be charged at home over night, run for a certain distance electrically on this charge, and then run on more standard fuel when the charge is out. The efficiencies are very impressive. Even if the electricity generated to charge the batteries is from coal, the related greenhouse gases produced are less per mile driven than with a similar internal combustion engine car.

I highly recommend seeing the documentary movie, "Who Killed the Electric Car?" Also, a new book just called "Plug-in Hybrids".

And wind power is starting to come on line in a big way.

In the long run, solar, geo-thermal, cellulosic ethanol, high-performance buildings, etc., will all be important. But if the energy/environmental challenges are attacked from many fronts, dramatic changes are possible.

Posted by: Steven Hult on 11 Feb 07

I think an essential point is being missed here. Energy economics is not solely a function of its generation and consumption, it also involves distribution. While it is true that electricity is not a dense substance like oil, the capability to retain it in a grid is an essential feature.

Worldwide, we have grids that are designed to operate at very large energy levels. This is fundamentally apposite with the reality of widely distributed energy generation, whose characteristics are small and staccato as against large and constant.

The current grid technology is therefore a monopolistic and restrictive approach to energy management that militates against more ecologically sound technologies.

We need a movement for a better solution.

Posted by: Vickram on 25 Feb 07



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