The photovoltaic effect was discovered long ago, back in 1839, by the French physicist A. E. Becquerel. For his work »On a Heuristic Point of View about the Creation and Conversion of Light« addressing the photoelectric effect, Albert Einstein was awarded the Nobel Prize in 1921.The first technical use of this effect, however, did not occur until 1958, when it was utilized for the energy supply of a satellite.
The pending challenges of energy and climate change will reveal new ways in exploiting the greatest energy resource available to us, the sun. Every year it emits approximately 15,000 times the world’s energy needs (about 1.5 · 1018 kWh) in our direction.
Sunlight is the purest form of energy. It can be »harvested« in various forms, including photovoltaic energy, solar thermal energy, wind energy, and energy from biomass. 40 square meters of photovoltaic surface are sufficient to meet the energy needs (about 4,000 kWh) of a family of 4. Currently, a photovoltaic plant supplies around 100 kWh per square meter per year.
Can the sun alone meet our energy needs? Even in Central Europe? Are decentralized and self-sufficient energy supplies also sound future strategies for highly industrialized regions? What are the prospects for North Africa?
The vision of a bright future
An integral part of our approach is to provide the visitors of the exhibition the opportunity to directly participate in development projects. LICHTZEIT offers links to existing, ongoing, self-initiated projects world wide.
We will create a space for projects demonstrating how a liveable, sustainable future can be created on the grounds of decentralized solar applications. Photovoltaic technology is directly applicable by anyone, anywhere – no power grids, no central power plants and no centralized energy industry are needed.
Africa may become a model for a real energy revolution from below. Examples are projects like »LittleSun« (http://littlesun.com), »Solar Light for Africa« (http://solarlightforafrica.org) or our »LICHTZEIT SCHOOL«. Solar energy is being used for charging mobile phones – or saved for having light to read or study at night – thereby conserving kerosene and firewood. Such technologies are a significant contribution to health and resource-saving.
LICHTZEIT accepts a global responsibility and wants to not only elucidate, but to act and encourage initiative. The LICHTZEIT SCHOOL is a central component of ourfar-reaching strategy.
Light makes us mobile
Without a doubt, the future of individual mobility lies in electric propulsion. We will, however, only benefit the environment if our means of mobility are powered by renewable energy. Vehicles developed for short-distance urban use are already on the roads. Two-wheel vehicles seem to be perfect for these purposes because they have to manage short distances only. Fleets and especially car-sharing systems with permanent parking areas are already using E-Mobiles.
The key to the development of electric mobili-ty lies within the solution to the energy storage problem. With the growing demand, the pressure to innovate seems to be increasing and thus the willingness to invest in this area. As a part of the smart grid, electric vehicles will become an integral part of the storage solution for solar energy surpluses. New storage technologies appear on the horizon. They promise 1,000 times the storage density compared to current lithium batteries.
But one thing is for sure: Light derived from fossil fuels will become increasingly expensive. Peak oil and the coupling of gas prices to oil prices have proven this. Renewable energies, by contrast, are certain to become cheaper due to mass production of corresponding systems. The cost gap between fossil and renewable energies is certain to increase, and it is no longer a question of whether renewable energies will be cheaper than fossil fuels, but when they will be.
Special mobility needs call for special solutions. Trams, commuter trains, subways, and German rail traffic are demonstrating ways to make mobility energy-efficient. When it comes to individual transportation, a change in mentality is underway.
The key question remains whether the necessary political objectives can be achieved to address this change.
Light as a tool
Our tools are changing. In industrial pro-duction, more and more processes are determined by light. The laser as a highly accurate tool for micro-machining is cutting, welding, drilling smallest holes and removing thin layers. Whether metals, ceramics and other materials: industries such as the semiconductor, photovoltaic, medical and consumer goods industries are increasingly dependent on the laser as a production tool. Shorter and shorter product cycles, as well as the miniaturization and individualization of production make it irreplaceable.
3D laser printers will soon have a wide variety of applications. In the automotive industry entire function prototypes are already »printed« digitally. Laser sintering conflates finest metal powder layer by layer into components, or even complete, high-power modules. Entirely new forms and modes of production become possible.
Light is particularly suitable for contact-free measurement.
Laser technology will take over more and more branches of production in the future. At the moment German engineering is
the world leader in this field.
A nanometer is one billionth of a meter (10-9 m). On the nanoscale, there is no longer any alternative to the laser. In the semiconductor industry, electronic chips are made by optical lithography. »Writing on a stone with light« is what photolithography means in the literal sense. Now the stones are wafers of silicon, on which lasers write tiny structures. A transistor itself can only be nanometers in size today.
According to Moore‘s Law, which states that the number of transistors on a chip doubles about every two years, the next generation is already coming up. This results in smaller and smaller structures. To keep this process going we will need better and better optical procedures and lasers with ever-shorter wavelengths. Photonic production technologies are the essential basis for microelectronics on their way to becoming nanoelectronics.
The limits of what is feasible are shifted into ever smaller dimensions with light.
Surgery with light
Lasers are not only used for correcting bad eyesight. By now lasers are employed in many other surgical procedures, specifically because they allow tissues to be preserved.
Today advanced minimally invasive surgical techniques make use of endoscopic procedures based on visual applications. In the future, the introduction of fluorescence techniques and the simultaneous use of cell-specific contrast agents will enable the surgeon to distinguish normal from abnormal tissue locally on cellular level. Already today, laser radiation is used for targeted treatment of tissues. The radiation that can pass through optical waveguides is precisely metered at a local level and, by selecting the right wavelengths, used with varying effects on the treated tissue.
Optical methods for clinical applications, such as ultra-short laser pulses for precision surgery of the eye, brain and nerves or the therapeutic use of lasers in new fields such as dentistry, are being developed.
Biophotonics and molecular diagnostics will herald a new era in life sciences and medicine.
In a clinical context, light is also continually exhibiting its finest qualities in nanometer precision and measurable energy impulse control.
Exchange of ideas as fast as lightning
The non-materials of the new millennium such as information, communication and therefore knowledge operate by using the »immaterial« light as a transmitter.
Light is currently used for data transfer and communication (fiber optics) and in data storage (Holographic Data Storage, CD and DVDs).
Even today, there is no phone call, no use of the internet without using light. Currently the earth is increasingly interconnected via glass fibers allowing speeds of hundreds of thousand kilometers per second. The internet is in the truest sense of the word »colored.« For its individual data channels it makes use of the color spectrum of light with a channel width of less than half a nanometer. Photons transport is already used to deliver well over 90 percent of all information.
The number of internet users will increase from the current two billion to four billion by 2020. Already we connect to the internet via mobile devices. Energy-saving, flexible screens like OLED displays are supporting this mobile usage. Not only mobile phones and PCs, but also household appliances, vehicles, machines and tiny sensors will be integrated. The number of connected devices is increasing fast.
In the laboratory, optical networks already reach transfer rates in the range of terabits. This corresponds to an amount of data equivalent to 25 DVDs per second. To realize this potential, the conversion of the »last mile« from copper to fiber connections (Fiber-To-The-Home) needs to be completed.
The interconnectedness of the world also contributes to cultural exchange. Within milliseconds, videos from Tahrir Square or from Syria can be found on the internet. The exchange of ideas at the speed of light makes the world smaller.
New ways of communicating will provide future generations with new challenges.
The Internet of Things is turning our lives upside down once more. We want to make this upcoming revolution tangible today.
Worlds of light
Massively immersive 3D-computer and online games turn into substitute worlds. These artificial worlds are becoming more and more realistic due to the exponentially increasing computer powers. The boundary between reality and synthetic worlds is beginning to blur.
3D movies in movie theaters and at home lead to completely new viewing patterns. This is a development that has just begun but, through advances in technology and the increasing quality of representation, it will expand its potential to fascinate people.
Science fiction becomes reality. Unreal worlds »on the wire« unfold. This intrigues but also confuses us. We try to gaze into the future. We are looking to spur discussion about the consequences of current developments.
Augmented / Virtual Reality
Layers of Reality
Google has just launched its project »glass«. The head-mounted display is not a new concept, but it will change the perception of our environment permanently.
A new generation of projectors is projecting images additively with diode lasers as a real image directly onto the retina. Thanks to mi-niaturization and voice command, augmented reality promises to change our perception of reality profoundly. Augmented reality will give us additional information about all things and people around us. Just like the cell phone, this will call for a new cultural technique we will have to adapt to.
How will our lives change when we can get all of the data available on another person, the building or other object standing in front of us, or just about any product while shopping?
The fire of the sun on earth
Nuclear fusion is a nuclear reaction in which two nuclei ›merge‹ into a new nucleus releasing energy during the process. This process is the reason that the sun and other stars shine.
Digression: Of crucial importance to achieving a nuclear fusion is the cross section, the degree of probability that the colliding nuclei will react with one another. Sufficiently large cross sections become available only when the nuclei collide at high energy. This is necessary to overcome the Coulomb barrier, the naturally existing, electrical repulsion that exists between positively charged nuclei. If the nuclei reach a distance of only about 10–15 m from one other, they bind together through strong interaction and merge. Exothermic fusion reactions can take place in the form of an energy chain reaction.
This is a key subject of ongoing research and development. The aim is to harness nuclear fusion for the purpose of generating electricity.
Calculating with light
In the foreseeable future photons, instead of electrons, will be used in optical computers. Quantum computers promise to change the physical limits of Moore‘s Law. Since quantum computing will no longer be based on binaries, it promises an enormous performance.
The photon corresponds to the light quantum, the smallest particle of the quantized electromagnetic field. A quantum computer is based on the particular laws of quantum mechanics. Unlike the digital computer, it is not working on the basis of the laws of classical physics and computer science, but on the basis of quantum mechanical states which significantly exceed the rules of the classical theory. The processing of these conditions is based on quantum mechanical principles. Here the principle of superposition and the so-called quantum entanglement are of particular importance.
For the greater part the quantum computer is currently still a theoretical concept. However, there are already a number of proposals on how quantum computers could be materialized. On a small scale, some of these concepts have been tested in laboratories and quantum computers with a few cubits have been implemented. Nevertheless, we are still far away from actual applications and practical uses.
Almost unlimited computing power promises a world without secrets.