10 SOLAR ENERGY TECHNOLOGIES - FUTURE OF POWER

FUTURE SOLAR ENERGY TECHNOLOGIES

SOLAR TECH

1. Generating power from rain drops - future panels

2. New material for solar cells with record break efficiency

   1. Silicon-based solar cells break efficiency records

   2. Japanese company develop new solar cells with record braking 26%+ efficiency.

   3. Perovskite

3. Converting solar energy in to liquid fuel

4. Flexible solar cell research

5. Concentrated Solar Power (CSP) System - Thermal Storage

6. Solar energy storage by using steam piston engines 

7. Transparent (or) Semi transparent solar cells 

8. 3D Solar cells 

9. Space based solar power technology

10. Liquid Metal Energy storage boost solar power

   1. Generating power from rain drops - future panels

Solar panels harness both visible light and infrared light in order to create usable electricity. Even during the grayest days, visible light still gets through rain and clouds. Many technical advances have solar cells quite efficient and affordable in recent years. A big disadvantage remains in the fact that solar cells produce no power when the climate change in raining season. 

Chinese scientist are now able to create electricity with the assistance of rain drops. Each raindrop has an impact energy that is highly dependent on the size of the drop; from a small drizzle drop that has 2 microjoules on impact, to a downpour size drop that carries 1 millijoule of impact energy. For the conversion of solar energy into electricity., the team from ocean university of china (Qindago) and Yunnan Normal University (Kunming, China) develop highly efficient dye-sensitized solar cell. 

Graphene layer could allow solar cells to generate power when it rains. Graphene is a two-dimensional form of carbon in which the atoms are bonded into a honeycomb arrangement. It can readily be prepared by the oxidation, exfoliation, and subsequent reduction of graphite. Graphene is characterized by its unusual electronic properties: It conducts electricity and is rich in electrons that can move freely across the entire layer (delocalized). In aqueous solution, graphene can bind positively charged ions with its electrons (Lewis acid-base interaction). This property is used in graphene-based processes to remove lead ions and organic dyes from solutions.

                                                                                                       These new solar cells can be stimulated by incident light on sunny days and raindrops when it’s raining, yielding an optimal energy conversion efficiency of 6.53 % under 1.5 atmosphere thickness irradiation and current over µA, along with a voltage of hundreds of mV by simulated raindrops.

The salt contained in rain separates into ions (ammonium, calcium and sodium), making graphene and natural water a great combination for creating energy. The water actually clings to the graphene, forming a dual layer (AKA pseudocapacitor) with the graphene electrons. The energy difference between these layers is so strong that it generates electricity.

The technology isn't perfect, and it is a lot less efficient than the top solar panels available at the moment. The rain panels convert about 6.5 per cent of the energy they receive, whereas the world's best solar panels can convert up to 22.5 per cent.

2.  New material for solar cells with record break efficiency

1. Silicon-based solar cells break efficiency records

An international team of researchers from the École Polytechnique Fédérale de Lausanne (EPFL), the U.S. Department of Energy's National Renewable Energy Laboratory (NREL), and the Swiss Center for Electronics and Microtechnology (CSEM), recently demonstrated the higher efficiency of silicon-based multijunction solar cells.

Research paper co-author Adele Tamboli explains that III-V/Si Solar Cells are a big leap forward because they provide high efficiency on the scale of solar cells made only of III-V materials, while providing cost-effectiveness — and this opens the door to creating innovative multi-junction solar cell materials and architectures.

The 35.9% efficiency result (just 2% below the overall triple-junction record) was achieved by adding a third cell consisting of a GaInP/GaAs (gallium arsenide/gallium indium phosphide) tandem cell that was mounted on a silicon bottom cell. This is in enormous contrast with the currently dominant single-junction silicon solar cells in existing photovoltaics, which only achieve 17% to 24% efficiency. The researchers have argued that solar cell-industry actors should move to the silicon-based dual-junction solar cell, which could bring efficiency levels to above 30%.

2. Japanese company develop new solar cells with record braking 26%+ efficiency. 

The silicon - based solar cells that make up a solar panel have a theoretical efficiency limit of 29%, but so far that numbers has proven elusive. Practical efficiency rates in the low 20% range have been considered very good for commercial solar panels. but researchers with Japanese chemical manufacture Kaneka Corporation have built a solar cell with a photo conversion rate of 26.3 percent, breaking the previous record of 25.6%. although it's just a 2.7% increase in efficiency improvements. 

For this record breaking solar cells, the Kaneka researchers also placed low-resistance electrodes towards the rear of the cell, which maximize the number of photons that collected inside the cell from the front. And, as is common on many solar cells, they coated the front of the cell with a layer of amorphous silicon and an anti-reflective layer to protect the cell's components and collect photons more efficiently.

3. Perovskite

In the present study, a team of researchers led by Professor Seok Sang-Il from the Ulsan National Institute of Science and Technology (UNIST) describe a method of producing PSCs that are both highly efficient and photostable. Using methaylammonium lead iodide as the perovskite material and lanthanum-doped barium stannate as the electrode, Furthermore, the new material retains 93 percent of its initial performance after 1,000 hours of exposure to sunlight, showing excellent photostability.

The research team has also proposed a new solar cell manufacturing methodology called the “Hot-Pressing Method.” This method uses temperature and pressure to tightly join two objects, allowing the production of low-cost, high efficiency and stable perovskite solar cells. “This study combines the newly-synthesized photoelectrode material and the hot-pressing method to lower the manufacturing cost to less than half of the existing silicon solar cells

https://www.asianscientist.com/2017/04/tech/perovskite-solar-cells-record-efficiency/

           3. Converting solar energy in to liquid fuel

Scientists Have Figured Out a Way to Convert Solar Energy Into Liquid Fuel. Researchers at Harvard have discovered how to convert solar energy into liquid fuel, potentially accelerating our switch to the alternative-energy source.

At the moment, solar energy can be converted into hydrogen by using photovoltaic cells. The hydrogen can then be stored in fuel cells for future use. But hydrogen has failed to make headway as an energy source in a world that is infrastructurally set up to handle liquid fuels.

 Now, however, scientists have figured out a way of using sunlight to split water into hydrogen and oxygen. They then use a bacterium to convert the hydrogen, plus carbon dioxide, into the liquid fuel isopropanol.

           4. Flexible solar cell research

Flexible solar cell research is a research-level technology, an example of which was created at the Massachusetts Institute of Technology in which solar cells are manufactured by depositing photovoltaic material on flexible substrates, such as ordinary paper, using chemical vapor deposition technology. Researchers develop a novel technique using graphene to create solar cells they can mount on surfaces ranging from glass to plastic to paper and tape, imagine a future in which solar cells are all around us - on windows and walls, cell phones, laptops, and more. 

Circuits of organic photovoltaic materials are deposited in five layers on ordinary paper substrates in a vacuum chamber. It is done by coating conformal conductive polymer electrodes with oxidative chemical vapor, a process known as chemical vapor deposition. Such solar panels are capable of producing voltages exceeding than 50V, which in turn can power appliances at normal lighting conditions.

 Flexible solar modules can be used on curved roofs, or roofs where it does not make sense to install a rack mounting system. In conventional solar panels, the supporting structures of the panel like glass, brackets etc. are mostly twice as costly as the photovoltaic materials manufactured on them. As paper costs approximately a thousandth of glass, solar cells using printing processes can be much cheaper than conventional solar panels. 

This advance in solar technology was enabled by a novel method of depositing a one-atom-thick layer of graphene onto the solar cell — without damaging nearby sensitive organic materials. Until now, developers of transparent solar cells have typically relied on expensive, brittle electrodes that tend to crack when the device is flexed. The ability to use graphene instead is making possible truly flexible, low-cost, transparent solar cells that can turn virtually any surface into a source of electric power.

Flexible Solar Cell Achieves 7.6% Efficiency

https://www.photonics.com/a60679/Flexible_Solar_Cell_Achieves_76_Efficiency

http://news.mit.edu/2017/mit-researchers-develop-graphene-based-transparent-flexible-solar-cells-0728

5. Concentrated Solar Power (CSP) System

CSP Tower technology uses a field of flat mirrors, known as heliostats that track the sun and reflect and concentrate the sun rays onto a boiler located a top of tower (the central receiver). the central receiver then converts the concentrated solar energy collected from the total surface of the heliostats into heat in the form of steam which is later sent to a traditional steam turbine generator to generate electricity.

POWER GENERATION IN TUNISIAThe Power plant will be situated on a 10,000 hectare site on a southern Tunisia. the project will consists of circa 18*125MV CSP towers with molten salt storage producing annual solar output of more than 10,000 Gwh pa (for fully 2.25gw)

                                                                                                                                                                                                            New computer modeling suggests that high temperature TPV conversion – which captures infrared radiation from very hot surfaces – could one day rival combined-cycle turbine systems when combined with thermal storage using liquid metal at temperatures around 1,300 degrees Celsius. Advances in high-temperature components and improved system modeling, combined with the potential for conversion costs an order of magnitude lower than those of turbines, suggest that TPV could offer a pathway for efficiently storing and producing electrical power from solar thermal sources, a new study suggests.

The underlying technologies of high temperature storage and thermophotovoltaic conversion could also be used to produce grid-scale batteries able to rapidly supplement other power sources by storing heat for quick conversion to electricity. The critical challenge to making renewable energy competitive with fossil fuels at the utility scale is making the electricity dispatchable. The cost advantages of thermal storage over electrochemical storage also make a TPV with thermal energy storage (TES) system attractive for converting and storing energy for use on the grid, said Hamid Reza Seyf, a graduate research assistant who did the system modeling.

                CSP SYSTEM WITH THERMAL STORAGE

        If the TPV power block could be made 60 percent efficient, it could compete with most cost effective and efficient heat engine that has ever been achieved commercially, which is accomplished through a tandem turbine based cycle. The cost of turbines is well established and unlikely to see significant decrease, hence the only way to reduce their cost is by increasing their efficiency. However, because current turbines are extremely efficient and operate near their thermodynamic limit, there is little room for efficiency enhancement.

The computational model shows that a TPV system coupled with concentrated solar and storage could be as much as 65 percent efficient. But attaining that would require a long-term research initiative.



6. Solar energy storage by using steam piston engines 

 A number of high-tech solutions for an energy storage system that can overcome that issue are being developed, but many of them have a high cost or are dependent on expensive materials.

However, an older technology could be a viable way forward for solar energy storage, by using steam piston engines and pressure vessels to accumulate and store the energy for when it's needed.

                                                                                                                                                                                                                                                                                                                                 A group of Australian engineers have been developing this novel energy storage solution, and their startup, Terrajoule, already has one demonstration system in place in California, and is taking aim at some promising cost figures by 2015.The Terrajoule system couples concentrated solar with steam engines and an integrated storage system using an insulated pressure vessel to deliver cost-effective solar energy 24 hours a day.

This storage method looks very promising as a robust and low-cost solution for distributed solar energy. since it is impractical to store gaseous steam for later use, the steam is condensed into the mass of water where the energy is stored. the energy lost in this steam-water phase change cycle is less than 2%. 

It combines inexpensive solar power with inexpensive storage and behaves like electric motor plugged into the rigid, or even like a diesel genset. in other words, it can operate 24 hours per day, but without the utility bill or the fuel cost. The result is storage at less than 20% of the cost of batteries, with no degradation, no cycle limits, no toxic or rare materials, and a useful life of at least 25 years.

 7. Transparent (or) Semi transparent solar cells 

The transparent or semi transparent solar cell can be used in a variety of ways. this new type of solar cell is likely to have impact on the technologies we use in daily life in the near future. Researchers at Tohoku University have developed an innovative method for fabricating semitransparent and flexible solar cells with atomically thin 2D materials. The new technology improves power conversion efficiency of up to 0.7% this is the highest value for solar cells made from transparent 2D sheet materials.

Transparent or semi-transparent solar cells with excellent mechanical flexibility have attracted much attention as next-generation smart solar cells. They can be used in various applications such as on the surfaces of windows, front display panels of personal computers and cell phones, and human skin. But issues remain with regards to improving their power conversion efficiency, optical transparency, flexibility, stability and scalability.

                                                                                         

Scientists create highly transparent solar cells for windows that generate electricity

Visibly transparent photovoltaic devices can open photovoltaic applications in many areas, such as building-integrated photovoltaics or integrated photovoltaic chargers for portable electronics. We demonstrate high-performance, visibly transparent polymer solar cells fabricated via solution processing. The photoactive layer of these visibly transparent polymer solar cells harvests solar energy from the near-infrared region while being less sensitive to visible photons. 

The top transparent electrode employs a highly transparent silver nanowire–metal oxide composite conducting film, which is coated through mild solution processes. With this combination, we have achieved 4% power-conversion efficiency for solution-processed and visibly transparent polymer solar cells. The optimized devices have a maximum transparency of 66% at 550 nm. 

                                  8. 3D Solar cells 

Solar energy and 3d printed solar cells are still in the future but closer to being a reality. Recently the technology of 3d printable solar cells has been developed. you can even fold it up to slip into a pocket, then unfold it and watch it generating  electricity again in the sunlight.

3D Printed Solar Palms Provide Sustainable Technology Hubs in Dubai

                                                                                                                                                                                                                          The palm trees, known as Smart Palms, are being developed as “community tech hubs” by D Idea Media, a media, marketing and design company based in Dubai. The 20-foot-tall trees are made from concrete and 3d printed, fiber-reinforced plastic with added ultraviolet and humidity protection. 

They are equipped with mono crystal solar panels, which collect enough solar power to not only provide illumination at night, but to act as WiFi hubs and access points for users to charge their phones, laptops and tablets. Currently, the trees have the capability of charging 50 devices at a time, and project a WiFi radius of approximately 53 meters.

 Touch screens provide information about the surrounding area. Crucially, the trees also have cameras attached, so visitors can take the ever-important selfie while waiting for their devices to charge.

Australian scientists develop 3D printed organic solar cells capable of powering a skyscraper

Among others, a team of 50 Australian scientist from various fields have been working over the past few years to develop paper-thin, organic printable solar cells as part of the victorian solar cell consortium. According to the researchers, the printable panels capable of powering entire skyscrapers and they are hoping to see commercial market production for the printable panels for use starting in low power applications in future.

The researchers have managed to reduce each of solar panel approximately the size of coin and have been able to achieve this manufacturing marvel thanks to 3d printers that have been modified to print with solar ink.

       9. Space based solar power technology

The United States, China, India and Japan all have projects at various stages of development that would see robots assemble solar arrays that could provide the Earth with massive amounts of clean and renewable energy delivered wirelessly. Some variants of the idea could even see as much as 1GW of energy beamed to receivers on Earth -- enough to power a large city.

                                                                                                     
                                                                                                                                                                                                                                                              In space there's no atmosphere, it's never cloudy, and in geosynchronous orbits it's never night: a perfect place for a solar power station to harvest uninterrupted power 24 hours a day, 365 days a year.

The concept has been around since the 1940s when science fiction writer Isaac Asimov posited the idea of a robot-manned space station that delivered energy to Earth via microwaves.

The laser beam option would involve sending small laser-transmitting satellites into space at the relatively low cost of between $500 million and $1 billion. The self-assembling satellite would lower costs and the small diameter of the laser beam would make it easier to collect on the ground. But at just 1MW to 10MW per satellite, many satellites would be needed to provide enough energy. As well as this, laser transmitting satellites would have difficulty beaming power through clouds and rain.

The microwave option would have the advantage of uninterrupted transmission through rain, hail or any other atmospheric conditions and could provide gigawatts of power. Microwave technology, Dr Jaffe explained, has been established for decades: as early as 1964, scientists were able to power a helicopter using microwaves. Dr Jaffe said with a large receiving area the energy from the microwaves was so dissipated that it would present no danger to life.

The chief disadvantage, however, is the fact that as many as 100 launches into space would be required to construct the space stations with costs running into tens of billions. Unfortunately, too, from a public relations standpoint, both microwaves and lasers have negative connotations for most people because they associate microwaves with the oven in their kitchen and lasers with science fiction space battles," Dr Jaffe said.

           10. Liquid metal storage boost solar power

The capturing of solar energy, holding it in a liquid state, and then releasing it as needed as heat, has been demonstrated at the laboratory scale by technologists working at the Chalmers University of Technology in Sweden.

Solar energy remains regarded by many as the main energy capture form of the future. However, the process is hampered by relative inefficiencies in terms of power conversion and with energy storage. There are also problems with the release of energy, making current technologies less adaptable to ‘energy on demand’ scenarios.

To allow captured solar energy to be stored and released as required the Swedish researchers have shown how solar energy can be transformed into energy stored in the bonds of a chemical fluid. This becomes what is termed a “molecular solar thermal system.” Key to this is the liquid used and a number of organic compounds have been scrutinized for this purpose, such as the norbornadiene-quadricyclane system. Here organometallic-diruthenium compounds have shown promising solar energy conversion and storage properties, which is a product of their inherent stability and large energy storage enthalpies (a measurement of energy in a thermodynamic system).

The Swedish development has made it possible to store and transport the stored solar energy and release it on demand, with near to full recovery of the storage medium, using the organic compound norbornadiene. On exposure to light the chemical converts into quadricyclane.

A group of researchers at the Massachusetts Institute of Technology (MIT) say liquid metals could provide the solution to the solar energy-storage problem, ensuring that the power is available at all times and not just when the sun is shining. 


The researchers are working on commercializing liquid-metal batteries that can store energy for less than $500 per kilowatt-hour. The group launched a startup company, Ambri Inc., and believes it has found an alternative to pumped-
water systems that currently comprise about 95 percent of the country’s energy-storage capacity.


MIT researcher Donald Sadoway said a new storage technology could change renewable energy.