Super-Thin Solar Cell

thincell

Solar energy will very likely be the main source of power as the world continues to strive toward greater sustainability. But it won’t be just the large panels that get the job done. In fact, I’m willing to bet that ultra thin and flexible solar cells that can be attached to virtually any surface will be the future. Which is why breakthroughs in this area are so important. And now a team of South Korea scientists has successfully created a super thin solar cell, which is so flexible it can be wrapped around a pencil without causing damage or too much strain to it.

The solar PV cell that they created is one micrometer thick (which is even thinner than a human hair) and it is this thinness that gives it the extreme flexibility it boasts of. It is made from a semiconductor gallium arsenide, which is stamped onto a flexible metal substrate. No adhesive is used in this process, instead it is fused with the electrode on the substrate with a cold welding process that involves applying pressure at 170 degrees Celsius. And the metal layer also acts as a reflector that directs light back onto the cell.

Testing the limits of the cell’s flexibility they found that it can be bent around an object with a radius of 1.4 millimeters. Despite their thinness, the solar cells have an energy conversion efficiency comparable to thicker ones. They also exhibited only one quarter of the strain from the bending compared to a 3.5 micrometers thick cell.

The real-world application of this type of cell would be far-ranging. It could be used on smartphones, fabric, and smart glasses, while it could also easily be integrated into self-powered devices, such as, for example, environmental sensors located in hard to reach places.

There is no definitive word yet on when and if they plan to bring this cell to market.

Super-Thin Solar Cell

thincell

Solar energy will very likely be the main source of power as the world continues to strive toward greater sustainability. But it won’t be just the large panels that get the job done. In fact, I’m willing to bet that ultra thin and flexible solar cells that can be attached to virtually any surface will be the future. Which is why breakthroughs in this area are so important. And now a team of South Korea scientists has successfully created a super thin solar cell, which is so flexible it can be wrapped around a pencil without causing damage or too much strain to it.

The solar PV cell that they created is one micrometer thick (which is even thinner than a human hair) and it is this thinness that gives it the extreme flexibility it boasts of. It is made from a semiconductor gallium arsenide, which is stamped onto a flexible metal substrate. No adhesive is used in this process, instead it is fused with the electrode on the substrate with a cold welding process that involves applying pressure at 170 degrees Celsius. And the metal layer also acts as a reflector that directs light back onto the cell.

Testing the limits of the cell’s flexibility they found that it can be bent around an object with a radius of 1.4 millimeters. Despite their thinness, the solar cells have an energy conversion efficiency comparable to thicker ones. They also exhibited only one quarter of the strain from the bending compared to a 3.5 micrometers thick cell.

The real-world application of this type of cell would be far-ranging. It could be used on smartphones, fabric, and smart glasses, while it could also easily be integrated into self-powered devices, such as, for example, environmental sensors located in hard to reach places.

There is no definitive word yet on when and if they plan to bring this cell to market.

Google Making Breakthroughs in Finding Better Energy Storage Solutions

Alphabet, the parent company of Google, has a so-called X division, which works on highly experimental projects. But a lot of these projects could prove very beneficial in solving some of the world’s biggest problems. This division created Google’s self-driving car, as well as Project Loon, which involves high altitude balloons carrying Wi-Fi. And now it is looking for more efficient and effective ways of high-density energy storage.

This project is called Malta and the energy storage solution they came up with features molten salt storage, which X has paired with cold storage using antifreeze. Molten salt energy storage has been looked at before as a viable solution for energy storage, and paired with antifreeze, it can store energy for days, possibly weeks. As such, it would be perfect for storing renewable energy, which is simply getting discarded in lots of places at the moment.

Reports show that China discards 17 percent of energy produced by wind per year, while Germany tosses away 4 percent. And this year alone, California has had to discard 300,000 megawatt hours of excess electricity from the grid, all of which came from renewable sources. If there was a way to store that energy, it would be enough to power thousands of homes.

The dual thermal energy storage tech that X has come up with can be used to store high densities of energy, while it will also be a lot less expensive than existing solutions. It is also very scalable, since all it would take to expand it would be adding more salt and cold liquid tanks to the system. Also, the salt used can be charged and re-charged several times over its lifespan.

They’ve already built a small prototype of this energy storage system in Silicon Valley. They’re now looking for partners, such as Siemens and GE, to develop a commercial prototype, which can be tested on the grid.

Water Filtration Using Wood Fibers

 

One of the key components of living off-the-grid is an effective method of water filtration, and a team of researchers at the Swedish KTH Royal Institute of Technology has uncovered a simple and affordable way of doing that. They have developed a technique to filter water using wood fibers.

The main aim of this project is to provide clean water in refugee camps, though the method could easily be used in any setting where a green and off-grid water filtration is needed.

The team created a new material out of wood fibers and a positively-charged polymer, which binds bacteria to its surface. In this way, the bacteria in the water are removed and the water is purified. Another use for this new material is also prevention of infection, since it can be used in bandages and plasters.

However, the main aim of this project is providing an affordable and easy to use filter for a portable water purification system, which isn’t reliant on electricity. All that’s needed for it to do its job is gravity, which forces the water through it. The bacteria is removed from the water by the material, while the filter itself doesn’t cause any toxic chemicals to enter the water as is the case with many currently used on-site water filtration options.

The filter they created works on the basis of the positively-charged polymer attracting the negatively charged bacteria and viruses in the water. The bacteria which are stuck to the surface of the polymer in this way cannot get unstuck or reproduce, and they eventually die. No chemicals or antibacterial agents are used in this process, which also means that creating bacterial resistance is not an issue.

Disposal is also easy, since the wood filter can simply be burned once it is no longer effective.

Solar Cells That Harvest Energy All Day Every Day

allweatherext

One huge drawback of going solar is the fact that it only makes sense in areas which get abundant sunshine year-round. However, a team of scientists from China has now come up with a new solar cell, which can harvest energy even when it’s raining.

This solar cell is made using graphene, which has proven to be a very promising material for use in the production of solar cells in the past. One of these properties of graphene is its conductivity, which is such that it allows electrons to flow freely across its surface. So when this material is put into an aqueous solution, the so-called Lewis acid-base reaction occurs, namely that pairs of positively charged ions bind with the material’s negatively charged electrons. Studying this property of graphene, the team developed a solar cell, which can generate power from raindrops.

Raindrops are comprised of various salts, which have positively and negatively charged ions. So when rainwater hits graphene the positive ions bind with the negative ions on its surface. Where the rainwater and graphene come into contact, they form a double-layer of electrons and positively-charged ions, which creates a so-called pseudocapacitor. The two layers thus have a difference in potential, which is sufficient to generate a voltage and current.

allweathercell

The scientists have produced a prototype dye-sensitized solar cell and applied a thin film of graphene to it. They tested this cell in a lab, using salty water made to closely resemble rain. The cell they tested successfully generated hundreds of microvolts and had the solar to electricity conversion efficiency of 6.5 percent. Their next step will be to further refine the cell, and they are confident that they will succeed in creating a market-ready all-weather solar cell soon.