Tag Archives: energy

Gravity, An Alternative Energy

A Dutch architect has developed a new technique to generate free energy in a sustainable way at home, whereby energy is released by perpetually unbalancing a weight — offering an alternative to solar and wind technology.

CLICK ON THE IMAGE TO ENJOY THE VIDEO

Gravity, an inexhaustible and always present source of power for harvesting energy from falling or tilting objects. 

CLICK ON THE IMAGE TO ENJOY THE VIDEO

Intuitively, I thought that gravity must have something to offer, given that everything is drawn to earth,” co-creator Janjaap Ruijssenaars of Universe Architecture said. “By unbalancing a weight at the top that is only just stable, using little force, a large force is created at the bottom at a single point. The idea was that this should yield something.”

Scientists are calling the patent-pending technique a breakthrough.

Thanks to clever use of gravity, the energy yield from the so-called Piezomethod, which converts mechanical pressure into electrical energy, is increased from 20 to 80 percent,” said Theo de Vries, system architect and senior lecturer of the group Robotics and Mechatronics, associated with the University of Twente. “Ruijssenaars literally turned the method on its head, as a result of which we, as scientists, have started to look at this method in a new light. Everything that is currently offered as mechanical energy will actually be useful, thanks to the invention.

In situations where we cannot work sustainably with solar modules, we may well be able to use this new technique,” said Professor Beatriz Noheda, faculty of Mathematics and Natural Science at the Rijksuniversiteit Groningen who believes piezoelectric energy harvesting is a real part of the future.

Practical applications are being sought for the technique, such as the manufacture of a sustainable and, therefore, “cleanphone charger, or a generator for lighting in homes, among endless other possibilities.

Source: https://www.reuters.com/
AND
http://www.uco.es/

Perovskite Solar Cells One Giant Step Closer To The Market

Harnessing energy from the sun, which emits immensely powerful energy from the center of the solar system, is one of the key targets for achieving a sustainable energy supplyLight energy can be converted directly into electricity using electrical devices called solar cells. To date, most solar cells are made of silicon, a material that is very good at absorbing light. But silicon panels are expensive to produce.

Scientists have been working on an alternative, made from perovskite structures. True perovskite, a mineral found in the earth, is composed of calcium, titanium and oxygen in a specific molecular arrangement. Materials with that same crystal structure are called perovskite structuresPerovskite structures work well as the light-harvesting active layer of a solar cell because they absorb light efficiently but are much cheaper than silicon. They can also be integrated into devices using relatively simple equipment. For instance, they can be dissolved in solvent and spray coated directly onto the substrate.

Materials made from perovskite structures could potentially revolutionize solar cell devices, but they have a severe drawback: they are often very unstable, deteriorating on exposure to heat. This has hindered their commercial potential. The Energy Materials and Surface Sciences Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), led by Prof. Yabing Qi, has developed devices using a new perovskite material that is stable, efficient and relatively cheap to produce, paving the way for their use in the solar cells of tomorrow. This material has several key features:

  • First, it is completely inorganic – an important shift, because organic components are usually not thermostable and degrade under heat. Since solar cells can get very hot in the sun, heat stability is crucial. By replacing the organic parts with inorganic materials, the researchers made the perovskite solar cells much more stable..  “The solar cells are almost unchanged after exposure to light for 300 hours,” says Dr. Zonghao Liu, an author on the paper.
  • Second feature: Inorganic perovskite solar cells tend to have lower light absorption than organic-inorganic hybrids, however, but the OIST researchers doped their new cells with manganese in order to improve their performance. Manganese changes the crystal structure of the material, boosting its light harvesting capacity.  “Just like when you add salt to a dish to change its flavor, when we add manganese, it changes the properties of the solar cell,” says Liu.
  • Thirdly, in these solar cells, the electrodes that transport current between the solar cells and external wires are made of carbon, rather than of the usual gold. Such electrodes are significantly cheaper and easier to produce, in part because they can be printed directly onto the solar cells. Fabricating gold electrodes, on the other hand, requires high temperatures and specialist equipment such as a vacuum chamber.

The findings are published in Advanced Energy Materials. Postdoctoral scholars Dr. Jia Liang and Dr. Zonghao Liu made major contributions to this work.

Source: https://www.oist.jp/