Tag Archives: green power

Blinds Harness The Sun’s Energy

Solargaps, an Ukrainian startup, have created blinds that generate power from windows.

If, like many Kyivans (inhabitants of Kiev), you live in an apartment, and your home doesn’t even have its own roof, there is now a solution. Enter Ukrainian startup SolarGaps, which has created a device that combines solar panels with venetian blinds to allow those who live in apartments to generate their own electricity.

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It’s not simple to install solar panels on roofs in big cities,” founder Evgeny Eric, 39, told the Kyiv Post. “Our solution helps people produce green energy more easily, cheaply and more accessibly.
Once installed on a window, the smart blinds with built-in solar panels can generate over 100 kilowatt of energy a month – the average amount of energy consumed monthly by one Ukrainian citizen, Eric said.

Any energy surplus can either be stored in batteries or be sold to the electricity company as green energy – for a higher price – although to do this a two-way electricity meter has to be installed by the local electricity provider.

To absorb as much solar radiation as possible, the panels, which are equipped with a light sensor, follow the light source, automatically changing angle according to the sun’s position. So that a room is bright enough during the day, the blinds automatically open when a person enters the room where they are installed. They also can be controlled via a smartphone application that currently connects to the device via Bluetooth. The latest app version will link to the device via the internet, using Android and iOS smartphones. The first prototype was created six months ago and installed in Eric’s apartment.

You just plug the blinds into a socket and they compensate for a part of your electricity consumption, that’s it,” Eric said. “We worked out this solution for ourselves, and now we’re offering it to others.

Source: https://solargaps.com/

Squeeze And Get More Power Out Of Solar Cells

Physicists at the University of Warwick have published new research in the Journal Science  that could literally squeeze more power out of solar cells by physically deforming each of the crystals in the semiconductors used by photovoltaic cells. The paper entitled the “Flexo-Photovoltaic Effect” was written by Professor Marin Alexe, Ming-Min Yang, and Dong Jik Kim who are all based in the University of Warwick’s Department of Physics.

The Warwick researchers looked at the physical constraints on the current design of most commercial solar cells which place an absolute limit on their efficiency. Most commercial solar cells are formed of two layers creating at their boundary a junction between two kinds of semiconductors, p-type with positive charge carriers (holes which can be filled by electrons) and n-type with negative charge carriers (electrons). When light is absorbed, the junction of the two semiconductors sustains an internal field splitting the photo-excited carriers in opposite directions, generating a current and voltage across the junction. Without such junctions the energy cannot be harvested and the photo-exited carriers will simply quickly recombine eliminating any electrical charge. That junction between the two semiconductors is fundamental to getting power out of such a solar cell but it comes with an efficiency limit. This Shockley-Queisser Limit means that of all the power contained in sunlight falling on an ideal solar cell in ideal conditions only a maximum of 33.7% can ever be turned into electricity.

There is however another way that some materials can collect charges produced by the photons of the sun or from elsewhere. The bulk photovoltaic effect occurs in certain semiconductors and insulators where their lack of perfect symmetry around their central point (their non-centrosymmetric structure) allows generation of voltage that can be actually larger than the band gap of that material. Unfortunately the materials that are known to exhibit the anomalous photovoltaic effect have very low power generation efficiencies, and are never used in practical power-generation systems. The Warwick team wondered if it was possible to take the semiconductors that are effective in commercial solar cells and manipulate or push them in some way so that they too could be forced into a non-centrosymmetric structure and possibly therefore also benefit from the bulk photovoltaic effect.

Extending the range of materials that can benefit from the bulk photovoltaic effect has several advantages: it is not necessary to form any kind of junction; any semiconductor with better light absorption can be selected for solar cells, and finally, the ultimate thermodynamic limit of the power conversion efficiency, so-called Shockley-Queisser Limit, can be overcome“,  explains Professor Marin Alexe  (University of Warwick).

Source: https://warwick.ac.uk/