Solar power engineering is taking to new heights as researchers around the world invent and reinvent methods to harness solar energy to its best capacity. Until now, improving the performance of photovoltaic cells involved only rearranging the layout of solar panels on a flat surface and bringing down their cost. But now, researchers at the Massachusetts Institute of Technology are working on avant-garde 3D designs that would look beyond the traditional outlook of arranging cells on a flat surface or motorized structures keeping them pointed towards the sun. (more…)
In Spain, Andalusia, near Seville, a high 100 metres tower is surrounded by gargantuan mirrors, that run about the tower in concentric circles. These rippling mirrors are able to track sunlight throughout the day and reflect it on to the tower where it is converted into solar energy. The energy created at the plant is sufficient enough to power 6000 homes. The name of the site is PS10. (more…)
Concentrated Solar Power (CSP) plants like Gemsolar and PS10 employ the heliostat layouts to focus a large area of sunrays onto a small area. The concentrated light so collected is converted into heat to generate electricity. However, large areas are required to make CSP plants economically feasible which is not always a logical solution. (more…)
The 'artificial leaf,' a device that can harness sunlight to split water into hydrogen and oxygen without needing any external connections, is seen with some real leaves, which also convert the energy of sunlight directly into storable chemical form. Photo: Dominick Reuter
A MIT research team led by professor Daniel Nocera have developed an ‘artificial leaf’ that aptly describes its job of converting sunlight directly into chemical fuel — hydrogen and oxygen gas which can be stored for later use as a source of energy.
The thin ‘artificial leaf’ made up of a thin silicon solar cell fastened on either side with different catalytic materials need no external circuits or controls to operate. When the leaf is placed in a container of water and exposed to sunlight it quickly starts releasing bubbles – oxygen on one side and hydrogen on another. If a barrier is used the separate the sides, then the bubbles can be collected separately and stored to generate power later. The streams of oxygen and hydrogen bubbles could be fed to a fuel cell which once again combines them into water to generate an electric current.
The ‘artificial leaf’ is lightweight, portable and the “solar water-splitting cells” can be used to power right from individual houses to utility-scale power plants. Other than capturing and storing the streams of bubbles, there is not much of equipment involved in the technology. Just drop it in a container and it does its job.
Nocera, the Henry Dreyfus Professor of Energy and professor of chemistry at MIT explains that they need to take the experiment a step further by breaking down the ‘artificial leaf’ into smaller particles to split water molecules similar to the process of photosynthetic algae rather than leaves. He reasons that small particles will have much more surface area available for efficient harnessing of the sun’s energy.
Commercial production of the ‘artificial leaf’ is still not on the cards as systems to collect, store and use the gases are yet to be developed. But Nocera is happy that the research is heading in the correct direction.
Professor James Barber, a biochemist from Imperial College London who finds this discovery as important as Nocera’s earlier findings of cobalt-based catalyst in 2008, warns that much works remains to be done to resourcefully use the protons derived from the water splitting reaction for hydrogen production.
Diagram shows the idealized arrangement of a vat of molten salt used to store solar heat, located at the base of a gently-sloping hillside that could be covered with an array of steerable mirrors all guided to focus sunlight down onto the vat. Image: Courtesy of Alexander Slocum et al.
MIT team of researchers are working on a system which can supply 24 hours solar energy by designing a concentrated solar power (CSP) that would store heat in molten salts containers. Though this technology has been implemented before by Spanish company Torresol Energy through its “power tower” system, MIT is focusing on lowering the installation, operation and maintenance costs. With extra costs saved, this system will effectively work to help small towns and communities switch themselves from grid to clean energy. (more…)
Graduate student Miles Barr hold a flexible and foldable array of solar cells that have been printed on a sheet of paper.
Just imagine folding a sheet of solar panel into a kiddie airplane or using a small solar sheet to electrify powerful gadgets around the house? Sounds amazing but impossible, doesn’t it! But that’s what a MIT News press release claims to have invented, making it possible to produce photovoltaic cells on paper or fabric looking very much alike to a printed sheet of paper. (more…)
