Indoor Light and Organic Solar Cells - Energy Without Sunlight

Image Credit: Thor Balkhed - Wuming Wang, PhD Student, and Jonas Bergqvist, Principal Research Engineer in the solar cell laboratory

The new organic solar cell, optimized to convert ambient indoor light to electricity, is being developed by scientists at Sweden's Linköping University, the Chinese Academy of Sciences, and the University of Science and Technology Beijing.

Although the power produced by it is low, the scientists believe it could be enough power to support the many products that the Internet of Things will bring online. 

Low energy consuming devices sensors that detect and measure moisture, particle concentrations, temperature, and other parameters will require small and cheap sources of renewable energy.

The researchers developed an active layer made up of donor and acceptor materials. The new combination - a non-fullerene acceptor blended with a polymer donor - supported the development of a photoactive layer allowing it to absorb the exact wavelengths of light that are typically found in most indoor environments. In a nutshell, donor materials absorb photons, while acceptors acquire electrons. Photovoltaic characterizations of the new solar cell revealed a low energy loss below 0.60 eV.

Two prototypes have been created so far, one measuring 1 square centimeter (0.2 sq in) and the other measuring 4 sq cm (0.6 sq in).

The optimized organic photovoltaic cell, with an area of 1 cm2, showed a power conversion efficiency of 26.1% with an open-circuit voltage of 1.10  V under an LED illumination of 1000 lux (2700 K).

“We are confident that the efficiency of organic solar cells will be further improved for ambient light applications in coming years, because there is still a large room for optimization of the materials used in this work,” said professor Jianhui Hou from the Chinese Academy of Sciences.

The technology is now being commercialized by a Linköping spin-off company. A paper on the research, which was led by the university's Assoc. Prof. Feng Gao, was recently published in the journal Nature Energy.

Sources: Linköping University & Newatlas

Solar City Tower Waterfall for Rio Olympics 2016

Rio de Janeiro, Brasil, was selected for the 2016 Olympic Games and it is planning on building a massive solar powered artificial waterfall called "Solar City Tower", designed by Swiss (Zürich-based) company - RAFAA Architecture & Design.

The 344.5-foot tall (105 meters) Solar City Tower is going to be located on the small Cotonduba Island in Guanabara Bay. The enormous waterfall is almost twice the height of Niagara Falls and will be large enough to accommodate the opening and closing Olympic ceremonies. It is one of the first buildings that are being designed for the 2016 Rio Olympics.

This solar energy generating tower will be using many solar panels to produse electricity for the Olympic village by day. Any excess energy would be used to pump seawater into reservoirs at the top, so that it can be released by night as a spectacular waterfall. The falling water would also help turbines create electricity for the nighttime village.

In addition to producing energy, the Solar City Tower would have an elevator to take visitors to the very top of the tower, where a “glass sky walk” offers panoramic views of the surrounding harbor and Rio. There's even a platform at 297 feet (90.5) that provides bungee jumping. The giant tower would also house an auditorium, cafeteria, shop and amphitheater on the ground level.

The Solar City Tower is RAFAA’s entry in the International Architecture Competition for the 2016 Olympics, where the Brazilian metropolis aims to represent the green city of the future and hope to achieve its goal to host the first-ever zero-carbon Olympics.

Solar Energy from Saharan Sun Could Power Europe

Solar thermal parabolic trough power plant;Source: Solar Millennium, TREC

According to an article published recently in the UK’s Guardian newspaper, EU scientists are working on an ambitious plan to harvest the sun in the Sahara desert in Africa to provide electricity for Europe. Europe needs a lot of electricity, but gets little sun. Vast solar power farms in the Sahara desert could provide clean electricity for the whole of Europe.

The EU scientists are calling for the creation of a series of huge solar farms - producing electricity either through photovoltaic cells, or by concentrating the sun's heat to boil water and drive turbines - as part of a plan to share Europe's renewable energy resources across the continent.

Speaking at the Euroscience Open Forum in Barcelona (ESOF), Arnulf Jaeger-Waldau of the European commission's Institute for Energy, explained how electricity produced in solar farms in Africa, each generating around 50-200 megawatts of power, could be fed thousands of miles to European countries by using high-voltage direct current (DC) transmission lines instead of the conventional alternating current (AC) lines. Energy losses on DC lines are far lower than AC ones where transmission of energy over long distances is uneconomic.

Depending on the size of the grid, building the necessary high-voltage lines across Europe could cost up to €1-billion a year every year till 2050, but Jaeger-Walden pointed out that the figure was small when compared to a recent prediction by the International Energy Agency that the world needs to invest more than $45-trillion in energy systems over the next 30 years.

Doug Parr, Greenpeace UK's chief scientist, welcomed the proposals: "Assuming it's cost-effective, a large-scale renewable energy grid is just the kind of innovation we need if we're going to beat climate change."

The idea for developing a major innovative super-grid based on renewable energy is already gaining political support in Europe, with both the UK Prime Minster Gordon Brown and and the President of France Nicolas Sarkozy, recently backing the north African solar plan.

The scientists say that harnessing solar energy from the Sahara would be especially effective, because the sunlight in that area is much more intense: solar photovoltaic panels in northern Africa could generate up to three times the electricity compared with similar panels in northern Europe. And it would require the capture of just 0.3%of the light falling on the Sahara and Middle East deserts to meet all of Europe's energy needs.

Source: http://www.guardian.co.uk/environment/2008/jul/22/solarpower.windpower?gusrc=rss&feed=environment

Note: An earlier article in Spiegel Online from April 30, describes the project and also how it will benefit Africa because it is important that such an ambitious development is sustainable and beneficial to both continents. Read more: "Is Desert Solar Power the Solution to Europe's Energy Crisis?"

For the original plan visit: http://www.desertec.org/concept.html

Rotating Skyscraper Powered by Wind and Sun in Dubai

The Italian architect David Fisher said he is ready to start construction on a  futuristic rotating skyscraper in Dubai that will be "the world's first building in motion". The modern "Dynamic Tower" construction, which would be energy self sufficient and cost about 700 million dollars to build, will represent an 80-storey tower with revolving floors that give it an ever-shifting shape. 

The spinning floors, hung like rings around an immobile central column, would offer residents a constantly changing view of the city's skyline and the Persian Gulf. Each floor will rotate independently at different speeds. It will take between one and three hours for the floors to make a complete rotation.

Rotating floors are just one of several futuristic features in the building. Using wind and solar power, it will generate more electricity than it uses. Horizontally mounted giant wind turbines fitted between each rotating floor will generate enough energy to power the tower and nearby buildings. 20% of each roof will be exposed to the sun and photovoltaic cells placed on the roof of each rotating floor will produce solar energy. For the interior of the luxury apartments will be used only natural and recyclable materials, including stone, marble, glass and wood.

The dwellings will be assembled in a factory outside Bari in southern Italy, equipped with plumbing and electricity systems, kitchens, bathrooms and ceilings. They will arrive also painted, decorated and, in some cases, with walls hung with artwork. An apartment will cost between $3.7 million to $36 million dollars. Lifts will allow penthouse residents to park their cars right at their apartments.

The plan was revealed by Mr Fisher in a press conference at the Plaza Hotel in New York on June 24. "Today's life is dynamic, so the space we are living in should be dynamic as well," he said. "Buildings will follow rhythms of nature. They will change direction and shape from spring to summer, from sunrise to sunset, and adjust themselves to the weather. In other words, buildings will be alive."

Construction of the rotating skyscraper is scheduled to be completed by 2010.

Update 2020: The project has not been completed yet.