New energy technologies promise brighter future

Nov 19, 2012

In three studies published in the current issue of Technology and Innovation – Proceedings of the National Academy of Inventors, innovators unveil creative technologies that could change our sources of energy, change our use of energy, and change our lives.

Untapped energy in the oceans

The kinetic in the Florida Current and in Florida's can be captured and used, said Howard P. Hanson of the Southeast National Marine Renewable Energy Center at Florida Atlantic University.

"Capturing the of the Florida Current will require both materials advances and new designs for marine current turbines and their efficient deployment," said Hanson. "The hydrokinetic energy of tidal and open-currents, as well as ocean waves, and the thermal potential of the oceanic stratification, can be recovered using ocean thermal conversion technology."

Hanson calls this concept "marine renewable energy," or MRE, and noted in his article that the U.S. Department of Energy has formed three national MRE centers to investigate the resource potential in the oceans and to advance the technology for recovering MRE.

Nanoscale "rectennas" can convert waste thermal energy to electricity

"Converting waste heat to electrical energy can be a reality by using a rectenna, a combination of high frequency antenna and a tunnel diode," wrote three clean energy engineers from the University of South Florida's Clean Energy Resource Center.

According to article co-author Yogi Goswami, , or the infrared (IR) portion of the , is often an overlooked source of and more than half of the power provided by the sun – both directed and re-radiated – lies in the infrared part of the spectrum.

"If the IR radiation potential of the earth could be harvested with 75 percent efficiency, it would generate more energy per unit area than a fixed orientation solar cell located in a prime solar location," said study co-author Subramanian Krishnan.

Rectenna components (antenna and rectifier) used to recapture wasted IR radiation is developed from the decades old concept of using the wave nature of light rather than its thermal effect. Recent advances in nanotechnology have made possible the harvesting of solar energy by rectenna more viable, they said. Recent research has shown that rectenna can be developed at IR frequencies with existing technology and used for IR energy conversion.

For co-author Elias Stefanokos, the approach of using a rectenna in combination with a plasmonic blackbody emitter would improve efficiency of all systems.

"This research will significantly increase the efficiency of photovoltaic cells, at little added cost, by integrating the plasmonic emitter with the cell," said Stefanokos.

Their paper presents the current state-of-the-art in the field of -based conversion with a focus on its critical components.

Nanotechnology solutions for greenhouse light

"Farmers are at the mercy of weather that can cause damage to their crops," wrote a team of physicists from the University of South Florida. "Consequently, greenhouse farming and urban agriculture are being looked at as a more efficient and cost effective way to grow produce."

Sarath Witanachchi, Marek Merlak and Prasanna Mahawela, of the USF Department of Physics, presented the specifics for a new nanophosphor-based electroluminesence lighting device that caters to the exact wavelengths of light required for photosynthesis in indoor, hydroponic agriculture. The new, nanotechnology-based grow light also has the potential to reduce energy costs significantly."

"Conventional technologies used in today's agriculture are inefficient and lead to natural resource waste and degrade the environment," said Witanachchi. "Urban agriculture will become the choice in the future. Nanophosphors required to fabricate the active layer of the electroluminescence device are grown by a microwave plasma process, which was developed at the University of South Florida. This process enables the growth of crystalline nanophosphors directly on a substrate as a uniform coating without further processing steps."

Explore further: Shedding light on solar power

add to favorites email to friend print save as pdf

Related Stories

Plasmonic device converts light into electricity

Nov 09, 2011

(PhysOrg.com) -- While the most common device for converting light into electricity may be photovoltaic (PV) solar cells, a variety of other devices can perform the same light-to-electricity conversion, such ...

Solar-thermal flat-panels that generate electric power

May 01, 2011

(PhysOrg.com) -- High-performance nanotech materials arrayed on a flat panel platform demonstrated seven to eight times higher efficiency than previous solar thermoelectric generators, opening up solar-thermal ...

Comparing energy conversion of plants and solar cells

Jan 16, 2012

Scientists now have a way to more accurately compare how efficiently plants and photovoltaic, or solar, cells convert sunlight into energy, thanks to findings by a research consortium that included a U.S. ...

Recommended for you

Shedding light on solar power

13 hours ago

Everyone wants to save energy, but not everyone knows where to start. Grid Resources, a startup based out of the Centre for Urban Energy's iCUE incubator, is developing a new website that seeks to help homeowners ...

Energy transition project moves into its second phase

13 hours ago

Siemens is studying new concepts for optimizing the cost-effectiveness and technical performance of energy systems with distributed and fluctuating electricity production. The associated IRENE research project ...

Smart data increases the efficiency of wind farms

15 hours ago

Siemens monitors thousands of wind power plants around the world to operate them as efficiently as possible. The company recently opened a remote diagnostics center in Brande, Denmark, where sensor data from ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

unknownorgin
not rated yet Nov 20, 2012
The IR rectenna will need a heatsink. A common thermalcouple is also a form of rectifier because it produces a direct current in the process of lowering the IR frequency with a heatsink. With a temperture difference of a few hundred degrees only a fraction of volt can be expected per junction or device and this reflects the total difference in energy levels between the two freqencys or temperatures. The laws of thermodynamics are difficult to break.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.