Greener Solar Cells are a Stepping Stone for Renewable Energy

Greener solar cells are now possible thanks to research done by Ayomi Perera, a doctoral student in chemistry, who graduated from Kansas State University.  While other researchers focus on the efficiency of solar cells, Perera’s research is making technology greener by improving dye-sensitized cells.  Perera combines less toxic dye with a bacteria in order to create cells that are more sustainable to living organisms and the environment.

Perera starts by using a special species of the bacteria Mycobacterium smegmatis, that can be found in cornflakes and in the soil.  It produces the protein MspA, which can be applied to various applications after it has been purified.  Once purified, the protein is combined with a dye that is less toxic than traditional dyes.  The mixture is then applied to individual solar cells and tested.

The technology is the first of its type, even though the process doesn’t improve the efficiency of the solar cells.  “This type of research where you have a biodegradable or environmentally friendly component inside a solar cell has not been done before, and the research is still in its early stages right now,” Perera said. “But we have noticed that it’s working and that means that the protein is not decomposed in the light and electric generating conditions. Because of that we believe that we’ve actually made the first protein-incorporated solar cell.”  As oil fields run dry, these new cells are a sustainable alternative for the future.

 

http://www.eurekalert.org/pub_releases/2012-04/ksu-rfb041012.php

A video about Perera’s research is available at http://youtu.be/70-RhGEL38I.

Turbulence Bad for Wind Energy?

Isn’t more wind always a good thing when it come to wind energy? Lawrence Livermore National Laboratory scientist Sonia Wharton and Julie Lundquist of the University of Colorado at Boulder and the National Renewable Energy Laboratory discovered atmospheric wind instability can actually reduce the overall power generated by a wind turbine.

Wind farmers could obtain greater amounts of wind power by studying atmospheric stability.  Wind turbines experiencing constant wind speeds,  rather than variable wind speeds, produce up to 15% more power.  Wharton noted “the dependence of power on stability is clear, regardless of whether time periods are segregated by three-dimensional turbulence, turbulence intensity or wind shear.”

Wind shear is the difference in the direction and wind speed over a short distance in the atmosphere.  It is often overlooked because many wind farmers tend to focus primarily on wind turbulence.

Wharton and Lundquist studied upwind turbines for a year on the West Coast.  By looking at upwind turbines, this reduced the chance of a wake from other turbines.  They discovered that wind speed and power production varied during the day and night, as well as during the four seasons.  During the spring and summer, wind speeds were both stable and unstable; wind during the day was almost always unstable, and more stable during the night.  If wind forecasts included atmospheric stability, then wind farmers would have a better estimate of their total power generated.

http://www.eurekalert.org/pub_releases/2012-01/dlnl-pgi011712.php

 

Developing Nations in Desperate Need of Sustainable Power

Did you know that about a quarter of the world, especially those in rural developing nations, are without access to electricity.  In sub-Sahara Africa, only 8% of the rural population has access.  These nations are in desperation mode when it comes to powering their homes, but the answer may not be through a typical grid system.

Based off their case study in Nigeria, Benedict Ilozor and Mohammed Kama of the Eastern Michigan University, in Ypsilanti, USA, believe renewable energy is the best option for developing nations.  Developed nations have quickly discovered the negative impacts of producing electricity and just how much it cost.  This is why it is vital for developed nations to provide 100% off-grid zero-energy solutions with little maintainance required to emerging nations.

 

From Flickr User SteenT

The researchers discovered that cost is the limiting factor for these nations.  Local community organizations and governments can do little to help the desperate need for electricity.  This leaves the payments of installation and maintenance up to the private sector, commercial banks, or charitable organizations. There has even been ideas for a proposed mortgage that would be paid back as areas grew economically.

If wind turbines, solar panels, or other renewable energy resources are put in place, then these nations will quickly develop. The standards of living will rise, and any loans will be paid off quickly.  Most importantly, the environment will remain healthy because of the extended use of renewable electricity in these developing nations.

 

“Renewable energy sources for generation of electrical power in developing and emerging nations” in African Journal of Economic and Sustainable Development, 2012, 1, 67-79.

http://www.eurekalert.org/pub_releases/2012-02/ip-dsp022812.php

 

 

Third-Generation Biofuel Could Remove Green House Gases and Produce Oil

What is so cool about algae, it grows everywhere but doesn’t seem to serve any purpose?  Scientists have found a way to produce third generation biofuels through the use of algae and sea weeds.  This could allow for a higher oil production yield, while reducing the amount of green house gas emissions in the environment.

Algae are present in all ecosytems and can survive in many different environmental conditions.  Using it as a biofuel could have an enormous amount of potential benefits.  Since algae uses carbon dioxide, it could grow in power plants and free more oxygen into the atmosphere.  In wastewater, algae can remove nitrogen and phosphorous and reduce pollution.  Microalgae can produce large amounts of lipids, proteins, and carbohydrates, which can be converted into biofuel.

What are biofuels?  Liquid, gas, and fuels normally produced from biomass such as methanol, biodiesel, or ethanol are all biofuels.  Biofuels emit lower emissions of exhaust gas, are biodegradable, and renewable. They are divided into two catagories: primary and secondary.  Primary biofuels such as wood are used mainly for heating or cooking.  They take a long time to grow and give off large amounts of carbon dioxide or methane.

Secondary biofuels consist of first, second, and third generation.  Second generation uses thermal and biological processing to turn agricultural biomass and municipal waste into biofuel.  This however requires lots of land that may be needed for food production, and the production process can decrease land-use efficiency.  Third generation avoids these drawbacks by using microscopic organisms such as algae.

The potential benefits are obvious for third generation biofuels; there are still problems with developing proper scale, land-use, and feedstock use.  The production process requires the newest technologies.  Through the use of either flue gas at power plants, or wastewater/sea water, enough carbon dioxide can be utilized to help reduce green house gases and produce biofuel.  With proper technology and more research, it is only a matter of time before algae biofuel enters a large production process.

 

Singh, A., Olsen, S. I. and Nigam, P. S. (2011), A viable technology to generate third-generation biofuel. Journal of Chemical Technology and Biotechnology, 86: 1349–1353. doi: 10.1002/jctb.2666

 

Solar Energy Given New Light

From Flickr User Living Off Grid

There is new hope for solar energy.  A research team of Xiaoyang Zhu’s at the University of Texas at Austin, have discovered a way to increase solar cell efficiency from 31 to 44 percent.  When one photon is absorbed in a semiconductor material, a one-hole electron pair is created.  By separating the pair, electric current can be channeled to a photovoltaic device.

Because excess kinetic energy is lost as heat, efficiency can only be as high as 31 percent.  Zhu has discovered a way to capture some of this lost energy by using a plastic semiconductor material.

In 2010, he and his team converted these hot electrons into electricity by using semiconductor nanocrystals.  66 percent efficiency could only be achieved by using highly focused sunlight rather than raw sunlight until Zhu’s most recent finding.  His team discovered that a photon creates a dark quantum “shadow state” where two electrons can be captured and converted into energy.

By doubling the electrons, efficiency could theoretically reach 44 percent.  This is a huge discovery for a rapidly expanding solar energy field.  Zhu published his findings in Science in 2011.