New technologies in Solar Energy
conversion
Following are some of the promising technologies to tap solar energy in future.
We list them one by one.
Development of catalyst to Ease breaking down of Carbon
Dioxide
Being able to use plain old CO2 as a carbon source for synthetic chemical reactions would open
up whole new areas of carbon chemistry, but to date, efforts in the lab have fallen short of
achieving what plants do with ease. Previously, chemical activation of carbon dioxide (breaking
the C-O bonds in CO2) has only been achieved with special metal catalysts that require a great
deal of input energy.
Now, however, a team of chemists headed by Markus Antonietti have taken an important step
toward much more efficient cleavage. Describing their work in the journal Angewandte Chemie,
Antonietti relates how his team has successfully activated CO2 for use in a chemical reaction by
using a special new type of metal-free catalyst: graphitic carbon nitride.
Antonietti says his team's use of a metal-free catalyst was inspired by plants, where
photosynthesis creates carbamates from the bonding of CO2 to nitrogen atoms. Subsequent
experimentation eventually revealed a new class of nitrogen-rich catalysts made of flat, graphitelike layers that allow the formation of carbamates. The individual layers consist of ring systems
of carbon and nitrogen atoms - which the team has dubbed graphitic carbon nitride.
Using the new catalyst, the researchers were able to oxidize benzene to phenol, the by-product
being carbon monoxide (CO), which can be used directly for chemical syntheses. Like
photosynthesis, the reaction seems to occur by way of carbamates. In the first step, CO2 binds to
individual free amino groups present in the carbon nitride. It then oxidizes the benzene to phenol,
and in the end the highly desirable CO separates from the catalyst. "This could make novel,
previously unknown chemistry of CO2 accessible," said Antonietti. "It may even be the first step
in artificial photosynthesis."
The research is being done at Max Planck Institute for Colloids and Interfaces.
CONVERTING CARBON DIOXIDE INTO FUEL BY
TAPPING SOLAR ENERGY (NANOTECHNOLOGY)
We all want to leave smaller carbon footprints, the more we learn how harmful carbon dioxide,
primarily in the form of exhaust from burning fossil fuels, can be to air quality. But imagine
being able to personally claim credit for removing millions of tons of CO2 from the atmosphere.
That's exactly what James C. Liao, the Chancellor's Professor of Chemical and Biomolecular
Engineering at the UCLA Henry Samueli School of Engineering and Applied Science, may soon
be able to boast.
His technological breakthrough — turning CO2 into alternative fuel — was acknowledged June
21 in Washington, D.C., when he was presented with the 2010 Presidential Green Chemistry
Challenge Award from the U.S. Environmental Protection Agency. The awards, launched 15
years ago, promote research on and development of technologies that reduce or eliminate
hazardous waste in industrial production.
While minimizing hazardous waste and other harmful byproducts, alternative technologies like t
Liao's also "often cost less, proving once again that what is good for the environment is also
good for our economy," Jackson told the crowd of several hundred packed into the Ronald
Reagan Building in downtown Washington.
Efforts to create alternative fuels from CO2 and other byproducts have long been hampered by
an inability to produce fuels with high energy.
Ethanol made by fermentation can be used as a fuel additive, but its use is limited by its low
energy content. Higher alcohols — those with more than two carbons in the molecule — have
higher energy content, but naturally occurring microorganisms do not produce them.
Dr. Liao and his colleagues have genetically engineered microorganisms to make higher alcohols
from glucose or directly from carbon dioxide. His work makes renewable higher alcohols
available for use as chemical building blocks or as fuel.
In particular, Liao has developed methods for the production of more efficient biofuels by
genetically modifying E. coli bacteria and by modifying cyanobacterium to consume CO2 to
produce the liquid fuel isobutanol — a reaction powered directly by energy from sunlight,
through photosynthesis.
Put more simply, Liao said, he and his team have discovered how to "turn exhaust into fuel."
"The first practical application will probably be to hook up to power plants and recycle some of
the CO2 and make it into fuel," Liao said. The technology has multiple uses but "the first goal is
to use it as a gasoline replacement."
James C. Liao accepts the 2010 Green Chemistry Challenge Award
Organisms typically produce a large number of amino acids, which are the building blocks of
proteins. In their research, Liao's team examined the metabolism of amino acids in E. coli and
changed the metabolic pathway of the bacterium by inserting two specially coded genes. One
gene, from a cheese-making bacterium, and another, from a type of yeast often used in baking
and brewing, were altered to enable E. coli's amino acid precursor, keto acid, to continue the
chain-elongation process that ultimately resulted in longer-chain alcohols.
They used E. coli because the genetic system is well known, it grows quickly and we can
engineer it very easily. But this technique can actually be used on many different organisms,
opening the door to vast possibilities in the realm of polymer as well as drug manufacturing.
ARTIFICIAL PHOTOSYNTHESIS ON A
NANOTECHNOLOGICAL SCALE
A team of MIT researchers has found a novel way to mimic the process by which plants use the
power of sunlight to split water and make chemical fuel to power their growth.
In this case, the team used a modified virus as a kind of biological scaffold that can assemble the
nanoscale components needed to split the hydrogen and oxygen atoms of a water molecule.
Splitting water is one way to solve the basic problem of solar energy: It’s only available when
the sun shines. By using sunlight to make hydrogen from water, the hydrogen can then be stored
and used at any time to generate electricity using a fuel cell, or to make liquid fuels (or be used
directly) for cars and trucks.
Now, let us see solar energy plus a virus named M13 that researchers at MIT are using to split
water into hydrogen and oxygen. This hydrogen could be used to fuel cars.
This process uses direct solar energy (no electricity is created) to stimulate the bacteria.
According to MIT, their research team, “…engineered a common, harmless bacterial virus called
M13 so that it would attract and bind with molecules of a catalyst (the team used iridium oxide)
and a biological pigment (zinc porphyrins). The viruses became wire-like devices that could very
efficiently split the oxygen from water molecules.”
The process is much less energy intensive than the brute force electrolysis of water to create
hydrogen fuel. The energy that would be spent will be on creating the devices to split the water
and not on the process itself of splitting water.
The photosynthesis that occurs in naturally plants is a twofold process. First, natural pigments
capture sunlight and second catalysts aid in splitting water. In the MIT method, solar panels will
capture energy and transfer that energy directly to the viruses and other nanoscale structures to
split water into hydrogen and oxygen.
Artificial photosynthesis is an important emerging field right now with many researchers
working concurrently on the solution of splitting water using algae, bacteria, or harmless viruses
to do the dirty work. More work of course is needed to perfect, scale up and commercialize these
processes. But, it’s only a matter of time until this happens on a large scale.
ARTIFICIAL PHOTOSYNTHESIS USING INORGANIC
WAYS
Daniel George Nocera (born 3 July 1957) is an American chemist and university professor. He
is presently the Henry Dreyfus Professor of Energy and Professor of Chemistry at MIT. Nocera
and his researchers received media attention beginning in 2007 when he declared that a better
understanding of the photosynthesis process could lead to economical storage of solar energy as
chemical fuel.
He later announced that his group had developed a highly efficient anode electrocatalyst (cobalt
phosphate) for use in electrolysis of water employing inexpensive materials. His work on
artificial photosynthesis centers around the basic mechanisms of energy conversion in biology
and chemistry, particularly in the theory of proton coupled electron transfer. He is also the
director of the Solar Revolution Project at MIT which seeks to create innovations in
photocatalytic water splitting towards the use of solar energy in large scale, mainstream
applications.
A great technological challenge facing our global future is the development of renewable energy.
Rising standards of living in a growing world population will cause global energy consumption
to increase dramatically over the next half-century. Energy consumption is predicted to increase
at least two-fold, from our current burn rate of 12.8 TW to 28 – 35 TW by 2050. A short-term
response to this challenge is the use of methane and other petroleum-based fuels as hydrogen
sources. However, external factors of economy, environment, and security dictate that this
energy need be met by renewable and sustainable sources with water emerging prominently as
the primary carbon-neutral hydrogen source and light as an energy input. This area of research in
our group is summarized by a simple equation:
solar light + H2O = fuel
The above equation is aimed at driving the energetically unfavorable, water-splitting reaction to
produce fuel – hydrogen and oxygen. The photon may be captured directly by a transition metal
catalyst or indirectly by a transition metal catalyst at the surface of a photovoltaic (PV) cell. The
transition metal complex can the use the solar converted energy (from the PV or directly) to act
on water and rearrange its bonds to produce hydrogen and oxygen – a solar fuel. In this way,
solar photons are converted into high-energy chemical bonds, the energy of which can be
released in a fuel cell. The construction of such a cycle, however, reveals daunting challenges
because it relies on chemical transformations that are not understood at the most basic levels.
Unexplored basic science issues are immediately confronted when the water splitting problem is
posed in the simplest chemistry framework,
The overall transformation is challenging because: (1) It is a multielectron process, (2) proton
transfer must accompany electron transfer (i.e., PCET) – both electron and proton inventories
need to be managed, and (3) strong bonds need to be activated to close a catalytic cycle.
Their research efforts have addressed the foregoing italicized research themes by expanding the
reactivity of metal complexes in ground and electronic excited states beyond conventional oneelectron transfer. They have created molecules that react in multielectron steps from their
electronic excited states. They are inventing a myriad of new ways to photoactivate stable metalligand bonds, especially those involving oxygen. Against this backdrop of knowledge, hydrogenand oxygen-producing catalysts have been developed and are continually being improved.
SOLAR ENERGY TAPPING FUTURE CITIES
The Botanical City Concept
We live remarkably convenient lives in cities that have developed along economic lines.
But happiness should be measured separately from material wealth. It should have Contact with
Nature, Time passed leisurely in cultural pursuits, Healthy and comfortable living and blending
into and living and growing harmoniously with Nature as part of the ecosystem.
We can make a city, like a single plant, that embodies these principles. Shimizu’s model of a
new environmental city was born from these aspirations. Its a city that grows just like a lily
floating on the water. A city of the equatorial region where sunlight is plentiful and the impact of
typhoons is minimal.
A City in the Sky with a Sense of the Sky and Greenery (City in the Sky: A Residential
Zone with 30,000 Inhabitants)
An area rising 700-1,000m above the equator.
Here you find an energy-conserving compact city that is pleasant and peaceful, with no strong
winds and a temperature of about 26-28°C year-round.
A Waterside Resort with a Sense of the Ocean and Greenery (Waterside: A Residential
Zone with 10,000 Inhabitants)
In the oceanfront area, the low-rise townhouses are bases for living. Summer beaches spread out
before your eyes, and the lagoons are teeming with fish and shellfish. Living here raises the
happiness index, not economic indexes.
New Industry Incubation Office and Plant Factory (Tower: A Work Zone for 10,000
People)
New business models are born here. Future businesses that fuse Nature and technology will
begin.
Human-Scale Distances and Configurations: An Urban Village That Grows Like a Lily
Floating on the Water
A compact village with a walkable radius of 1km is defined as a cell (district).
Cells are added to form modules (cities), which join to form units (countries).
DEVELOPMENT OF ENERGY EFFICIENT BIOFUELS
Algae fuel, also called algal fuel, algaeoleum or second-generation biofuels, is a biofuel which
is derived from algae. During photosynthesis, algae and other photosynthetic organisms
capture carbon dioxide and sunlight and convert it into oxygen and biomass. Up to 99% of the
carbon dioxide in solution can be converted, which was shown by Weissman and Tillett (1992)
in large-scale open-pond systems. Several companies and government agencies are funding
efforts to reduce capital and operating costs and make algae fuel production commercially
viable. The production of biofuels from algae does not reduce atmospheric carbon dioxide
(CO2), because any CO2 taken out of the atmosphere by the algae is returned when the biofuels
are burned. They do however eliminate the introduction of new CO2 by displacing fossil
hydrocarbon fuels.
The United States Department of Energy estimates that if algae fuel replaced all the petroleum
fuel in the United States, it would require 15,000 square miles (40,000 km2). This is less than 1⁄7
the area of corn harvested in the United States in 2000. However, these claims remain
unrealized, commercially.
Trials have been carried with aviation biofuel by Air New ZealanD, Continental Airlines and
Virgin Airlines.
In February 2010, the Defense Advanced Research Projects Agency announced that the U.S.
military was about to begin large-scale production oil from algal ponds into jet fuel. After
extraction at a cost of $2 per gallon, the oil will be refined at less than $3 a gallon. A larger-scale
refining operation, producing 50 million gallons a year, is expected to go into production in
2013, with the possibility of lower per gallon costs so that algae-based fuel would be competitive
with fossil fuels. The projects, run by the companies SAIC and General Atomics, are expected to
produce 1,000 gallons of oil per acre per year from algal ponds.
Research into algae for the mass-production of oil is mainly focused on microalgae; organisms
capable of photosynthesis that are less than 0.4 mm in diameter, including the diatoms and
cyanobacteria; as opposed to macroalgae, such as seaweed. The preference towards microalgae is
due largely to its less complex structure, fast growth rate, and high oil content (for some species).
However, some research is being done into using seaweeds for biofuels, probably due to the high
availability of this resource.
The following species listed are currently being studied for their suitability as a mass-oil
producing crop, across various locations worldwide.
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Botryococcus braunii
Chlorella
Dunaliella tertiolecta
Gracilaria
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Pleurochrysis carterae (also called CCMP647)
Sargassum, with 10 times the output volume of Gracilaria.
In addition, due to its high growth rate, Ulva has been investigated as a fuel for use in
the SOFT cycle, (SOFT stands for Solar Oxygen Fuel Turbine), a closed-cycle power
generation system suitable for use in arid, subtropical regions
Algae can produce up to 300 times more oil per acre than conventional crops, such as rapeseed,
palms, soybeans, or jatropha. As Algae has a harvesting cycle of 1–10 days, it permits several
harvests in a very short time frame, a differing strategy to yearly crops (Chisti 2007). Algae can
also be grown on land that is not suitable for other established crops, for instance, arid land, land
with excessively saline soil, and drought-stricken land. This minimizes the issue of taking away
pieces of land from the cultivation of food crops (Schenk et al. 2008). Algae can grow 20 to 30
times faster than food crops.
University of Texas plant physiologist Jerry Brand has spent the past decade lovingly tending the
world's largest collection of pond scum.
The basic idea is simple: Algae are little machines that convert solar energy into oily material
that can be processed into biofuel. Technically, it's possible to harvest a batch of algae, process
the oils into fuel and run a combustion engine like the ones in cars and trucks. To get more oil,
just grow more algae.
"Algae have been on the back burner of most people's minds. It's pond scum. It's seaweed," he
says. "Those of us who have studied algae for decades realize there is a tremendous genetic
potential."
But even Mr. Brand didn't recognize that potential right away. He came to algae as a Ph.D.
student studying photosynthesis in the 1970s. Algae proved to be convenient test subjects.
Meanwhile, the university acquired the algae collection in 1976. The samples' roots are traced to
1939, when scientist Ernst G. Pringsheim fled Prague ahead of the Nazis, leaving behind most of
his belongings but taking his algae collection. The samples went first to Cambridge, then left
England for Indiana University and ended up here in Austin.
Thanks to his longstanding work with algae, Mr. Brand was tapped as director of the collection
in 1998.
The collection continues to expand; scholars bring Mr. Brand individual samples from around
the world, and occasionally a scientist retires and looks for a new home for his own collection. In
2003, E. Imre Friedmann, a microbiologist interested in how life adapts to extreme
environments, turned over much of the algae he acquired on trips to Antarctica and to the Gobi
desert in Mongolia.
But biofuels entrepreneurs are picky. They're searching for algae that produce oil -- not all of
them do -- and ones that grow quickly. The ideal is algae that do both.
One of the more popular algae strains among biofuel scientists is Neochloris oleoabundans,
physically undistinguished green dots remarkable for their ability to produce large quantities of
oil when deprived of nutrients. The collection's samples of these algae, stored in flasks on
shelves and frozen in thermoses filled with liquid nitrogen, are the descendants of samples found
in the 1950s in a sand dune in Rub al Khali, Saudi Arabia's legendary sea of sand known as the
Empty Quarter.
Lunar Solar Power Generation -LUNA RINGThe Energy Paradigm Shift Opens the Door to a Sustainable Society. A shift from economical
use of limited resources to the unlimited use of clean energy is the ultimate dream of all
mankind. The LUNA RING, our lunar solar power generation concept, translates this dream into
reality through ingenious ideas coupled with advanced space technologies.
Virtually inexhaustible, nonpolluting solar energy is the ultimate source of green energy that
brings prosperity to nature as well as our lives. Shimizu Corporation proposes The LUNA RING
for the infinite coexistence of mankind and the Earth.
How Lunar Solar Energy Reaches the Earth
The Solar Belt Made from Lunar Resources -Constructing a
lunar solar power plantExploiting Lunar Resources
Lunar resources will be used to the fullest extent possible in constructing the Solar Belt.
Water can be produced by reducing lunar soil with hydrogen that is imported from the Earth.
Cementing material can also be extracted from lunar resources. These materials will be mixed
with lunar soil and gravel to make concrete. Bricks, glass fibers and other structural materials
can also be produced by solar-heat treatments.
The Solar Belt Configuration
1. Lunar solar cells
To ensure continuous generation of power, an array of solar cells will extend like a belt
along the entire 11,000km lunar equator. This belt will grow in width from a few
kilometers to 400km.
2. Electric power cables
The cables will transfer the electric power from the lunar solar cells to the transmission
facilities.
3. Microwave power transmission antennas
The 20km-diameter antennas will transmit power to the receiving rectennas. A guidance
beacon (radio beacon) brought from the Earth will be used to ensure accurate
transmission.
4. Laser power transmission facilities
High-energy-density laser will be beamed to the receiving facilities. A guidance beacon
(radio beacon) brought from the Earth will be used to ensure accurate transmission.
5. Transportation route along the lunar equator
Materials needed for the construction and maintenance of the Solar Belt will be
transported along this route. Electric power cables will be installed under the
transportation route.
6. Solar cell production plants
The plants will move automatically while producing solar cells from lunar resources and
installing them.
Better photovoltaic efficiency
It seems like every day we hear about a new technology that may provide the next generation of
clean, green power. Whether it's algae, wind, biomass, geothermal or some improvement on an
existing technology, supposed saviors are always around the corner. Into this fraught landscape,
enter nano flakes -- a semiconductor nanostructure that may point the way for the next
generation of solar-cell energy production.
Nano flakes are the work of Dr. Martin Aagesen, a researcher at the University of Copenhagen.
In 2007, Aagesen claimed that he "discovered a perfect crystalline structure" that could allow the
harvesting of 30 percent of solar energy directed at a surface
Currently, solar panels, at best, are only able to convert about 15 to 20 percent of sunlight into
energy
Aagesen’s nano flake technology distinguishes itself by its promises of greater efficiency but
also by its structure. Silicon that is arranged in a pure crystalline structure normally doesn't
conduct electricity well. That's why most silicon-based solar panels have impurities built in -- to
allow electrons to move around and fill in gaps, creating an electric field.
Some experts argue that $1 per watt of energy production is the proverbial tipping point for solar
power, and it remains a much-talked-about milestone for solar-power producers [source:
Hutchinson]. In February 2009, a company called First Solar announced that it had surpassed the
vaunted $1 per watt threshold. But there are still many barriers in the way, including the
extraction costs associated with the cadmium telluride, the material that First Solar uses in its
panels, instead of silicon.
In June 2007, Sanyo announced a prototype of a silicon-based solar cell that has an efficiency of
22 percent
Besides cutting costs, large-scale solar adoption may also depend on finding innovative ways to
use the technology. Massive solar arrays -- such as the one planned for the Ivanpah Valley in the
Mojave Desert that would use 318,000 mirrors -- pose environmental hazards, as they require
clear-cutting huge tracts of scrub and desert lands that support wildlife and also absorb carbon
dioxide. One possible solution is distributed energy generation, in which millions of homes,
buildings and private properties have small solar-panel arrays that harvest energy and sell the
excess back to a smart grid.
With that in mind, here are some other emerging technologies to look for:
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More efficient methods of solar energy storage, such as heating liquids into steam (and
keeping them in that state)
Cheaper ways to produce solar cells, such as by using inkjet printing
A solid-state heat engine created by the Super Soaker inventor that boasts 60 percent
efficiency
Cheap, super-thin CIGS (copper, indium, gallium, selenide) solar films that aren't made
from silicon
Dye-laden glass or plastic plates that help to focus photons onto solar arrays
A liquid solar array that places a solar panel on the surface of a body of water and uses a
plastic lens to concentrate incoming sunlight