Tag Archives: renewable energy

So you’re telling me that my electric car’s battery is in the paint?

What comes to mind when you picture a battery? The familiar Duracell Coppertop AA battery? A clunky  automotive battery? The small rectangular battery in your cell phone? Researchers at Rice University are reinventing the concept of batteries and battery packaging by creating a lithium-ion battery with spray paint. That’s right, your local neighborhood hoodlum taggers can now be more energy forward than you sitting at home watching Cops.

A team of researchers from Rice University have demonstrated in a paper in Nature Scientific Reports that special “spray paints” can be used sequentially to build up the layers needed to form a lithium-ion battery. A spray-on battery could be used on a variety of materials, both rigid and flexible. They point out that the technology could be coupled to energy conversion devices such as solar cells.

Simply put, a lithium-ion battery is created by tightly layering cathodes and anodes like in the image shown below. The researchers at Rice University replicate this cylindrical design in a customizable form using the spray coatings that they developed. They applied the battery painting process to a variety of materials including stainless steel, glass, ceramic tile, and flexible polymer sheets. An SEM image of a cross section of the battery is shown below. Each of the spray painted batteries performed as a typical battery. They even applied the spray paint to a coffee mug to spell out the name of their Alma mater while also storing energy. They added that more complicated surface geometries could be possible using different spray nozzle designs that are tailored to the different viscous properties of the paints.

The are a few drawbacks to a spray painted lithium-ion battery. For one, the materials are highly toxic, corrosive, and flammable, hence why they are always tightly packaged and hidden away in their conventional form. Secondly, the batteries are highly sensitive to oxygen and moisture. This sensitivity currently restricts their widespread use because they still have to be packaged like their conventional brethren, reducing their novel promise. A spray painted battery is shown below on a glazed ceramic tile alongside its final packaged form. One of the researchers’ next steps is to develop a sealing layer to protect the batteries from these elements. Because who wants to paint their electric vehicle with a new battery but then have the painter tell them that they always have to keep the car cover on.

Typical lithium-ion battery construction.

Conventional and spray painted lithium-ion batteries.

sem

SEM image of spray painted lithium-ion battery cross section.

prepared

Glazed ceramic tile with spray painted battery prior to packaging (left) and post-packaging (right)

 

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Salinity gradient power rising as a realistic renewable energy source

Estuaries are the locations where river water mixes with seawater. They are found along coastlines throughout the world, but what most people don’t realize is the significant potential to produce clean energy from these mixing water streams. The salinity gradient between the two streams of water contains a large amount of osmotic power, which can be thought of as the available energy (or chemical potential) from the differences in salt concentration between the fresh water and seawater. The enormous amounts of energy released where freshwater and seawater meet “can be utilized for the generation of power through osmosis”, which is “defined as the transport of water through a semi-permeable membrane.” [1]

The idea of obtaining energy from osmosis, or salinity gradient power, has been studied for decades, but in early 2009 two teams were racing to be the first to build a working prototype power plant making salinity gradient power a feasible method for renewable energy generation. Both teams have been working on the development and implementation of a membrane based osmotic process, but their approaches for generating the electricity are very different [2]. Westus (The Centre for Sustainable Water Technology), located in the Netherlands, is focusing on the Reverse Electrodialysis (RED) method to produce electricity. They claim that they will utilize fresh water from the Rhine river and saltwater from the North Sea to construct a type of battery by employing two membranes permeable to ions, but not to water. Utilizing the saltwater, one membrane will allow the passage of positively charged sodium ions into a stream of fresh water and the other membrane will allow the passage of negatively charged chloride ions into another channel of freshwater. The separated charged particles with electrodes placed in both streams makes up the chemical battery, which directly produces electricity. [2] Statkraft, a leading renewable energy group located in Norway, is focusing on Pressure Retarded Osmosis (PRO) as their method to extract electricity from salinity gradients. This method utilizes a membrane, permeable to water, to draw fresh water into the concentrated salt water, thus increasing the pressure in the salt water chamber. The resulting pressure can then be used to drive a turbine to produce electricity. In November of 2009, Statkraft opened the world’s first prototype osmotic power plant in Tofte Norway. [3] This facility had a limited production capacity (of around 4 kW) and is mainly used for testing and validation of data, hopefully leading to the construction of a large commercial power plant by 2015.

While the idea of harvesting free energy from estuaries and salinity gradients may seem like a flawless idea, it comes with both pros and cons. On one side, the technology is considered “as green as it gets”, with the only waste product being brackish water, which flows into the sea mixing with the sea water [2].  It is a constantly flowing source of renewable energy, unlike the intermittent energy provided by sources such as solar or wind power. It can also easily be combined with existing power plants and industries and can be built underground, thus reducing costs and visual pollution [2]. On the other side, the membrane technology still has a long way to go. The membranes are prone to bio-fouling from algae and silt, which reduce the membrane’s lifetime and efficiency. Salinity gradient power is mainly suitable only for places where there is an abundant supply of freshwater meeting saltwater, which clearly favors countries with a large coastline [2]. Also, the environmental impact and environmental policy should be considered for future plants of this type. First off, there are many species of aquatic life that are adapted to survive in waters with a specific range of salinity concentrations, and these power plants could affect the salinity of an area of water. It has been found that large salinity changes in aquatic environments can result in low densities of plants and animals [4]. Then one must consider the environmental policy and impact of structures that intake such large volumes of river water and sea water. These power plants must conform to strict construction permits and environmental regulations.

While many issues dealing with the viability of salinity gradient power as a renewable energy source are still being addressed, advancements in the technology are constantly being made. In June of 2012, Statkraft’s head of osmotic power said “We see that the development of technology is accelerating and that an industry is emerging. The membranes we are testing at Tofte this summer are ten times more efficient than the ones we installed during the opening of the prototype in the autumn of 2009” [5]. Earlier this year, researchers discovered a new more efficient way to harness osmotic power utilizing Boron nitride nano tubes [6]. They claim that a 1 meter-squared membrane using this technology could have the same 4 kW capacity as the whole Statkraft prototype power plant. This experimental device, which is three orders of magnitude more efficient than the current system, could significantly enhance the commercial viability of salinity gradient power as a realistic source of energy [6]. While the ultimate future of salinity gradient power is unknown, it has the potential to be one of the prominent renewable energy sources on the planet.

[1] http://www.statkraft.com/energy-sources/osmotic-power/

[2] http://www.gizmag.com/salinity-power-renewable-energy-osmosis/11206/

[3] http://www.gizmag.com/statkraft-osmotic-power/13451/

[4] Montague, C., Ley, J. A Possible Effect of Salinity Fluctuation on Abundance of Benthic Vegetation and Associated Fauna in Northeastern Florida Bay. Estuaries and Coasts. 1993. Springer New York. Vol. 15 No. 4. Pg. 703-717

[5] http://www.statkraft.com/presscentre/news/statkraft-considering-osmotic-power-pilot-facility-at%20sunndalsora.aspx

[6] http://www.gizmag.com/osmotic-salinity-gradient-power-nanotubes/26623/

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SOOCER BALL- ELECTRICITY GENERATION ( Another Epitome of Ingenuity)

Why I chose this topic ?

Science has always fascinated me. I choose topics which are novel yet unique, where simplicity and ingenuity are the icings on the cake. This topic is truly an epitome of simplicity. Whats even more intriguing is that how is it that a soccer ball which we have been playing for decades has not been thought in the way the inventors from the Harvard school have seen it. Let us analyse the rampant scale of the game of soccer better known as Football worldwide.

SOCCER ( Popularly known as Football ). Is it just a game or a Universal Language ?

Soccrer- A Universal Language.

 

Football is more than just a game in continents like Europe, Africa and Asia. It is more of a religion in various parts of Europe and Brazil. Players like Maradona and Ronaldo are worshipped till date.According to the latest statistical study from FIFA ( Federal International Football Association) about 265 million people play football worldwide [1]. This is almost four percent of the worlds population thus making it the largest played sport in the world [2]. In the United states alone about 8 million soccer balls are made each year. It is to note that Soccer is not popular in the United states. This shows the tremendous scope if we could generate electricity from each soccer ball worldwide.

How did the idea of SOccket Ball originate ?

Soccket Ball- The need of the hour.

Jessica Mathews one of the co-inventors of this technology is from Nigeria.[3] On sharing her experience with us she tells us that power cuts are frequent in Nigeria. Likewise there are millions of developing countries in the world where day to day electicity is a boon.  Their initial idea on designing electiricity generating through football stems from the need to provide power to the under previlaged through affordable ways. On understanding that football is a widely played sport even on the streets, she was fascinated and this paved the foundation for Soccketball ( the brandname for the football which produces electricity). The diesel engines still being used in Nigeria where alarming amounts of pollution were released was also a huge factor to this invention. From shared experiences, the Harvard team also came to realise the bitter truth that many children in the developing countries spent their evenings studying under candlelight, streetlight, or even worse, next to precarious expensive and eco-unfriendly kerosene lamps [4].

How SOckketBall Works- A Simple Concept Of Physics.

Simple High School Physics of the Soccketball.

The working of this ball stem from the simple concept of Faradays Laws of Electicity which all of us must have learnt in at some point of time during our High School. The ball is designed to have an internal inductive coil in its interior core. The kicking of the ball causes a motion kind of like an oscillating one. This motion even if it originates from a mild kick is significant from the physics standpoint. This Movement of the ball during playing forces a magnet through the coil that produces voltage which in turn is tapped throug a capacitor to store electricity. The generated electricity could be tapped if we are discharging this capacitor. You can then simply take the ball to home or to work and plug in a lamp to do work that you might otherwise struggle to do without a reliable and efficient light source. It’s pretty simple like yet extremely effective. The electiricity generated in the ball could be stored for weeks with not a very significant drop in the voltage.

A Video to Illustrate The Working Of The SOckketball .

Pricing of the Soccketball :

Last but not the least, let us discuss the economic aspect of this ball. The only add ons for this device are the magnets, coils and capacitors. These constitute more than 90 percent of the electronic equipment on board of the Soccketball. The cost of building this prototype of course is reasonably high as with any case. It costed close to 70$ [5] for manufacturing. However if manufactured in large scale the inventors from Harvard say they can hit the markets at affordable prices of just 10$. It is to note that a conventional ball could cost anywhere between 5-8$ [6] , thus making the Soccketball not very expensive from the conventional balls. The innnovative idea, affordable price and simplicity make the Soccketball truly more than an innovation of the year. It does has tremendous scope and am certain would reach Zenith’s height.

REFERENCES :

1. http://www.fifa.com/mm/document/fifafacts/bcoffsurv/emaga_9384_10704.pdf

2. http://www.fifa.com/mm/document/fifafacts/bcoffsurv/emaga_9384_10704.pdf

3. http://www.bbc.com/future/story/20120614-dawn-of-a-new-footballing-power

4.  http://www.nutmegradio.com/soccket-the-energy-producing-soccer-ball-takes-the-next-step-in-development/

5. http://matadornetwork.com/sports/the-soccer-ball-that-powers-homes/

6. http://answers.yahoo.com/question/index?qid=20070725164151AAASDdT

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The Evolution of Geothermal

You can only operate a geothermal power plant in the presence of abundant geothermal energy, right? Wrong! Well, sort of.

Source: Personal Collection

Geysir, Iceland
Source: Personal Collection

Historically, the building and operation of geothermal power plants has been tightly restricted to geothermally active areas. Think places like New Zealand, Iceland and the Philippines, where energy literally comes bubbling out of the ground in the form of hot springs, geysers and steam. These areas are usually found on the boundaries of the huge tectonic plates that make up the earth’s lithosphere. Along the borders of these plates, geothermally heated aquifers often flow relatively close to the surface, and these sources of energy are simply begging to be harnessed. The problem is, however, that the areas where these conditions exist make up less than 10 percent of Earth’s dry land.

What About the Cool 90 Percent?

Here is the good news. Geothermal energy originates below the earth’s crust, where the steady decay of naturally radioactive materials produces heat continually. Theoretically, this source of energy is available virtually everywhere, albeit at a greater depth than in the previously mentioned, geothermal areas. The total amount of thermal energy within a depth of 10 km from the earth’s surface is estimated to be 50,000 times greater than all the natural gas and oil resources in the world.

Efforts to harness this hidden energy are already being made in various places across the globe, using a new technology called Enhanced Geothermal Systems (EGS). The method essentially expands traditional geothermal energy production through the use of hydraulic fracturing. It consists of drilling a well to a depth of about 3 to 10 km, where temperature levels are usually between 70 and 315°C. In contrast to EGS, traditional geothermal power plants usually only require wells that are 2 to 3 km deep, in order to reach the same temperature levels. Upon reaching this depth, water is pumped into the dry layers of hot rock at high pressure, which causes the rocks to break and thus increases their permeability. Cold water is then pumped down through an injection well, where it flows through the hot rocks before returning back to the surface as steam, through a separate well. The steam is then run through a turbine where it produces electricity, before it is cooled and condensed, and pumped back into the ground.

Source: EERE

The EGS Process
Source: EERE

An Earth-Shaking Prospect

This technology offers a number of different benefits. First of all, it introduces a vast supply of geothermal energy potential to areas that have hitherto been considered too cold for such ventures. The EGS technology also enjoys many of the same benefits associated with traditional geothermal energy production. It is a steady, renewable source of energy and geothermal plants require very little land space per MW produced, in comparison to other types of power plants. However, drilling in itself is a messy and expensive business, and as the technology is still in its infancy, the upfront cost of an EGS project remains very high.

The technology also has to deal with the issue of induced seismicity, as the injected water can act as lubricant on highly stressed layers of rock near geological fault lines. In 2009, a $60 million EGS venture was cancelled in Basel, Switzerland, due to a flurry of earthquakes that were generated as a result of the project. While the momentum of EGS has been lessened by setbacks such as the Basel shutdown, as well as the under-delivery of other ongoing projects, the potential benefits that the technology promises are hard to negate. Proponents of EGS are still willing to brace the significant learning curve that lies ahead, before the technique becomes both technologically refined and cost competitive, and geothermal becomes a global source of renewable energy.

 

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Is the Future of CSP Dim?

Concentrated solar power (CSP) is an often overlooked method to generate electricity from the sun. As the name implies, CSP systems concentrate the sun’s energy, and do so with the use of reflective mirror surfaces. In commercial CSP plants, the concentrated sunlight is typically used to heat a working fluid which in turn generates steam to produce electricity via a steam turbine. Although commercial CSP plants have existed since the 1980s, a number of factors have hindered the technology’s penetration into the energy market. What are the factors holding this technology back? And (perhaps more importantly) is there any hope for the technology to grow in to a competitive source of electricity?

In recent times, photovoltaic (PV) prices have dropped dramatically, leading to a strong interest in installing utility-scale PV. This has also had the secondary effect of reducing the investment in CSP, since it is currently a more expensive method to generate electricity from the sun. Because of cost, investors have opted for PV over CSP – so much so that many planned CSP plants are instead being converted to utility-scale PV plants. Environmental factors have also had an effect. Last year, BrightSource Energy’s planned 500-megawatt CSP plant encountered an obstacle after surveyors discovered fossil deposits on the planned building site. Further concerns on the site’s impact on wildlife, as well as the cost of the plant forced BrightSource to put the project on hold.

However, CSP does have marked advantages over other forms of renewable energy. Of particular interest are the methods with which CSP can overcome intermittency problems. Power plants which combine CSP and traditional primary sources of energy can provide electricity day and night. Integrated thermal storage seeks to overcome this problem as well – the working fluid which drives the CSP plants can be stored in tanks and then utilized at a later time to generate electricity at night or during periods of low sunlight. This provides a greater flexibility to the grid than PV and wind typically provide. Recent studies back up this claim, showing that thermal storage adds a market value of up to $14/MWh, and a capacity value of up to $30.50/MWh.

Domestically, companies such as SolarReserve has taken advantage of thermal storage, and have projects underway which will prove the technology’s viability. Furthermore, the largest solar thermal energy generating facility in the world operates on both solar and natural gas and powers over 200,000 homes according to NextEra Energy Resources, the company that owns the facility. 

In total, over 1.4 GW of CSP plants were under construction in the US last year. Once operational, these projects will help to demonstrate the feasibility of CSP in the US. This information, coupled with the success of overseas companies (see Abengoa) and projects (such as in Abu Dhabi, Spain, etc.) will ultimately show the viability of CSP in the coming years. Therefore, although there is definitely hope for the technology to grow, its success will ultimately rely on the ability to drive prices down through methods such as thermal storage. Only then, it seems, will investors be more willing to add a greater share of CSP into the renewable energy sector.

References:
(http://www.renewablegreenenergypower.com/solar-energy-facts-concentrated-solar-power-csp-vs-photovoltaic-pv-panels/#.UQUpV79X1TI)
http://www.researchandmarkets.com/research/938nd4/concentrated
(additional references linked in article)

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Solar Panels: A True Carbon-Free Source of Energy?

“Today I challenge our nation to commit to producing 100 percent of our electricity from renewable energy and truly clean carbon-free sources within 10 years.”

-Al Gore, 2008

Our political leaders have a huge influence in how our population views technologies.  The former statement, while laudable, is distilled to the point of necessitating further analysis.  While the goal of ubiquitous carbon-free energy sources is certainly worth pursuing, it is vital that we do not discount the carbon footprint entailed in the adoption of those sources.

Let’s just take a look at solar photovoltaic (PV) systems. According to [1] and [2], the energy required to make a solar panel (by Siemens-like processes in 2007) was 4354 MJ/m2, which equates to 1210 kWh/m2 of panel produced. If this panel produces about 168 kWh/m2 in a year, then the estimated energy payback time (EPBT*) is about 2.2 years. This is great news.  However, if you then consider the carbon footprint of creating this solar panel and divide it over the panel’s lifetime (~30 years), the aggregate carbon emissions amount to 32 g/kWh produced. Fortunately, given improvements in technology, this value was expected to drop to 24 g/kWh by the end of 2011. So even though solar panels do not release CO2 during their normal operation (because they don’t need fuel to operate), the manufacture of solar panels does have a nontrivial carbon footprint. The upside of the story is that this footprint is still dwarfed by those of coal, oil, and natural gas (see table III below).

Image

Source: [2]

So far, I’ve spoken only of the carbon emissions from the manufacture of PV arrays.  This is only one side of the CO2 payback time equation.  Another vital consideration is the carbon that is displaced by using solar energy in lieu of dirtier energy sources from the existing energy infrastructure — namely, coal and natural gas.  To quantify this carbon offset, one must consider both the energy source that would have been used were it not for the solar panel, as well as the amount of power being displaced by the solar panel.  Furthermore, the amount of power provided by a panel is a function of both its efficiency (largely driven by technology) as well as the solar panel’s environment. For example, according to [3], it would take twice as much time for a panel in the UK than in California to offset the energy used for its production. This is due to California’s favorable sunshine conditions of about 1,700kWh/m2 per year, compared to the UK’s less favorable 700-900 KWh/m2 of solar energy per year.

So, in the end, solar power is a lot cheaper in terms of CO2 emissions and this is why I support their adoption. But it is at times appropriate to recall the famous quip from science fiction author Robert Heinlein: “there ain’t no such thing as a free lunch.”

*“EPBT is defined as the number of years a PV system must operate before it generates sufficient energy to equal the amount it consumed in manufacturing” [1]

References:

[1] P. Zhai and E.D. Williams, “Dynamic Hybrid Life Cycle Assessment of Energy and Carbon of Multicrystalline Silicon Photovoltaic Systems,” accepted for publication by Environmental Science & Technology (Sept.3, 2010).
[2] Y. Jiao, A. Salce, W. Ben, F. Jiang, X. Ji, E. Morey, and D. Lynch, “Siemens and Siemens-like Processes for Producing Photovoltaics: Energy Payback Time and Lifetime Carbon Emissions” JOM, 63 (1) (2011), pp. 28–31. Can be accessed here: http://www.springerlink.com/content/93h4wh6718251270/fulltext.pdf
[3] http://info.cat.org.uk/questions/pv/what-energy-and-carbon-payback-time-pv-panels-uk


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by | 15 April 2012 · 9:35 pm

Can the United States Ever Reach Energy Independence?

What is Energy Independence?

Energy independence has been a topic floating around the United States for decades. It wasn’t until recently that it became an idea that was actually achievable. Everyone knows energy is one of the most important aspects of life in not just the US, but across the globe, as well. It’s what drives our technological advances in society day after day.

In the US, even though we produce a vast amount of energy, a significant portion of energy is imported from foreign nations. While this is standard for some countries, for the US it has been something that has been hanging over our head since the 70’s.

A closed nation from the rest of the world is not a requirement for energy independence. A collaborated world is something that America embraces. The creation of significant alternative energy used widespread can be an example of energy independence. The switch to a notable exporter can also be a declaration of independence. [1]

Why should we seek it?

As mentioned earlier, since the 70’s the topic of independence has been heating up. In October of 1973, Arab nations of the Organization of Petroleum Exporting Countries, or OPEC, placed an embargo against the United States for its support of their enemy Israel during a time of war. This embargo put America in an almost immediate recession. Gas shortages were widespread and tactics such as lowering the speed limit became commonplace. The times were terrible for the US. [2]

Ever since this embargo, independence has become that much more significant. Friedman of the New York Times even goes into detail on why we might be interested in joining OPEC ourselves in the near future. He believes we could benefit greatly and that we can almost achieve independence within the next decade or so. We could establish a stronger reputation with the rest of the world and influence other countries into seeking their own independence. [3]

Energy Independence in Recent News

With issues such as gas prices skyrocketing towards $5/gal, energy independence has been extremely popular amongst the nation and especially politicians. The people want lower gas prices and politicians will say whatever the people want to hear in order to get elected. Not going into the actual politics surrounding it, one can see that both the Republican and the Democratic figures of our nation see the importance of it. President Obama spoke extensively about it in his most recent State of the Union speech. [4]

In his speech Obama had a whole segment on oil and natural gas as well as clean energy. He especially spoke on how our natural gas supply will propel us forward. Even the Republican presidential candidate, Newt Gingrich, preaches of how he will bring gas prices back to $2.50/gal.  He plans to release multiple ads highlighting this topic.[5]

Perhaps the most reputable claim of energy independence outside politicians would come from the energy industry itself. BP claims that the US will be free from foreign oil by 2030.

http://screen.yahoo.com/energy-independence-for-the-u-s-28220030.html

This in itself is monumental. They forecast Europe needing to import 94% of its oil whereas the US will be expanding its natural gas production to new bounds. It will lead us into the future to become a dominant force in the world. [6]

Summary

While energy independence is a major player in society today, it still needs some years to grow. I personally believe that the natural gas sources that we have will indeed push us to the next level, but not at the speed of which BP and Friedman suggested. Those speeds are more hype than anything to get the US up and moving. I foresee more of a 2050 date if anything. Of course, our reliance on foreign imports will decrease, and in my opinion, if anything like the oil embargo of the 1973 happens again, we will be prepared and the hit will be more of a jab rather than a knockout.

References

[1]http://americanenergyindependence.com/

[2] http://american-business.org/2300-arab-oil-embargo-of-1973.html

[3] http://www.nytimes.com/2012/02/26/opinion/sunday/friedman-a-good-question.html

[4] http://www.nytimes.com/interactive/2012/01/24/us/politics/state-of-the-union-2012-video-transcript.html

[5]http://savannahnow.com/news/2012-02-23/gingrich-buy-half-hour-ads-touting-energy-independence#.T1GaXfHXFv4

[6]http://finance.yahoo.com/blogs/daily-ticker/energy-independence-u-143030440.html

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