Posts tagged ‘Solar energy’

Graphene: Solar Cells of the Future?

A southern California University team has come up with what could be the alternative new breed of economical and flexible solar cells. For some decades now, organic photovoltaic cells (OPV) have been acclaimed as the new solar cell prototypes and extolled for their light weight, flexible substrates, low cost and easy manufacturability. Research is now being done on them.

http://koreaittimes.com/image/solar-cells

Features of OPV cell:
The most unique aspect of the OPV cell devise is the transparent conductive electrode. This allows the light to react with the active materials inside and create the electricity. Now graphene/polymer sheets are used to create thick arrays of flexible OPV cells and they are used to convert solar radiation into electricity providing cheap solar power. 

New OPV design:

Now a research team under the guidance of Chongwu Zhou, Professor of Electrical Engineering, USC Viterbi School of Engineering has put forward the theory that the graphene – in its form as atom-thick carbon atom sheets and then attached to very flexible polymer sheets with thermo-plastic layer protection will be incorporated into the OPV cells. By chemical vapour deposition, quality graphene can now be produced in sufficient quantities also. 

Differences between silicon cells and graphene OPV cells:
The traditional silicon solar cells are more efficient as 14 watts of power will be generated from 1000 watts of sunlight where as only 1.3 watts of power can be generated from a graphene OPV cell. But these OPV cells more than compensate by having more advantages like physical flexibility and costing less.

More economical in the long run:

According to Gomez De Arco, a team member, it may be one day possible to run printing presses with these economically priced OPVs covering extensive areas very much like printing newspapers. In Gomez’ words – “They could be hung as curtains in homes or even made into fabric and be worn as power generating clothing…. imagine people powering their cellular phone or music/video device while jogging in the sun.”

Advantages of OPVs:
The flexibility of OPVs gives these cells additional advantage by being operational after repeated bending unlike the Indium-Tin-Oxide cells. Low cost, conductivity, stability, electrode/organic film compatibility, and easy availability along with flexibility give graphene OPV cell a decidedly added advantage over other solar cells.

The team:
The USC team, consisting of Chongwu Zhou, Cody W. Schlenker, Koungmin Rye, Mark E. Thompson, Yi Zhang and Gomez De Arco published a paper about their research in ACS Nano journal and are very much excited about the future potential advantages and uses that are possible with the OPV grapehne cells.

Wind Energy Instruments getting Bigger & Better

Renewable energy production and demand growth is gaining momentum in many ways across the world. There is a booming demand of wind power today and all wind energy equipment manufacturers are gearing up to meet the demand and take advantage of it. Wind power capacity growth will be reaching 447GW in the next five years and by year 2014 end, Asia will lead the world in installed wind capacity. Enercon is amongst the other manufacturers who are focusing on 3MV-class wind turbines based on E-82/2.0. Without increasing the component sizes, there are new designs to operate at 3MW power. There will be a 3-6% increased yield because of these innovative designs as claimed by the Enercon.

Class I and II wind sites:
The International Electrotechnical Commission (IEC) has rated wind sites as Class I and II wind sites – IA and IIA sites. Various designs are being tested for low-wind speed inland sites as well as high-wind speed sites. E-82/2.3MW and E-82/3MW are for strong wind sites and E-1-1/3MW is for low-wind speed sites.

New designs at EWEC 2010:
The European Wind Energy Conference & Exhibition was held in Warsaw in Poland in April and REPower Systems AG presented two new improvements on their 3.XM series for sites with low-wind speed. 3.2M114 and 3.410 are optimal for less windy spots and 3.4104 on a 93 meter tower was specifically done for UK market as well special designs for Canada too.

Onshore wind turbines:
Large onshore wind turbines are now the forte of Alstom Wind. Easy maintenance and markedly ergonomically viable design make ECO 110 – their flagship – a successful larger scale rotor wind turbine.

New machines on display:
The EWEC 2010 showcased quite a few new designs and Gamesa and Siemens Energyare two of the companies putting up their G128-4.5 MW platform and wind turbine, and SWT-3.0-101 Direct Drive wind turbine respectively. Nordex SE has displayed N80, N90, and N100 wind turbines. Compact designs and superior specifications make these wind turbines remarkably efficient and noteworthy. They will increase the profitability with an assurance of quality and reliability.

Measures to improve energy output:
There are growing demands for more versatile machines which can be relied upon, durable and at the same time economical both while working with trouble-free maintenance. The people who invest in wind power want reliable and accurate data collection which can be reviewed easily. Today all the major wind power machine manufacturing companies are vying with each other to provide detailed and instant knowledge about wind and weather forecasting to improve energy output.

Future of Wind power:
Future of wind power is bright and shining as detailed studies by EWEA have already shown that power generation from wind energy is most economical. The consumers are reaping good benefits financially from wind power. There is no doubt”That wind is already directly curbing European electricity prices is perhaps less obvious, and all the more significant for it.”

Source:

http://www.sadoun.net/forums/energy-news-announcements/19523-wind-energy-instruments-getting-bigger-better.html

Converting Waste Heat to Electricity

With rapid industrialization, the world has seen the development of a number of items or units, which generate heat. Until now this heat has often been treated as a waste, making people wonder if this enormous heat being generated can be transformed into a source of electric power. Now, with the physicists at the University of Arizona finding new ways to harvest energy through heat, this dream is actually going to become a reality. 

University of Arizona Research Team: The research team is headed by Charles Staffor. He is the associate professor of physics, and he along with his team worked on harvesting energy from waste. The team’s findings were published in the September 2010 issue of the scientific journal, ACS Nano.

Justin Bergfield who is an author and a doctoral candidate in the UA College of Optical Sciences shares his opinion, “Thermoelectricity can convert heat directly into electric energy in a device with no moving parts. Our colleagues in the field tell us that they are confident that the device we have designed on the computer can be built with the characteristics that we see in our simulations.”

 Spiking a conventional thermoelectric material with sodium and selenium creates regions in the crystal that conduct electricity more readily (blue and gold), boosting the material’s performance.

Advantages: Elimination of Ozone Depleting materials: Using the waste heat as a form of electric power has multiple advantages. Whereas on one hand, using the theoretical model of molecular thermoelectric helps in increasing the efficiency of cars, power plants factories and solar panels, on the other hand efficient thermoelectric materials make ozone-depleting chlorofluorocarbons, or CFCs, outdated. 

More Efficient Design: The head of the research team Charles Stafford is hopeful about positive results because he expects that the thermoelectric voltage using their design will be 100 times more than what others have achieved. If the design of the team, which they have made on a computer does work, it will be a dream come true for all those engineers, who wanted to catch and make use of energy lost through waste but do not have the required efficient and economical devices to do so.

No need for Mechanics: The heat-conversion device invented by Bergfield and Stafford do not require any kind of machines or ozone-depleting chemicals, as was the case with refrigerators and steam turbines, which were earlier used to convert waste into electric energy. Now, the same work is done by sandwiching a rubber-like polymer between two metals, which acts like an electrode. The thermoelectric devices are self-contained, need no moving parts and are easy to manufacture and maintain. 

Utilization Of Waste Energy: Energy is harvested in many ways using the car and factory waste. Car and factory waste can be used for generating electricity by coating exhaust pipes with a thin material, which is a millionth time of an inch. Physicists also take advantage of the law of quantum physics, which though not used often enough, gives great results when it comes to generating power from the waste.  

Advantage Over Solar Energy:

Molecular thermoelectric devices may help in harvesting energy from the sun and reduce the dependence on photovoltic cells, whose efficiency in harvesting solar energy is going down.

How It Works

Though having worked on the molecule and thinking about using them for a thermoelectric device, Bergfield and Stafford had not found anything special till an undergraduate discovered that these molecules had special features. A large number of molecules were then sandwiched between electrodes and exposed to a stimulated heat source. The flow of electrons along the molecule was split in two once it encounters a benzene ring, with one flow of electrons following along each arm of the ring.

The benzene ring circuit was designed in such a way that the electron travels longer distance round the rings in one path, which causes the two electrons to be out of phase when they reach the other side of the benzene ring. The waves cancel out each-other on meeting. The interruption caused in the flow of electric charge due to varied temperature builds up voltage between electrodes.

The effects seen on molecules are not unique because any quantum scale device having cancellation of electric charge will show a similar effect if there is a temperature difference. With the increase in temperature difference, energy generated also increases.

Thermoelectric devices designed by Bergfield and Stafford can generate power that can lit a 100 Watt bulb or increase car’s efficiency by 25%.

Solar Wind Power: Generating Power In The Future

As the world discovers new ways to meet its growing energy needs, energy generated from Sun, which is better known as solar power and energy generated from wind called the wind power are being considered as a means of generating power. Though these two sources of energy have attracted the scientists for a very long time, they are not able to decide, which of the two is a better source to generate power. Now scientists are looking at a third option as well. Scientists at Washington State University have now combined solar power and wind power to produce enormous energy called the solar wind power, which will satisfy all energy requirements of human kind.

Advantage of Solar wind power.

  • The scientists say that whereas the entire energy generated from solar wind will not be able to reach the planet for consumption as a lot of energy generated by the satellite has to be pumped back to copper wire to create the electron-harvesting magnetic field, yet the amount that reaches earth is more than sufficient to fulfill the needs of entire human, irrespective of the environment condition.
  • Moreover, the team of scientists at Washington State University hopes that it can generate 1 billion billion gigawatts of power by using a massive 8,400-kilometer-wide solar sail to harvest the power in solar wind.
  • According to the team at Washington State University, 1000 homes can be lit by generating enough power for them with the help of 300 meters (984 feet) of copper wire, which is attached to a two-meter-wide (6.6-foot-wide) receiver and a 10-meter (32.8-foot) sail.
  • One billion gigawatts of power could also be generated by a satellite having 1,000-meter (3,280-foot) cable with a sail 8,400 kilometers (5,220 miles) across, which are placed at roughly the same orbit.
  • The scientists feel that if some of the practical issued are solved, Solar wind power will generate the amount of power that no one including the scientists working to find new means of generating power ever expected.

 

How does the Solar wind power technology work?
The satellite launched to tap solar wind power, instead of working like a wind mill, where a blade attached to the turbine is physically rotated to generate electricity, would use charged copper wire for capturing electrons zooming away from the sun at several hundred kilometers per second.

Forecasting Wind Data with Cell Phone Towers

Wind data provider Onesemble has developed sensors which can keep note of wind date for around 95% of the wind farms existing in the Texas area. The help of cell phone towers is sought for this purpose. Onesemble Network Sensors collect accurate data by getting to know the wind speed at a great height. This is done by placing the sensor at the height of the turbine rotor or the blades. Onesemble Network Sensors assembles figures on wind speed, direction and temperature in a cell phone tower, which are then analyzed on a computer to point out what is going to happen in times to come.

How censors work

Onesemble has put the sensors on the cell phone towers, which are 80-120 meters above the ground. Forecasting can be enabled every 10 minutes with the help of real time data from the sensors fed into its system. The data fed and the predictions that are attained this way are both quite precise.

To seek the help of cell phone towers for wind farms, data is supplied to the Electricity Reliability Council of Texas (ERCOT) through a network of 100 sensor centers. These centers are put in a proper manner near the wind farm all over Texas by the ERCOT, which manages 75% of Texas’s electric grid. Wind farms use behavior patterns and predictions to analyze the change in availability of electricity in a given area with these towers and data.

 The need for wind data

The need for power grid will increase with the increase in the wind farms and the uneven output of these wind farms. This is a huge problem but its solution can be found the following ways:

  • By making long-distance transmission capacity by connecting all local and regional grids with each-other.
  • By optimum use of wind by estimating how much wind is needed every hour. By providing accurate wind data.

Advantages of Wind Data Forecasting by Cell Towers

  • Cell Towers already exist. By taking their help for wind forecasting data, you are putting them to duel use.
  • It helps make wind more productive.
  • It increases the efficiency of the power plant.