Stanford scientists have developed featherweight, pliable batteries and supercapacitors in the form of everyday paper.

By coating a sheet of paper with ink made of carbon nanotubes and silver nanowires, the scientists were able to construct a highly conductive storage device that’s both low-cost and high-performance.

(The difference between a battery and a capacitor, you ask? both hold energy to be converted to electricity, but capacitors hold it for a shorter period of time. On the other hand, they can store and discharge energy much more rapidly.)

The batteries are so strong that you can crumple them and the performance does not degrade.Led by assistant professor of materials science and engineering Yi Cui, who previously created nano-size batteries using plastics, the researchers developed a solution that is more durable than conventional batteries.

Source: Smart Planet

A new biodegradable battery made of cellulose promises to offer thin, flexible, lightweight, inexpensive and environmentally-friendly batteries made without metal parts.

The battery is made from green algae known as Cladophora, found along freshwater beaches around the world.

The key to the battery’s success is its large surface area. Made from algae-derived cellulose with 100 times the surface area of the cellulose found in sheets of notebook paper, the battery can manage far more conducting polymer than in previous incarnations.

That means better recharge, hold and discharge capabilities.

Source: Smart Planet

1. Choosing the right solar panel for your needs is like choosing a battery.

In the same way that a bigger battery will provide more power for longer, a larger Solar panel will collect more energy in less time. The right size of panel will depend on variables such as the power required by the appliance, the length of time you want to use it and how much sunshine you get at the time of year.

2. There are three things to consider when choosing a solar panel or creating a solar system.

You need to know what appliances you will be using and how much energy they require, how much energy your battery can store and which solar panel will replenish your ‘stock’ of energy in the battery in line with your pattern of use.

3. How much energy will your appliance(s) use over a period of time?

The power consumption of appliances is given in Watts (e.g. 21” fluorescent light, 13W). To calculate the energy you will use over time, just multiply the power consumption by the hours of use.  The 13W light fitting, on for 2 hours, will take 13 x 2 = 26Wh from the battery.  Repeat this for all the appliances you wish to use, then add the results to establish total
consumption.

4. How much energy can your battery store?

Battery capacity is measured in Amp Hours (e.g. 17Ah). You need to convert this to Watt Hours by multiplying the AH figure by the battery voltage (e.g. 12V).  For a 17Ah, 12V battery the Watt Hours figure is 17 x 12 = 204Wh.  This means the battery could supply a 13W fluorescent for 15 and a half hours, 204W for 1 hour, or 102W for 2 hours, i.e. the more energy you take, the faster the battery
discharges.

5. How much energy can a solar panel generate over a period of time?

The power generation rating of a solar panel is also given in Watts (e.g. STP010, 10W).  To calculate the energy it can supply to the battery, multiply Watts by the hours exposed to sunshine, then multiply the result by 0.85 (this factor allows for natural system losses).  For the solar 10W panel in 4 hours of sunshine, 10 x 4 x 0.85 = 34Wh. This is the amount of energy the solar panel can supply to the battery.

Source: GreenWeld

During the initial years of electricity distribution, Edison’s direct current was the standard for the United States^[1] and Edison was not inclined to lose all his patent royalties. Direct current worked well with incandescent lamps that were the principal load of the day, and with motors. Direct current systems could be directly used with storage batteries, providing valuable load-leveling and backup power during interruptions of generator operation. Direct current generators could be easily paralleled, allowing economical operation by using smaller machines during periods of light load and improving reliability. At the introduction of Edison’s system, no practical AC motor was available. Edison had invented a meter to allow customers to be billed for energy proportional to consumption, but this meter only worked with direct current. As of 1882 these were all significant technical advantages of direct current.

From his work with rotary magnetic fields, Tesla devised a system for generation, transmission, and use of AC power. He partnered with George Westinghouse to commercialize this system. Westinghouse had previously bought the rights to Tesla’s polyphase system patents and other patents for AC transformers from Lucien Gaulard and John Dixon Gibbs.

Several undercurrents lay beneath this rivalry. Edison was a brute-force experimenter, but was no mathematician. AC cannot be properly understood or exploited without a substantial understanding of mathematics and mathematical physics, which Tesla possessed. Tesla had worked for Edison but was undervalued (for example, when Edison first learned of Tesla’s idea of alternating-current power transmission, he dismissed it: “[Tesla's] ideas are splendid, but they are utterly impractical.”^[3]). Bad feelings were exacerbated because Tesla had been cheated by Edison of promised compensation for his work.^[4][5] Edison would later come to regret that he had not listened to Tesla and used alternating current.^[6]

Source: Wikipedia

President Obama tried out a bit of political jiu jitsu last Friday, reframing the climate change debate from “green” to “competitive.”

In his MIT speech the President talked less about polar bears and more about markets such as lighting, solar panels, batteries and turbines, markets that can be retaken with the right incentives.

Don’t say green, say competitive.

Speaking this language is essential because former Bush DoE official Karen Harbert, now heading the U.S. Chamber of Commerce Energy Institute, continues pushing climate change as a business vs. government divide when it is increasingly a battle between industries.
Source: smartplanet