Monthly Archives: September 2013

Are current batteries cost effective for wind and solar power storage on the grid?

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Renewable energy holds the promise of reducing carbon dioxide emissions. But there are times when solar and wind farms generate more electricity than is needed by consumers.

Duane Tilden‘s insight:

>”We calculated how much energy is used over the full lifecycle of the battery – from the mining of raw materials to the installation of the finished device,” Barnhart said. “Batteries with high energetic cost consume more fossil fuels and therefore release more carbon dioxide over their lifetime. If a battery’s energetic cost is too high, its overall contribution to global warming could negate the environmental benefits of the wind or solar farm it was supposed to support.” […]

In addition to batteries, the researchers considered other technologies for storing renewable energy, such as pumped hydroelectric storage, which uses surplus electricity to pump water to a reservoir behind a dam. Later, when demand for energy is high, the stored water is released through turbines in the dam to generate electricity. […]

Storage is not the only way to improve grid reliability. “Energy that would otherwise be lost during times of excess could be used to pump water for irrigation or to charge a fleet of electric vehicles, for example,” Dale said.

See on phys.org

Industrial networking expands PLC functionality – Energy Efficiency

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Combining real-time Ethernet with visualization, control, and communication capabilities allows PLCs to open the door to a new level of visibility and control for manufacturers.

Duane Tilden‘s insight:

>The days when workers served as the brain and brawn in manufacturing are long gone, while human-machine interaction has become commonplace on the factory floor. A prime example of this is the PLC, which has been the workhorse in automation and manufacturing industries across the board for many years. By interfacing with everything from sensors and machine guards to motion control and advanced identification devices, PLCs ensure operations run smoothly (see Figure 1). Through the flexibility offered with PLCs, manufacturers can manage multiple machines at once—achieving a higher level of integration and process automation machines and improving production quality and cost of operation.

The benefits of the PLC are well known. Their contributions toward efficiency enhancement and the behind-the-scenes support of industrial Ethernet make this heightened control possible. Together, these technologies make communication between humans and machine a seamless, profitable combination. Consisting of various protocols, industrial Ethernet was developed with deterministic capabilities to provide a cost-effective alternative to legacy automation systems.

With advanced capabilities, sophisticated functionality, and simplified installation, the PLC is a cornerstone of modern manufacturing. However, to effectively use these devices, users must understand the crucial role networking plays and the individual requirements that must be considered for an effective solution.  […]<

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Clay key to high-temperature supercapacitors

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Clay, an abundant and cheap natural material, is a key ingredient in a supercapacitor that can operate at very high temperatures, according to researchers who have developed such a device.

Duane Tilden‘s insight:

>”Our intention is to completely move away from conventional liquid or gel-type electrolytes, which have been limited to low-temperature operation of electrochemical devices,” said Arava Leela Mohana Reddy, lead author and a former research scientist at Rice.

“We found that a clay-based membrane electrolyte is a game-changing breakthrough that overcomes one of the key limitations of high-temperature operation of electrochemical energy devices,” Reddy said. “By allowing safe operation over a wide range of temperatures without compromising on high energy, power and cycle life, we believe we can dramatically enhance or even eliminate the need for expensive thermal management systems.”

A supercapacitor combines the best qualities of capacitors that charge in seconds and discharge energy in a burst and rechargeable batteries that charge slowly but release energy on demand over time. The ideal supercapacitor would charge quickly, store energy and release it as needed.<

See on www.sciencedaily.com

Geothermal Energy: Iceland could provide renewable energy to the UK

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Under plans currently being discussed by both the UK and Icelandic governments, renewable electricity could be provided by Iceland to the UK at a cheaper cost than offshore wind.

Duane Tilden‘s insight:

>The plans being discussed by the two governments concern a 1,000km undersea cable with a capacity of 1GW. The package is worth an estimated £4 billion with the inclusion of related generation and onshore transmission investments and could be operational by 2022.  […]

 

At present, Iceland benefits from some of the lowest electricity prices in Europe given that much of their renewable energy comes from hydroelectricity and geothermal. […] the interconnector could provide power to the UK at around 60 to 70 percent of the price of offshore wind and that whichever way you look at it there are big potential benefits. However, in order to be successful, the Icelandic government must also convince their own citizens that there are also benefits for Iceland and there are concerns that exposure to a larger market could increase domestic energy prices.<

See on www.renewableenergymagazine.com

Regenerative Suspension: How Bumps In The Road Can Generate Electrical Power

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ZF Friedrichshafen AG and Levant Power Corp. have joined together to produce the first fully-active advanced suspension system that recovers energy and directs it to charge the battery while the car is moving.

Duane Tilden‘s insight:

>Gas2 says it’ll be “a while” before the system will go mainstream — likely several years — but it seems a no-brainer for every hybrid and electric vehicle to install this system or one like it to eke out battery charge through energy that is normally wasted. Gas-powered cars also have batteries that get a charge while the engine is running, but they use a belt attached to the engine itself to charge the battery. This causes gas-powered engines to be less efficient, and with most conventional cars using only around 15 percent of the potential energy of gasoline, efficiency comes at a premium.

Most hybrid car drivers will be familiar with the concept of recovering energy from normal car functions because of the increasingly frequent use of brake systems that, when used, transfer heat and friction of normal braking to the battery. As fuel economy standards improve over the next decade, car manufacturers are looking for anything they can do to make cars more efficient.<

See on thinkprogress.org

Net Energy Metering Policies Helping To Spur Solar Growth

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All across the United States, rooftop solar panels are popping up on homes, businesses and schools like mushrooms in a forest, and utility-scale solar projects are bringing huge amounts of clean energy into our communities.  Why?

Duane Tilden‘s insight:

>Today, smart policies — likeRenewable Portfolio Standards (RPS) and Net Energy Metering (NEM) — are helping to fuel solar’s explosive growth. Our industry now employs 120,000 Americans at 5,600 U.S. companies. What’s more, we’re now generating enough electricity to power more than 1.5 million homes…

Part of this amazing success story can also be attributed to the fact that the average cost of a solar system has dropped by nearly 40 percent over the past two years and by a whopping 50 percent since 2010.  As a result, American consumers, businesses and schools are flocking to rooftop solar.  According to the most recent statistics, the residential market alone grew by 48 percent in the second quarter of 2013 compared to the same time period a year ago. […]

NEM has significantly contributed to this growth.  Simply put, NEM is a credit on your bill that represents the full value of electricity delivered.  Think of it this way: surplus energy generated by a home or business system is exported to the electricity grid, allowing a consumer’s meter to spin backwards.  This allows the homeowner or business owner to have greater control over their energy use and prices.  […]”<

See on www.renewableenergyworld.com

Call for Energy Efficient Air-Conditioning with Technological Development

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Innovations could cut the growing amount of energy used for air-conditioning and refrigeration

Duane Tilden‘s insight:

>Conventional air conditioners employ refrigerants such as chlorofluorocarbons to absorb heat from the room to be cooled. That heat is then expelled outside, requiring electrically powered pumps and compressors.

One idea to conserve energy is to replace coolant fluids and gases—which are often super-powered greenhouse gases capable of trapping more than 1,000 times more heat than CO2—with solid materials, such as bismuth telluride.

A new device from Sheetak, developed in part with ARPA-E funding, uses electricity to change a thermoelectric solid to absorb heat, and could lead to cheaper air conditioners or refrigerators.

Such refrigerators, which lack moving parts and are therefore less likely to break down, can be lifesavers in remote, rural areas for keeping medicines cool or food fresh.<

See on www.scientificamerican.com

Monitoring Motivates Less Electricity Use

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Researchers found that families that were simply told they were in a study to track electricity use reduced electricity use more than 2.5 percent.

Duane Tilden‘s insight:

>The general phenomenon is called the Hawthorne effect: study subjects change their behavior because they’re being observed. So researchers collaborated with a utility to test for the Hawthorne effect in electricity use.

They monitored almost 5,600 randomly selected households. Half received a postcard saying that their energy use would be monitored for a month for research purposes. They also got four follow-up reminder postcards over the month. They received no other information, instructions or incentives.

The control group monitored for the study got no notifications. That group continued using the same amount of electricity. But the families being tracked reduced energy use 2.7 percent. And when the study period ended, their energy use shot back up. The report is in the Proceedings of the National Academy of Sciences. [Daniel Schwartz et al., The Hawthorne effect and energy awareness]<

See on www.scientificamerican.com

Art about climate change: a new trend

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This post comes to you from Culture|Futures “Wow, I wish I knew someone dealing with climate change. How is it that no artists are working with the most compelling issue that affects all of us?” (more)

See on www.sustainablepractice.org

Supply of Renewable Wind Power Surges in Texas with some Plant Closures

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Market Upheaval In the U.S., hydraulic fracturing techniques used to drill shale have produced a flood of cheap natural gas. That, combined with the growth in wind and tepid customer demand, is upending power markets, leading to plant closures and bankruptcy for some generator owners.

Duane Tilden‘s insight:

>Traditional power companies across the U.S. and Europe are struggling to compete in wholesale markets with newer generators supplying subsidized wind and solar energy. In Texas, wind has more than doubled in the past six years and now makes up 13 percent of the state’s generation capacity.[…]

Falling Prices – Electricity prices for 2014 also have fallen. The on-peak North Texas power price for next year has dropped 19 percent since reaching a peak on May 23, according to data compiled by Bloomberg.

During a heat wave in the first week of August, ample wind supplies served to keep a lid on prices that would’ve normally spiked from the higher demand, NRG Chief Executive Officer David Crane said during a call with investors on Aug. 9. “Wind energy reduces electricity prices and that is good for consumers,” said Michael Goggin, an analyst for the American Wind Energy Association, an industry trade group. “Wind energy has no fuel costs, allowing it to replace more expensive and polluting sources of energy.”

Once complete, Oncor’s power lines will be part of a system that can eventually deliver about 18,500 megawatts of wind power, nearly double the amount now available in Texas and 25 percent of the state’s current generation capacity.<

See on www.renewableenergyworld.com