The heat given off by electronics, automobile engines, factories and other sources is a potentially huge source of energy, and various technologies are being developed in order to capture that heat, and then convert it into electricity. Thanks to an alloy that was recently developed at the University of Minnesota, however, a step in that process could be saved – the new material is able to convert heat directly into electricity.

The multiferroic alloy, with the catchy name Ni45Co5Mn40Sn10, was created by combining its various elements at the atomic level. Multiferroic materials are known for having unique elastic, magnetic and electric properties, and in the case of this alloy, that takes a form of an usual phase change. When heated, the non-magnetic solid material suddenly becomes a strongly magnetic solid.

In a lab test, upon becoming magnetic, the material absorbed heat in its environment and proceeded to produce electricity in an attached coil. Although some of the heat energy is lost in a process known as hysteresis, the U Minnesota researchers have developed a method of minimizing that energy loss.

“This research is very promising because it presents an entirely new method for energy conversion that’s never been done before,” said aerospace engineering and mechanics professor Richard James, who led the research team. “It’s also the ultimate ‘green’ way to create electricity because it uses waste heat to create electricity with no carbon dioxide.”

The research was recently published in the journal Advanced Energy Materials.

Sourced & published by Henry Sapiecha

to more efficiently harness wasted heat

Thermoelectric materials offer the potential to harness electricity from otherwise wasted heat. Continuing research in the field could yield applications scavenging energy from vehicle exhaust systems, industrial processes and equipment, and even sunlight. Now researchers have created a material with a higher energy conversion efficiency that could make such systems more feasible.

Researchers at Northwestern University created the new material by dispersing nanocrystals of rock salt (SrTe) into lead telluride (PbTe). While this kind of nanoscale inclusion in bulk material had previously been shown to improve the energy conversion efficiency of lead telluride, it also increased the scattering of electrons, which reduced the material’s overall conductivity. The Northwestern team’s study offers the first example of using nanostructures in lead telluride to reduce electron scattering and increase the energy conversion efficiency of the material. The researchers say the resultant material is expected to enable 14 percent of waste heat to electricity.

“It has been known for 100 years that semiconductors have this property that can harness electricity,” said Mercouri Kanatzidis, the Charles E. and Emma H. Morrison Professor of Chemistry in The Weinberg College of Arts and Sciences. “To make this an efficient process, all you need is the right material, and we have found a recipe or system to make this material.”

Vinayak Dravid, professor of materials science and engineering at Northwestern’s McCormick School of Engineering and Applied Science adds, “we can put this material inside of an inexpensive device with a few electrical wires and attach it to something like a light bulb. The device can make the light bulb more efficient by taking the heat it generates and converting part of the heat, 10 to 15 percent, into a more useful energy like electricity.”

Kanatzidis says any industry that uses heat to make products, such as the automotive, chemical, brick and glass industries, could use the material to make their system more efficient. But maybe the researchers aren’t thinking big enough. An estimated 90 percent of the world’s electricity is generated by heat energy that typically operates at 30 to 40 percent efficiency, losing roughly 15 terawatts of power in the form of heat to the environment. Harnessing 10 to 15 percent of this currently wasted heat energy would translate to a substantial amount of electricity.

The results of the Northwestern University team’s study are published in the journal Nature Chemistry.

Sourced & published by Henry Sapiecha

One estimates that half of the energy consumed by data centres goes toward cooling computer processors, with most of the removed hot air simply being blown into the atmosphere. Instead, IBM sees that heat being captured & used to warm the air in other areas of the building, to heat water, or to be converted into usable electricity. The company has already developed an on-chip water-cooling system for computer clusters, which is being demonstrated on the Swiss Aquasar supercomputer. It utilizes a network of microfluidic capillaries inside a standard heat sink, attached to the surface of each chip. Water flows within a few microns of the semiconductor material, picking up heat from it, then piping the warm water to a heat exchanger – from there, the cooled water returning to the computers, using a closed loop system.

As with last year’s list, given that all of these technologies are already in experimental use, it’s a very good bet that they will indeed one day find their way into our lives. Whether that day is within the next five years, however, is another thing-time will tell

Sourced & published by Henry Sapiecha

RavenSkin insulation stores up daytime heat for release when temperatures drop

RavenBrick, the company that brought us the smart tinting RavenWindow, has added to its folio of temperature regulating building materials with RavenSkin. Unlike traditional insulation that blocks all heat equally, this innovative wall insulation material absorbs heat during the day to keep the interior cool and slowly releases the stored heat at night to warm the building when the sun goes down. Read More

Sourced & published by Henry Sapiecha

Powering Up

the Battery-Free World

Though the thermoelectric conversion device is small, the heat exchanger used to attain the high efficiency for a given temperature differential is relatively large. This component is expected to account for the majority of module cost. The heat exchanger is critical in determining electric conversion efficiency, and can as much as double output. Research in this area is sparse, and it is likely to develop into a major battleground for peripheral components.

Expanding Application in Wireless Sensor Networks

Advancement in high-efficiency peripheral circuits and generators with low power consumption has finally made energy harvesting a practical technology. And now that the foundations are in place, the applications are beginning to take shape. The technology is likely to be used diversely, not only in existing switch applications for lighting and such (Fig. 7).

Fig. 7 New Ideas Pioneer New Applications

There is a wide range of possible applications. Especially promising ones include health monitoring for bridges and vehicles, and implementations in animal husbandry and agriculture. (Illustration: Reiko Kusumoto)

One of the most promising applications is wireless sensor networks. Data acquired by the sensors only has to be transmitted a few times an hour, which means power consumption is low. This level is quite possible for an energy harvesting system (Fig. 8).

Fig. 8 New Wireless Sensor Node

The “Mr. Shoene” wireless sensor node released by Seiko Instruments (SII) in Sept. 2010 uses the firm’s proprietary special low-power wireless technology. Power consumption is low and the device is non-directional, making it possible for signals to route around obstacles.

Sourced & published by Henry Sapiecha

by Cynthia Booth

New Jersey school of architecture professor presents us how to construct an environmental-friendly home with limited funds

Did you know 2 New York based architects designed an asymmetrical home with a fixed cost of $250,000?

Architects and Jersey City residents Richard Garber (assistant tutor at the Newjersey Institute of Technology’s College of Architecture and Design in Newark) and Nicole Robertson of GRO Architects in New York City rose to the challenge of designing and managing the construction of a single-family house that’s an authentic evidence of both revolutionary design and environmental-friendly technologies.

Denis Carpenter not too long ago bought one small vacant lot and, to accomplish his concern for the planet, wanted a house that was cost-efficient and easy to maintain.

What’s so exceptional about this home?

- In the home, on the floor level, radiant heating below the exposed cement floor gets warm the full bathing room and a couple of bedrooms.

- In the loft-like second level, sleek aluminum and stainless steel railings accent the bamboo stairway to the mezzanine, living room and an artfully designed kitchen made with salvaged home appliances and cabinetry.

- Passive air conditioning strategies like ceiling fans and clerestory windows make it easy for home owners to remain cool during summer months and warm during winter months.

- The roof consists of 260 sq ft of solar panels that provide nearly 2,000 kilowatts of energy annually to a battery stored in the basement.

This single family 1,600-square-foot home was constructed in six months and won a 2009 American Institute of Architects merit award and the 2010 Green Building of the Year Award from the Jersey City Redevelopment Agency.

Now what? How could you convert your home into an environmentally-friendly home without investing too much money?

If you’re remodeling a home, perform an energy audit first to help you identify what energy efficiency improvements should and can be made to your home. In this way you’ll evaluate how much energy your home needs.

My personal favorite eco-friendly methodology is the passive solar cooling/heating design.

Passive solar usually means that your home’s windows, walls, and floors can be designed to collect, store, and distribute solar power in the form of heat in the winter season and reject solar heat in the summer time.

Existing houses can be adapted or “retrofitted” to passively collect and store solar heat too.

The next five aspects constitute a comprehensive passive solar home design:

The Collector – The area through which sunlight enters the building (usually windows).

The Absorber – The hard, darkened surface of the storage element. Sunlight hits the surface and is absorbed as heat.

The Thermal Mass – The components that retain or store the heat produced by sunlight below or behind the absorber surface.

The Distributor – The system by which solar heat circulates from the collection and storage points to different areas of the house.

The Controller – Roof overhangs may be used to shade the aperture area during warm weather or Thermostats that signal a fan to turn on.

The author – Cynthia Booth contributes articles for the <a href=”http://www.architecturecareers.org/”>architecture careers advice</a> blog. It’s a nonprofit web-site dedicated to provide help for beginning architects who need resources for their careers. With this she would like to raise the awareness on eco-friendly home design and change the general public conception of energy efficiency.

Spray-on film turns windows into solar panels

Imagine if all the windows of a building, and perhaps even all its exterior walls, could be put to use as solar collectors. Soon, you may not have to imagine it, as the Norweigan solar power company EnSol has patented a thin film solar cell technology designed to be sprayed on to just such surfaces. Unlike traditional silicon-based solar cells, the film is composed of metal nanoparticles embedded in a transparent composite matrix, and operates on a different principle. EnSol is now developing the product with help from the University of Leicester’s Department of Physics and Astronomy. Read More

Sourced & published by Henry Sapiecha

Innovation Puts Next-Generation

Solar Cells on the Horizon.

Could dye from berries be the answer??

ScienceDaily (Dec. 2, 2009) — In a world first, a Monash University-led international research team has developed an innovative way to boost the output of the next generation of solar cells.

Scientists at Monash University, in collaboration with colleagues from the universities of Wollongong and Ulm in Germany, have produced tandem dye-sensitised solar cells with a three-fold increase in energy conversion efficiency compared with previously reported tandem dye-sensitised solar cells.

Lead researcher Dr Udo Bach, from Monash University, said the breakthrough had the potential to increase the energy generation performance of the cells and make them a viable and competitive alternative to traditional silicon solar cells.

Dr Bach said the key was the discovery of a new, more efficient type of dye that made the operation of inverse dye-sensitised solar cells much more efficient.

When the research team combined two types of dye-sensitised solar cell — one inverse and the other classic — into a simple stack, they were able to produce for the first time a tandem solar cell that exceeded the efficiency of its individual components.

“The tandem approach — stacking many solar cells together — has been successfully used in conventional photovoltaic devices to maximise energy generation, but there have been obstacles in doing this with dye-sensitised cells because there has not been a method for creating an inverse system that would allow dye molecules to efficiently pass on positive charges to a semiconductor when illuminated with light,” Dr Bach said.

“Inverse dye-sensitised solar cells are the key to producing dye-sensitised tandem solar cells, but the challenge has been to find a way to make them perform more effectively. By creating a way of making inverse dye-sensitised solar cells operate very efficiently we have opened the way for dye-sensitised tandem solar cells to become a commercial reality.”

Although dye-sensitised solar cells have been the focus of research for a number of years because they can be fabricated with relative simplicity and cost-efficiency, their effectiveness has not been on par with high-performance silicon solar cells.

Dr Bach said the breakthrough, which is detailed in a paper published in Nature Materials, was an important milestone in the ongoing development of viable and efficient solar cell technology.

“While this new tandem technology is still in its early infancy, it represents an important first step towards the development of the next generation of solar cells that can be produced at low cost and with energy efficient production methods,” he said.

“With this innovation we are one step closer to the creation of a cost-efficient and carbon-neutral energy source.”

Sourced and published by Henry Sapiecha 8th June 2010

A view inside the National Ignition Facility’s target chamber, a space easily big enough for technicians to stand inside. It is hoped the NIF will eventually be a major source of carbon-free energy.

(Credit: Lawrence Livermore National Lab)

LIVERMORE, Calif.–Think clean energy is a fantasy? What if the power of a star was applied to the problem?

That’s the approach being explored at the National Ignition Facility, a huge-scale experiment in laser fusion based at the Lawrence Livermore National Laboratory here. Scientists are looking at NIF as a potential key to producing large amounts of carbon-free power.

It’s not known if the system will ever bear the kind of fruit the scientists and administrators who run NIF would like. Still, the facility is a scientific wonder that can transform a single laser beam no wider than a human hair into 192 beams–each of which is 18 inches wide. Together, the beams are designed to produce 4 million joules, the amount of power that would produce 4 million watts of power in a single second.

The NIF was completed in early 2009 and eventually will be used by the U.S. Department of Energy, as well as technicians from national laboratories, fusion energy researchers, academics, and others. It is “the world’s largest and highest-energy laser, [and] has the goal of achieving nuclear fusion and energy gain in the laboratory for the first time,” according to the Lawrence Livermore National Lab, “in essence, creating a miniature star on Earth.”

This is serious high technology. The NIF employs a series of amplifiers and mirrors known as switchyards to route and split the original hair’s-width laser beam over a total distance of 1,500 meters. After being separated by pre-amplifiers into 48 beams, each beam is then split into four beams, and then all are injected into the 192 main laser amplifier beamlines, according to the NIF.

The hope is that NIF will be online as a power plant within 15 to 20 years. For now, the facility is a proof-of-concept system, albeit one comprising two 10-story buildings and more than $3 billion of investment. Eventually, the 192 laser beams reunite to focus on a target fuel pellet that is just millimeters in size, yet placed inside a target chamber that towers over the technicians who sometimes work inside.

And 192 laser beams of this magnitude create some serious heat. The theoretical maximum, according to LLNL retiree and docent Nick Williams, is 100 million degrees Celsius.

For now, because of the amount of power necessary to produce the beams, and the heat created, scientists are only able to fire the laser system once every two or three hours. Eventually, the idea would be to fire it many times a second.

And by 2030, it is hoped, the NIF will be helping produce commercial power and helping scientists and researchers better understand the nature of the universe. That, it would seem, would be a main benefit of producing what amounts to a small star, right here in the middle of Northern California.

On June 24, Geek Gestalt will kick off Road Trip 2010. After driving more than 18,000 miles in the Rocky Mountains, the Pacific Northwest, the Southwest and the Southeast over the last four years, I’ll be looking for the best in technology, science, military, nature, aviation and more throughout the American northeast. If you have a suggestion for someplace to visit, drop me a line. In the meantime, you can follow my preparations for the project on Twitter @GreeterDan and @RoadTrip.

Sourced and published by Henry Sapiecha 7th June 2010