Renewable Energy

Flexible Plastic Nano Solar

September 21, 2006 - 02:13:20 AM

Using oil to produce flexible nano enabled polymers that generate electricity from the sun is certainly a higher and better use than burning such complex hydrocarbons in cumbustion engines. This is the innovation upon which Massachestts based Konarka is building its company.

According to the company, "Konarka’s products take light in and deliver power out. This direct current (DC) electrical energy can be used immediately, stored for later use, or converted to other forms of energy. Because Konarka’s technology utilizes a wider range of the light spectrum than conventional solar cells, all visible light sources — not just sunlight — can be used to generate power."

With funding from investors Silicon Valley Bank, Chevron, the Massachusetts Technology Collaborative and a host of venture capital firms, Power Plastic (tm) might actually get to market.

Guess who is getting a first crack at this new technology? Why the military of course! Currently Plastic Power is being developed for portable, electric-generating quonset huts. Other military applications include battery charging on the battlefield, remote power for unmanned vehicles and soldiers, and solar-powered sensor networks.

Konarka also envisions using the power-generating capabilities of Power Plastic(tm) to structures including tents, awnings, roofs, windows and window coverings. And they plan to be the power supply of choice for consumer electronics such as cell phones and portable music players as well as business products such as PDAs, and laptops.

There are no hard specs or effeciency analyses on the company's website as far as I can tell.

The big breakthrough lies in the claim that the photo reactive material is lightweight, coatable, flexible, more versatile, printable and uses ubiquitous roll-to-roll, easy to scale manufacturing technology. All this is supposed to translate to truly affordable photvoltaics.

No wonder they won the 2005 Popular Mechanics Breakthrough Award among numerous others.

Bring it on!  READ MORE »

PV's with Concentrators Yield 35% Efficiency Rate

August 28, 2006 - 02:13:20 AM

The Boeing Company has signed a contract to provide 600,000 solar concentrator cells to SolFocus, Inc., a California-based renewable energy company that is developing renewable terrestrial energy alternatives.

Under the 12-month contract from SolFocus, Inc. of Palo Alto, Calif., Spectrolab will build and deliver 600,000 solar concentrator cells that will be used to convert the sun's rays into affordable electricity for homes and businesses. The cells produced for SolFocus will be capable of generating more than 10 megawatts of electricity, or enough to power about 4,000 U.S. homes. With the average solar cell efficiency above 35 percent at concentration, Spectrolab's concentrator photovoltaic cells generate electricity at a rate that can be more economical than electricity generated from conventional, flat panel photovoltaic systems.

A significant advantage of concentrator systems is that fewer solar cells are required to achieve a specific power output, thus replacing large areas of semiconductor materials with relatively inexpensive optics that provide optical concentration. The slightly higher cost of multi-junction cells is offset by the use of fewer cells. Due to the higher efficiency of multi-junction cells used in the concentrator modules, only a small fraction of the cell area is required to generate the same power output compared to crystalline silicon or thin-film, flat-plate modules.

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World's First Maglev Wind Generator

August 20, 2006 - 02:13:20 AM

Chinese developers unveiled the world's first full-permanent magnetic levitation (Maglev) wind power generator at the Wind Power Asia Exhibition 2006 held June 28 in Beijing. Magnetic levitation, maglev, or magnetic suspension is a method by which an object is suspended above another object with no support other than magnetic fields. The electromagnetic force is used to counteract the effects of the gravitational force.

Regarded as a key breakthrough in the evolution of global wind power technology — and a notable advance in independent intellectual property rights in China—the generator was jointly developed by Guangzhou Energy Research Institute under China’s Academy of Sciences and by Guangzhou Zhongke Hengyuan Energy Science & Technology Co., Ltd. The Maglev generator is expected to boost wind energy generating capacity by as much as 20 percent over traditional wind turbines. This would effectively cut the operational expenses of wind farms by up to half, keeping the overall cost of wind power under 0.4 yuan ($US 5 cents), according to Guokun Li, the chief scientific developer of the new technology. Further, the Maglev is able to utilize winds with starting speeds as low as 1.5 meters per second (m/s), and cut-in speeds of 3 m/s, the chief of Zhongke Energy was quoted as saying at the exhibition. When compared with the operational hours of existing wind turbines, the new technology will add an additional 1,000 hours of operation annually to wind power plants in areas with an average wind speed of 3 m/s.

Photo Caption/Credit: Using magnetic levitation for a frictionless air bearing  READ MORE »

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Solar Generator Uses Mass Produced Autoparts to Cut Costs

August 20, 2006 - 02:13:20 AM

A set of prototype solar concentrators installed in Lesotho. (Courtesy of Amy Mueller.)
Matthew Orosz, an MIT graduate student advised by Harold Hemond, professor of civil and environmental engineering are working on alternative approaches to solar-based electricity that could significantly cut costs compared to photovoltaics panels. Their goal is to put the ability to harvest electricity from the sun into the hands of villagers in poor countries.
According to Kevin Bullis of MIT's Technology Review the system works like this:

"The basic design of Orosz's solar generator system is simple: a parabolic trough (taking up 15 square meters in this case) focuses light on a pipe containing motor oil. The oil circulates through a heat exchanger, turning a refrigerant into steam, which drives a turbine that, in turn, drives a generator."

"The refrigerant is then cooled in two stages. The first stage recovers heat to make hot water or, in one design, to power an absorption process chiller, like the propane-powered refrigerators in RVs. The solar-generated heat would replace or augment the propane flame used in these devices. The second stage cools the refrigerant further, which improves the efficiency of the system, Orosz says. This stage will probably use cool groundwater pumped to the surface using power from the generator. The water can then be stored in a reservoir for drinking water."

"The design uses readily available parts and tools. For example, both the feed pump and steam turbine are actually power-steering pumps used in cars and trucks. To generate electricity, the team uses an alternator, which is not as efficient as an ordinary generator, but comes already designed to charge a battery, which reduces some of the complexity of the system. And, like power-steering pumps, alternators, including less-expensive reconditioned ones, are easy to come by."

"As a result, the complete system for generating one kilowatt of electricity and 10 kilowatts of heat, including a battery for storing the power generated, can be built for a couple thousand dollars, Orosz says, which is less than half the cost of one kilowatt of photovoltaic panels."

original article  READ MORE »

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Dutch Wind Mill Tree

August 04, 2006 - 02:13:20 AM

A proposition by One Architecture, Ton Matton and NL Architects, comissioned by the Dutch government, for a next generation windmill. The proposed mill is shaped like a tree and can hold up to 8 turbines and be as high as 120 meters! A tree shaped mill is less intrusive in the flat Dutch landscape than the mill-parks they use.

via Inhabitat

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New Vertical Axis Wind turbine promises a "Quiet Revolution"

March 13, 2006 - 02:13:20 AM

Elegant looking indeed, but what will make this vertical wind turbine perform any diffferent than other vertical axis sytems that have apperared over the years, only to receed quietly into obscurity. Common knowledge says that energy output per dollar invested cannot compare to the advanced horizontal turbines that are spreading like wildfire. But according to Treehugger, the UK company called Quiet revolution LTD might be offering something revolutionary -- at least interms of simplicity of design (very few moving parts result in vibration free and virtually silent operation) and double-duty functionality by integrating LED lighting in the blades to provide decorative lighting or even messaging. The product was developed by XC02, an appropriate name for an engineering and design studio dedicated to providing low-corbon solutions in the built environment.

According to Treehugger:

Trials were carried out at the end of last year and with the results XCO2 say that the Quiet Revolution will be capable of producing 10,000 kWh per year based on an average wind speed of 5.8 m/s. "If you had two of them that would satisfy the 10% renewable energy requirement for a 1200 square-metre office building," says their marketing director Julia Grove.

  • Physical dimensions: 5m high x 3.1m in diameter
  • Generator: Direct drive, mechanically integrated, weather sealed 6kW permanent magnet generator
  • Power control: Peak power tracking constantly optimises turbine output for all sites and windspeeds
  • Operation mode: Max wind speed: 16m/s; Min wind speed: 4.5m/s
  • Design life: 25 years (annual inspections recommended)
  • Rotor construction: Carbon fibre & epoxy resin blades and connection arms
  • Brake & shutdown: Over-speed breaking above 14m/s wind speed, auto shutdown in high wind speeds (above 16m/s)
  • Remote monitoring: Event log can be accessed via GSM Dial up. Remote monitoring stores operation and kW hours of electricity generated
  • Warranty: Two years on components

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