Tawanai

As reported by Stanford News, a new solar energy conversion process discovered by Stanford engineers could revamp solar power production. This
process simultaneously combines the light and heat of solar radiation to generate electricity could offer more than double the efficiency of existing solar cell technology, say the Stanford engineers who discovered it and proved that it works. The process, called “photon enhanced thermionic emission,” or PETE, could reduce the costs of solar energy production enough for it to compete with oil as an energy source.

Clean Technology, Energy, Renewable Energy, Solar, Technology, research

As part of our new technology series, this post looks at use of nano particles to improve solar energy performance. This report comes via Technology Review.

Inexpensive thin-film solar cells aren’t as efficient as conventional solar cells, but a new coating that incorporates nanoscale metallic particles could help close the gap. Broadband Solar, a startup spun out of Stanford University late last year, is developing coatings that increase the amount of light these solar cells absorb.

Solar antenna: The square at the center is an array of test solar cells being used to evaluate a coating that contains metallic nanoantennas tuned to the solar spectrum. Credit: Brongersma lab, Stanford

Based on computer models and initial experiments, an amorphous silicon cell could jump from converting about 8 percent of the energy in light into electricity to converting around 12 percent. That would make such cells competitive with the leading thin-film solar cells produced today, such as those made by First Solar, headquartered in Tempe, AZ, says Cyrus Wadia, codirector of the Cleantech to Market Program in the Haas School of Business at the University of California, Berkeley. Amorphous silicon has the advantage of being much more abundant than the materials used by First Solar. The coatings could also be applied to other types of thin-film solar cells, including First Solar’s, to increase their efficiency.

Broadband believes its coatings won’t increase the cost of these solar cells because they perform the same function as the transparent conductors used on all thin-film cells and could be deposited using the same equipment.

Broadband’s nanoscale metallic particles take incoming light and redirect it along the plane of the solar cell, says Mark Brongersma, professor of materials science and engineering at Stanford and scientific advisor to the company. As a result, each photon takes a longer path through the material, increasing its chances of dislodging an electron before it can reflect back out of the cell. The nanoparticles also increase light absorption by creating strong local electric fields.

Energy, Innovation, Solar, research

A Swiss company says it has developed rechargeable zinc-air batteries that can store three times the energy of lithium ion batteries, by volume, while costing only half as much. ReVolt, of Staefa, Switzerland, plans to sell small “button cell” batteries for hearing aids starting next year and to incorporate its technology into ever larger batteries, introducing cell-phone and electric bicycle batteries in the next few years. It is also starting to develop large-format batteries for electric vehicles.

This graphic illustrates the multilayered structure of a ReVolt rechargeable zinc-air battery. From top to bottom: the battery cover, which lets in air; a porous air electrode; the interface between electrodes; the zinc electrode; the casing. Credit: ReVolt

The battery design is based on technology developed at SINTEF, a research institute in Trondheim, Norway. ReVolt was founded to bring it to market and so far has raised 24 million euros in investment. James McDougall, the company’s CEO, says that the technology overcomes the main problem with zinc-air rechargeable batteries–that they typically stop working after relatively few charges. If the technology can be scaled up, zinc-air batteries could make electric vehicles more practical by lowering their costs and increasing their range.

Unlike conventional batteries, which contain all the reactants needed to generate electricity, zinc-air batteries rely on oxygen from the atmosphere to generate current. In the late 1980s they were considered one of the most promising battery technologies because of their high theoretical energy-storage capacity, says Gary Henriksen, manager of the electrochemical energy storage department at Argonne National Laboratory in Illinois. The battery chemistry is also relatively safe because it doesn’t require volatile materials, so zinc-air batteries are not prone to catching fire like lithium-ion batteries.

Via Technology Review

Electronics, Energy, Innovation, research batteries, volt

The world of today desperately needs a breakthrough in solar power. The challenge has been to bring the price down. Here’s one more effort in this direction: Photovoltaic cells made from organic polymers, rather than crystalline silicon, could make solar power much cheaper.

Last year Konarka, a startup based in Lowell, MA, opened a factory for such solar panels, which are flexible and produced in a process akin to printing (see “Mass Production of Plastic Solar Cells”).

The first application of Konarka’s potentially transformative technology? Umbrellas. SkyShades, based in Orlando, FL, is incorporating the panels into umbrellas designed for outdoor seating areas in places like restaurants and bars. Patrons can recharge mobile devices such as laptops and cell phones from outlets built into the stem of the umbrella. The four-meter-wide Powerbrella can generate up to 128 watts of electricity, which charges a bank of batteries located in its base.

Via Tech Review.

Clean Technology, Consumers, Energy, Solar, research invention, photovoltaic cells

Via Technology Review.

Stirling Energy Systems (SES), based in Phoenix, has decreased the complexity and cost of its technology for converting the heat in sunlight into electricity, allowing for high-volume production. It will begin building very large solar-power plants using its equipment as soon as next year.

The company is currently building a 1.5-megawatt, 60-unit demonstration plant that will use the company’s latest design. Stirling expects to finish that project by the end of the year. It also has contracts with two California utilities to supply a total of 800 megawatts of solar power in Southern California. The first of the plants that will supply this power could be built starting the middle of next year, pending government permits and loan guarantees from the U.S. Department of Energy (DOE).

The projects are part of a resurgence in what’s known as solar thermal power. Various solar thermal technologies were developed starting in the 1970s, but a breakdown in government funding and incentives caused them to stall before they reached a scale of production large enough to drive down costs and allow them to compete with conventional sources of electricity. “It was a classic problem with solar. The market support to bring solar to high volume wasn’t there,” says Ian Simington, the chairman of SES and chief executive of the solar division of NTR, a company based in Dublin, Ireland, that bought a controlling share of SES last year.

Recent state mandates and incentives for renewable energy have led to a new push to commercialize the technology. There are over six gigawatts of concentrated solar power under contract in the southwestern United States right now, says Thomas Mancini, program manager for concentrated-solar-power technology at Sandia National Laboratory in Albuquerque, NM. That’s equivalent to about six nuclear-power plants. BrightSource Energy has contracts to provide 2.6 gigawatts of solar power with concentrated solar power (a previous version of this story sited only one of two 1.3 gigawatt contracts), and Solar Millenium has announced a project that would generate nearly one gigawatt of power.

Electricity, Energy, Innovation, Renewable Energy, Solar, research

I came across a really good article (from consulting firm McKinsey and company) about the global state of solar power and its economics. Leave a comment if you want the full paper.

Solar energy is becoming more economically attractive as technologies improve and the cost of electricity generated by fossil fuels rises. By 2020, hundreds of billions of dollars of investment capital will probably boost global solar-generating capacity 20 to 40 times higher than its current level.

As the new sector takes shape, producers of solar components must drive their costs down, utilities must place big bets despite enormous technological uncertainty, and regulators must phase out subsidies with care. The actions these players take will determine the solar sector’s scale, structure, and performance for years to come.

Economics, Energy, Renewable Energy, Solar, research

Pakistan Council of Scientific and Industrial Research (PCSIR) was established in 1953 under Societies Act to promote the cause of Science and Technology in the country. I remember their facility on Ferozpur road Lahore. PCSIR is one of the important research institution with a rich history and has evolved throughout the years.

In a recent blog post, a PCSIR officer mentioned the need and desire to work on cost-effective local solar cell production. We wish them the best of luck and hope that they are successful in getting the funds for such work.

A PCSIR officer said that “Rice husk contains 13 % oil which can be further processed to be used as biofuel. The remaining husk has a lot of quartz content which is needed to make solar cells. We have yet to determine the exact yield of quartz from rice husk, but initial tests have indicated a good percentage.”

It is to be noted that Pakistan is the world’s third largest rice producer and tons of rice husk is wasted or put to fire, which can be used in the production of low-cost, high quality solar cells.

Energy, Pakistan, Solar, research PCSIR