We have had the ability to produce fabrics that produce electricity from physical movement for a few years, but now researchers at Georgia Institute of Technology are developing a fabric that can gather solar energy and motion energy concurrently. The combination of these two generators of electricity into a textile will allow for developing clothes that can provide their own source of energy to power smartphones and global positioning systems (GPS). This fabric will alleviate the issue of charging devices while conducting research in the field because it can harness energy from the wind and sun.
This development was spearheaded by Zhong Lin Wang, a Regents professor in the Georgia Tech School of Materials Science and Engineering. This new material would be 320 micrometers thick woven together with strands of wool, and could be integrated into tents, curtains or wearable garments. To construct the fabric, Wang’s team used a commercial textile machines to interlace together solar cells constructed from lightweight polymer fibers with fiber-based triboelectric nanogenerators. Triboelectric nanogenerators use a combination of the triboelectric effect and electrostatic induction to generate small amount of electrical power from mechanical motion such as rotation, sliding or vibration. Fiber-based triboelectric nanogenerators capture the energy created when certain materials become electrically charged after they come into moving contact with a different material. For the sunlight-harvesting part of the fabric, Wang’s team used photoanodes made in a wire-shaped fashion that could be woven together with other fibers. Continue reading →
Forecasts about the future of solar energy tend to be rosy and optimistic, but is the solar revolution really a nobody-loses scenario? A study lead by Aixue Hu (2017) titled “Impact of solar panels on global climate” addresses some infrequently mentioned concerns.
It turns out that solar energy systems have consideration-worthy regional consequences. But you may ask: why? Solar panels are not 100% efficient, they are actually fairly far from it. The most efficient solar panels on the market today run at around a 40% efficiency, with some new technologies promising around 60%, however most are much lower. A few issues arise in the conversion of solar energy into electricity. Firstly, a small percent of the solar radiation is reflected, as a result of solar panels’ glare. Then, another few percent are lost in the conversion of direct-current into alternating current and along the transmitting wires to centers of population. The authors estimate the mentioned causes to sum to about a 10% loss. Continue reading →
Silicon photovoltaics are a proven sustainable energy solution and take up 90% of the solar cell market. Silicon cells have many practical advantages associated with them, including high cell efficiency, stability and longevity. They are also extremely cost effective. The cost of mass produced silicon cells has dropped below $1/W, in some cases as low as $0.3/W. At the same time, efficiency continues to increase to 20%. The biggest hindrance to further increases in efficiency are high rates of recombination at the surface of the cells, which is what Shinde et. al (2016) have been working on.
In order to lower the rates of recombination, the technique of passivation has been employed. SiNx and SiO2 compounds have been used for passivation in the past. Although the desired surface passivation is accomplished, these compounds require high process temperatures (300° – 1000° C). At these temperatures, the properties of the silicon crystalline structure are affected. If these temperatures are reduced, efficiency and longevity are expected to increase.
To combat high process temperatures, new techniques have been presented. It has been shown that passivation can be achieved by using Si-O and Si-H and organic passivation. Shinde et. al (2016), look at passivation of n-type emitter by organic cover layer Oleylamine (OLA). This passivation technique will increase efficiency and has the ability to be processed at room temperature. Continue reading →
The once assumed fact, that Photovoltaic (PV) solar technologies could not be cost effective and energetically viable, is slowly crumbling. Relatively low-cost and powerful solar cells are produced in large quantities throughout the world, making the levelized cost of electricity (LCOE) of these cells competitive with other energy-related technologies. A similar thought process was assumed when discussing the possibilities for ion implant technology in solar applications. This assumption is slowly being proven wrong too. Ion implanting technology is slowly becoming a favorable method for doping formation in semiconductors (silicon is commonly used in present PV cells). By using this technique, higher-efficiency solar cells can be mass produced. Two hurdles must be faced in order to make this technology more accessible: high costs and low throughput. These hurdles have been faced most head on by a semiconductor company, Kingstone. By developing a simpler ion implanter, Kingstone believes they can cut 90% of their current operations cost while producing a very high thoroughput (>1500 wafers/hour). Continue reading →
Tom Phillips’ article on China’s construction of the world’s largest solar panel farm is a useful primer on the various perspectives surrounding the project. China’s grandiose scale of renewable energy initiatives can be read as a strategic move to increase their global soft-power. This is prescient in a world where many global superpowers regard climate change as a serious threat. Phillips acknowledges this upscaling as stratagem when he notes its concurrence with the election of a U.S. President who is a climate-denier. But a single solar farm, no matter the grandeur of its sobriquet, cannot nullify the environmental impact of an entire nation, and issues of curtailment – energy produced that does not reach the grid – undercut the potential reformative power of China’s green energy production. According to a New York Times article also on the new solar farm, 19% of China’s wind energy produced in the first six months of 2016 was curtailed, compared to “negligible” amounts of energy lost in the U.S. [www.nytimes.com/2017/01/05/world/asia/china-renewable-energy-investment.html]. And while China’s current enthusiasm for energy reform is a hopeful sign, long-term commitment is necessary for real change. If current initiatives are only political maneuvers made in a global climate that is changing with the succession of a Trump presidency, then the difference Phillips reports between “a climate leader but not the climate leader” will be felt in their, the initiative’s, long-term ineffectiveness. Is a China-as-world-climate-leader that unimaginable in a world of said radical change? Continue reading →
The Mexico City Metropolitan Area (MCMA) has a population of 8.851 million people (2010), making it the largest and most populated urban area in the country. It is well within the “sun-belt” of Earth, with solar incidence areas of over 5 kWh/m2/ day radiation. Though there is a high potential for renewable energy, there is little incentive by policymakers to take advantage of an energy source that could better conserve the environment, limit the amount of natural and/or technical interruptions, and be an economic relief to the MCMA. The authors support the development of and rationalize that solar photovoltaic (PV) technology to harvest its energy potential. This technology is economically competitive to give energy to vulnerable areas that often do not require as much power. Because energy transition diagnostic is not very organized, it is vital for decision-makers to be aware of the social and economic difficulties in MCMA. Continue reading →
Solar energy as a viable business is crucial to the world’s energy market. The jury has been out on this question: is it possible to make money in the solar business?With oil prices at an all time low, the viability question becomes even more relevant as development related investments in the solar energy sector could dramatically reduce. The world’s dependence on fossil fuels — coal, oil, etc — over the years has resulted in an environmental degradation of an unprecedented level. Hence it is crucial that alternative energies, like wind and solar, become viable businesses. Continue reading →
A study conducted in Taiwan and published in Nanoscale Research Letters, found that the use of silicon nanowires can be used to improve solar thermal energy efficiency. Solar energy is the most abundant source of renewable energy on our planet, and using thermal energy to capture this energy could play a key role in increasing our use of this form of alternative energy. Solar thermal energy is comparatively inexpensive, easy to implement, and efficient compared to many other forms of energy, and using silicon nanowires could be the latest breakthrough in improving this efficiency. Silicon and silicon nanowires are used extensively in photovoltaic electrical energy generation, but have not traditionally been used extensively in thermal energy collection. However, new research into the thermal properties of silicon nanowires has found they are significantly more efficient in thermal conversion than traditional silicon plates. Continue reading →
An MIT research team has recently developed what is believed to be the thinnest, most lightweight, and flexible photovoltaic cell, with the ability to be installed onto any surface and the potential to charge any portable electronic device. The solar cell is so light that it is able to rest on a soap bubble without the bubble being popped. The real key to this innovation Is a one-process approach in manufacturing the ultra-thin solar cell and the unique substrate that supports it. Continue reading →
In October 2015, California Governor Jerry Brown signed in the country’s largest solar bill designed for low-income renters, creating the Multifamily Affordable Housing Solar Roofs Program under AB693. This new program is the successor to the Multifamily Affordable Solar Housing (MASH) Program established in 2008 as part of the California Solar Initiative, and aims at expanding the program to have a larger impact on low-income households.
The California Public Utilities Commission cites great demand and success in green developers collaborating in low-income housing projects to install rooftop solar as a reason for updating the program, and aims to increase renewables by setting a goal of at least 300 megawatts of rooftop solar POV on each multifamily affordable housing project. Continue reading →