Removing the rare element limitations from solar energy must happen for solar to cost-compete with coal and natural gas.
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Our future energy requirements depend on reaching the Holy Grail of electricity generation – a cost competitive alternative to coal and natural gas. Despite the environmental impact and waning supply of fossil fuels, the market continues to drive their widespread use as our overwhelming choice in generating more than 70% of our global electricity. The availability of an alternative energy source would also contribute significantly to energy self-sufficiency in North America.
Every hour more energy from the sun hits the earth than the world's entire population consumes in a single year. Given this abundance, solar energy is our world's most obvious energy choice. However, 2010 data indicated only 1% of our global electricity supply came from solar energy. The number is small, but the PV market has grown from a mere 1.75GW of installation in 2006 to an industry projection of 100GW in 2013 (EPIA Global Market Outlook for 2015). The continued reality of the imbalance between solar electric, coal and natural gas is pure economics.
In 2010, The National Academy of Sciences reported the real cost of using fossil fuels (pollution and greenhouse gas emissions) added another $120 billion to market cost, not to mention the long-term costs to our environment, some irreversible. However, in a market-driven economy, future impact is not the driving force, but rather the reality that the wholesale cost of electricity from natural gas and coal is substantially lower than solar energy today.
Primary Barriers
Despite the huge growth of solar photovoltaic (PV) installations in 2010 – with 129% growth, the global market reached16.6GW – the market continues to experience limitations involving either efficiency or expense. These limitations have prevented solar power from competing effectively with fossil fuels. Additionally, many of the cutting-edge thin-film technologies require rare elements that are a finite resource already in short supply. There simply is not enough material on the planet to make these devices for worldwide consumption.
"The biggest barrier to solar energy becoming the dominant source of electricity globally is expense," says Dr. Andras G. Pattantyus-Abraham, chief technology officer, Quantum Solar Power Corp. "The obvious lesson learned from the bankruptcy of Solyndra and Evergreen is the industry is focused on price. Currently, the most cost-competitive solutions are the thin-film PV technologies, CdTe and CIGS, but in the long term, given the short supply of indium and tellurium, an alternative solution will need to be developed within thin-film manufacturing in order to remain cost competitive."
In order for solar energy to meet current economic demands, it must solve three key issues that have previously limited its acceptance – efficiency, price, and the removal of rare elements used in production. Current solar PV technologies generate electrical power by converting solar radiation into an electric current using semiconductor layers made from either crystalline silicon or what is called a thin-film layer of exotic materials. Silicon PV technologies have been the standard approach since the 1950s, currently offering the highest efficiencies. Although silicon ingot prices have dropped in recent years, silicon PV remains more expensive than thin-film modules. While novel crossover approaches, such as amorphous silicon, have gained ground by applying silicon semiconductors at a thin-film level, the least expensive PV module is a cadmium telluride (CdTe) thin-film product. Despite thin-film's cost advantage and increasing efficiencies, it remains 3% to 7% less efficient than the leading silicon PV. The elephant in the thin-film room is, however, materials.
Strangling Solars Reach
The leading thin-film products primarily use rare elements to create their semiconductor layers at a very small scale (1µm to 8µm). Elements such as gallium arsenide, tellurium, and indium, have limited global supplies that are controlled by only a few countries. In the case of tellurium, used in the leading thin-film First Solar (CdTe), there is only two known high concentration deposits – located in China and Mexico. Tellurium is the second scarcest byproduct metal, next to gold, and is mainly a byproduct of copper ore production. With consumption steadily climbing, and only a little over 125MT being produced annually, tellurium prices have more than doubled since 2007. In fact, looking at First Solar's projections for reducing their $/watt manufacturing costs, materials are not mentioned as an area in which they see potential reductions. If thin-film is to emerge as a viable alternative, and is indeed the Holy Grail photovoltaic solution, it must overcome this rare element restriction.
 In the fall of 2008, 4D LABS and a team of scientists began work at Simon Fraser University (SFU), a Canadian public research university in British Columbia, Canada. |
Lastly, with China now a major producer of crystalline silicon PV, it is likely they will more strictly control exports of tellurium in the future as they move into thin-film markets. Hanergy, a Chinese solar PV company recently announced a $626 million investment in new 1.5GW thin-film production, research, and development facilities. Other Chinese manufacturers have hinted at moving in the direction of thin-film as well, and some already are. Seven out of the top 10 solar PV manufacturers are currently Chinese companies. The estimated 2011 production capacity of the top 10 manufacturers is more than 19GW. The Chinese represent 13GW of this amount. Therefore, as these companies begin to move in the direction of thin-film production, the issue of rare element supply becomes more serious.
Comparing Technologies
Quantum Solar Power Corp. is developing a solar PV device that will address all three critical success factors – high efficiency, low cost, and high scalability, with an abundance of non-toxic materials. Our approach focuses on eliminating the costly and sometimes exotic semiconductor absorbers used in the vast majority of PV. Utilizing widely available materials, the Quantum device aims at cutting thin-film material costs in half. If material costs represent 45% or more of PV manufacturing, a 50% reduction would be a monumental step toward solar becoming the obvious economic choice.
Leading silicon efficiencies in the industry are currently at 20% to 22% power conversion efficiency (PCE) for crystalline silicon PV and 15% to 17% for thin-film. Quantum engineer modeling demonstrates a potential to achieve efficiencies PCEs of more than 20%, thereby fulfilling another of the critical competitive factors related to the PV industry. Although cost is driving the PV market currently, long-term success is dependent on maintaining high levels of efficiency in order to maximize electrical capacity.
Quantum engineers evaluated the leading solar technologies and determined the limitations on solar were related to the methods used for absorbing energy. The device currently in development is expressly focused on this component of solar PV, with the goal of delivering a PV device that matches or exceeds the highest efficiencies currently available, while fitting into a thin-film manufacturing model that eliminates rare elements, and in turn, drastically cutting module costs.
Game-Changing Technology
In the fall of 2008, Dr. Gary Leach, lead scientist, Quantum, and director, Photonic Systems, 4D LABS, and a team of scientists began work at Simon Fraser University (SFU), a Canadian public research university in British Columbia. SFU was identified early on in the formation of Quantum Solar Power as a key resource, given their newly built, state-of-the-art research and fabrication facilities. 4D Labs opened in 2007 as a cutting-edge facility for optics and nanoscience research, and has edge tools and a 4,000ft2 cleanroom.
After a careful analysis of the limitations to PV technologies at that time, in concert with novel ideas of their own, the team hypothesized a completely new approach to solar cell design. In October 2008, they embarked on a proof of concept design for a new device. By March 2009, it became apparent to Leach and his team that their proof of concept was indeed viable. Dr. Andras G. Pattantyus-Abraham met Leach at a nanotechnology presentation at SFU in the summer of 2009. Pattantyus-Abraham was engaged in semiconductor nanoparticle research at the Sargent Group at the University of Toronto at the time. Convinced that Quantum's approach promised a true Holy Grail solution, he joined Quantum in late 2009 as CTO.
Since early 2010, Quantum's lab in Burnaby, British Columbia, Canada, with its team of 14 leading experts in nanotechnology, physical chemistry, optics, and physics, has been fine-tuning a prototype PV device. In June 2011, Quantum researchers entered their second phase of research, ramping up the device's output results. Future research and development will focus on key partnerships in research and manufacturing, as well as National Renewable Energy Lab (NREL) certification.
Solar Power's Role
It is important for our geopolitical future that we create a clean energy economy along with a strong energy policy. A sunny future for our children demands that we continue to create green sector jobs, replacing our dependency on fossil fuels with renewable energy through wind turbines, hydro-electric power, and solar PV technologies that make solar energy a globally-deployable, environmentally-smart energy source.
If the barriers to cost, efficiency, and scalability can be met with technology as promising as the developments at Quantum Solar, the solar industry could shift dramatically from making a marginal contribution on our energy supply to becoming the dominant force in coming years.
Any solar cell technology that can achieve matching or superior efficiencies to leading technologies, at a lower cost while remaining free of rare materials, is unquestionably a disruptive technology, and will significantly contribute to making solar PV the dominant electricity resource for our planet.
Quantum Solar Power Corp.
Vancouver, BC, Canada
quantumsp.com
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