Sunlight reaching American households is enough to supply at least 50 percent of the total electricity needs of America. Recently, scientists concluded that progress in the field of affordable solar-energy technology is fundamentally necessary for people to opt to invest in roof shingles that can generate electricity power. Actually, shingles that are capable of generating electrical power from the sunlight, can be installed like traditional roofing. This is currently a commercial reality. However, new advance in science can allow solar cells to be constructed from materials that are earth-abundant. This would make solar cells more affordable and also facilitate the integration of PV (Photovoltaic) into different parts of the building.
At the 244th National Meeting & Exposition of the American Chemical Society, the scientists’ report was part of the symposium on sustainability. Below are some of the other abstracts from other presentations.
One of the lecturers, Dr. Harry A. Atwater told that sustainability is developing technology that has the capacity of being fruitful over the long-term. This implies introducing resources that can fit today’s needs naturally.
Materials like zinc and copper are abundant and less-expensive materials, and that is what the new PV technology will use. They will use these abundant materials instead of the so-called rare-materials like gallium and indium. Rare materials are costly and also supplied mostly by foreign countries. China is withdrawing more than ninety presences of these rare substances; necessary for magnets, batteries for hybrid vehicles, high-tech products and electronics. Dr. James C. Stevens and Atwater are relating efforts to replace high-cost and rare material to produce PV cells with low-cost materials that are abundant and of course more sustainable.
Dr. Atwater is a physicist with the California Institute of Technology; Dr. Stevens is a chemist at the Dow Chemical Company; together, they are leading a partnership between both organizations in order to develop new electronic materials that can be used in devices for solar energy conversion. Both said that the development and testing of the new devices broke records when it comes to voltage and the electrical current; these conversion devices contain copper oxide and zinc phosphide. Atwater said that all these advances demonstrate that materials like copper oxide and zinc phosphide will be capable of reaching high efficiency while producing electrical power at a lower cost; according to Atwater, such goal could be accomplished in as little as 20 years!
Dr. Stevens supported the development of the Dow’s PowerHouse Solar Shingle that was launched in 2011 (October). It can generate electricity power through traditional roofing. These shingles use gallium, indium and copper diselenide PV technology but now the group is looking forward to incorporating sustainable and abundant materials into the Dow’s PowerHouse Solar Shingle in order to make them even more commonly accessible.
Dr. Stevens stated that the U.S. possessed 69 billion square feet of residential rooftops. The rooftops have all the necessary conditions to generate electricity from the sun. In fact, the solar light that falls on those large areas of rooftops can generate sufficient electricity to satisfy at least half (50%) of the U.S. energy needs. Some people go further and estimate a value close to 100%. With the technology that uses materials widely available on Earth, the electrical energy produced would be significantly more environmentally friendly.
In the symposium, other interesting presentations took place; here are some of them:
• In order to increase the production of earth-rare elements using greener and cheaper technology in the United States, Molycorp (mining company) is modernizing and expanding its facilities (Mountain Pass, Colo).
• An overview was conducted on the different challenges when it comes to maintaining a sustainable source of “critical materials” from rare elements such as indium vs abundant elements such as copper.
• Oil, mining and gas drilling produces 800 billion gallons of wastewater each year. In the symposium, they discussed a new material to recover rare materials from that wastewater.
Source: Science Codex