Researchers at Wake Forest University have developed a new type of polymer solar-thermal device that combines photovoltaics with a system that captures the Sun‘s infrared radiation to generate heating. By taking advantage of both heat and light, researchers say the device could deliver up to 40 percent savings on the cost of heating, as well as helping reduce power bills by producing electricity.
The hybrid cell is designed with an integrated array of clear tubes, five millimeters (approx 1/4 inch) in diameter. Lying flat, visible sunlight shines into the clear tube which is filled with an oil blended with a proprietary dye, heating the oil which then flows into a heat pump to transfer the warmth inside a home.
Electrical current is produced via a polymer photovoltaic sprayed onto the back of the tubes.
The result is a solar-thermal device with an impressive 30 percent conversion efficiency.
In comparison to flat solar cells, the tube design also has the advantage of being able to capture light at oblique angles, so it can accumulate power for a much longer stretch in the day and be more readily integrated into building materials – it could be produced to resemble a roofing tile for example.
The research team aims to produce a 3 foot square solar thermal cell over the coming months, a key step in bringing the technology closer to market.
“It’s a systems approach to making your home ultra-efficient because the device collects both solar energy and heat,” said David Carroll, Ph.D., director of the Center for Nanotechnology and Molecular Materials at Wake Forest University. “Our solar-thermal device takes better advantage of the broad range of power delivered from the sun each day.”
We’ve heard about ideas for floating data centers and floating wind turbines; it was only a matter of time before we heard about floating solar power plants. Australian solar power company Sunengy has just gotten approval for a pilot project in India through a partnership with Tata Power.
The floating solar power units, called Liquid Solar Arrays (LSA), use concentrated photovoltaic technology where a lenses direct the light onto solar cells and move throughout the day to follow the sun.
The company says the advantage to floating a solar power plant is that it erases the need for expensive structures to protect it from inclement weather and high winds — when rough weather comes along, the lenses just submerge. Floating on water, whether it be the ocean, a lake or a tiny pond, also keeps the solar cells cool, which increases their efficiency and lifespan. You can see a video demonstration of the technology here.
The pilot project should begin construction this August. Sunengy as another larger array in the works for 2012 and if both projects go well, they plan to go into full production.
The U.S. Department of Energy (DOE) has awarded 3M $4.4 million as part of DOE’s SunShot Initiative. SunShot aims to reduce the total costs of photovoltaic solar energy systems by about 75 percent, so that they are cost-competitive with other forms of energy without subsidies. SunShot calls for achieving this goal by the end of the decade. The sum of the 3M award is estimated at $4.4 million over three years.
The goal of 3M’s project is to accelerate efforts toward further development and commercialization of 3M™ Ultra Barrier Solar Film. The funding will support a reliability test program to validate the lifetime performance of the film as well as development of second-generation 3M Ultra Barrier Solar Film with enhanced performance and reduced costs.
As part of the initiative, 3M will collaborate with DOE’s National Renewable Energy Laboratory (NREL) to test the performance and durability of Ultra Barrier Solar Films. NREL recently confirmed moisture vapor transmission rates in the range of 2*10-5 – 8*10-5 g/m2/day for 3M’s current Ultra Barrier Film 9L product using its electrically based calcium moisture vapor transmission rate (MVTR) test. “Technology for economical production of transparent barrier films has been a missing link in the flexible CIGS photovoltaic supply chain for a long time, and we are looking forward to working with 3M in the development of this technology,” says NREL senior scientist Mike Kempe.
“We are delighted that DOE has recognized the relevance of 3M’s Ultra Barrier Solar Film toward achieving its goals for driving down the cost of solar,” says Derek DeScioli, business development manager for the 3M Renewable Energy Division. “High-efficiency flexible solar modules manufactured with 3M’s Film not only have the potential to significantly reduce the total system costs for rooftop solar installations, but also have an array of niche applications where our customers can take advantage of the unique module form factor.”
Designed to address the needs of flexible thin film solar manufacturers, 3M Ultra Barrier Solar Film acts as a replacement for glass with high light transmission, moisture barrier performance and strong weatherability.
The windows called high power density photovoltaic glass units are being made by Pythagoras Solar. They will retain views and daylighting for the floor, reduce heat and produce as much electricity as a traditional solar panel. The windows consist of monocrystalline silicon solar cells sandwiched between two layers of glass with an internal prism that directs the sunlight onto the solar cells, while letting diffuse light through. The result is a cooler, natural lighting environment inside the skyscraper and a more efficient solar panel.
The windows are part of a bigger project by the tower’s owner and Pythagoras to show the benefits of a building integrated PV system (BIPV). For large towers all over the world, this could be a key component in both energy efficiency and renewable energy production.
Europe remained one of the most promising markets for solar energy, as 5.8 GW of the 7.4 GW of newly installed photovoltaic systems globally, were installed in that region in 2009 according to the European Commission Joint Research Center reported.
Europe also accounted for 16 GW, or 70%, of the world’s 22 GW total installed photovoltaic capacity, which consists of existing and newly installed solar facilities. One GW of photovoltaic capacity can provide enough electricity for about 250,000 European households during one year.
Germany led the European nations with 3.8 GW of new solar capacity and 9.8 GW of cumulative capacity, of which 2.3 GW were linked to the power grid by the fourth quarter of last year. Italy ranked second in terms of new installed capacity with 0.73 GW, while Spain was second in terms of cumulative installed capacity with 3.5 GW.
However, the European photovoltaic market is still in its infancy stage. The commission estimated that only 0.4% of the total supplied electricity in the European Union came from photovoltaic power in 2009 – representing a mere 0.1% in the world’s total supplied electricity.
Imagine a building where all windows and perhaps even its exterior walls, could be used as solar collectors. Well, Norweigan solar power company EnSol is closed to that as it has patented a thin film solar cell technology designed to be sprayed on to just such surfaces.
Unlike traditional silicon-based solar cells, the film is composed of metal nanoparticles embedded in a transparent composite matrix, and operates on a different principle. EnSol is developing the product assisted by the University of Leicester’s Department of Physics and Astronomy.
“One of the key advantages is that it is a transparent thin film that can be coated onto window glass so that windows in buildings can also become power generators,” said Chris Binns, Professor of Nanotechnology at Leicester.