3D-Textured Solar Cell Will Be Tested in Space
An experimental 3D-textured solar cell is set to be bolted to the outside of the International Space Station for testing.
Today’s solar cell technology has its roots in the early days of America’s space program, when in 1958, NASA launched the solar-powered Vanguard I satellite. Solar power technology has become more efficient. But the cost is still two to four times more than other energy sources. Like the space race did a half century ago, the international race for renewable energy technology has a similar sense of urgency. The winners will capture new technology, jobs, new manufacturing industry, and greater energy security. But to cross the finish line, governments need to offer support and require that utilities buy solar power. A pricing structure called a feed-in tariff helps by establishing a fixed price guaranteed for a period of time. Those countries still new to the solar power arena could do well to look at the success being achieved by countries already a long way down the solar road. Here are ten countries, chosen because of how much electricity and other energy they produce from solar power, and for their existing government support, commitment to technology and success in developing a solar industry.
Getty Images/ Darrell Gulin
10. The Netherlands
Most solar energy in The Netherlands comes from solar cells on rooftops. This power replaces electricity that individuals or businesses would otherwise buy from their local utilities. The Netherlands must now meet the European Union’s April 2009 directive that its member countries purchase 20 percent of their energy from renewable sources, such as solar power, by 2020. Renewable purchase requirements, as opposed to targets, have proven effective in encouraging solar power.
France’s feed-in tariffs and tax credits have been very successful in encouraging solar power and developing solar power industries. France has emphasized research and development in solar panels, recently adopted new feed-in tariffs for solar cells on large commercial buildings and established a tax credit on solar cell equipment, says the International Energy Agency. Most solar power in France is produced from small installations connected to the power grid. But it established national goals for the construction of large solar cell plants like the new one in Narbonne, located in southwestern France.
Getty Images/Bruno Herdt
With its large land mass and remote locations, most of Australia’s solar power comes from solar cells that are not connected to the power grid. Off-grid uses include non-domestic applications such as the water pump in the middle of the desert near Alice Springs in central Australia. Australia is not high on the list because it has “not added significant solar cell capacity since 2006 and has really bad market development strategy,” says Sven Teske, a lead spokesperson on solar power for Green Peace International. According to the International Energy Agency, the most effective national support for encouraging solar power in Australia has been the doubling of a residential grant for small scale solar cell installations.
Getty Images/Alexander Hassenstein
Italy has feed-in tariffs and new building requirements that require the installation of solar cells. “Italy may be the first country to obtain grid parity for solar,” says Teske. At its simplest level, this will allow easier connection by solar producers to the power grid and encourage additional solar power. According to the European Photovoltaic Industry Association, Italy has the potential to become one of the strongest markets for electricity produced from solar cells because of the sunny climate and available land.
Getty Images/Kevin Forest
6. South Korea
South Korea’s solar cell capacity more than doubled in 2007, according to the International Energy Agency. About half of this power is produced from centralized plants that sell electricity to utilities for resale to households and businesses. The solar power plant in Sinan, in southern Korea, is Asia’s largest power plant. South Korea has set national goals to achieve a low carbon society and to develop its solar industry. According to the International Energy Agency, South Korea views the solar cell industry as a major target for economic growth for exports.
Getty Images/John Wang
China leads the world in solar water and heat with about two-thirds of the total. Applications include space heating from properly placed windows and hot water systems that use collectors and a storage tank. Because solar water and solar heat are not reported with other data, China does not show up in solar power production or installed capacity data. In addition to its solar water and heat use, China also is now the world leader in solar panel manufacturing; it overtook Japan in 2008. Other major manufacturers of solar cells are Germany, Japan and the United States.
4. United States
Through the Department of Energy, the United States is a leader in funding solar power research and development. It also is one of only two countries in the world that has existing large scale concentrating solar power, says Yasmina Abdelilah, a solar energy analyst with the International Energy Agency. The warm sunny climate in the southwestern United States provides a favorable location for concentrating solar power, which uses heat to power electric generation. But thus far only 1 percent of all renewable energy in the United States, itself only about 7 percent of total consumption, is solar. Solar power has grown primarily from state support. California, the leading state, has a limited form of feed-in tariff, as well as a 20 percent renewable purchase requirement. There has been federal action, for example, to expand tax credits for solar hot water installation. But the federal government has not adopted a national renewable purchase requirement, currently something that is under consideration in Congress, or feed-in tariffs, which policymakers deem to be unworkable in the United States due to the way electricity is regulated.
Getty Images/Tom Bonaventure
Japan has set a goal of developing the technology to increase solar cell efficiency, which refers to the rate that electrons inside solar cells get knocked off of atoms when hit by photons. Japan wants to increase the current 10 percent to 15 percent rate to 40 percent through government subsidies and field tests. Japan has numerous solar power tax and subsidy programs intended to create solar cell industries. Its “long-term industry strategy behind the development of solar cell technology is quite unique," says Teske. Japan’s plan to become a low carbon society includes a target increase in solar cell produced electricity ten fold by 2020 and forty fold by 2030.
With a new mandated feed-in tariff pricing structure in 2007, Spain’s solar power capacity from solar cells grew in 2008 five times that of the prior year, according to an International Energy Agency report. This increase in solar cell capacity placed Spain ahead of Japan. The favorable tariff encouraged construction of many large “solar farms” like those in La Salana, Milagro, and La Magascana, Spain. Spain also has a favorable climate for concentrating solar power production. Spain, along with the United States, has implemented large scale power generation from concentrating solar power.
Getty Images/Skip Nall
Germany has had a very successful experience with the feed-in tariff. This pricing structure has consistently supported growth in solar cell capacity since 2004, says the International Energy Agency. Germany’s commitment has led not only to increased solar power use and installed capacity but to the growth of solar industries such as silicon wafers and solar cell equipment. Historically, Germany has strongly emphasized technological development. Its focus on solar power “has its roots in the nuclear movement” and its conscious commitment “to move away from nuclear and search for alternatives,” says Teske. Together, the government, through supports and commitment to technology, has proven successful in encouraging solar power.
An experimental 3D-textured solar cell is set to be bolted to the outside of the International Space Station (ISS), where it will experience 16 "sunrises" each day as part of a harsh performance test.
A proposal submitted by W. Jud Ready, a professor of materials science at Georgia Tech, to study the performance of his "3D" textured solar cell in space was recently accepted by the Center for the Advancement of Science in Space (CASIS), the organization that manages research onboard the ISS. His solar cell, made from carbon nanotubes coated in an experimental light-absorbing material, will hitch a ride to the ISS sometime next year.
"It will be placed out on what they euphemistically call the back porch of the Japanese Experiment Module...It plugs into, literally, a USB port," Ready said. Scientists 'Evolve' a Super-Efficient Solar Cell
The ISS has served as an orbiting laboratory for scientists, academics and even schoolchildren for years, but typically, the experiments are performed inside the space station. The installation of the solar panels will be one of the first experiments to take place outside the space station, on the Nanoracks External Platform.
As the ISS orbits the Earth every one and a half hours, the panels will be hit by sunlight from all directions, giving Ready and the team a way to test multiple configurations very quickly.
"If you were to go through all the possible configurations on Earth, it would be very challenging," Ready said.
The team will be testing the cells, coated with a copper-zinc-tin-sulfur mixture, for the optimum size and spacing of the tiny 3D bumps.
Ready’s 3D thin-film solar cells have been tested on Earth and were found to outperform flat/untextured thin-film cells of the same composition. Because of the 3D structure (which looks like millions of tiny skyscrapers when viewed under a microscope), when light hits the cell, it bounces deeper into the structure and is trapped, rather than reflecting away.
In a flat cell — especially early and late in the day, when the sun is at an angle — "the performance really suffers," Ready said.
On the other hand, the performance of the 3D solar cell actually improves at sunset, as light strikes it at a sharper angle.
Ready said he estimates the panels will last just a few months in space, because they will experience wild and rapid temperature fluctuations — 250 degrees Fahrenheit (121 degrees Celsius) on the sun side to minus 250 degrees Fahrenheit (minus 157 degrees Celsius) on the dark side 45 minutes later — and are at risk of micrometeorite impacts and atomic oxygen attack.
Nonetheless, Ready hopes the solar cells will stay in space longer. "In my proposal," he said, "I said to leave them up there until they all failed."
Get More from TechNewsDaily
Top Ten Green Gadgets
10 Incredible 3-D Printed Products
Coolest Vehicles You'll Never Get to Ride
This article originally appeared on TechNewsDaily. http://www.technewsdaily.com/17655-3d-textured-solar-cells-will-be-tested-in-space.html Copyright 2013 TechNewsDaily, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.