Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Global solar photovoltaic industry is likely now a net energy producer

09.04.2013
The rapid growth of the solar power industry over the past decade may have exacerbated the global warming situation it was meant to soothe, simply because most of the energy used to manufacture the millions of solar panels came from burning fossil fuels. That irony, according to Stanford University researchers, is coming to an end.

For the first time since the boom started, the electricity generated by all of the world's installed solar photovoltaic (PV) panels last year probably surpassed the amount of energy going into fabricating more modules, according to Michael Dale, a postdoctoral fellow at Stanford's Global Climate & Energy Project (GCEP). With continued technological advances, the global PV industry is poised to pay off its debt of energy as early as 2015, and no later than 2020.


Brian Webster (left) and Mario Richard install photovoltaic (PV) modules on an Englewood, Colo., home. Manufacturing and installing solar panels require large amounts of electricity. But Stanford scientists have found that the global PV industry likely produces more electricity than it consumes.

Credit: Dennis Schroeder/NREL

"This analysis shows that the industry is making positive strides," said Dale, who developed a novel way of assessing the industry's progress globally in a study published in the current edition of Environmental Science & Technology. "Despite its fantastically fast growth rate, PV is producing – or just about to start producing – a net energy benefit to society."

The achievement is largely due to steadily declining energy inputs required to manufacture and install PV systems, according to co-author Sally Benson, GCEP's director. The new study, Benson said, indicates that the amount of energy going into the industry should continue to decline, while the issue remains an important focus of research.

"GCEP is focused on developing game-changing energy technologies that can be deployed broadly. If we can continue to drive down the energy inputs, we will derive greater benefits from PV," she said. "Developing new technologies with lower energy requirements will allow us to grow the industry at a faster rate."

The energy used to produce solar panels is intense. The initial step in producing the silicon at the heart of most panels is to melt silica rock at 3,000 degrees Fahrenheit using electricity, commonly from coal-fired power plants.

As investment and technological development have risen sharply with the number of installed panels, the energetic costs of new PV modules have declined. Thinner silicon wafers are now used to make solar cells, less highly refined materials are now used as the silicon feedstock, and less of the costly material is lost in the manufacturing process. Increasingly, the efficiency of solar cells using thin film technologies that rely on earth-abundant materials such as copper, zinc, tin and carbon have the potential for even greater improvements.

To be considered a success – or simply a positive energy technology – PV panels must ultimately pay back all the energy that went into them, said Dale. The PV industry ran an energy deficit from 2000 to now, consuming 75 percent more energy than it produced just five years ago. The researchers expect this energy debt to be paid off as early as 2015, thanks to declining energy inputs, more durable panels and more efficient conversion of sunlight into electricity.

Strategic implications

If current rapid growth rates persist, by 2020 about 10 percent of the world's electricity could be produced by PV systems. At today's energy payback rate, producing and installing the new PV modules would consume around 9 percent of global electricity. However, if the energy intensity of PV systems continues to drop at its current learning rate, then by 2020 less than 2 percent of global electricity will be needed to sustain growth of the industry.

This may not happen if special attention is not given to reducing energy inputs. The PV industry's energetic costs can differ significantly from its financial costs. For example, installation and the components outside the solar cells, like wiring and inverters, as well as soft costs like permitting, account for a third of the financial cost of a system, but only 13 percent of the energy inputs. The industry is focused primarily on reducing financial costs.

Continued reduction of the energetic costs of producing PV panels can be accomplished in a variety of ways, such as using less materials or switching to producing panels that have much lower energy costs than technologies based on silicon. The study's data covers the various silicon-based technologies as well as newer ones using cadmium telluride and copper indium gallium diselenide as semiconductors. Together, these types of PV panels account for 99 percent of installed panels.

The energy payback time can also be reduced by installing PV panels in locations with high quality solar resources, like the desert Southwest in the United States and the Middle East. "At the moment, Germany makes up about 40 percent of the installed market, but sunshine in Germany isn't that great," Dale said. "So from a system perspective, it may be better to deploy PV systems where there is more sunshine."

This accounting of energetic costs and benefits, say the researchers, should be applied to any new energy-producing technology, as well as to energy conservation strategies that have large upfront energetic costs, such as retrofitting buildings. GCEP researchers have begun applying the analysis to energy storage and wind power.

This article was written by Mark Golden, Precourt Energy Efficiency Center at Stanford University.

Related Information:
Stanford on YouTube
http://youtu.be/t1tuzvT1hck
Environmental Science & Technology
http://pubs.acs.org/doi/abs/10.1021/es3038824
Global Climate and Energy Project
http://gcep.stanford.edu/

Mark Golden | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Power and Electrical Engineering:

nachricht The role of Sodium for the Enhancement of Solar Cells
17.07.2018 | Max-Planck-Institut für Eisenforschung GmbH

nachricht Behavior-influencing policies are critical for mass market success of low carbon vehicles
17.07.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>