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 Silicon solar cell of ISFH yields 25% efficiency with passivating POLO contacts
08.12.2016 | Institut für Solarenergieforschung GmbH

nachricht Robot on demand: Mobile machining of aircraft components with high precision
06.12.2016 | Fraunhofer IFAM

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>