Paper highlights need for correctly measuring solar cell efficiency

Feb 27, 2012 by Lisa Zyga weblog
A new guide outlines the correct procedures for measuring solar cell efficiency. Image credit: Wikimedia Commons CC BY 3.0

(PhysOrg.com) -- As the pace of solar cell research continues to accelerate, the question for every new design is “what’s its efficiency?” Since measuring how efficiently a solar cell converts sunlight into electricity involves several factors, making a correct measurement can be challenging. Henry Snaith, a physicist at the University of Oxford who designs solar cells, estimates that compounding small mistakes in measuring efficiency can result in overestimations of up to five times that of the actual value.

To address this problem, Snaith has written a guide for researchers on correctly measuring solar cell efficiency for different types of . As he explains in the paper published in Energy & Environmental Science, a uniform method for measuring efficiency is essential for enabling valid comparisons.

“There's an ongoing stream of papers in which it's not entirely clear exactly how the measurements have been made,” Snaith said in an article in Chemistry World. “If, for example, someone claims their hybrid solar cell has an efficiency of 4% when it's really more like 1%, that makes it problematic for someone else to write an exciting paper when they've genuinely improved something to 1.5%.”

One of the most common potential sources of error that Snaith identifies involves how to mask the cells, which determines the size of the test area. Other problems can occur due to light source calibration and how the cell is positioned during testing. Snaith outlines standards for all these steps, and explains how small deviations can inadvertently cause errors.

Snaith emphasized that the purpose of the guide is not to find fault, but to address the challenges involved in the rapidly growing field of solar cell technology that is attracting researchers from diverse backgrounds. He hopes that the guide will encourage new ideas and increase the rate of new breakthroughs.

“The research field of photovoltaics is booming due to the recognized imperative to realize long-term solutions to clean and inexpensive power generation,” he writes. “…If these standard protocols are adhered to across the field, then a much better comparison between literature values of can be made and more rapid and well-directed technological advancements will occur.”

Explore further: Solar-powered two-seat Sunseeker airplane has progress report

More information: Henry Snaith. “How should you measure your excitonic solar cells?” Energy Environ. Sci., 2012, Accepted Manuscript. DOI: 10.1039/C2EE03429H

via: Chemistry World

Related Stories

Device can heat home, save money

Apr 19, 2011

(PhysOrg.com) -- A new polymer-based solar-thermal device is the first to generate power from both heat and visible sunlight – an advance that could shave the cost of heating a home by as much as 40 percent.

World's most efficient nanoplasmonic solar cells developed

Feb 14, 2012

(PhysOrg.com) -- In a boon for the local solar industry, a team of researchers from Swinburne University of Technology and Suntech Power Holdings have developed the world’s most efficient broadband nanoplasmonic ...

Nano-tuned solar cells

May 18, 2011

Solar cells that are more effective and cost less in production: Within the EU-project N2P (Nano to Product) researchers developed nano tuned surfaces to gain both.

Research sparks record-breaking solar cell performances

Nov 07, 2011

(PhysOrg.com) -- Theoretical research by scientists with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has led to record-breaking sunlight-to-electricity conversion ...

Recommended for you

Switch on sunlight for a brighter future

7 hours ago

Imagine sitting in a windowless room yet having the feeling of the sun shining on your face. This unique experience is now possible thanks to the COELUX EU-funded project which recreates the physical and ...

US urged to drop India WTO case on solar

23 hours ago

Environmentalists Wednesday urged the United States to drop plans to haul India to the WTO to open its solar market, saying the action would hurt the fight against climate change.

Is nuclear power the only way to avoid geoengineering?

Apr 23, 2014

"I think one can argue that if we were to follow a strong nuclear energy pathway—as well as doing everything else that we can—then we can solve the climate problem without doing geoengineering." So says Tom Wigley, one ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Lurker2358
5 / 5 (2) Feb 27, 2012
The device efficiency should be defined with respect to how much light of the light in the entire incident plane that it converts to energy, as in a real-world setting.

That is to say, if 1000watts per square meter hits the entire device, the efficiency should be determined by what percentage of 1000watts was actually converted to electricity, as would be the case in real-world application. NOT determining it by some absurd standard like quantum scale dots, which have a lot of wasted space between them, and ignoring light incident on wasted space...that terribly inflates the numbers compared to real world applications.

A PV system's efficiency should therefore be the same standard as a parabolic trough vacuum tube boiler, which is to say:

Watts out / Watts in : over the whole collection surface.

System efficiency vs device efficiency are two different things.

system efficiency suffers with regard to space, since you need access for maintenance via roads and ladders, etc...
kaasinees
1 / 5 (1) Feb 27, 2012
That is to say, if 1000watts per square meter hits the entire device, the efficiency should be determined by what percentage of 1000watts was actually converted to electricity


Was here to say that, the rest of the post was unnecessary though.

More news stories

Amazon launches grocery service for Prime members

Amazon is taking aim at grocery stores and discounters like Wal-Mart with a grocery service that lets its Prime loyalty club members fill up to a 45-pound box with groceries and get it shipped for a flat rate of $5.99.

Study suggests targeting B cells may help with MS

A new study suggests that targeting B cells, which are a type of white blood cell in the immune system, may be associated with reduced disease activity for people with multiple sclerosis (MS). The study is released today ...