Organic photovoltaic needs higher efficiency, low cost, higher reliability and longer lifetime – and field experience in order to make progress
By OPV Today staff writer
Last year Paula Mints, Principal Analyst with Navigant Consulting’s PV Service Department, said that organic photovoltaic (OPV) technology is young on its development timeline, so a critique of this nascent technology would be unfair.
Mints highlighted that OPV has goals similar to thin film (inexpensive, flexible, et al), and development hurdles (low efficiency, stability, short lifetime) to overcome.
In terms of future applications, the technology promises inexpensive swap-able modules for rooftop applications, but, the modules need to reach sufficient efficiency and stability to be viable in the marketplace. Also, the likelihood of the market accepting the short lifetime indicated by a swap-able module is low. The consumer power application (batteries, tents, automotive) was described as an entry point, but, at <30-MWp of total (3-gigawatts) in 2007, this application didn’t offer sufficient megawatts to support the OPV industry. Still, it was reiterated that considering the nascent stages, only time will tell if scientists can overcome technical and market barriers to offer an alternative to the technologies currently in commercial development.
A year after
Assessing the commercialisation of the technology at this juncture, Mints says it depends on the application area the OPV industry wishes to compete in – for the grid connected market, high reliability, efficiency ~10%, and industry standard lifetime (25 years) is required. She reiterated the unlikelihood of swap-able modules finding acceptability.
For most of the remote applications, habitation and industrial, >6% efficiency, 25-year lifetime and high reliability are necessary. For consumer power (automotive, battery charging, tents, etc.), and consumer indoor (calculators and watches), lower efficiency, lower lifetime and moderate reliability are fine, said Mints, who is scheduled to speak at the forthcoming OPV Summit 2009, to be held in Boston (October 15-16).
Mints added, “However, the consumer power and consumer indoor applications are not in the gigawatt range, so the OPV industry is looking at access to ~40-MWp a year instead of ~5-gigawatts a year. If the industry wants to be competitive in the grid connected application it needs to work towards increased efficiency, lower cost (for margin cushion), longer lifetime and high reliability.”
From regulatory and business environment perspective, too, Mints feels efficiency, lifetime and reliability need to improve before policy will be much of a help.
“However, assuming that these things improve, the PV industry still requires incentives to drive grid connected demand (not discussing remote markets). Also, market development needs to take place in more countries so that the industry has a portfolio of incentives to rely on instead of relying on >70% of its demand from Europe,” added Mints.
From lab to commercial viability
Progress is definitely being made if one goes by certifications gained over the past few months.
For instance, Heliatek, in a joint R&D-project with the IAPP (Technische Universität Dresden, Germany) and BASF SE, has achieved a record value for organic solar cells based on vacuum deposited small molecules. According to Heliatek, which was founded in 2006, a power conversion efficiency of 5.9% for an active area of 2 cm² has been confirmed by the National Renewable Energy Laboratory (NREL). The highest previously confirmed value for organic solar cells with an active area exceeding 1cm2 was 5.4% for a polymer-based device. The objective of Heliatek, BASF and Bosch within their joint development agreement is to further increase the device efficiency to 9-10% and establish a first pilot production line by 2011.
NREL has already certified that Konarka’s organic based photovoltaic solar cells have demonstrated 6.4% efficiency this year. Konarka stated that this is the highest performance recorded by NREL for an OPV solar cell.
But there is still a long way to go as far as commercial viability is concerned.
Approach
A couple of years ago, Eitan Zeira, director of electronic printing technologies, Konarka, was quoted as saying (by Machine Design): “Customers don't care about efficiency, they care about total power. If you need more power from a plastic cell, you just make the footprint longer.”
Mints says this assumption is categorically incorrect – except in the sense that customers aren’t thinking in terms of efficiency. They are, however, thinking in terms of energy production (kWh), reliability and lifetime – efficiency is very important in terms of production.
“Also, the statement about footprint ignores the struggle thin films have had for years. Area penalty remains an important concept,” pointed out Mints.
It is believed that the key to significantly increasing efficiency is the use of new materials, and improvements in efficiency can be achieved by use of a new architecture, making the gap smaller, optimising the morphology for better charge collection, increasing open circuit voltage and use of a tandem cell structure. And as Dr. Alan Heeger, Professor of Physics at the University of California, Santa Barbara, Nobel Prize laureate in chemistry, and co-founder of Konarka, says the trick is doing it all at the same time.
Organic Photovoltaics Summit 2009
OPV Today is to conduct its Organic Photovoltaics Summit 2009, to be held in Boston (October 15-16) this year.
For more information, click here:
http://www.opvtoday.com/usa/index.shtml
or Contact:
Joshua Bull - Event Director
UK Tel: +44 (0) 207 375 7227
E-mail josh@thinfilmtoday.com
Recent Comments
Start the Conversation!