Liten is a major European research institute and a driving force behind the development of the sustainable energy technologies of the future. The institute is spearheading the EU’s efforts to limit dependency on fossil fuels and reduce greenhouse gas emissions in three key areas: renewable energy, energy efficiency/storage and development of materials.
Our platforms, sophisticated tools for industry & the scientific/technical infrastructure/expertise to overcome technological hurdles
Liten's research teams work across a vast portfolio of renewable energy technologies. Cutting-edge photovoltaic technologies are developed at INES, the French National centre for solar research and R&D with Hydrogen and Biomass activities being managed from the LITEN's main site in Grenoble, Rhone-Alpes.
“Radically improving energy efficiency will reduce the need for investment in energy infrastructure, cut fuel costs, increase competitiveness, lessen exposure to fuel price volatility, increase energy affordability for low-income households and cut local and global pollutants improving consumer welfare” Source OECD Energy report, 2014
From nanosecurity, nanocharacterisation,and anti-counterfeiting technology to the development of advanced materials and point of sale: a comprehensive offering.
Transverse activities help add value to our technology portfolio. An optimised modeling and characterisation model, for example, can help reduce time to market. Browse this section to find out more....
High-yield photovoltaic cells: achieving new levels of performance while lowering manufacturing costs
The growth of photovoltaic solar energy conversion in the global energy mix has been unprecedented since the 2000s. The installed PV base increased tenfold from 2007 to 2012, and rising demand for energy will continue to drive increasing numbers of end users to solar worldwide. One of Liten’s key PV research areas is crystalline silicon, by far the leading material used in PV cells with 90% to 95% of the global market share. Our current research spans the entire value chain, from the material itself through to complete PV systems.
Our PV materials, cell, and module research focuses on overcoming two major hurdles:
Lowering manufacturing costs to ensure that PV energy costs are equivalent to or cheaper than the cost of “traditional” energy supplied by the grid.
Raising PV cell and system energy yields to generate more power at an affordable cost.
The growing proportion of PV in the global energy mix is proof that we are close to reaching these objectives. And yet, research must continue to keep brining costs down across the PV value chain. The result will be more affordable PV systems (cost per watt) and cheaper utility rates (cost per kWh).
We have a number of industrial partnerships covering everything from prototyping to scaling up new manufacturing processes so that our partners—multinational corporations and equipment manufacturers that export their products internationally, for example—can stay at the leading edge of the PV industry. “Our strategy is to develop wafer, cell, and module manufacturing technologies for companies in Europe and, ultimately, around the globe. We are poised to assist equipment and materials suppliers in penetrating global markets with high-performance solutions,” said the head of Liten’s PV materials and cells R&D.
The CEA Tech nanocharacterization platform provides equipment and know-how that are unique in Europe. Liten researchers and partners can use this world-class facility at any time to test the quality and reproducibility of the new materials and processes developed.
Our research and development work has resulted in yields of 18% to 19% for traditional monocrystalline silicon cells. For more advanced cell technologies, we have achieved yields of 22% to 23% at a cost that makes solar energy competitive with energy from other sources. In the coming years we will continue to focus our efforts on securing substantial additional improvements—25% to 26%—in operating yields. Higher yields are crucial to anchoring PV in a fast-paced business environment where changes like a three-fold reduction in PV panel costs in five years are not uncommon.
Technologies that bring benefits to every link in the PV value chain
Our research covers the entire PV value chain, from materials to installed systems; we also study electrochemical energy storage. This holistic approach privileges actual operating conditions, keeping us in touch with the needs of our industrial partners.
We use firmly-established processes that have proven successful in real operating conditions, enabling us to make best use of new technologies developed alongside proven technologies.
We also develop new processes leveraging emerging technologies such as monolike Si and double-sided PV, for example.
We continue to invest in equipment to stay at the forefront of efforts to increase yields and develop new processes.
Our broad, deep experience cuts across several fields, positioning us to address the entire value chain holistically; this makes Liten unlike any other solar energy research institute in the world.
Liten has developed, patented, and transferred to industrial partners several technologies along the value chain:
Silicon: Our researchers have developed alternative, lower-cost solutions for sourcing PV-grade silicon; these include a physical (fusion, aggregation, and plasma) process for purifying metallurgical-grade silicon.
Crystallization: We use a directed solidification process to obtain crystalline silicon (monolike); this is a flagship Liten technology that could potentially address 60% of the global market. In 2014 the furnace design and thermal treatment cycle developed for 60 kg (G2) monolike ingots were successfully tested on industrial-grade 450 kg (G5) and, subsequently, 600 kg (G6) completely-monocrystalline ingots—a world first. PV yields were also improved, getting closer to those of monocrystalline ingots, but at production costs that are far lower.
Our researchers also used a high-purity crucible coating—made from silazane, an inorganic polymer—to produce enhanced G2 (60 kg) ingots. Silicon quality at the core of the ingot was better, resulting in higher cell conversion yields. These improvements in yield more than offset the additional cost of the coating, which was patented in 2014.
Wafer slicing: We continue to work with several industrial partners to improve the diamond-wire wafer-slicing process, for higher throughput, better quality, and thinner wafers. A prototype line was set up in 2013 and used to scale up a technology for an industrial partner.
Cells: We are developing high-temperature homojunction and heterojunction processes—which offer higher yields—at different degrees of industrial readiness in parallel. We are also looking at several ways to improve the cells’ optical confinement and, therefore, yields.
Modules: We are experimenting with copper wires to connect PV cells and with electrically-conductive adhesives to eliminate the welding step in the manufacturing process; we are also working on cell encapsulation to improve module performance over time. Module durability is studied via accelerated aging tests.
Manufacturing equipment: Liten researchers at INES (the French National Solar Energy Research Institute) worked with AET to develop a machine that automatically estimates the quality of monocrystalline wafers; the machine detects the main wafer defects caused by the presence of oxygen. A prototype was installed at Liten for testing in industrial conditions and for sales demonstrations in conjunction with our partner. A manually-loaded version was also developed for wafer and PV cell R&D. This product is now commercially available.
Liten is also involved in several EU research projects, including two major projects that will shape the future PV industry (Liten is coordinator):
The Hercules project focuses on developing very-high-yield PV cells (heterojunction and backside contact). The project consortium includes some of Europe’s most prestigious research institutes (FhG-ISE, CSEM, ISFH); industrial partners include Meyer Burger and EDF R&D.
The Cabriss project aims to develop end-of-lifecycle recycling processes for PV panels taking into account all the environmental concerns inherent to this kind of process. The project brings together top-tier research institutes (SINTEF, IMCE, INES) and small European business seeking to carve out a position on this high-potential market.
About Liten's PV modules that passed succesfully IEC 61215 certification testing (click here). About monolike silicon (click here). About PV modules with advanced BIST (built-in self-test) capabilities (click here).
More than 200 researchers
30 patent applications per year (average)
Over 20 Publications:
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CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.