The market outlook for utility-scale PV installations is very positive. These PV plants have the capability of supporting grid operation, and the ability to do this is being increasingly required in grid codes. Testing the capabilities of very large PV inverters, however, is demanding for laboratories. Gunter Arnold, Diana Craciun, Wolfram Heckmann and Nils Schäfer from Fraunhofer IWES discuss current developments and resulting challenges and address the gaps and diversity in testing guidelines and standardisation.
As early as 2010, Phoenix Solar along with Saudi Aramco installed the first of three PV test facilities in Dhahran, Saudi Arabia, putting four different module technologies (monocrystalline, amorphous-microcrystalline, CdTe and CIS) to the test in extreme climatic conditions. Klaus Friedl of Phoenix Solar LLC shares some hints and lessons learned from the tests.
Maximising production from a PV system is critical, since nearly all of the investment is made prior to system activation. Monitoring of PV systems allows operators to identify any performance or safety problems early so that they can be repaired quickly, thus minimising energy losses. Joshua Stein of Sandia National Laboratories and Mike Green of M.G. Lightning Electrical Engineering discuss some new monitoring strategies that are necessary for expeditiously identifying and locating system faults.
New inverter technologies offer installers the choice of central of distributed systems for PV arrays. Deciding which system is the most optimal to use isn’t always based on the size of a solar system, writes Alvaro Zanon.
A significant part of the risk management process associated with large-scale solar PV installations is ‘technical due diligence’, which seeks to define and minimise all technical risks associated with the project. Fred Martin and Nick Morley of TÜV Rheinland explore due diligence challenges for PV power plants in Japan.
More than ever, the global PV market provides attractive new investment opportunities, but the elements driving such rapid expansion also increase the risk of solar financial assets failing to meet long-term fiscal and performance goals. Boris Farnung, Björn Müller and Klaus Kiefer of Fraunhofer ISE, and Peter Bostock and John Sedgwick of VDE Americas explore major quality-assurance measures and the challenges today for achieving bankability of utility-scale PV plants.
A shift from free-abrasive/steel wire sawing to fixed-abrasive diamond wire sawing is expected to take place in the PV cell manufacturing industry, with 2018 being the anticipated pivotal point for market dominance. This shift is due to several key advantages of diamond wire sawing, such as higher throughput, less wire per wafer, no slurry and the possibility of kerf recycling. However, in order for diamond wire sawing to realize its promise as the next-generation workhorse for the slicing of silicon PV wafers, inherent fundamental challenges must be properly identified and successfully addressed by the PV industry. As a first step to increasing the current collective understanding of the critical needs/challenges of diamond wire sawing, the c-Si programme of the U.S. PVMC held a workshop on July 8th, 2014 in San Francisco, California. One of the key products of this workshop was an extensive list of short- and long-term challenges. This article expands on some of the most important challenges identified at the workshop through the collective discussions and dialogue among a variety of PV industry experts and stakeholders.
The manufacturers of silicon wafer solar cells are constantly looking into cost-effective ways to increase the efficiency of their solar cells. Most of these enhancements result from incremental improvements and can be achieved by optimizing existing processes. However, it is widely recognized that in order to further improve the silicon wafer solar cell efficiency, new solar cell architectures are required. This will in turn require new manufacturing processes, which will typically involve new production equipment and consumables. New consumables can play an important role in the applicability or success of a new process step; in this paper a specific focus will be on the precursors used for the deposition of surface passivation films, such as silicon nitride and aluminium oxide.
In edition 26 of Photovoltaics International the rebirth of PV manufacturing capacity expansions in 2014 was analysed; this covered announcements on a global basis from a wide range of companies and included thin film and dedicated solar cell and module assembly lines, as well as integrated cell and module assembly lines. Because of the current level of capacity expansion announcements, a roughly quarterly analysis of such plans will be undertaken during 2015.
Ion implantation offers significant process simplification potential for the fabrication of back-junction back-contact (BJBC) solar cells. First, the number of high-temperature steps can be reduced to one when applying a co-annealing process which includes an in situ growth of a silicon oxide passivation layer. Second, the implanted regions can be patterned in situ by utilizing shadow masks. ISFH's results from evaluating both aspects are reported in this paper. With fully ion-implanted, co-annealed and laser-structured small- area cells, efficiencies of up to 23.41% (20mm x 20mm designated area) have now been achieved. It is shown that the excellent recombination behaviour of 156mm x 156mm BJBC cells patterned in situ implies a potential for realizing efficiencies greater than 23%; however, back-end issues have so far limited the efficiency to 22.1% (full-area measurement). Ion implantation can also be utilized for the doping of BJBC cells with carrier-selective junctions based on polycrystalline silicon. The current status of ISFH's work in this direction is presented.
