Warranties | PV module manufacturers, O&M companies, owners, insurance companies and financial stakeholders employ independent engineers (IEs) to conduct plant surveys at critical milestones, such as impending plant warranty expiration (e.g. EPC warranty), or on a periodic basis. The result of the plant survey is a status report that identifies improvement potential and, in the case of specific failures or failure indicators, their corresponding root causes. Mitigating actions are mediated by the IE with all the involved stakeholders. Bill Shisler and Matthias Heinze of TUV Rheinland describe a procedure and a sample case for identifying and investigating the performance and possible safety shortcomings of PV modules, triggered by an impending asset sale.
Utility solar | Recent years have seen huge decreases in the cost of electricity from utility PV arrays. However, with PV’s grid parity battle not yet entirely won, competition to drive out further costs is still fierce. Ben Willis looks at some of the technological evolutions that will shape the next generation of PV power plants.
Policy | As one long-running policy saga finally draws to a close, a series of attacks on renewable energy support have offset any progress that had been made. Tom Kenning explores the latest setbacks and where the possibilities for progress may lie.
Solar auctions | The proposed closure of the UK’s Renewable Obligation programme to solar from next March would leave the Contracts for Difference programme as the only form of support for large-scale PV. Finlay Colville looks at the prospects for an auction-based system taking off in the UK.
Solar support policy | The UK’s solar industry has grid parity within reach, but recent proposals to cull various subsidy schemes threaten to pull the rug from beneath its feet. Liam Stoker asks whether the UK can embrace alternative forms of support to help solar achieve long-term freedom from subsidy.
State energy policy | Acceptance of solar in the boardrooms and living rooms of America along with President Obama’s Clean Power Plan potentially put the US on the precipice of huge solar growth, but the patchwork of state solar policies remains a barrier. John Parnell and Tom Kenning look at some of the US’ leading solar states and ask what others could learn.
The global PV capacity reached 177GW at the end of 2014, and by 2020 the PV Market Alliance forecasts that 630GW of PV could be installed. The entire value chain of the PV industry needs accurate data and a clear vision of how markets could develop in the future in order to avoid repeating past mistakes, and especially the damaging price war that led to a dramatic industry consolidation. The question of PV market evolution will be acute in 2015 and 2017, which will represent the next two important milestones for PV development: for the first time in years, the PV industry could approach its production capacity limits.
Newly developed high UV light transmission ethylene vinyl acetate (EVA) has recently been extensively introduced for use in PV modules. It has been proved that this type of EVA can result in potential power gain because of the better blue light response of the solar cell, which in turn can further reduce the cost per watt of the PV module. However, if only high UV transmission EVA is used as an encapsulant, too much UV light irradiates the backsheet, which can cause the backsheet to yellow. In order to improve the reliability and durability of the modules, SUNTECH, as a module manufacturer, therefore uses combined EVA, i.e. high UV transmission EVA as the front encapsulant and conventional UV cut-off EVA as the rear encapsulant, to protect the UV-sensitive backsheet. This paper presents the results of an investigation of the reliability and durability of high UV transmission EVA in PV modules, through an enhanced UV test which exceeds IEC standards.
One of the main concerns of module manufacturers is the power loss that takes place when the solar cells are incorporated in PV modules. This power loss, known as cell-to-module (CTM) loss, results from the influence of many factors which occur during module production. Some of these factors lead to a gain in power at the end of the process; on the other hand, some are responsible for a loss of power and offset the positive effects of other ones, resulting in a net power loss. In this paper the CTM losses will be addressed from an industrial point of view and for standard crystalline PV modules. The focus will first be on some of the most frequent issues detected in production lines and their influence on module power loss. More extensive research is then carried out to arrive at an explanation of their origin. This paper describes some of the mentioned factors along with the different ways of detecting them.
Of the various copper indium gallium diselenide (CIGS)-formation processes, a so-called ‘two-stage process’, consisting of sputtering and selenization, has been successfully applied in large-scale production thanks to its stable process scheme and high-fidelity production equipment. A CIGS module with a power of 231W, corresponding to a total area-based efficiency of 16% for 902mm × 1,602mm, was demonstrated when this twostage process was employed in a pilot production line at Samsung (although all the technology concerning CIGS production has now been transferred to Wonik IPS, whose main business is to provide production equipment for the semiconductor and display industry). The high-power module suggests significant potential for CIGS modules to compete with multicrystalline Si modules in terms of both cost and performance. This paper addresses the
important process technologies for achieving high efficiency on large-area substrates, and presents a cost analysis using the data obtained from the operation of the pilot production line. As a result of the synergistic effect of low material cost and high efficiency of the two-stage process, the CIGS manufacturing cost is expected to be reduced to US$0.34/W.
