Power & Energy Solutions

The premier renewable energy publication

The role foundations play in the deployment of larger, heavier, more powerful wind turbines, in deeper waters and further from shore, has perhaps not received the attention it deserves. But it is crucial in driving down offshore wind’s levelised cost of energy to the point where it can compete with fossil fuel and nuclear sources. Technology and costs compared Fixed foundations, whether monopile, jacket or gravity base designs, now support towers and turbines that weigh well over 1,000 tonnes and have a tip height of more than 200 metres. The foundations need to be able to do this, in high winds and heavy seas, for at least the 25 years of the turbine’s anticipated operating life. Monitoring the structural integrity of the foundations, especially in the critical areas of greatest strain – just above and below the seabed – requires high expertise and state of the art test and measurement technology. This is a field where industry development has outstripped design standards. There is no easy guide for offshore developers. In this report, technology leader HBM Test and Measurement compares resistive and fiber-optical gauge systems for offshore wind foundations. To help design verification, or as a system to provide long-term assurance that the foundations

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The history of the global PV industry is one that is defined by innovation. And now, more than ever, the continuing growth and sustained health of the solar sector is further enabling companies to invest in R&D. From tech start-ups to global electronics companies, new components that deliver marginal improvements or game-changing solutions, the efficiency and performance of PV systems across the world continues to be advanced by technological innovation. One characteristic that unites innovators across the solar industry is the unwavering focus on optimizing solar PV systems, always looking to deliver higher yields, reduce O&M costs and increase the ROI for system owners. So, it’s perhaps unsurprising that in recent years there has been a significant increase in the use of module-level power electronics (MLPE), such as power optimizers or microinverters. As the name suggests, MLPE place power electronics on the modules of the PV system, with the aim of isolating individual panels in order to improve overall system performance. The introduction of MLPE marks a shift from the conventional PV system design, where the inverter would be responsible for handling so many of the functions and processes that a PV plant is required to carry out. The proliferation of

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With bifacial PV devices a large gain in solar power generation in the range of 10%-20% can be achieved in the field. Despite this, selling bifacial devices at higher prices is still a difficult task. With peak-performance of solar cells and modules at standard testing conditions being the price meter, true bifacial testing is a key step to achieve bifacial pricing in the future of PV. We present deeper insight into bifacial testing and analyse the economic impact of different approaches. Large-scale production of bifacial solar cells and modules has become possible mainly by three developments over the last few years – dielectric passivation layers on both sides of the solar cells, thinner glass for solar modules and alternatively transparent backsheets. Offering a major increase in electricity generation at a comparably low increase in costs for device manufacturing, bifaciality has become one of the largest industry trends in photovoltaics in the recent years. Bifacial devices achieve a gain in power generation of 10% – 20% compared to monofacial references [1-5], depending on system design, albedo of the systems’ location as well as the bifaciality coefficient of the modules. This gain, which corresponds to 2% – 4% higher solar cell efficiency, is

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High purity argon (greater than 99.999%) is used as a shield gas in the production of silicon ingots, to be fabricated into wafers for solar cells and micro-electronic devices. The argon is used to control the impurity levels present during the manufacturing process to an acceptable level. In response to rising costs, the trend in the solar industry has been to reduce the argon purge flows to a minimum, typically about 30slm; however, this cost reduction comes at the expense of wafer purity which can result in lower performance solar cells. Ultra-High purity wafers for use in micro-electronic applications typically utilise two to three times as much argon as for the solar PV application, so rising argon costs are an even more critical issue in this sector. The current trend in the Solar PV wafer market is to move to higher purity high performance and/or n-type doped wafers, to maximise the efficiency of the resulting solar cells and generate added value. This requires argon purge gas flows to increase up to about 70-90slm. The supply of high purity argon is primarily a by-product of the air separation process generating oxygen used in steel making. This means, at best the, supply of high purity

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Solar panel manufacturers strive to minimize cost and maximise efficiency of their modules. Their success is confirmed by the substantial decrease in $/Wp factor for the modules. In 2006, crystalline silicon based module prices were approximately 5.2$/Wp. By 2017, this had dropped to 0.42$/Wp, over an order of magnitude decrease in ten years. There has also been a massive relocation of the cell and module manufacturing industry. In 2006, China and Taiwan produced ~7% of the world production of solar modules as expressed as MWp. At that time, over 40% of production was in Japan, and over 30% in Europe. By 2017, China and Taiwan dominated module manufacturing, with over 70% of the world production, ~60% of that being in China alone. Both Japan and Europe had dropped to less than 5%. It is important to stress that $/Wp values are dominated by availability and cost of capital, land prices, environmental regulatory restrictions, and production scale – these parameters contribute to operating costs more than labor. Module efficiency contributes to the $/Wp performance indicator. The table provides absolute and relative module efficiencies. The best heterojunction modules are 50% more efficient than those modules based on thin films. The Chinese government has been very actively

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Ron Corio is the founder of Array Technologies, pioneers of solar tracking technology. Array Technologies built its first tracker for bifacial modules in 2009 and has been studying bifacial modules coupled with utility scale trackers at a test-site for the last year, and recently launched a new partnership with a national laboratory in New Mexico. At Intersolar North America 2018, Array explained that it will continue to push its study of the convergence of bifacial and tracking technologies; namely how these studies will help to better identify and interpret the multitude of factors which go into predicting the energy output of future plants combining these two technologies. Innovation has driven the growth and development of the PV industry. With that innovation has come increased reliability, bankability, optimized energy yields, and higher efficiencies – making solar more and more appealing to stakeholders. One of the most promising innovations is the emergence of bifacial PV cell and module technology. By producing electricity from both the front and backside of a solar module, PV project owners and developers can profit from increased energy yields from the diffused light hitting the backside of the module. When coupled with an optimized and reliable PV tracking system, bifacial

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PES is delighted to bring you this latest advanced technology solution from ZF Wind Power. Over the last few years total wind turbine noise, which is mainly generated by the interaction of the wind and the wind turbine structure, has changed from being one of the properties of a wind turbine to a true differentiator between different wind turbine OEMs: the less noise the wind turbine generates, the more wind turbines can be placed on the same piece of land without violating the prevailing noise regulations. To achieve this, wind turbine OEMs are investigating among other things reducing overall noise levels by utilising optimised low noise blade design using e.g. serrations and improving controller strategies to include a wide variety of low noise modes. As the overall wind turbine noise is used to mask the noise coming from the mechanical components inside a wind turbine such as the generator and the gearbox, these noise sources also need to be optimised. The low noise blade designs, which are still being studied, have a direct impact on the overall wind turbine noise and thus require the mechanical noise to be reduced at the same pace. Next to that, the increased number of low

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Jose Vega-Lozano, Director at Aerial Vision Ltd, gives PES a thought provoking look in to the world of UAV providers. He suggests caution and questioning before deciding who to use: make sure your chosen company can deliver what you need and what you expect. There are many drone services out there, but which one is for you? Buyer beware One of the main benefits that the internet has brought to procurement, buying services and/or products, is that information is now freely available to the buyer, whereas before it was not. Previously, the vendor and his sales team often held the balance of power; in that the weight of knowledge between the buyer and the vendor was stacked massively in the salesman’s favour. Caveat emptor ‘Buyer Beware!’ was then sage advice. Nowadays buyers are often as knowledgeable as salesmen in a given situation; detailed research and meticulous analysis being usually only a few key strokes away thanks to the internet. But is this rebalancing of knowledge (and therefore buying power) true of the most modern, cutting edge and innovative products/services? Can a layperson really debunk charlatans and cowboys in the developing industry of UAS service provision? Or do you feel that you will

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PV energy has become indispensable for power companies. About 390 GW are installed around the world and a growth of 113 GW is expected this year. PES investigates the importance of monitoring. Why PV monitoring is important There are many reasons for the success of PV energy. It is decentralised, has a simple technology and, above all, it is cost-effective to produce. In fact it’s the most cost-effective way of generating energy. Most PV plants even pay for themselves thanks to feed-in tariffs, direct marketing, net-metering, and self-consumption. Thus, every hour of sunshine is worth hard cash, which needs to be ensured. PV energy is becoming more and more relevant. Real interest in solar PV power began about 20 years ago. Slowly but surely, the new technology for generating power from sunshine established itself. As it became more popular, the technology was optimised and became more efficient and durable. At the same time, the price for modules decreased, accelerating the spread of PV power. However, a growing PV market also means rising investments. More and more money from companies or private entities goes towards solar power generation and PV is becoming essential as a reliable power supply. It is critical, regardless of whether or not it

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