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The integration of Grid-Connected PV systems into buildings or public areas is one of the most usual applications of the photovoltaic solar energy in developed countries. Since early 2009, the University is working on an ambitious project, the so-called UNIVERSOL project, where its main goal is to convert the University Campus in a big public area which combines the PV electricity generation with the common uses of a university place. The aim of this paper is to show to the scientific community the main results of this project and that the methodology proposed for the “large urban-area photovoltaic potential” estimation can be easily exportable to other locations with similar characteristics, so the photovoltaic generators integration examples proposed in this project, and the software tools used to represent it, can be helpful for other designers, taking into account that this project has been adapted to the new Spanish legislation. 26th European Photovoltaic Solar Energy Conference and Exhibition; 4068-4072

The requirements for the contact metal deposited on solar cells are rising as the size of solar cells grows. Particularly, the improvement of the electric properties – especially the conductivity – is attracting interest. Light-induced plating is deemed to be a sophisticated approach to deposit a highly conductive metal layer on an arbitrarily generated seed layer. Although already in industrial operation to some extent, the mechanism is not understood in detail. In addition, the aim of avoidance of cyanide containing electrolytes for silver deposition is high. We will show voltammetric techniques are an appropriate approach investigating these topics. 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 1785-1788

Cryptographic primitives with low-latency performance have gained momentum lately due to an increased demand for real-time applications. Block ciphers such as PRINCE enable data encryption (resp. decryption) within a single clock cycle at a moderately high operating frequency when implemented in a fully-unrolled fashion. Unsurprisingly, many typical environments for unrolled ciphers require protection against physical adversaries as well. Yet, recent works suggest that most common SCA countermeasures are hard to apply to low-latency circuits. Hardware masking, for example, requires register stages to offer resistance, thus adding delay and defeating the purpose of unrolling. On another note, it has been indicated that unrolled primitives without any additional means of protection offer an intrinsic resistance to SCA attacks due to their parallelism, asynchronicity and speed of execution. In this work, we take a closer look at the physical security properties provided by unrolled cryptographic IC implementations. We are able to confirm that the nature of unrolling indeed bears the potential to decrease the susceptibility of cipher implementations significantly when reset methods are applied. With respect to certain adversarial models, e.g., ciphertext-only access, an amazingly high level of protection can be achieved. While this seems to be a great result for cryptographic hardware engineers, there is an attack vector hidden in plain sight which still threatens the security of unrolled implementations remarkably – namely the static power consumption of CMOS-based circuits. We point out that essentially all reasons which make it hard to extract meaningful information from the dynamic behavior of unrolled primitives are not an issue when exploiting the static currents for key recovery. Our evaluation is based on real-silicon measurements of an unrolled PRINCE core in a custom 40nm ASIC. The presented results serve as a neat educational case study to demonstrate the broad differences between dynamic and static power information leakage in the light of technological advancement. IACR Transactions on Cryptographic Hardware and Embedded Systems, Volume 2020, Issue 4

Technical Report (2012). doi:10.3204/XFEL.EU/TR-2012-002

To minimize shading when interconnecting single solar cells to solar modules the shingling technique can be used. Having an electrically conductive substrate this interconnection technique can be applied without any modification of the single solar cells itself. In case of electrically isolating substrates a contacting of the back metal electrode from the backside is in general not possible without modification of the substrate. Within this paper we present a possibility to interconnect flexible CIGS thin film solar cells on polyimide substrate using the shingling technique. To expose the molybdenum layer from the backside the polyimide substrate has been removed locally with a pulsed Excimer laser (248 nm wavelength, 20 ns pulse duration). To interconnect the exposed back contact with the front contact of the next solar cell the blind vias can be filled with a conductive adhesive. The surface of the exposed back contact of the CIGS solar cells has been characterized using optical microscope and SEM to acquire information on the completeness of the polymer etching and possible damages of the thin films. To characterize the exposed thin films electrically conductive-AFM images were made. First solar cells have been contacted from backside and electrically characterized. 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 3414-3417

Photovoltaic (PV) is one of the fastest growing electricity generation technologies in the world. Average annual growth rates of global PV-installations have reached around 45% for the last 15 years, which triggered a fast and ongoing reduction of production cost in PV industry. The presented work aims at consolidating historical price and cost information, deriving refined learning curves for PV modules and systems, and analysing the main factors of learning. For c-Si modules a valid learning rate of 17% is found based on a meta-analysis of various studies. In early years, even a learning rate of 30% is observed. As an example for thin-film PV, CdTe module cost reduce by 16% as the cumulated production output doubles. Interestingly, efficiency improvements contribute only in second order to the overall cost reduction for both technologies, emphasising the relevance of production excellence and economies of scale. On PV system level, a cost reduction of 14% per doubling of cumulated installed capacity is derived. Finally, a sensitivity analysis reveals that learning rate variations are only of minor influence on the overall global PV market potential. 26th European Photovoltaic Solar Energy Conference and Exhibition; 4697-4702

This paper evaluates various aspects of flexibility in power systems worldwide within the multi-country study framework of IEA Wind Task 25, including grid components and actions which have been favoured for enhancing flexibility in different areas/countries/regions, and how TSOs/ISOs/ utilities intend to manage variable generation in their operating strategies. One methodology to evaluate the diversity of flexibility sources is a "flexibility chart”, which can illustrate several flexibility parameters (e.g. hydro, CCGT, CHP, interconnection) in a polygonal radar (spider) chart.

A new concept of a system for Combined Heat and Power generation is presented. The concept is based on hybrid use of two renewable energy sources, direct solar (thermodynamic solar) and biomass (indirect solar energy). Biomass combustion is conducted using a fluidized bed combustor. A second source of energy, given by the direct irradiation of the bed with a concentrated solar radiation, is integrated in the same system, using the fluidized bed as solar receiver. A Stirling engine converts heat into mechanical power. A Scheffler type mirror is adopted to allow irradiation of the system in a fixed focal point. Advantages of the proposed solution are illustrated and some preliminary results on the performance of the system, obtained with a simple model, are presented. The principal improvements with respect to existing systems of similar size and primary energy source are illustrated. The most important are the enhanced heat transfer processes that are realized with the help of the fluidized bed, and the possibility of continuous cogeneration during the day. Different working conditions are considered to estimate the contribution given by the burning of fuel, in presence as well as in absence of sun irradiation (as during the night). The distribution of energy shares among the different flux contributes is reported versus the amount of biomass burned per unit time. The results clearly demonstrate the advantage of coupling, in the same system, two sources for heat generation, thus maintaining the option of producing electricity without the supply of biomass fuel.

In this paper we argue for the need to apply a cognitive approach to understand deep dynamics and determinants of technological evolutions. After examining main contributions from innovation studies to the conceptualization of innovation and change in complex socio-technical environments, we highlight the contribution coming from the application of the cognitive approach to evolutionary studies on technologies and we introduce the concept of technological memory as an interpretative tool to understand those changes. We discuss our hypothesis with reference to several observations carried out in different local contexts – Mexico, India and Italy – in relation to technological change in the water sector. In those cases deliberate attempts to substitute traditional technologies with modern ones led to interesting trajectories of change ranging from the collapse of old technologies to the development of multifaceted hybridization patterns. Tema. Journal of Land Use, Mobility and Environment, 2014: INPUT 2014 - Smart City: planning for energy, transportation and sustainability of the urban system