• Energy Research
• Restricted close
• BE close
• IN close
• Renewable Energy close

Organic photovoltaics (OPV) have developed into a vast research area. Progress in various directions has made it difficult to monitor the technology's precise development state. We offer a patent landscape analysis over all OPV devices, their substrates and encapsulation materials to provide an overview of patenting activity from a historical, organizational, geographical and technological point of view. Such an exercise is instrumental for private companies and research institutes aiming at both internal or external technology creation. We discuss our findings in the context of the Industrial Life Cycle model and find OPV still residing in the fluid technology development phase. Technology development is still following an exponential growth path, with the majority of patents coming from the Asian continent and in general private companies. For devices, the main technological focus can be traced back to the " H01L-031" international patent classification (IPC) main group. For the queried substrates, the most attention has gone to glass, but paper and textile have drawn significant interest too. Finally, encapsulation is found to be a less mature research field given the smaller number of patent families. The latter shows that the technology has not matured to the level where processing is carried out on a commercial scale

Hydraulic experiments using physical scale models of monopile scour protections typically have high ex-perimental uncertainties and data scattering. These uncertainties may severely affect the accuracy of the experimental results and need to be analysed quantitatively. This paper presents a study on the quantification of experimental uncertainties in monopile scour protection damage tests following the Guide to the expression of Uncertainty in Measurement (GUM) (ISO, 2008). The uncertainty analysis is performed using the three-dimensional damage number S3D and the widely applied STAB number. Through the analysis of the S3D number from individual test and repeated tests, it is found that the uncertainty analysis method for an individual test can be efficiently applied to predict the experimental uncertainty. The wave peak period and the current velocity are identified as the two major sources of uncertainties for the S3D number. The flow turbulence and correlations between input parameters can be neglected when estimating the uncertainty. The uncertainty analysis of the STAB number shows that the experimental uncertainty due to measurement can be up to 5% to 7% of the obtained STAB result. This uncertainty range is wide in comparison with the narrow margin of a dynamic scour protection design in DNV's recent recommended practice (DNV-RP-0618). The uncertainty of the STAB number is more affected by the armour stone density, wave peak period and significant wave height.

Abstract Regulatory risk is commonly accepted as one of the most important risks in the energy business, particularly renewable energy. With the recent changes (in June 2014) in the Spanish regulatory framework, investors' returns might be significantly affected. Further, as the Spanish and the Portuguese electricity systems are integrated, a change in the regulatory framework of Spain might also affect renewable energy policies and investment strategies in Portugal. This study is a projection of business risk under the assumption that the Portuguese government may adopt similar regulatory changes. Monte Carlo method is used to simulate the data under different scenarios. Applying Net Present Value and Real Options approaches, a 50 MW wind power project is evaluated. This study has considered the delay option to study five regulatory scenarios. A higher value for the delay option suggests that a high financial loss is expected if new wind power projects of similar capacity are implemented under the new regulatory framework.

To generate a substantial amount of power, Wave Energy Converters (WECs) are arranged in several rows or in a ‘farm’. Both the power production and cost of a farm are lay-out dependent. In this paper, the wave power redistribution in and around three farm lay-outs in a near shore North Sea wave climate, is assessed numerically using a time-dependent mild-slope equation model. The modelling of the wave power redistribution is an efficient tool to assess the power production of a farm. Further, for each lay-out an optimal (low cost) submarine cable network is designed. The methodology to assess the power production and cost of a farm of WECs is applied to the Wave Dragon Wave Energy Converter (WDeWEC). The WDeWEC is a floating offshore converter of the overtopping type, which captures the water volume of overtopped waves in a basin above mean sea level and produces power when the water drains back to the sea through hydro turbines. It is observed that the cable cost is relatively small compared to the cost of the WDeWECs. As a result, WDeWECs should be installed in a lay-out to increase power production rather than decrease cable cost, taking spatial and safety considerations into account. WDeWECs arranged in a single line produce the highest amount of power, but require an available sea area with a large width (51 km). Installing a single line of WDeWECs in front of a farm of wind turbines increases the time window for accessing the wind farm (applied to Horns Rev II e significant wave height smaller than 1e2 m during 8 h at minimum) by 9e14%. 2011 Published by Elsevier Ltd.

Woody crops such as orchards and olive groves require annual pruning operations, which leave abundant residues on the ground. These must be removed both for disease control and for facilitating the following tending activities. The resulting biomass can be managed as a waste or a by-product, in both cases incurring in a cost for farmers. A harvester prototype for collecting and comminuting apple pruning residues was tested and compared to a traditional mulcher. In particular, the study aimed at: 1) quantifying productivity and costs of the two systems, 2) evaluating the possible influence of apple variety, tree age and machine type on the productivity per hectare, and 3) estimating and comparing the energy balance of the two working options.

Bioelectrochemical systems (BESs) are unique systems capable of converting chemical energy into electrical energy (and vice-versa) while employing microbes as catalysts. Such organic wastes including low-strength wastewaters and lignocellulosic biomass were converted into electricity with microbial fuel cells (MFCs). Likewise, electrical energy was used to produce hydrogen in microbial electrolysis cells (MECs) or other products including caustic and peroxide. BES were also designed to recover nutrients, metals or removal of recalcitrant compounds. Moreover, photosynthetic micro-organisms as well as higher plants were implemented to use solar energy for electricity generation. The diversity on microbial and enzymatic catalysts offered by nature allows a plurality of potential applications. As compared to conventional fuel cells, BESs operate under relatively mild conditions and do not use expensive precious metals as catalysts. The recently discovered microbial electrosynthesis (MES) of high-value chemicals has greatly expanded the horizon for BES. Newer concepts in application as well as development of alternative materials for electrodes, separators, catalysts along with innovative designs have made BES very promising technology. This article discusses the recent developments that have been made in BESs so far, with the emphasis on their various applications beyond electricity generation and resulting performances as well as existing limitations.

One of main challenge of proton exchange membrane (PEM) water electrolysis is the achievement of a long-term durability exceeding 100 khours. Accordingly, degradation mechanisms of membrane electrode assemblies (MEAs) and stack components of PEM electrolysers deserve large attention. An important objective of the EU ELECTROHYPEM project was to develop components for PEM electrolysers with enhanced activity and stability in order to reduce stack and system costs and to improve efficiency, performance and durability. The focus of the project was concerning mainly with electrocatalysts and membranes development and validation of these materials in a PEM electrolyser. In this work, a first set of MEAs, used for 3500-5700 h in a PEM electrolyser, was investigated using electrochemical and physico-chemical techniques. The goal was to individuate key degradation issues and to provide a reliable estimation of the MEA endurance under real life operation. Specific approaches to mitigate the degradation mechanisms are discussed.