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Habitat degradation and climate change are globally acting as pivotal drivers of wildlife collapse, with mounting evidence that this erosion of biodiversity will accelerate in the following decades1-3. Here, we quantify the past, present and future ecological suitability of Europe for bumblebees, a threatened group of pollinators ranked among the highest contributors to crop production value in the northern hemisphere4-8. We demonstrate coherent declines of bumblebee populations since 1900 over most of Europe and identify future large-scale range contractions and species extirpations under all future climate and land use change scenarios. Around 38-76% of studied European bumblebee species currently classified as 'Least Concern' are projected to undergo losses of at least 30% of ecologically suitable territory by 2061-2080 compared to 2000-2014. All scenarios highlight that parts of Scandinavia will become potential refugia for European bumblebees; it is however uncertain whether these areas will remain clear of additional anthropogenic stressors not accounted for in present models. Our results underline the critical role of global change mitigation policies as effective levers to protect bumblebees from manmade transformation of the biosphere.

Abstract Hydrogen co-firing in a gas turbine is believed to cover an energy transition pathway with green hydrogen as a driver to lower the carbon footprint of existing thermal power generation or cogeneration plants through the gradual increase of hydrogen injection in the existing natural gas grid. Today there is limited operational experience on co-combustion of hydrogen and natural gas in an existing gas turbine in an industrial environment. The ENGIE owned Siemens SGT-600 (Alstom legacy GT10B) 24 MW industrial gas turbine in the port of Antwerp (Belgium) was selected as a demonstrator for co-firing natural gas with hydrogen as it enables ENGIE to perform tests at higher H2 contents (up to 25 vol%) on a representative turbine with limited hydrogen volume flow (1 truck load at a time). Several challenges like increasing risk of flame flashback due to the enhanced turbulent flame speed, avoiding higher NOx emissions due to an increase of local flame temperature, supply and homogeneous mixing of hydrogen with natural gas as well as safety aspects have to be addressed when dealing with hydrogen fuel blends. In order to limit the risks of the industrial gas turbine testing a dual step approach was taken. ENGIE teamed up with the German Aerospace Center (DLR), Institute of Combustion Technology in Stuttgart to perform in a first step scaled-burner tests at gas turbine relevant operating conditions in their high-pressure combustor rig. In these tests the onset of flashback as well as the combustor characteristics with respect to burner wall temperatures, emissions and combustion dynamics were investigated for base load and part load conditions, both for pure natural gas and various natural gas and hydrogen blends. For H2 < 30 vol% only minor effects on flame position and flame shape (analyzed based on OH* chemiluminescence images) and NOx emission were found. For higher hydrogen contents the flame position moved upstream and a more compact shape was observed. For the investigated H2 contents no flashback event was observed. However, thermo acoustics are strongly effected by hydrogen addition. In general, the scaled-burner tests were encouraging and enabled the second step, the exploration of hydrogen limits of the second generation DLE burner installed in the engine in Antwerp. To inject the hydrogen into the industrial gas turbine, a hydrogen supply line was developed and installed next to the gas turbine. All tests were performed on the existing gas turbine hardware without any modification. A test campaign of several operational tests at base and part load with hydrogen variation up to 25 vol% has been successfully performed where the gas composition, emissions, combustion dynamics and operational parameters are actively monitored in order to assess the impact of hydrogen on performance. Moreover, the impact of the hydrogen addition on the flame stability has been further assessed through the combustion tuning. The whole test campaign has been executed while the gas turbine stayed online, with no impact to the industrial steam customer. It has been proved that co-firing of up to 10% could be achieved with no adverse effects on the performance of the machine. Stable operation has been observed up to 25%vol hydrogen co-combustion, but with trespassing the local emission limits.

Abstract The key to achieve an economically more attractive concentrated solar power plant is to work at higher operating temperatures, allowing both higher power conversion efficiencies resulting in a smaller heliostat field for a given energy output, and higher temperature ranges in the storage tanks, with increased energy storage density and smaller size, hence less expensive. This fostered the development of using particle suspensions as heat transfer media. This paper presents a theoretical framework for the energy analysis of a particle-in-tube solar power plant, hybridized, with topping air-Brayton cycle turbine, and bottoming steam block. From studying the effects of essential design parameters on the energy efficiency, the heat transfer efficiency of the turbine air preheater is of paramount importance to increase the solar contribution within the hybrid concept, while the energy efficiency moreover increases by an optimum air-Brayton cycle turbine operation (mostly through the pressure ratio, less by the operating temperature). The overall efficiency of the concept varies from about 40% when using combined low and high pressure Brayton cycle turbines only, to over 48% in a fully combined air-steam concept. Energy efficiency findings are in agreement with the literature data.

Abstract This paper gives an overview on the traditional Jatropha curcas L. (physic nut) production practices as a multipurpose vegetable resource in the Totonacapan, Mexico, and the social acceptability of changes involved both in its agronomic management and use, promotion by the Mexican Energy Ministry through a special program, which, in the case for J. curcas L., includes, exclusively, toxic genotypes. In this region, there is important infra-specific genetic diversity for non-toxic genotypes, which have been used by the local indigenous population for centuries, mainly for human consumption (roasted seeds). In contrast with other studies about the industrial-scale productivity of physic nut as a monoculture for biodiesel yield, this research assessed the several functions of this species within local, traditional agroecosystems and as part of the family’s diet. In order to evaluate the pertinence of its diffusion in relation with the Totonac economy, the feasibility of implementing the official program was critically assessed, by using a binary logistic mathematical model for the “farmers’ willingness to adopt it. The results show the following barriers to agricultural adoption: (1) a low financial capacity of farmers; (2) the current price instability of J. curcas seeds; (3) the Totonac familys’ need to cultivate all the plant species involved in their agroecosystems for economic and cultural reasons. Nevertheless, J. curcas remains as a very important plant resource for the local people, with several important contributions to farmers’ livelihoods, and multiple roles (economic, ecological and cultural) that add resilience to the Totonac’s traditional agroecosystems. The monoculture of J. curcas established only for biodiesel production in different regions of Mexico, has not led to a significant increase in the income of local farmers, because government policies have been ineffective in recognizing the several functions of this species in the local agroecosystems from the peasant’ perspective. This critical situation could be repeated in the Totonacapan, negatively affecting, not only the local non-toxic genotypes, but also this ancestral culture and consequently the Totonac’s economy.

Procedures for testing organic solar cell devices and modules with respect to stability and operational lifetime are described. The descriptions represent a consensus of the discussion and conclusions reached during the first 3 years of the international summit on OPV stability (ISOS). The procedures include directions for shelf life testing, outdoor testing, laboratory weathering testing and thermal cycling testing, as well as guidelines for reporting data. These procedures are not meant to be qualification tests, but rather generally agreed test conditions and practices to allow ready comparison between laboratories and to help improving the reliability of reported values. Failure mechanisms and detailed degradation mechanisms are not covered in this report. © 2011 Elsevier B.V. All rights reserved.

Abstract Monolithic solar modules made from thin-film crystalline-silicon layers of high quality on glass substrates could lower the price of photovoltaic electricity substantially. This paper describes three different approaches that we are currently investigating to address the challenge to form high-quality crystalline-silicon layers on glass substrates. The SLiM-Cut approach is a wafering technique that results in 50-micron thick layers with a minimum of material loss. We show that crack initiation can be used as a means to better control the lift-off process. The epifree approach involves the lift-off of ultra-thin monocrystalline films formed by reorganization of cylindrical macropore arrays in silicon upon annealing. So far, films with a thickness of around 1 μm and very simple cells with an efficiency of up to 4.1% have been achieved. Finally, a seed layer approach is presented based on the epitaxial thickening by thermal CVD of monocrystalline silicon layers bonded on glass-ceramic substrates. Very promising cell efficiencies of 11% and Voc values of up to 610 mV have been achieved using a very simple and non-optimized cell structure.