• Energy Research
• engineering and technology close
• English close
• SDSN Greece close

This paper conveniently skips any controversy associated with the science of climate change. On the assumption that greenhouse gas emissions are causing climate change that is detrimental to humanity, the paper focuses on some economic dimensions of the issue which seem to be poorly understood by Australian media commentators, policy analysts, interest groups and the political parties. Using a neoclassical welfare economics framework the paper explores the costs and benefits of greenhouse gas abatement with reference to the findings of the Stern Report, the setting of greenhouse gas targets by Australian political parties, the danger of the government “picking winners” and the emerging carbon theory of value. The paper concludes with a brief review of the relative merits of a carbon tax and a cap and trade approach. Key Words: This paper conveniently skips any controversy associated with the science of climate change. On the assumption that greenhouse gas emissions are causing climate change that is detrimental to humanity, the paper focuses on some economic dimensions of the issue which seem to be poorly understood by Australian media commentators, policy analysts, interest groups and the political parties. Using a neoclassical welfare economics framework the paper explores the costs and benefits of greenhouse gas abatement with reference to the findings of the Stern Report, the setting of greenhouse gas targets by Australian political parties, the danger of the government “picking winners” and the emerging carbon theory of value. The paper concludes with a brief review of the relative merits of a carbon tax and a cap and trade approach.

In this article, a large area bifacial solar cell on n-type silicon substrates using novel process and only industrial facilities is introduced. The boron emitter is formed by BCl3 precursor and the phosphorus BSF is made by ionimplantation followed by in-situ front and rear side passivation with silicon oxide. Meanwhile, the wafer source and cell series resistance affiliated to process control variability are analyzed. The resulting cell efficiency achieved 19.7% on 156 PSQ n-type Cz wafers. Moreover, such process was adopted on 156 inch n-type mono-like wafers and achieved cell efficiency up to 18.9%. 28th European Photovoltaic Solar Energy Conference and Exhibition; 1053-1056

Lignite-fired power plants in Northern Greece produce about 50% of the electricity and account for nearly 60% of the allocated CO2 emissions. The implementation of biomass co-firing is considered a cost effective and efficient method for minimizing GHG emissions. However, despite a favorable legislative framework, co-firing in Greece has not progressed since low lignite costs and distance of power plants from harbor facilities limit access to internationally traded solid biomass. The improvement and optimization of local biomass supply chains is thus a strategic priority in the national context. The purpose of the present work is to present preliminary investigations of a wheat straw supply chain for a Greek lignite-fired power plant to be converted into biomass co-firing operation. On¬field demonstration data are analyzed in order to estimate costs for supply chains involving either pelletized straw or straw bales. Information of energy consumption is also presented for different cases and GHG emissions calculated according to the methodology of (COM 2010)11. Results indicate that the cost of straw delivered at the power plant varies depending on whether pelletization is included as a supply chain step. Overall, over short distances, transfer of baled biomass is more economic and results in lower GHG emissions, however the increase in the cost of the supply chain suggest that a pelletization step should be considered for longer distances. The transport cost of the supply chain also depends on whether the vehicles are assumed to return empty at their starting point or loaded. Also, compared to imported or domestic wood pellets, straw pellets have lower prices and could be more attractive to plant operators. Long-term fuel contracts are essential in order to ensure the financial viability of co-firing, especially if a reduction in the feed-in tariff is expected. Proceedings of the 20th European Biomass Conference and Exhibition, 18-22 June 2012, Milan, Italy, pp. 136-142

This work has been developed under the AGROinLOG Project, “Demonstration of innovative integrated biomass logistics centres for the Agro-industry sector in Europe”. An Integrated Biomass Logistics Center (IBLC), is based on the introduction of new production chains into existing agro-industries by using new biomass feedstock. The AGROinLOG Project has dedicated great attention to investigate the potential of cereal chaff as a valuable resource.Chaff is the fine fraction of the thrashing residues, not usually collected. Chaff is made up of glumes, seed husks, rachis and the tinner part of the cereal stems, whole and cracked kernels, as well as weed seeds.Currently there are several mechanical solutions available on the market for chaff recovery, and others are still at prototype stage, but theyare not so common and very often unknown to the farmers.So far, the literature reportsfew cases of chaff collection with the specific purpose of weed seeds removal, but it still lacks specificexperiments on these machinesintentionally used for biomass collection.For this reason, during the Project AGROinLOG a series of large field tests were performed using an independent scientific approach with different kind of chaff harvesting technologiesin France, Sweden and Italy from 2017 to 2019.The present study collects the results of these activities with the aim to fill that gap and provide deeper understanding in the possibility to enhance the current cereal harvesting method, in order to improve the quantity of biomass collected by including the chaff. Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 62-68

A short overview of different piezoelectric structures and devices for generating renewable electricity under mechanical actions is presented. A vibrating piezoelectric device differs from a typical electrical power source in that it has capacitive rather than inductive source impedance, and may be driven by mechanical vibrations of varying amplitude. Several techniques have been developed to extract energy from the environment. Generally, “vibration energy” could be converted into electrical energy by three techniques: electrostatic charge, magnetic fields and piezoelectric. Mechanical resonance frequency of piezoelectric bimorph transducers depends on geometric size (length, width, and thickness of each layer), and the piezoelectric coefficients of the piezoelectric material. Manufacturing processes and intended applications of several energy harvesting devices are presented.

Solar power appears to be one of the most promising resources to meet the medium and long term renewable energy targets. The integration of large amounts of photovoltaic (PV) generation into distribution networks faces some limitations due to the network constraints. The PV community became well aware of these limitations in the last years. While first solutions have been pointed out mainly for large installations connected to the medium voltage network, the specificities of low voltage networks are still not fully understood. This paper aims at explaining the challenges associated to the planning and operation of low voltage network with high PV penetration. The actual impact of PV infeed is quantified on the basis of real and accurate network, load and generation data. Results from unsymmetrical load-flow computations are presented and the implementation of reactive power-based voltage control is shortly discussed. 26th European Photovoltaic Solar Energy Conference and Exhibition; 4469-4478

Exhaust hoods are commonly used to capture all emissions from stationary combustion systems that are open to the environment, such as residential heaters or stoves. For experimental purposes, emissions are sampled at one, or more, discrete locations downstream in the exhaust duct. Point-wise measurements in the duct are often taken with the assumption that the emissions are homogeneously distributed across the duct cross-section, because the flow is turbulent and therefore believed to be thoroughly mixed. However, the length of such systems is rarely sufficient to ensure fully-developed flow, and the actual homogeneity is seldom assessed. In the present work the mixing within the duct is investigated by simulating the emissions distribution within various hood and duct configurations. The simulations include a straight duct with and without baffles and two different exhaust hood configurations, namely at the Stove Testing Lab at Lawrence Berkeley National Laboratory (LBNL) and at the University of Adelaide that meet standard requirements. The air flow in the ducts was simulated using Reynolds-averaged (RANS) turbulence modelling, with carbon monoxide (CO) as a representative combustion product, injected at three locations in the straight duct and two locations (centre and side) in the exhaust hoods. Simulations predict that, in isolation, neither a straight duct without baffles, nor a hood with a 90° elbow followed by a straight duct without baffles, provide sufficient mixing to achieve a near uniform distribution of CO at the sampling locations. However, simulations show that adequate mixing of dilution air and CO is achieved with baffles-induced flow detachment and recirculation, not from turbulent mixing in the straight section of the duct itself. The simulations also suggest that elbows, baffles, expansions or other geometrical features are needed to induce thorough mixing. For example, in the Stove Testing Lab at LBNL, flow disturbance is induced by an expansion into a larger diameter straight duct immediately downstream of the hood and the 90° elbow. Although these two systems demonstrate sufficient mixing of CO within the exhaust, the RANS simulations in this study suggest that other systems relying solely on mixing within a specified duct length (viz. 8–12 diameters) may not be sufficient. Refereed/Peer-reviewed

Two studies conducted in Guadeloupe (West Indies) and Réunion (Indian Ocean) islands were designed to investigate the benefits of producing sugarcane as an energy crop and to assess the influence of agroclimatic factors on energy efficiency, respectively. In this context, it is essential to know the low heating value of the dry above-ground biomass (LHVd, MJ/kg) and its energy yield (EY, MJ/m2) in order to select the best varieties and set up a payment method for growers. Eighteen Poaceae (sugarcane and Erianthus) cultivars were compared under wet tropical environmental conditions in Guadeloupe. Three sugarcane cultivars were studied in four contrasting environments in Réunion. The partition sampling and biomass measurement procedures were identical at both locations. Low heating value (LHV) predictions were achieved using near-infrared reflectance spectroscopy (NIRS) after specific calibration (Guadeloupe), or arithmetically after lignocellulosic compound prediction (Réunion). In both studies, LHV variability was very low and slightly dependent on the site, cultivar and above-ground biomass components (millable stalks and tops, and green and dead leaves). Considering the overall dry above-ground biomass (DAB, kg/m2), the LHVd was calculated by averaging 159 samples (mean 16.65 MJ/kg) in Guadeloupe and 315 samples (mean 16.45 MJ/kg) for Réunion. An excellent linear relationship between the DAB and its EY, regardless of cultivar, age and environment, was found (n = 474 and R² = 0.99). Sugarcane energy content assessment could thus be simplified by measuring the DAB, while enabling development of a faster method of payment for growers based on the DAB measurement and the correlation between DAB and EY. Finally, the findings of this study should allow growers to rapidly determine the commercial value of their sugarcane crops, and also enable purchasers to assess the amount of recoverable energy. (Résumé d'auteur)

The harmony between environment and buildings is the strongest point of vernacular architecture. In this context, the Mediterranean vernacular architecture is harmonized with its local context, including culture and traditions. In addition, it respects environmental and climatic factors, construction materials and morphology. In the past, people in Palestine built their houses according to their possibilities, needs, available materials, topography, and culture. Without any control from the government or any legal limitations or architects, it was people architecture, simple architecture. This paper discusses the differences between vernacular and contemporary cities of Palestine at the urban scale. The research methodology adopts explanatory qualitative analysis and comparative synthesis methods for both the old and the new area of the city of Nablus and considers many parameters of the cities such as the city layout, skyline, infrastructure and public spaces. The outcomes of this research allow understanding how the new city is far away from the sustainability principles and how the old city is closer to it and how the architects and stakeholders could learn from the strategies of vernacular architecture. The paper draws a set of recommendations for more in-depth studies, based on quantitative survey with energy efficiency measurements in the Mediterranean climate.