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AbstractAn Eco-Design methodology based on two abridged Life Cycle Assessment tools (eVerdEE [1] developed by ENEA [2] and the French Standard NF 01-005) plus TRIZ [3] Eco-guidelines is presented. This method is one of the outputs of the European project REMake [4] (started September 2009 ended December 2012), which had the goal of developing and testing new approaches for eco-innovation, recycling and material consumption for manufacturing small and medium sized enterprises (SMEs). The number of SMEs involved in the project has been around 250, in six countries.The proposed method consists of a preliminary scanning of a given product or process in order to disclose all the material involved and the energy flows, and to assess their environmental impact by means of a simplified Life Cycle Assessment (LCA) approach and the related indexes. The “hot spots” of the product or process are then identified by adding a brand new index called “IFR (Ideal Final Result) index”, conceived from the TRIZ “Ideal System” concept [5], to classical LCA criteria.Once the hot points are identified, a set of over 300 TRIZ based eco-design guidelines [6,7] are selectively introduced to develop design variants to the given system with the aim of providing a lower global environmental impact. An in-depth explanation about ECO guideline implementation is given, together with a case study concerning a manufacturer of machine tools.

Abstract This work presents the measured performance data related to the very-first Energy+ building in Dubai certified by the Passive House Institute. The building is a two-floor office structure, with 550 m2 total surface, designed under the guide and the scientific supervision of a Bergamo University research group, jointly to the Mohammed Bin Rashid Space Centre (MBRSC). The goal of the project was to assure a high level of internal comfort all over the year by using only solar energy. The building architecture has been designed to minimize the cooling load and the energy demand. The energy system is based on a 40 kWp PV field coupled with a 48 kWh electric storage and a high-efficiency chiller (reversible heat pump). Transient simulations by Trnsys code have been carried out to optimize both the thermal envelope and the energy plants so to make the building energy-autonomous 24/7. The numerical predictions of the energy performance (including cooling load, PV production and power consumption for chiller, lighting and appliances) are compared to the real data measured by a sophisticated monitoring system, including sensors located in the roof, in the external walls and in the energy systems. The field measurements confirm that the model predictions were accurate both in terms of peak and annual values. The small variations between prediction and real data show that both thermal envelope and PV field perform better than expected. This building is a pioneering pilot-project: the goal was to show that new sustainable construction standards using only solar energy are possible in the United Arab Emirates (UAE) and that this is a viable solution to reduce the carbon footprint in all the Gulf region. The strategic importance of an accurate modeling activity leading to an optimal design has been proved. The monitored data under real operating conditions have confirmed that the expected targets in terms of energy savings and carbon footprint reduction have been successfully achieved.

The complex flow field in the tip region of a turbomachine rotor, including the tip leakage flow and tip leakage vortex (TLV), has been studied for decades. Yet many associated phenomena are still not understood. This paper provides detailed data on the instantaneous and phase averaged inner structure of the tip flow, and evolution of the TLV. Observations are based on series of high resolution planar particle image velocimetry measurements performed in a transparent waterjet pump fitted into an optical refractive index matched test facility. Velocity distributions and turbulence statistics are obtained in several meridional planes inside the rotor. We observe that the instantaneous TLV structure is composed of several unsteady vortex filaments that propagate into the blade passage. These filaments are first embedded into a vortex sheet generated at the suction side of the blade tip, and then they wrap around each other and roll up into the TLV. These vortices do not have sufficient time to merge into a single compact structure within the blade passage. We also find that the leakage vortex induces flow separation at the casing endwall and entrains the casing boundary layer with its counter-rotating vorticity. As it propagates in the rotor passage, the TLV migrates towards the pressure side of the neighboring blade. Unsteadiness associated with observed vortical structures is also investigated. We notice that, at early stages of the TLV evolution, turbulence is elevated in the vortex sheet, in the flow entrained from the endwall, and near the vortex core. Interestingly, the turbulence observed around the core is not consistent with the local distribution of turbulent kinetic energy production rate. This mismatch indicates that, given a TLV section, production likely occurs at preceding stages of the vortex evolution. Then, the turbulence is convected to the core of the TLV, and we suggest that this transport has substantial component along the vortex. Because we observe that the meandering of vortex filaments dominate the flow in the passage, we decompose the unsteadiness surrounding the TLV core to contributions from interlaced vortices and broadband turbulence. Results of this decomposition show that the two contributions are of the same order of magnitude. The TLV is investigated also beyond the trailing edge of the rotor blade. During these late stages of its evolution, the TLV approaches the pressure side of the neighboring blade and vortex breakdown occurs, causing rapid broadening of the phase average core, with little change in overall circulation. Associated turbulence occupies almost half the width of the blade passage and turbulence production there is also broadly distributed. Proximity of the TLV to the pressure side of the neighboring blade also affects entrainment of flow into the incoming tip region.

In recent years, a renewed interest in value creation for stakeholders has been witnessed in different contexts. Different tools have been proposed to try to grasp and measure such value(s) but, in many cases, the main perspective remains that of the shareholders. To contribute to the field of research that aims to discuss novel ways of thinking about value creation measurement, this paper addresses the relationship between ESG (Environmental, Social, and Governance) ratings and Value Added, as proxies of value creation and distribution for stakeholders. In particular, we consider whether ESG ratings are able to capture companies that are characterized by their capacity for generating higher Value Added for stakeholders. Our analysis uses the frontier methodology combined with means comparison. Data from 2018 were downloaded from EIKON, for all companies within the Euro zone and for all sectors (1932 companies, of which 399 held an ESG rating, compared with 1533 without ESG analysis). Our analysis reveals that, although ESG is theoretically considered a good social responsibility proxy, ESG indices cannot be used as an indicator of value creation for stakeholders but, rather, must be considered as only one of the components. This implies a need to review the limitations of ESG ratings and establish that the relevant indices are not suitable for use in universal or absolute decision-making.

The global increase in energy consumption is forcing the energy sector to evaluate the energy transition from fossil-based systems to renewable energy sources. Unfortunately, the impact of non-dispatchable generation affects grid stability and the ability to meet night time loads. In addition, a shift from summer to winter is required to increase the penetration of renewables. The introduction of storage technologies and the energy mix could overcome some of the problems associated with the green revolution. The aim of the work is to assess the best combination of generation systems and storage to meet the electricity needs of a 100 MW peak load city in the Latvian region with an annual energy load of 700 GWh. The energy hub considered, shown in the figure, represents a valuable evolution of a traditional gas-fired power plant coupled with the most cost-effective renewable resource generators: photovoltaic and wind turbines. To exploit the renewable surplus, part of the electricity is converted into hydrogen, which drives a fuel cell and a methanation system linked to the gas turbine. The method used is Trnsys-based numerical modelling coupled with multivariable particle swarm optimization to minimise the levelized cost of electricity under different renewable penetration scenarios. The LCOE is 0.96 EUR/kWh for a 50 % RES production and doubles for a fully renewable system. The optimised energy mix includes an electrolyser with a capacity equivalent to 24 % of the renewable capacity. The results of the analysis show the crucial role of the H2 system, which is 20 times larger than the CH4 system.

Generation and Transmission Expansion Planning (GTEP) to achieve decarbonisation targets in the power sector requires installing relevant shares of production from Renewable Energy Sources (RES). GTEP optimization models determine expansion plans over a long-term horizon so as to minimize the total investment and operation cost. In the presence of high shares of non-dispatchable RES power plants, operation costs must be evaluated taking into account the different operating conditions due to the intermittency of RES power generations. In this work we consider a GTEP model for a power system based on thermal, solar and wind power generation and we introduce a novel approach to select representative days (RDs), discretized in hours, in order to obtain accurate estimates of the operational costs. The RDs are not connected, in order to get a decomposable problem. A procedure is introduced to assign the ON/OFF status of every thermal unit at the beginning of each RD. Numerical results on a test case of suitable dimension show that the proposed method provides expansion plans very close to those obtained by the complete hourly model, while dramatically reducing computational costs.