Future pathways for decarbonization and energy efficiency of ports: Modelling and optimization as sustainable energy hubs

The increasing energy demand in harbour areas, coupled with the need to reduce pollutant emissions, has led to the development of renewable energy-based polygeneration systems to face the carbon footprint of ports and ships at berth. In this way, in the coming years, ports can be converted into modern energy hubs. From this point of view, this paper presents a new dynamic simulation model for assessing and optimizing the energy and economic impact of ports. Here, energy systems and renewable sources can be designed to be connected to national electricity and natural gas grids and can include also alternative fuels (hydrogen, biomethane, etc.) and thermal energy networks, as well as different biomass fluxes (to be exploited for energy aims). Energy availability/demands of near towns and port buildings/infrastructures, as well as on-shore power supply are also included in the dynamic assessments. Hourly weather data and different prices for all the considered energy carriers are taken into account hour by hour. A multi-objective optimization approach is also implemented in the model considering energy and economic indexes to be optimized. The whole model is implemented in a computer tool written in MATLAB. For showing the capability of the developed model, a novel case study referred to the port of Naples (South-Italy) is presented. Here, several renewable energy sources are considered, including an anaerobic biodigester for producing biogas from the organic waste of docked cruise ships. A combined heat and power system (fed by biogas) is implemented in the port energy hub also for supplying absorption chillers. PV panels, and marine power generators are also included. In the conducted analysis, optimization targets are the maximization of system self-consumption and self-sufficiency as well as the minimum simple payback period. The proposed system can effectively contribute to the decarbonization of the port energy demand and reduce harmful pollutant emissions. Results showed that very high rate of renewable energy produced on-site can be exploited (up to 84%) by the considered port facilities, ensuring increasing independency from utility power grid (self-sufficiency index up to 40%). By the obtained results and through the developed simulation/optimization tool, novel design and operating criteria can be achieved for future port energy hubs featured by renewables and bi-directional energy exchange between ships and port

Design and environmental sustainability assessment of energy-independent communities: The case study of a livestock farm in the North of Italy

Abstract This paper investigates the energy and economic performance of several energy schemes that could potentially be applied to agricultural and zootechnical communities contributing to the international objectives of sustainable development. The proposed energy schemes involve integrated energy efficiency technologies and novel system layouts aiming at reaching the zero-energy goal at a community level, by considering collective energy actions with provision of benefits for members and stakeholders. The proposed scenarios include different innovative technologies, such as anaerobic digestion, cogeneration, biogas upgrading, solar, district heating and cooling. These layouts are modelled in TRNSYS simulation environment to perform dynamic simulations and parametric analyses of the pivotal system parameters. Such analyses are conducted to find out the best scenario and the size of its system components which optimize different energy and economic objective functions. To assess the feasibility of all proposed scenarios and energy schemes, as well as to investigate the potential of the developed models, proposed scenarios are studied for an existing community. This existing agricultural community named "La Bellotta", is served through different technologies, including a gas fuelled co-generator and an anaerobic biodigester. Simulation results show that the investigated scenarios allow for achieving very high self consumption ratios of energy produced on-site (from 57 to 100%), high economic performance (measured by the profitability index up to 1.35 for the best investigated scenario) and environmental benefits. The case study provides examples of energy schemes in which citizens and communities have a major benefit to invest in projects including renewables technologies, energy efficiency, and positive energy services

Solar electricity & hot water for dispersed off-grid households in Botswana:Demand-based sizing & Prototype testing initial results

Jones Huguette. O. F. Robinson, Penal Practice and Penal Policy in Ancient Rome, 2007. In: L'antiquité classique, Tome 78, 2009. p. 608

Sustainability and energy self-sufficiency assessment for small islands by adopting dynamic simulation approach

Small islands are usually characterized by high energy demand and no electricity network access with a consequent high fossil fuel energy consumption. This issue could be overcome by increasing the adoption of renewable energy systems and by enhancing the systems’ energy efficiencies. In this framework, the adoption of dynamic simulation and optimization analyses is crucial. For such a reason, in this paper, a novel approach based on dynamic simulation is presented and a suitable case study is conducted. Such an approach is developed with the twofold aim of increasing renewable energy penetration and improving the sustainability of small islands. The convenience in the dynamic simulation adoption is proven by investigating a suitable case study referring to the existing island community of El Hierro. The case study analysis focuses on the feasibility of converting its energy systems into an autonomous one by mixing different renewable-based technologies to traditional ones. The considered polygeneration system includes: i) wind turbines; ii) hydroelectric plants; iii) diesel engines; iv) solar thermal collectors; properly mixed to satisfy the electricity and hot water needs. Furthermore, to identify optimal configurations and maximize the share of renewable energy, a suitable parametric analysis is presented. Also, a hypothetical future scenario characterized by an island population increase is also investigated. Numerical results demonstrate the feasibility of the investigated polygeneration system, as well as the potentiality of the proposed methodology. Specifically, the dynamic simulation approach allows one to determine design criteria and to properly obtain a remarkable increase in terms of renewable energy exploitation and energy independence. In particular, the considered system configuration provides up to 85% of the annual electricity demand and about 82% of the annual thermal energy needs by renewable sources with substantial economic savings