Use Of Local Renewable Resources Research Articles

Optimal scheduler for energy consumption reduction in multi-vector energy management systems: A case study at the Port of Borg

The objective of microgrid operation is to supply the energy demanded by the loads at minimum cost. To achieve this goal, new tools are being proposed in the literature, such as the use of optimal schedulers in the field of multi-vector management systems. An optimal scheduler provides the hourly schedule of the flexible loads that exist in a microgrid to maximize the use of local renewable resources. This work aims to investigate the application in the context of five optimization algorithms in terms of energy and computation costs and to demonstrate how optimal schedulers can contribute significantly to reducing energy operating costs in new and real microgrid scenarios. The analysis of the algorithms is carried out through an experimental process on the existing installations at Port of Borg (Norway), which contains photovoltaic production and different types of flexible assets, such as cranes, electric vehicle charging stations, and electrical storage. Real data gathered at the port's premises is used to assess the energy cost reduction when the optimal scheduler is part of the energy management system, and the computations are performed in real time to apply the proposed schedule to the pilot. The results show how the use of optimal schedulers can reduce operation costs up to 17.2%, augmenting local energy production utilization, and that using two OS algorithms in cascade can also reduce the computation time.

Exergo-economic comparisons of solar cooling systems coupled to series/parallel absorption chiller types considering the lowest heat transfer area

District solar assists cooling systems can make full use of local renewable resources, and reduce the fossil fuel consumption and greenhouse gas emissions. After modelling and validation of solar cooling systems, the exergo-economic method is carried out to explore the economic performance by considering the lowest heat transfer areas of two chiller types based on the yearly ambient parameters in Beijing, China. The sensitivity analysis of key parameters is searched to depict the impacts of initialized parameters. The results show that the solar cooling system coupled to parallel chiller needs the lowest solar installation area, 602 m2, and corresponds to the highest coefficient of performance, 1.15, and exergy efficiency, 21.91%. However, due to the higher heat transfer areas of parallel chiller, the specific exergo-economic cost of chilled water, 3.93 $/kWh, is higher than the one of series cooling system, 3.78 $/kWh. The sensitivity analysis demonstrates that except for temperatures of cooling water, returned chilled water, and temperature difference of driving steam from solar unit, other parameters have positive impact on exergo-economic performance.

Development of Renewable Energy Sources in the European Union in the Context of Sustainable Development Policy

Renewable energy sources play a key role in decarbonizing the economy of the European Union (EU) and the world. The aim of this research is to present the development of the renewable energy sources (RES) sector in the European Union (EU), with particular emphasis on sustainable development. The EU guidelines, requirements, and directives were analyzed in order to meet the provisions of the energy policy to ensure energy and climate security. The potential of the RES was studied in the EU countries, and the possibility of its use in cogeneration with the use of local renewable resources. The results are presented in tabular, graphic, and descriptive forms. The results are presented based on the extensive literature on the subject and data from Eurostat. The data covered 2004–2019. We used different methods to evaluate the changes in the RES in the EU countries. First, we compiled descriptive statistics; second, we used the Augmented Dickey–Fuller test (ADF test); and, finally, we used the Generalized Autoregressive Conditional Heteroscedasticity model (GARCH model). Our analysis found that the EU increased the share of RES. The biggest share of energy from renewable energy sources was found in 2019 in Iceland (78%), Norway (74%), and Sweden (56%). The biggest increase in the share of RES in 2004–19 was found in Malta (8322%), Great Britain (1126%), and Luxemburg (784%). The results demonstrate the development of RES in the EU countries. However, not all countries achieved the planned goal in 2019.

Economic evaluation of Nearly Zero Energy Cities

As a contribution to the study of the urban energy transition, this paper proposes a novel model of energy-economic evaluation of the cities self-sufficiency and presents its application in the form of a case study. The objective of this study was to analyse the scope of the investment in the photovoltaic self-consumption of buildings in order to promote the creation of Prosumers communities within the cities. The operation of this model is based on the scalability of the Nearly Zero Energy concept from buildings to cities and seeks to evaluate Nearly Zero Energy Cities (nZEC): cities made up of Nearly Zero Energy Buildings (nZEB) and other installations of distributed generation to cover their energy demand by use of local renewable resources to the detriment of external resources. By using public data, we apply this model with the aim of economically evaluating the investment of six packages of energy rehabilitation and photovoltaic self-consumption in 17% of the residential buildings (37,800) in the city of Barcelona. To do this, we simulated 37 years of electricity distribution among Consumers, Producers and a hypothetical peer-to-peer community of Prosumers during the period 2014–2050 in hourly time intervals. The results indicated that the photovoltaic self-consumption and the local markets of Prosumers help to reduce primary energy consumption, the energy costs, and the CO2 emissions.

Techno-economic analysis of a local district heating plant under fuel flexibility and performance

Brovst is a small district in Denmark. This paper analyses the use of local renewable resources in the district heating systems of Brovst. The present use of fossil fuels in the Brovst district heating plant (DHP) represents an increasing environmental and climate-related load. Therefore, an investigation has been made to reduce the use of fossil fuels for district heating system and make use of the local renewable resources (biogas, solar, and heat pump) for district heating purposes. In this article, the techno-economic assessment is achieved through the development of a suite of models that are combined to give cost and performance data for this district heating system. Local fuels have been analyzed for different perspectives to find the way to optimize the whole integrated system in accordance with fuel availability and cost. This paper represents the energy system analysis mode, energyPRO, which has been used to analyze the integration of a large-scale energy system into the domestic district heating system. A model of the current work on the basis of information from the Brovst plant (using fossil fuel) is established and named as a reference option. Then, four other options are calculated using the same procedure according to the use of various local renewable fuels known as “biogas option,” “solar option,” “heat pump option,” and “imported heat option.” A comparison has been made between the reference option and other options. The greatest reduction in heat cost is obtained from the biogas option by replacing a new engine, where 66 % of the current fuel is substituted with biogas.

Wood-based bioenergy value chain in mountain urban districts: An integrated environmental accounting framework

Using wood biomass for bioenergy production in mountain urban settlements can represent a win–win strategy when it combines a continuous energy provision to households with a sustainable management of local forests, also boosting rural development and stakeholders’ cooperation. In this study, we implemented a multi-method environmental accounting framework aimed at investigating environmental costs and impacts of a bioenergy value chain located in Sarentino Valley (North Italy). This assessment framework encompasses material, energy, and emergy demands as well as main emissions generated at each step of the chain: (1) forestry, (2) logistics, and (3) conversion.The resulting global to local ratios of abiotic material calculated for forestry, logistics, and conversion subsystems show that the global (direct and indirect) consumption of abiotic matter was respectively 3.6, 3.2, and 7.6 times higher than the direct material demand. The Energy Return on Energy Investment (EROI) of wood biomass and wood chips production (37.1 and 22.4) shows a high energy performance of these processes, while the EROI of heat generation (11.35) reflects a higher support of human-driven inputs. The emergy renewable fraction, ranging from 77% to 37% across the value chain, shows a high use of local renewable resources in the bioenergy value chain. The total CO2 emissions of the bioenergy value chain (4088tCO2yr−1) represent only 7.1% of the CO2 sequestration potential of the Sarentino Valley forest ecosystem, highlighting the capability of the local forests to offset the CO2 emissions released by the value chain. The scenario analysis indicates that using both local sawmill residues and local forest wood chips to power the heating plant could further lower the environmental burden of the bioenergy chain, maximizing local and renewable resources use while reducing waste disposal.The multi-method environmental accounting framework provided a large set of performance and sustainability indicators useful for both local managers and policy makers in charge of ensuring a sustainable management of local forests and energy security of urban settlements.

Emergy synthesis of a combined food and energy production system compared to a conventional wheat (Triticum aestivum) production system

It is a major challenge to produce food and energy sustainably for the ever increasing world population as today's conventional food production and energy needs are met by the fossil based resources, causing enormous environmental load. A novel, combined food and energy (CFE) agro-ecosystem, was designed for sustainable production of food, fodder and energy without chemical inputs (fertiliser, herbicide and fungicide). The objective was an emergy synthesis of the CFE system compared to a conventional wheat (Triticum aestivum) production system to assess resource use efficiency. The emergy indices, used to assess the environmental performance and sustainability, exhibited contrasting differences between the two production systems in terms of outputs (Y), total emergy use, solar transformity, relative use of local renewable resources, environmental loading ratio (ELR), emergy yield ratio (EYR) and emergy sustainability index (ESI). The Y in the CFE consisted of grain, straw, fodder and woodchip production of 4020, 3580, 6100 and 10,000kg/ha/yr respectively whereas Y in the conventional wheat consisted of 7250 and 3770kg grain and straw/ha/yr respectively. The Y in the CFE was 81% (2.80E+11J/ha/yr) higher with 13.5 times (6.40E+03seJ/J) lower solar transformity compared to the Y (1.54E+11J/ha/yr) and solar transformity (8.63E+04seJ/J) in the conventional wheat, exhibiting highly resource intensive production in conventional wheat. The local renewables constituted 19.2% and 2.6% of the total emergy input in the CFE and the conventional wheat respectively with a corresponding lower ELR (4.21) and 22.5% higher EYR (1.26) in CFE compared to conventional wheat. CFE was more reliant on local renewable emergy flows and compatible with the local environment with higher ESI (0.30) compared to conventional wheat (0.03), where 64.5% of the total emergy input constituted chemical inputs. The study demonstrated that the innovative agro-ecosystem, exemplified by CFE, is considerably less resource demanding and more amenable to sustainable production, whether defined in terms of outputs, solar transformity, relative use of local renewable resources, EYR, ELR or ESI.

Very low temperature radiant heating/cooling indoor end system for efficient use of renewable energies

Solar or solar-assisted space heating systems are becoming more and more popular. The solar energy utilization efficiency is high when the collector is coupled with indoor radiant heating suppliers, since in principle, lower supply temperature means lower demand temperature and then the system heat loss is less. A new type radiant end system is put forward for even lower supply temperature compared to the conventional radiant floor heating systems. A three dimensional model was established to investigate its energy supply capacities. Simulation results show that 50 W per meter length tube can be achieved with the medium temperature of 30 °C for heating and 15 °C for cooling. The predicted results agree well with the actual data from a demonstration building. Furthermore, it is demonstrated that a supply temperature of 22 °C in winter and of 17 °C in summer already met the indoor requirements. The new end system has good prospects for effective use of local renewable resources.

Is GIS appropriate technologyquest;

Abstract Appropriate technology (AT) has become an integral part of the programmes for decentralized regional development in the Third World. ‘Appropriate’ techniques are usually low in capital costs; they can be maintained without a high level of expertise; and they do not involve patents, expensive copyrights and royalties. By these criteria a commercial geographical information system (GIS) is not an appropriate technology to be used in decentralized development However, the use of local renewable resources involves the adoption of end-use analysis for matching end-uses to specific sources so as to minimize the consumption of material and energy (i.e., minimize entropy). This matching requires much information which leads to what may be called the 'information-entropy trade-off; minimization of entropy requires an inverse increase in information. In this respect computers and GIS have an important contribution to make to decentralized regional planning. Drawing on a case study in Sri Lanka, this paper ...