scholarly journals Two-Stage Multi-Objective Meta-Heuristics for Environmental and Cost-Optimal Energy Refurbishment at District Level

2019 ◽  
Vol 11 (5) ◽  
pp. 1495 ◽  
Author(s):  
Diana Manjarres ◽  
Lara Mabe ◽  
Xabat Oregi ◽  
Itziar Landa-Torres
Keyword(s):  
Performance Optimization ◽  
Energy Demand ◽  
Harmony Search ◽  
Economic Assessment ◽  
District Level ◽  
The European Union ◽  
Two Stage ◽  
Nsga Ii ◽  
Multi Objective ◽  
Payback Time

Energy efficiency and environmental performance optimization at the district level are following an upward trend mostly triggered by minimizing the Global Warming Potential (GWP) to 20% by 2020 and 40% by 2030 settled by the European Union (EU) compared with 1990 levels. This paper advances over the state of the art by proposing two novel multi-objective algorithms, named Non-dominated Sorting Genetic Algorithm (NSGA-II) and Multi-Objective Harmony Search (MOHS), aimed at achieving cost-effective energy refurbishment scenarios and allowing at district level the decision-making procedure. This challenge is not trivial since the optimisation process must provide feasible solutions for a simultaneous environmental and economic assessment at district scale taking into consideration highly demanding real-based constraints regarding district and buildings’ specific requirements. Consequently, in this paper, a two-stage optimization methodology is proposed in order to reduce the energy demand and fossil fuel consumption with an affordable investment cost at building level and minimize the total payback time while minimizing the GWP at district level. Aimed at demonstrating the effectiveness of the proposed two-stage multi-objective approaches, this work presents simulation results at two real district case studies in Donostia-San Sebastian (Spain) for which up to a 30% of reduction of GWP at district level is obtained for a Payback Time (PT) of 2–3 years.

scholarly journals Multi-Objective Optimization of Two-Stage Centrifugal Pump using NSGA-II Algorithm

2018 ◽  
Vol 11 (4) ◽  
pp. 929-943 ◽  
Author(s):  
M. Benturki ◽  
R. Dizene ◽  
A. Ghenaiet ◽  
◽  
◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Multi Objective Optimization ◽  
Two Stage ◽  
Nsga Ii ◽  
Multi Objective

scholarly journals Economic Assessment of Biodiesel Production for Hungarian Farmers

2002 ◽  
pp. 72-76
Author(s):  
Attila Bai
Keyword(s):  
Energy Demand ◽  
Raw Materials ◽  
Economic Assessment ◽  
Electrical Energy ◽  
Good Method ◽  
Biodiesel Production ◽  
Plant Production ◽  
Electricity Production ◽  
The European Union ◽  
Oil Plant

Utilisation of oil of plant origin as a fuel is gaining acceptance in the European Union and elsewhere. Besides environmental protection, energy saving, and decreasing over-production of food. Additionally, the subsidisation of farmers and the development of rural sub-regions also contribute to its spread. This study specifically focuses on the direct effects biodiesel's raw materials and final products are now having on farmers, while reviewing and quantifying these effects. I have purposely restricted my analysis to these two elements of the biodiesel chain.The biodiesel chain seems to be a great method for improving the economic and social position of participant farmers in many ways. Presently, the profitability of raw materials’ production looks to be the crucal point in the chain, and could be strengthened best with intensive, habitat-specific agrotechnic. It would only be possible to reach a favourable profit margin for farmers if yields reach unrealistic averages or if there is a significant hike of the 2000 producer’s price in the oil plant branch.The main attraction of sunflower- and oilseed rape production lies in the stabilization of market conditions, which is not only gong to appear in oil plant branch but – thanks to the reduction of outputs – also in the cereal branches. Better economic safety for farmers may play a role at least on the same level as in plant production, which involves more risks than profit maximalization.The reduction of the prime cost of biodiesel could be possible through the direct combustion of the whole oilseed plant or its residues or electricity production using them. Whereas energy demand for biodiesel production is low (appr. 5%) but it needs subsidization and the prices of natural gas and electrical energy presently look favourable in Hungary. Additionally harvesting and baling of the residues is technically problematic, which is why their use may seem to be reasonable just over the middle or long term. Another possible factor of cost reduction could be the centralization of some partial operations, which needs serious financial resources to reduce amortization cost per product, provided there be several biodiesel projects near each other during establishment. Creation and operation of a logistical system could also be a good method for improving the viability of the biodiesel chain, in order to optimize transport schedule and distances. However there are also some organizational difficulties in this case.

Multi-Objective Optimization of Two Stage Spur Gearbox Using NSGA-II

2017 ◽  
Author(s):  
Maruti Patil ◽  
Penchaliah Ramkumar ◽  
Shankar Krishnapillai
Keyword(s):  
Multi Objective Optimization ◽  
Two Stage ◽  
Nsga Ii ◽  
Multi Objective ◽  
Spur Gearbox

A two-stage surrogate model based on ANN and AdaBoost for multi-objective parameter optimization of the Variable Infiltration Capacity model

2020 ◽  
Author(s):  
Yue-Ping Xu ◽  
Haiting Gu ◽  
Ma Di
Keyword(s):  
River Basin ◽  
Surrogate Model ◽  
Stage Model ◽  
Variable Infiltration Capacity ◽  
Infiltration Capacity ◽  
Two Stage ◽  
Nsga Ii ◽  
Xiangjiang River ◽  
Vic Model ◽  
Multi Objective

<p>Distributed hydrologic models have been widely used for its functional diversity and rationality in theory. However, calibration of distributed models is computationally expensive with a large number of model runs, even if an efficient multi-objective algorithm is employed. To alleviate the burden of computation, we develop a two-stage surrogate model by coupling backpropagation neural network with AdaBoost to calibrate the parameters of the Variable Infiltration Capacity (VIC) model. The first stage model selects the parameter sets with simulated outputs in the crucial range and the second stage model estimates the values of outputs accurately with the parameter sets picked out by the first stage model. The developed surrogate model is tested in three different river basins in China, namely the Lanjiang River basin (LJR), the Xiangjiang River basin (XJR) and the Upper Brahmaputra River basin (UBR). With sufficient samples generated by ε-NSGA II, the surrogate model performs very well with a low error rate of classification (ER) and root mean square error (RMSE). The streamflow simulated with the surrogate model is nearly the same as that from the original VIC model, indicating that the surrogate model does gain a remarkable speedup compared with the original VIC model.</p>

scholarly journals Techno-Economic Assessment of BIPV Systems in Three Cities of Iran

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1474 ◽  
Author(s):  
Farivar Fazelpour ◽  
Niloufar Ziasistani ◽  
Parsa Nazari ◽  
Pouria Nazari ◽  
Nastaran Ziasistani
Keyword(s):  
Energy Demand ◽  
Residential Building ◽  
Economic Assessment ◽  
Climatic Conditions ◽  
Payback Time ◽  
Building Integrated Photovoltaic ◽  
Pv Modules ◽  
Te Modules ◽  
Minimum Ratio ◽  
Efficiency Rate

In all over the world, huge parts of energy are consumed by buildings. Building integrated photovoltaic (BIPV) systems have attracted much attention with the purpose of providing energy demand of buildings. This paper introduces the examinations of BIPV system on a residential building under different climatic conditions of Iran by considering different PV modules. The building orientation has been analysed in order to find higher efficiency rate of PV modules through DesignBuilder. It was found the maximum rate of energy generation for all three cities occurs in south side of the building. Also for Tehran and Tabriz the minimum ratio of energy consumption is at the angle of 180° while for Bandar Abas it is in north side. Moreover, applying Cd-Te modules contribute to reducing payback time.

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