Smart Energy-Aware Manufacturing Plant Scheduling under Uncertainty: A Risk-Based Multi-Objective Robust Optimization Approach

Energy management of renewable energy-based combined heat and power systems: A review

A review of power system planning and operational models for flexibility assessment in high solar energy penetration scenarios

Biofuel plant size is one of the key variables in biofuel supply chain analysis as it plays a pivotal role in controlling the efficacy of both feedstock supply and feedstock-to-biofuel conversion. The unit production cost and greenhouse gas (GHG) balance of biofuels vary with plant size. We develop an analytical framework for integrating biofuel production costs and GHG balance derived from life-cycle analysis into supply chain optimization, followed by its application to ethanol production using forest biomass in the southern United States. We derive formulas for determining the optimal biofuel plant size and the corresponding feedstock supply radius based on the minimization of biofuel production costs less GHG benefits. Our results indicate that though biofuel plant size and feedstock supply radius should be augmented by considering GHG benefits, the GHG price will have a more significant impact on net biofuel production costs than on conversion plant size or feedstock supply radius. With a rise in the GHG price the net biofuel production cost tends to increase while the directions of change in plant size and feedstock supply radius are uncertain, depending upon the costs and GHG emissions of biomass transport and feedstock-to-fuel conversion. Combining GHG offset values with biofuel production costs enables us to more holistically examine the biofuel supply chain.

Benefits of transmission switching and energy storage in power systems with high renewable energy penetration

The process planning decisions on detailed steps of machining a part including selection of operations, machines, tools and operation sequences are crucial, directly impacting the carbon emissions associated with machining. Operation sequencing generates the optimal order of operations by reducing production time and cost. A need is felt to explore operation sequence optimization by balancing economic and environmental considerations that very few studies have so far addressed. Our study proposes an approach for multiobjective operation sequence optimization by simultaneously minimizing carbon emission and total production cost in machining. Firstly, machining operations are selected and carbon emissions are quantified for individual operations. Secondly, the proposed multiobjective optimization model for operation sequencing is applied. Due to NP-hard nature of this problem due to the exponential growth of potential solution sequences as the number of operations increases, making it computationally challenging to find an optimal sequence, it is often challenging and very time-consuming to solve using exact mathematical models. However, metaheuristic approaches can potentially offer near-optimal solutions in a more reasonable time frame. We implemented Non-dominant Sorting Genetic Algorithm-II(NSGA-II), Multiobjective Particle Swarm Optimization (MOPSO) and Multiobjective Ant colony Optimization (MOACO). Finally, a case study is used to validate and compare their effectiveness in providing low-carbon emissions with cost-effective sequences. NSGA-II is found to have higher computational time but a superior Pareto tradeoff between reducing carbon emissions and production costs.

Current and future economic performance of first and second generation biofuels in developing countries

Life cycle assessment of ethanol derived from sawdust

To calculate the cost of goods manufactured, the analytical tool used is the full costing method. This research is aimed to find out how to calculate the cost of water production in the Tirta Musi Palembang PDAM in the 2016-2017 period, to find out how to calculate the selling price at the Tirta Musi Palembang PDAM in the 2016-2017 Period, and to find out how to calculate the cost of production as the basis for determining prices sell at PDAM Tirta Musi Palembang. This research method uses secondary data, with descriptive research, the research method used is case studies, and the research uses qualitative and quantitative descriptive methods. The results showed the cost of production in 2016-2017 PDAM Tirta Musi Palembang, seen increasing every year. This happened because of an increase in total business costs. The cost of production in 2016 is Rp. 661,886,491 and the cost of production in 2017 of Rp. 699,585,427. the selling price in 2016-2017 shows that the selling price experienced an increase. PDAM Tirta Musi Palembang in calculating water tariffs using a basic rate. In 2016 the basic tariff of Rp. 4097.14 cubic meters, and in 2017 Rp. 4,579.28 cubic meters. It appears that the company is making a profit. Keywords: Cost Accounting, Cost of Production and Selling Prices

Tri-level expansion planning for transmission, energy storage, and renewable energy considering carbon emission limitation

Multi-objective optimization of thermoeconomic performance for an innovative combined energy system in the supply chain based on externally reformed-Molten carbonate fuel cell

In this paper, the potential carbon dioxide emissions (CDE) reduction from the use of a combined heat and power system with two power generation units (D-CHP) is examined for a restaurant building in nine different climate conditions. The performance of the D-CHP system is evaluated on the basis of CDE and operational cost savings. In addition, the results from the D-CHP optimised scheme are compared with the optimised results of a base-loaded CHP (BL-CHP) system and a CHP system operated following the electric load (CHP-FEL). Results show that the D-CHP system produces greater savings over BL-CHP and CHP-FEL for most of the locations examined, whether optimised based on CDE or based on cost. Moreover, the effect of the emissions and cost spark spreads for each location on the D-CHP system performance is analysed. Results indicate that higher spark spreads are shown to yield greater savings for all CHP configurations.

Guest Editorial: Situational awareness of integrated energy systems

Microturbines are ideally suited for distributed generation applications due to their flexibility in connection methods. They can be stacked in parallel for larger loads and provide stable and reliable power generation. One of the main applications of microturbines is operating as the prime mover in a combined heat and power (CHP) system. CHP systems are considered to be one of the best ways to produce heat and power with efficient fossil fuel consumption. Further, these systems emit less pollution compared to separate productions of the same amount of electricity and heat. In order to optimally benefit from combined heat and power systems, the proper sizing of prime movers is of paramount importance. This paper presents a technical-economic method for selecting the optimum number and nominal power as well as planning the operational strategy of microturbines as the prime movers of small scale combined heat and power systems (capacities up to 500 kW) in three modes of operation: one-way connection (OWC) mode, two-way connection (TWC) mode, and heat demand following (HDF) mode. In the proposed sizing procedure both performance characteristics of the prime mover and economic parameters (i.e. capital and maintenance costs) are taken into account. As the criterion for decision making Net Present Worth (NPW) is used. In our analysis we have also considered the impact of carbon tax on the economics of generation. The proposed approach may also be used for other types of prime movers as well as other sizes of CHP system.

With increasing heating demand and installed capacity of wind farms, combined heat and power (CHP) systems with inflexible generation are confronted with a major challenge for the efficient utilization of the wind power. Distributed heat sources (DHSs), such as electric boilers and heat storage, offer an effective way to enhance wind power penetration in a combined heat and power system by reducing the electric-heat coupling of the CHP unit. In this paper, an assessment approach for the wind power penetration of a CHP system with DHSs is proposed, and a two-stage multiple types of DHSs optimal configuration strategy to realize the minimum construction cost at a certain permissible wind power curtailment rate is established. After that, the proposed strategy is applied to a case study of a practical CHP system with in-depth analysis and detailed discussion, which reveals the effectiveness of the proposed strategy and indicates its promising applications for DHS configuration.

Analysis and optimization of the use of CHP–ORC systems for small commercial buildings