Parametric Study on Economic Feasibility of Microturbine Cogeneration Systems by an Optimization Approach

2003 ◽  
Author(s):  
Satoshi Gamou ◽  
Koichi Ito ◽  
Ryohei Yokoyama
Keyword(s):  
Energy Demand ◽  
Unit Cost ◽  
Maximum Energy ◽  
Optimal Number ◽  
Economic Feasibility ◽  
Optimization Approach ◽  
Energy Demands ◽  
Equation Problem ◽  
Non Linear Equation ◽  
Cogeneration System

Economic feasibility of microturbine cogeneration systems is investigated by analyzing relationships between the optimal number of microturbine units and the maximum energy demands under various conditions. For this purpose, a method to obtain the maximum energy demand at which the optimal number changes is proposed by combining a non-linear equation problem and an optimal unit sizing problem hierarchically. Based on the proposed method, a map expressing the aforementioned relationships can be illustrated. Through numerical studies carried out on systems installed in hotels by changing the electrical generating efficiency and the capital unit cost of the microturbine cogeneration unit as parameters, the influence of the parameters on the economic feasibility of the microturbine cogeneration system is clarified.

Parametric Study on Economic Feasibility of Microturbine Cogeneration Systems by an Optimization Approach

2005 ◽  
Vol 127 (2) ◽  
pp. 389-396 ◽  
Author(s):  
Satoshi Gamou ◽  
Ryohei Yokoyama ◽  
Koichi Ito
Keyword(s):  
Energy Demand ◽  
Unit Cost ◽  
Maximum Energy ◽  
Optimal Number ◽  
Economic Feasibility ◽  
Optimization Approach ◽  
Energy Demands ◽  
Equation Problem ◽  
Numerical Studies ◽  
Cogeneration System

Economic feasibility of microturbine cogeneration systems is investigated by analyzing relationships between the optimal number of microturbine units and the maximum energy demands under various conditions. For this purpose, a method to obtain the maximum energy demand at which the optimal number changes is proposed by combining a nonlinear equation problem and an optimal unit sizing problem hierarchically. Based on the proposed method, a map expressing the aforementioned relationships can be illustrated. Through numerical studies carried out on systems installed in hotels by changing the electrical generating efficiency and the capital unit cost of the microturbine cogeneration unit as parameters, the influence of the parameters on the economic feasibility of the microturbine cogeneration system is clarified.

Analysis of Optimal Unit Numbers and Sizes for Microturbine Cogeneration Systems

2004 ◽  
Author(s):  
Satoshi Gamou ◽  
Koichi Ito ◽  
Ryohei Yokoyama
Keyword(s):  
Energy Demand ◽  
Large Scale ◽  
Maximum Energy ◽  
Mixed Integer ◽  
Small Scale ◽  
Optimization Approach ◽  
Operational Strategies ◽  
Energy Demands ◽  
Exhaust Heat ◽  
Annual Total

The relationships between unit numbers and capacities to be installed for microturbine cogeneration systems are analyzed from an economic viewpoint. In analyzing, an optimization approach is adopted. Namely, unit numbers and capacities are determined together with maximum contract demands of utilities such as electricity and natural gas so as to minimize the annual total cost in consideration of annual operational strategies corresponding to seasonal and hourly energy demand requirements. This optimization problem is formulated as a large-scale mixed-integer linear programming one. The suboptimal solution of this problem is obtained efficiently by solving several small-scale subproblems. Through numerical studies carried out on systems installed in hotels by changing the electrical generating/exhaust heat recovery efficiencies, the initial capital cost of the microturbine cogeneration unit and maximum energy demands as parameters, the influence of the parameters on the optimal numbers and capacities of the microturbine cogeneration units is clarified.

Economic Feasibility Study of Micro Gas Turbine Cogeneration Systems by an Optimization Approach

2001 ◽  
Author(s):  
Satoshi Gamou ◽  
Katsuhiro Joko ◽  
Ryohei Yokoyama ◽  
Koichi Ito
Keyword(s):  
Gas Turbine ◽  
Energy Demand ◽  
Optimization Method ◽  
Economic Feasibility ◽  
Economic Effects ◽  
Office Buildings ◽  
Optimization Approach ◽  
Operational Strategies ◽  
Micro Gas Turbine ◽  
Economic Characteristic

Economic characteristic of micro gas turbine cogeneration systems for commercial and public purposes is evaluated rationally by an optimization method. The number of multiple kinds of micro gas turbine cogeneration units, capacities of other pieces of equipment and utility maximum contract demands are determined so as to minimize the annual total cost in consideration of operational strategies for energy demand requirements. Numerical studies are carried out on systems installed in hotels or office buildings. Through the studies, the following are clarified: (a) the relationships between the number of the installed micro gas turbine cogeneration units and the maximum electricity demands of hotels and office buildings, and (b) the economic effects of the micro gas turbine cogeneration units.

Energy-Saving Evaluation of SOFC Cogeneration Systems With Solar Cell and Battery

2014 ◽  
Vol 11 (6) ◽  
Author(s):  
Akira Yoshida ◽  
Koichi Ito ◽  
Yoshiharu Amano
Keyword(s):  
Solar Cell ◽  
Energy Saving ◽  
Energy Supply ◽  
Energy Savings ◽  
Optimization Theory ◽  
Maximum Energy ◽  
Planning Problem ◽  
Energy Supply System ◽  
Energy Demands ◽  
Cogeneration System

The purpose of this study is to evaluate the maximum energy-saving potential of residential energy supply systems consisting of a solid oxide fuel cell (SOFC) cogeneration system (CGS) combined with a solar cell (SC) and a battery (BT), compared with a reference system (RS). This study applies an optimization theory into an operational planning problem to measure actual energy demands over the course of 1 year. Eight different types of energy supply system were compared with each other by changing the components of the SOFC-CGS, SC, BT, and RS. Meaningful numerical results are obtained, indicating the maximum potential energy savings.

scholarly journals A Sizing Method for PV–Battery–Generator Systems for Off-Grid Applications Based on the LCOE

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1988
Author(s):  
Ioannis E. Kosmadakis ◽  
Costas Elmasides
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Temporal Distribution ◽  
Electrical Energy ◽  
Optimal Number ◽  
Diesel Generator ◽  
Levelized Cost Of Electricity ◽  
Sufficient Power ◽  
Battery Energy

Electricity supply in nonelectrified areas can be covered by distributed renewable energy systems. The main disadvantage of these systems is the intermittent and often unpredictable nature of renewable energy sources. Moreover, the temporal distribution of renewable energy may not match that of energy demand. Systems that combine photovoltaic modules with electrical energy storage (EES) can eliminate the above disadvantages. However, the adoption of such solutions is often financially prohibitive. Therefore, all parameters that lead to a functionally reliable and self-sufficient power generation system should be carefully considered during the design phase of such systems. This study proposes a sizing method for off-grid electrification systems consisting of photovoltaics (PV), batteries, and a diesel generator set. The method is based on the optimal number of PV panels and battery energy capacity whilst minimizing the levelized cost of electricity (LCOE) for a period of 25 years. Validations against a synthesized load profile produced grid-independent systems backed by different accumulator technologies, with LCOEs ranging from 0.34 EUR/kWh to 0.46 EUR/kWh. The applied algorithm emphasizes a parameter of useful energy as a key output parameter for which the solar harvest is maximized in parallel with the minimization of the LCOE.

scholarly journals Experimental Data and Simulations of Performance and Thermal Comfort in a Typical Mediterranean House

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Thermal Characterization ◽  
Energy Performance ◽  
Building Stock ◽  
Energy Demands ◽  
Dwelling House ◽  
Account Standard

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.

scholarly journals Processing Methodologies of Wet Microalga Biomass Toward Oil Separation: An Overview

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 641
Author(s):  
Vânia Pôjo ◽  
Tânia Tavares ◽  
Francisco Xavier Malcata
Keyword(s):  
Food System ◽  
Lipid Extraction ◽  
High Energy ◽  
Economic Feasibility ◽  
Alternative Source ◽  
Microalgal Biomass ◽  
Energy Demands ◽  
Chemical Profiles ◽  
System Sustainability ◽  
Industrial Level

One of the main goals of Mankind is to ensure food system sustainability—including management of land, soil, water, and biodiversity. Microalgae accordingly appear as an innovative and scalable alternative source in view of the richness of their chemical profiles. In what concerns lipids in particular, microalgae can synthesize and accumulate significant amounts of fatty acids, a great fraction of which are polyunsaturated; this makes them excellent candidates within the framework of production and exploitation of lipids by various industrial and health sectors, either as bulk products or fine chemicals. Conventional lipid extraction methodologies require previous dehydration of microalgal biomass, which hampers economic feasibility due to the high energy demands thereof. Therefore, extraction of lipids directly from wet biomass would be a plus in this endeavor. Supporting processes and methodologies are still limited, and most approaches are empirical in nature—so a deeper mechanistic elucidation is a must, in order to facilitate rational optimization of the extraction processes. Besides circumventing the current high energy demands by dehydration, an ideal extraction method should be selective, sustainable, efficient, harmless, and feasible for upscale to industrial level. This review presents and discusses several pretreatments incurred in lipid extraction from wet microalga biomass, namely recent developments and integrated processes. Unfortunately, most such developments have been proven at bench-scale only—so demonstration in large facilities is still needed to confirm whether they can turn into competitive alternatives.

scholarly journals Optimising the Operation of Tidal Range Schemes

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2870 ◽  
Author(s):  
Jingjing Xue ◽  
Reza Ahmadian ◽  
Roger Falconer
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Maximum Energy ◽  
Energy Output ◽  
Tidal Range ◽  
Marine Renewable Energy ◽  
Modelling Methodology ◽  
Similar Operation ◽  
Swansea Bay ◽  
The Uk

Marine renewable energy, including tidal renewable energy, is one of the less exploited sources of energy that could contribute to energy demand, while reducing greenhouse gas emissions. Amongst several proposals to build tidal range structure (TRS), a tidal lagoon has been proposed for construction in Swansea Bay, in the South West of the UK, but this scheme was recently rejected by the UK government due to the high electricity costs. This decision makes the optimisation of such schemes more important for the future. This study proposes various novel approaches by breaking the operation into small components to optimise the operation of TRS using a widely used 0-D modelling methodology. The approach results in a minimum 10% increase in energy output, without the inclusion of pumping, in comparison to the maximum energy output using a similar operation for all tides. This increase in energy will be approximately 25% more when pumping is included. The optimised operation schemes are used to simulate the lagoon operation using a 2-D model and the differences between the results are highlighted.

scholarly journals Economic Feasibility of Energy Supply by Small Modular Nuclear Reactors on Small Islands: Case Studies of Jeju, Tasmania and Tenerife

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2587 ◽  
Author(s):  
Sanghyun Hong ◽  
Barry Brook
Keyword(s):  
Energy Demand ◽  
Nuclear Reactors ◽  
High Energy ◽  
Economic Feasibility ◽  
System Level ◽  
Small Island ◽  
Small Islands ◽  
Hydroelectric Power ◽  
Generation Cost ◽  
Electricity Grids

Small modular nuclear reactors (SMRs) offer the promise of providing carbon-free electricity and heat to small islands or isolated electricity grids. However, the economic feasibility of SMRs is highly system-dependent and has not been studied in this context. We selected three case-study islands for such an evaluation: Jeju, Tasmania and Tenerife based on their system complexity. We generated 100,000 electricity-mix cases stochastically for each island and examined the system-level generation-cost changes by incrementing the average generation cost of SMRs from USD$60 to 200 MWh−1. SMRs were found to be economically viable when average generation cost was <$100 MWh−1 for Jeju and <$140 MWh−1 for Tenerife. For Tasmania the situation was complex; hydroelectric power is an established competitor, but SMRs might be complementary in a future “battery of the nation” scenario where most of the island’s hydro capacity was exported to meet peak power demand on the mainland grid. The higher average generation cost of SMRs makes it difficult for them to compete economically with a fossil fuel/renewable mix in many contexts. However, we have demonstrated that SMRs can be an economically viable carbon-free option for a small island with a limited land area and high energy demand.

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