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In this study, the performance of a novel trigeneration system with a gas turbine prime mover, an ammonia–water refrigeration system, and a hot water generation system is investigated from thermodynamic and economic standpoints. The effects of various operating conditions on energy efficiency and the levelized cost of energy are investigated. The proposed system has a production capacity of 45.4 kW power, 14.07 kW cooling rate, and 16.32 kW heat rate. The efficiency of the gas turbine cycle is 49.7%, and it becomes 83.0% after the implementation of the trigeneration system. Through combined heating, cooling, and power generation, primary energy input and the CO2 emissions will be 49% lower compared to separate production. According to the exergy analysis, the combustion chamber is the main component where the greatest exergy destruction occurs. Sensitivity analysis revealed that an increase in the ambient temperature results in a decrease in the energy utilization factor and the net power output. The LCOE of the system is around 0.02 $/kWh, whereas the unit price of the local electricity from the grid is 0.09 $/kWh. The payback period of the absorption sub-cycle is between 4 months and 4 years, depending on the annual operation time of the chiller.

Utilizing electricity from renewable resources is very attractive to decrease the dependence on fossil fuels. As a result, hybrid power systems are gaining more attention. This paper focuses on the optimal design and dynamic simulation of renewable-based, hybrid standalone power systems. The designed system is able to meet the energy need of a building with 5 kW peak electricity demand. Both the technical and economic feasibility of the system was investigated under various climatic conditions of Turkey. Diesel fuel consumption, energy cost and annual CO2 emissions were estimated and compared with the diesel generator-only system. A parametric analysis was also conducted to understand the impact of the capacity of the PV array, wind turbine and the battery on the CO2 emissions and the levelized cost of energy. The system in each location was optimized based on the minimum energy cost and CO2 emissions. (C) 2020 Elsevier Ltd. All rights reserved.

This work presents a thermodynamic evaluation of an operating geothermal ORC power plant. The model is realized by using measured data of AFJET geothermal power plant which has 3MWe net power output capacity. Thermodynamic assessment of the system is conducted to see the energy and exergy efficiencies of each component, and the whole plant. Additionally, a parametric study is conducted to understand the effects of various operating conditions on the system performance. Different from previous studies, daily and annual net power output profile of the plant was investigated with considering ambient temperature fluctuations. Results revealed that net power output can drop as significant as 36% from winter to summer months. Also, between nighttime to daytime, the net power expectation may decrease by 5%. The exergy destruction rate of re-injection process constitutes the most significant part (38.1%) of the total exergy destruction of the plant. The conversion and exergy efficiencies of the system are calculated as 11.24% and 39.03%, respectively. Also, to enhance the performance of the plant, an internal heat recovery system is recommended. The analyses show that the implementation of an internal heat recovery system improves the energy and exergy efficiencies of the plant by 15%.

In this study, a PV/Wind hybrid power generation system was studied with using meteorological data of Bursa province. Two specific years (2011, 2014) were chosen for the dynamic simulations. The designed hybrid system consists of PV panels and a wind turbine. The outcome of the study shows that with the proposed 1 MW PV + 2 MW wind turbine system, it is possible to generate enough electricity to compensate the annual electricity requirement of 450 households which can be considered as a small district area. Levelized cost of energy is found a value between $ 0.413-0.568/kWh. PBP of the system is found a value around 20 years. It was concluded that it is essential to offer adequate incentives for renewable-based power applications to make them economically beneficial.

In this study, a solar-powered absorption cooling system was modelled using the TRNSYS software. The performance of the system was investigated using dynamic modelling under the weather conditions of Mugla, Trabzon, Izmir, Konya, Canakkale and Istanbul. The external catalog data file of the absorption chiller model was created to get more realistic results. A parametric study was carried out to evaluate the selected parameters’ influence on system efficiency. Various parameters such as solar collector type, area, storage tank volume, collector slope, boiler setpoint temperature, room thermostat set point temperature were investigated to see their impact on the performance of the solar-absorption system, in every city. Instead of using a constant boiler setpoint temperature, a novel control strategy is proposed. Besides, the payback period and the levelized cost of cooling of the optimized systems were studied. Results showed that, in terms of financial analysis, Izmir is the most suitable city for solar-based absorption cooling system applications with a payback period of 10.7 years. Trabzon is found to be the least suitable city due to the longest payback period, and the highest levelized cost of cooling among all locations.

Recent studies show that demand for green buildings with minimal environmental impact is increasing. Among the buildings in anywhere, existing buildings consume more energy than new ones. Because of that, building energy efficiency retrofit plays a very important role for achieving sustainable building targets. In addition to creating possibilities to reduce energy consumption, retrofitting also improves occupants’ health and comfort. Tourism sector is one of the largest energy consuming sectors in the world. However conducted energy retrofit studies mainly focused on domestic buildings so far. The focus of this paper is to make a literature review of energy efficiency retrofits and present an approach to find the most appropriate, energy efficient and cost effective way renovate a hotel building. In this paper, a hotel building is energy efficiently retrofitted according to the TSE Green Building Certificate standards. Results from the analysis ensure that energy efficiency retrofit, helped to reduce energy consumption of the building and decreased in operational costs and CO2 emissions.

Existing buildings consume more energy than the new ones and building energy efficiency retrofit has a major effect in order to achieve sustainable building targets. Retrofitting not only creates possibilities to reduce energy consumption and carbon dioxide emissions of all buildings but also improves occupants' health and thermal comfort. Making a decision for a retrofit action is very important in order to select the most appropriate, energy-efficient and cost-effective scenario for the building. The industrial sector is one of the largest energy consumers with 25.6% of the overall energy consumption in Europe in 2012. However, conducted energy retrofit studies have mainly focused on domestic buildings so far. The focus of this chapter is a literature review of energy-efficiency retrofits and presentation of an approach to find the most convenient, energy-efficient and investor-friendly retrofit scenario for an industrial building. Eventually, the idea is to be able to convince building owners and investors to renovate with energy-saving solutions. In this chapter, energy consumption of a cement factory during its operation, before and after the energy retrofit application, is examined. Results from the analysis ensure that energy-efficiency refurbishment helped to reduce energy consumption of the building and eventually decreased operational costs and carbon dioxide emissions in a very short payback period. Reduction in energy consumption in the building led to an energy cost savings of $169,725 per year. Carbon dioxide emissions decreased by 87%.

A healthy and comfortable indoor environment is the most basic requirement of human beings. The importance of indoor air quality has been increasing day to day. Although ventilation systems have an essential role in improving indoor air quality, it is inevitable to clean the particulates, microorganisms and pollutant gases in the outside fresh air before being transferred to the indoor environment. Electrostatic precipitators are commonly used for collecting particles mostly in industrial plants. This paper presents a review of electrostatic filtration technology. In this study, theoretical and technical developments of electrostatic precipitators, design parameters that effect filtering performance, advantages, challenges, and limitations are discussed.