Annual Performance Analysis Research Articles

Transition to a 100 % renewable power supply in galapagos islands: Long-term and short-term analysis for optimal operation and sizing of grid upgrades

Owing to their remarkable biodiversity and endemic ecosystems, the Galapagos Islands are one of the most important World Heritage sites. However, due to their isolation and remote geographical location, around 83.6 % of the energy supply in Galapagos relies on the use of fossil fuels, which are polluting the air, the land and the sea, therefore requiring an adequate energy planning for the efficient transition towards a more sustainable and environmentally friendly energy sources. Although there were several previous studies of the decarbonization of Galapagos’ energy supply, there is a need for a more comprehensive approach that will combine planning (long-term) and operational (short-term) analysis to evaluate both, the future investment plans and performance of evolving energy supply system, as well as to provide an in-depth evaluation of required system upgrades in terms of locally available renewable energy resources. In order to fill this gap, this paper presents results of two different studies for the optimal decarbonization and transition to a 100 % renewable energy supply of the Galapagos Islands, giving details on the development of modelling tools required for the analysis of different scenarios and various techno-economic constraints. The first study is used for a long-term for analysing and strategic planning of the energy matrix until 2050, starting from existing power plants and following projections for the deployment of new renewable-based energy generation and dedicated energy storage sources to determine the optimal sizing and timing of required grid upgrades. The second study is a short-term annual performance analysis, which considers days of minimum, average and maximum available renewable energy resources to optimize system operation with existing and additional renewable energy generation and storage sources that will minimize, or keep at a certain target level, contributions from diesel generation. The two presented studies complement each other, allowing to evaluate transition to a 100 % renewable energy supply in Galapagos from both the investment/planning perspective and from the operational point of view. The results of two studies are very close in terms of the sizes of required new PV generation and associated energy storage in Baltra-Santa Cruz islands by 2050 (around 50 MW of PV and 145 MW of storage), with the short-term study allowing to identify curtailed PV generation (on average around 140 MWh per day) as an opportunity to connect new controllable loads, and with the long-term study allowing to evaluate interim targets for decarbonization pathways to Net Zero by 2050 through the related techno-economic optimization.

Transient analysis of an efficient solar assisted air-conditioning system for subtropical climate with various solar thermal collectors

The air conditioning demand of the world is largely fulfilled by vapor compression systems; however, these systems are also responsible for depleting ozone layer due to the nature of refrigerants. Desiccant cooling systems integrated with solar thermal energy technologies could be an attractive alternative with some performance enhancement techniques. In this study, transient seasonal performance investigation is performed for an innovative solar integrated desiccant cooling system that uses regenerative evaporative cooler known as solar assisted desiccant integrated Maisotsenko cycle cooler for better cooling performance. Furthermore, transient annual performance analysis of solar system for meeting thermal energy requirement for regenerating the desiccant wheel in summer season and handling heating load of the building in winter season is also carried out with three different solar thermal collector technologies for finding out more efficient technology. The key performance indicators in this study are useful energy gain, solar source efficiency, auxiliary energy sharing, coefficient of performance, and solar fraction. The results of the key performance parameters are reported as monthly average values. The proposed integrated system resulted to be very efficient with a maximum COP value of 1.13 in April when latent cooling loads are low and 0.78 in August when latent cooling loads are higher. The system’s maximum cooling capacity is 24 kW in April corresponding to a sensible heat factor of 0.720. Furthermore, the regeneration temperature requirements ranged from 50 °C to 78 °C, respectively that makes it favorable to use low grade thermal energy through non concentrating solar thermal collectors. The regeneration thermal energy requirement for desiccant wheel fluctuates throughout the year, maximizing in August due to higher dehumidification requirements. The study also revealed that the evacuated tube collector technology is most suitable with average annual efficiency of around 36 %.

Annual performance analysis of solar-assisted raw-water source heat pumps at low water temperatures

With the increase in energy consumption for building heating and cooling, raw-water source heat pumps (RWSHPs) have garnered strong attention because of their advantages of high efficiency and utilization of a clean heat source. However, RWSHPs exhibit poor performance at low water source temperatures. Thus, this study proposes a solar-assisted raw-water source heat pump (SA-RWSHP) to solve the performance degradation of RWSHPs. The SA-RWSHP can improve performance during the heating period by elevating the entering water temperature (EWT) using solar collectors. During the cooling period, a solar heat source can be used to produce domestic hot water. Optimal design parameters are determined by analyzing the performance of SA-RWSHP using the TRNSYS. Additionally, the performance of SA-RWSHP is compared with that of RWSHP. During the heating period, the unit COP (COPhp) of SA-RWSHP was 12.7% higher than that of RWSHP on average, owing to the increase in the EWT. Furthermore, the annual total system COP of SA-RWSHP was approximately 18% higher than that of RWSHP owing to the high COPhp and effective use of solar energy. Overall, the SA-RWSHP exhibited superior performance throughout the year, resulting in a substantial reduction in building energy consumption.

Optimization analysis of Organic Rankine Cycle powered by waste heat of a supermarket transcritical CO2 multi-ejector refrigeration cycle

The exploitation of low-grade heat sources that are available from existing thermal systems processes consists a promising concept for the production of energy. In this research, the integration of an Organic Rankine Cycle (ORC) unit on a supermarket transcritical CO2 refrigeration system with ejectors is investigated, which is supplied with low-grade heat by the common discharge of the compressors. The optimization analysis proves that for different combinations of CO2 temperature and pressure in the ORC evaporator, as well as for different ORC condensation temperatures, there is a different optimum ORC evaporation temperature that leads to the highest energy production. Concerning the annual performance analysis conducted for the city of Athens, Greece, operation with isopentane is found to provide the greatest energy production with 10.36 MWh annually, which corresponds to a 3.69% reduction in the refrigeration system's energy consumption. For operation under the ambient temperature of 40 °C, the corresponding reduction of the refrigeration system consumption due to the presence of ORC is 7.54%. Finally, the financial analysis reveals that toluene is the most advantageous solution, leading to a payback period of 3.9 years, with a net present value by the end of the project's lifetime equal to 34.32 k€.

New solar-biomass assisted thermophotovoltaic system and parametrical analysis

This paper proposes a new technical route of solar-biomass assisted thermophotovoltaic (TPV) system for power generation which uses renewable fuel and contributes to carbon neutrality. Here, a thermophysics model is established for solar-biomass assisted TPV based on energy-balance principle. The effects of some key parameters on the new system performance are investigated, including concentrate ratio, emitter area, biomass fuels, etc. Besides, biomass fuel saving after adding solar energy is investigated. The results show that the solar-biomass assisted TPV system can not only increase the output power of photovoltaic cells by more than 10 kW/m2 compared to biomass-driven TPV but also increase the electrical efficiency by nearly 10 percentage points. It is pointed out that improving the absorptance of solar absorber is the key for system optimization. Furthermore, the annual performance analysis shows that it also saves biomass fuel by up to 60% in one year. This study provides a reference for the design and application of renewable TPV technology.

Annual thermal performance analysis and optimization of earth-air heat exchanger by using a new 1D-2D hybrid numerical model

Thermal performance potential analysis is necessary when using the earth-air heat exchanger (EAHE) as a passive way to reduce ventilation energy consumption or achieve thermal comfort in buildings. This work aimed to develop a new simulating model, investigate parametric influence, and build an optimizing criterion. This paper built a 1D-2D hybrid transient numerical model, integrating a number of 2D explicit diffusion models in the earth domain and two 1D implicit convection-diffusion models in the air region. A novel splitting discrete scheme was built on the earth-air coupled interface to separate computations in the two domains while considering their interactions. EAHE thermal performance was analyzed in terms of the outlet temperature/humidity and annual cooling/heating capacity. This paper originally suggested the outlet temperature or cooling/heating capacity limit in an entire year as the criterion for optimizing EAHE's length and depth in any climate.36 one-year-duration simulations of single-pipe EAHE, 27 one-year-duration simulations and a ten-year-duration simulation of multi-pipe EAHE were conducted to analyze influences of the velocity, diameter, length, depth, and pipe-to-pipe space. Results show that this new model could be an effective tool and the novel optimizing criterion is feasible. Both the single-pipe and multi-pipe EAHEs have the same limit of outlet temperature/humidity and it depends on the pipe depth only given a specific climate. The optimal/effective depth is 6 m. The optimal/effective pipe length is independent of pipe depth and increases with air velocity and diameter. Multi-pipe EAHE can be treated as single-pipe EAHE given the pipe-to-pipe space is greater than 3 m.

Economic evaluation and annual performance analysis of a novel series-coupled PV/T and solar TC with solar direct expansion heat pump system: An experimental and numerical study

Hybrid photovoltaic/thermal (PV/T) systems are proposed to harvest the two renewable forms of energy, thermal and electrical. The PV/T system generates low-temperature thermal and electrical energy, which is usually not much and might meet the demand for residential building heating and hot water. This research presents the economic evaluation and annual energy performance of a novel series-coupled PV/T and a solar thermal collector (TC) with a solar direct expansion heat pump system. A comprehensive approach was developed and utilized to evaluate the quantitative and qualitative performance of the hybrid refrigerant-based PV/T-TC system using the 1st (energy) and 2nd (exergy) laws of thermodynamics. A 0.5234 kW rating heat pump prototype system with a PV/T-TC area of 3.5 m2 was built and tested under the real conditions of Karachi, Pakistan, and a simulation model was developed via MATLAB to predict the annual energy performance. The experimental results show that the PV/T-TC system's mean daily electrical, thermal, overall energy and exergy efficiencies were 14.08%, 60.12%, 74.20%, and 18.12%, respectively. The numerical results reveal that a PV/T-TC assisted solar heat pump system can generate 303.51 kWh of electricity and 3213.12 kWh of thermal energy annually. The annual average COP of the hybrid refrigerant-based PV/T-TC system is 5.68. According to the comparison of economic performance between the PV/T assisted direct-expansion heat pump system and PV/T-TC assisted direct-expansion heat pump system, the hybrid refrigerant-based PV/T-TC assisted direct-expansion heat pump system has a payback period of 5.20 years, whereas the refrigerant-based PV/T assisted direct-expansion heat pump system has a payback period of 7.15 years. The experimental data is consistent with the simulation outcomes, with an average relative error of 3.30%.

Annual thermal performance analysis and economic assessment of an evacuated tube coupled solar still for Indian climatic conditions.

In this experimental study, the annual performance and economic analysis of an evacuated tube augmented solar still is presented from June 2020 to May 2021. The experiments are also performed simultaneously on a conventional still as well. The experiments are performed throughout the year at 6cm water depth for both solar stills in the climate of Kurukshetra City, India. The main output parameters, namely, maximum daily water output, maximum hourly water output, thermal efficiency, and maximum basin water temperature have been taken into account and represented in this study. In addition, thermal analysis for both solar stills is performed in this study. The results from experimentation showed 149% improvement in the daily freshwater output from the modified still in comparison to the conventional still. Also, an increase of 1.7% in overall thermal efficiency is achieved for the modified still in comparison to the conventional still. The maximum still performance is achieved in the month of June 2020. In the economic analysis, the cost of water obtained per litre after distillation is $0.0098 for a conventional still and $0.022 in the case of a modified still.

Annual performance analysis of heat pump drying system with waste heat recovery

Recently, heat pump drying with heat recovery is popular in agricultural products for its high efficiency, fine product quality, and low energy consumption. However, while the heat pump drying performance depends on the ambient conditions, especially when operating continuously throughout the year, little work has been done on the long-term performance evaluation of heat pump drying. Therefore, a meteorological data model is introduced into the mathematical model of a heat pump drying system with waste heat recovery in order to study the annual performance and analyze the total yearly energy consumption, including the effects of the set temperature, the ambient temperature, and the relative humidity on the amount of waste heat recovered, the power consumption, the coefficient of performance, and the specific moisture extraction ratio of the system. The results show that the utilization of outdoor fresh air by the heat pump drying/waste heat recovery system during continuous operation depends on the moisture differences between the air supplied to the drying oven and the outdoor air. At the three set temperatures of 50, 55, and 60 °C, the ratio of annual waste heat recovery to total heat requirement of the heat pump drying system is 57.2, 56.5, and 55.7%, respectively. This reduces the power consumption by 58.2, 57.8 and 57.1%, respectively. Due to the availability of fresh air, the specific moisture extraction ratio is higher between September and June than that in July to August. The maximum value is more than 3.0 in early April when the temperature is relatively high and the humidity is low. The perspective for annual performance analysis in this study helps to further elucidate the energy consumption of heat pump drying, and to provide guidelines for its operation control and design.

건물유형 및 지역을 고려한 하천수 이용 수열 히트펌프 시스템의 연간 성능 분석

Recently, as interest in renewable energy has increased, research in various fields has been continuously conducted. Among them, interest in hydrothermal energy is increasing due to the revision of the enforcement decree in 2019. However, although various studies have been conducted on system demonstration, performance and economic feasibility analysis, heat exchangers, etc., studies on the performance of the water heat pump system considering the domestic region and building type are insufficient. Thus, in this study, an annual performance analysis of the water source heat pump system was performed using dynamic energy simulation considering the domestic region and building type. The regions were assumed to be Seoul, Daejeon, Busan, and Gwangju, and the building types were assumed to be office buildings, apartment houses, and greenhouses. As a result of heat pump Coefficient of Performance(COP) analysis, the cooling COP was an average of 4.01 by region and 3.99 by building type. Heating COP was 3.13 and 3.43, respectively. Also, when comparing the performance deviations by region and building type, the heating performance differed greatly depending on the building type, and the cooling performance showed a significant difference according to the region. Overall, it was confirmed that the cooling performance of the hydrothermal heat pump system was approximately 15% superior to the heating performance.

Designing and Energy Estimation of Photovoltaic Energy Generation System and Prediction of Plant Performance with the Variation of Tilt Angle and Interrow Spacing

The focus of this research is to design a ground-mounted photovoltaic system at optimal tilt angle and interrow space to meet high demand of electrical energy. The Department of Electrical Engineering and Technology, GC University Faisalabad has been considered to perform the simulation test. This study is conducted using Meteonorm software for solar resource assessment. Furthermore, HelioScope software is used for modeling of a ground-mounted photovoltaic system, study of PV system’s performance in terms of annual generation, system losses and performance ratio and analysis of photovoltaic module’s performance, current-voltage and power-voltage curves for different irradiance levels. From SLD, it is seen that 11 strings are connected to each inverter and inverters output power are combined by using 20.0 A circuit interconnects. The performance of photovoltaic systems is impacted by tilt angle and interrow spacing. From simulation results of all cases, it is concluded that the PV system installed at 15° tilt angle with 4 feet interrow spacing are more efficient than the other installed PV systems, because total collector irradiance is maximum (1725.0 kWh/m2) as compared to other tilt angles. At 15° tilt angle, the annual production of photovoltaic system is 2.265 GWh and performance ratio of PV system is 82.0%. It is envisioned that this work will provide the guidance to energy system designers, planners and investors to formulate strategies for the installation of photovoltaic energy systems in Pakistan and all over the world.

Energy and Economic Sustainability of a Trigeneration Solar System Using Radiative Cooling in Mediterranean Climate

The spreading of nearly zero-energy buildings in Mediterranean climate can be supported by the suitable coupling of traditional solar heating, photovoltaics and radiative cooling. The latter is a well-known passive cooling technique, but it is not so commonly used due to low power density and long payback periods. In this study, the energy performance of a system converting solar energy into electricity and heat during the daytime and offering cooling energy at night is assessed on the basis of a validated model of a trifunctional photovoltaic–thermal–radiative cooling module. The key energy, CO2 emission and economic performance indicators were analyzed by varying the main parameters of the system, such as the spectral emissivity of the selective absorber plate and cover and thermal insulation thickness. The annual performance analysis is performed by a transient simulation model for a typical residential building and two different climates of the Mediterranean area (Trapani and Milano). For both climates, glass-PVT–RC is the best solution in terms of both overall efficiency (electric + thermal) and cooling energy capacity, even better with a thicker insulation layer; the annual electrical, heat and cooling gains of this system are 1676, 10,238 and 3200 kWh for Trapani, correspondingly (1272, 9740 and 4234 kWh for Milano, respectively). The typical glass-PVT module achieves a performance quite similar to the best ones.

Annual performance analysis of a dual-air-channel solar wall system with phase change material in different climate regions of China

Applications of phase change material (PCM) in buildings have significant energy-saving potential. In this work, a dual-air-channel solar wall system with PCM is proposed, which has the following main functions: electricity generation, hot water supply, passive indoor space heating and ventilation cooling. Continuous experimental tests were conducted through two hot-box rooms in Hefei to confirm the energy saving effects of the system. Mathematical model of the system is established and validated against the experimental results. With the validated model, the annual performance of the system in three selected cities (Urumqi, Beijing and Hefei) is investigated. Annual electricity generation and average electrical efficiency of the three cities are 179.67 kWh, 179.21 kWh, 119.28 kWh and 11.22%, 10.67%, 11.06%. Annual energy saved are 863.24 kWh, 770.53 kWh and 576.43 kWh. Parametric analyses are also conducted. Proper increase of PV coverage is beneficial to the comprehensive performance of the system. Decrease of the thickness ratio of the outer and inner channel and increase of depth-to-width ratio of the channel can both enhance the thermal performance in heating season. The selection of melting temperature and thickness of PCM should be based on the weather condition of the region where the system is applied.

Annual performance analysis of small scale industrial waste heat assisted solar tower power plant and application of nanofluid

BackgroundConcentrated solar energy systems use mirrors to focus a lot of light in one receiver. When focused light is converted to heat can drive a steam turbine connected to a power generator and electricity is generated. The purpose of this research is to analyze a small-scale industrial waste heat assisted solar tower power plant. MethodThe thermal performance of the system has been modelled based on the transient heat transfer analysis of the storage tank and a boiling heat transfer modeling of steam generator. Performance parameters such as working fluid temperature at the exit of components, hourly power output, as well as thermal efficiency of steam cycle has been computed. Moreover, in order to increase the efficiency of the system a CFU U-tube heat exchanger was selected and cooled using nanofluid. FindingsA 16.6 kW constant power output was computed for 8760 hour of simulation time, and 19% thermal efficiency of the steam cycle is computed in this analysis. Moreover, using nanofluid in the condenser instead of water can improve heat transfer in the heat exchanger. The use of nanofluid also leads to lower temperature of liquid leaving the condenser, which increases the efficiency of the solar system.

Using photovoltaic thermal technology to enhance biomethane generation via biogas upgrading in anaerobic digestion

Anaerobic Digestion (AD) is identified to be a promising method to address the dilemma of solid waste recycling, and biogas produced from AD has also been identified as an important alternative to fossil fuels, pertaining to energy crisis and climate change. As the applied technology of anaerobic digestion is fixed, required thermal energy for biogas production in an anaerobic digester varies dramatically with the ambient temperature. The conventional way is to combust the biogas on the spot for heat preservation in the digester, and the additional natural gas will be needed for supplement in colder area. To mitigate the consumption of fossil fuel and increase the amount of available biogas for bio-methane production, a hybrid system by integration of Concentrated PhotoVoltaic Thermal (CPVT) collectors and biogas upgrading technology is proposed. The heat produced from CPVT collectors is for heat preservation in the digester, and generated electric power is used in the biogas plant and biogas upgrading unit for bio-methane production. The annual performance analysis indicates that, comparing with the conventional design, the new design saves 2.6% amount of natural gas consumption, reduces 48.38% amount of electricity from power grid and increases 86.08% amount of biomethane production. Besides, the new design can supply 829.4 MWh electricity to the power grid in a year. This research provides a new way to utilize biogas by integration with solar utilization technologies.

Annual performance of the second-generation variable-geometry oscillating surge wave energy converter

Recent studies in wave energy have highlighted the need for a structured innovation approach in wave energy converter (WEC) design because cost-of-energy estimates have remained high. One such innovation being investigated by the National Renewable Energy Laboratory is WEC geometry control, which uses control surfaces in combination with an oscillating surge WEC (OSWEC) to increase device availability and power generation while limiting structural costs. This study performs the first analysis of annual performance for a novel OSWEC with geometry control to understand how the geometry control affects availability, annual power generation, and structural loadings like the power-take-off (PTO) torque or surge foundation force. Device hydrodynamic coefficients are calculated using linear potential theory for six geometry configurations. A nonideal PTO system is assumed and quadratic viscous damping losses are considered. Annual performance is evaluated and compared for three U.S. wave energy sites. The WEC geometry and PTO system are controlled on a sea-state basis to optimize for power capture while remaining under limits set on motion amplitude and structural loads. Results indicate that geometry control can increase availability up to 25 days in an average year depending on design limits, increase average power generation, and significantly reduce peak structural loads.

Off-design and annual performance analysis of supercritical carbon dioxide cycle with thermal storage for CSP application

Supercritical Carbon Dioxide (sCO2) cycles can achieve higher efficiency compared to steam-Rankine or Air-Brayton cycles, therefore they are promising for concentrated solar power applications. Although sCO2 cycles show higher design efficiency, the off-design efficiency is highly sensitive to the ambient conditions, impacting the power block net-power and heat input. In the present work a recompression sCO2 cycle is connected to a central-tower solar field with two-tank thermal storage delivering molten chloride salt at 670 °C. The temperature of the molten-salt exiting from the power block and returning to the cold storage tank increases by 46 °C with respect to the design value when the compressor inlet temperature is raised by 13 °C relative to the design condition of 42 °C, which implies that the capacity of the thermal storage reduces by 25%. The main focus of this work is to investigate the off-design performance of a sCO2 recompression cycle under variable ambient temperature, molten-salt inlet temperature and molten-salt flow rate. Multi-objective optimisation is carried-out in off-design conditions using an in-house code to explore the optimal operational strategies and the Pareto fronts were compared. Since the power cycle can either be operated in maximum power mode or maximum efficiency mode, this study compares these two operational strategies based on their annual performance. Results indicate that the capacity factor of the concentrated solar power can be increased by 10.8% when operating in maximum power mode whilst the number of start-ups is reduced by about 50% when operating in maximum efficiency mode.

Annual performance analysis of the PV/T system for the heat demand of a low-energy single-family building

The interest in the energy efficiency of buildings and the integration of new technologies to reduce the heating and cooling loads through the building envelope is not new. The European Union (EU) is committed to decarbonising its building stock as almost 50% of the Union’s final energy consumption is for heating and cooling, of which 80% is used in buildings. The article analysis the performance of a PV/T system (with a heat mat) for the heat demand of a low-energy two-zone, single-family building during the year. For this purpose, a building model was built in TRNSYS using Multizone building model and TRNbuild in two variants of heating (internal - as reference and external). Then the building model was connected to a mechanical ventilation system providing heating during winter for which the heat source is a PV/T system to demonstrate if the heating requirements for the household can be provided during different seasons of the year. Additionally, it was indicated how much energy consumption reduction can be obtained in comparison to the case when a heating unit is used.

Energy Performance Evaluation for Exterior Insulation System Consisting of Truss-Form Wire-Frame Mullion Filled with Glass Wool

Heat loss and gain through opaque envelopes of buildings are major factors that affect the overall cooling and heating loads in buildings. The government has enforced regulations to strengthen the thermal transmittance requirement level as a major means of reducing greenhouse gas emissions in the building sector. In addition, the thermal bridge is considered to be one of the major factors in heating load of buildings. In this study, truss-form wire frame was developed in order to minimize thermal bridge of steel mullion in exterior insulation system. In the case of thermal transmittance test for specimen of 0.145 W/m2 K as design value, the value of the steel pipe was 0.190 W/m2 K and the value of the truss-form wire frame was 0.150 W/m2 K, respectively. This means the other is much smaller than the one in thermal bridge. For four cases, annual energy performance analysis was calculated using Passive House Planning Package (PHPP)—ideal condition without thermal bridge, steel pipe mullion without insulation in the rear side, steel pipe mullion with insulation in the rear side, and truss-form wire-frame mullion filled with glass wool. As results, the annual heating energy demands were 15.68 kWh/m2, 25.42 kWh/m2, 16.78 kWh/m2, and 16.09 kWh/m2, respectively.

Experimental and numerical analysis of an efficiently optimized evacuated flat plate solar collector under medium temperature

Medium temperature solar thermal systems have a great prospect to be an efficient energy source for practical industrial applications. Although the evacuated flat solar collector is a potential non-concentrating collector for this application, current designs have not fully demonstrated its superiority. In this paper, a medium-scale (50.96 m2) solar thermal system based on an efficiently optimized evacuated flat plate solar collector structure is designed. A systematic four months long real-time experiment under the natural environment is conducted for medium solar thermal applications in a region with four distinct seasons. An annual performance analysis is then conducted in four different locations through a validated numerical model. Experimental results demonstrate that, when the inlet temperature is 123.0 °C, the ambient temperature is 35.7 °C and the solar irradiation is 835.2 W/m2, the thermal efficiency and exergy efficiency can reach 59.67% and 14.35%, respectively. The efficiently optimized evacuated flat plate solar collector can also achieve a stable annual average thermal efficiency at the four studied locations with values reaching up to 50%. Therefore, the superiority of this efficiently optimized evacuated flat plate solar collector design over previous ones is demonstrated.