Design and Optimization of Integrated Distributed Energy Systems for Off-grid Buildings

2021 ◽  
pp. 1-27
Author(s):  
Jian Zhang ◽  
Heejin Cho ◽  
Pedro Mago

Abstract Off-grid concepts for homes and buildings have been a fast-growing trend worldwide in the last few years because of the rapidly dropping cost of renewable energy systems and their self-sufficient nature. Off-grid homes/buildings can be enabled with various energy generation and storage technologies, however, design optimization and integration issues have not been explored sufficiently. This paper applies a multi-objective genetic algorithm (MOGA) optimization to obtain an optimal design of integrated distributed energy systems for off-grid homes in various climate regions. Distributed energy systems consisting of renewable and non-renewable power generation technologies with energy storage are employed to enable off-grid homes/buildings and meet required building electricity demands. In this study, the building types under investigation are residential homes. Multiple distributed energy resources are considered such as combined heat and power systems (CHP), solar photovoltaic (PV), solar thermal collector (STC), wind turbine (WT), as well as battery energy storage (BES) and thermal energy storage (TES). Among those technologies, CHP, PV, and WT are used to generate electricity, which satisfies the building's electric load, including electricity consumed for space heating and cooling. Solar thermal energy and waste heat recovered from CHP are used to partly supply the building's thermal load. Excess electricity and thermal energy can be stored in the BES and TES for later use. The MOGA is applied to determine the best combination of DERs and each component's size to reduce the system cost and carbon dioxide emission for different locations. Results show that the proposed optimization method can be effectively and widely applied to design integrated distributed energy systems for off-grid homes resulting in an optimal design and operation based on a trade-off between economic and environmental performance.

Author(s):  
Jian Zhang ◽  
Heejin Cho ◽  
Pedro Mago

Abstract Off-grid concepts for homes and buildings have been a fast-growing trend worldwide in the last few years because of the rapidly dropping cost of renewable energy systems and their self-sufficient nature. Off-grid homes/buildings can be enabled with various energy generation and storage technologies, however, design optimization and integration issues have not been explored sufficiently. This paper applies a multi-objective genetic algorithm (MOGA) optimization to obtain an optimal design of integrated distributed energy systems for off-grid homes in various U.S. climate regions. Distributed energy systems consisting of renewable and non-renewable power generation technologies with energy storage are employed to enable off-grid homes/buildings and meet required building electricity demands. In this study, the building types under investigation are residential homes. Multiple distributed energy resources are considered such as combined heat and power systems (CHP), solar photovoltaic (PV), solar thermal collector (STC), wind turbine (WT), as well as battery energy storage (BES) and thermal energy storage (TES). Among those technologies, CHP, PV, and WT are used to generate electricity, which satisfies the building’s electric load, including electricity consumed for space heating and cooling. Solar thermal energy and waste heat recovered from CHP are used to partly supply the building’s thermal load. Excess electricity and thermal energy can be stored in the BES and TES for later use. The MOGA is applied to determine the best combination of DERs and each component’s size to reduce the system cost and carbon dioxide emission for different locations. Results show that the proposed optimization method can be effectively applied to design integrated distributed energy systems for off-grid homes resulting in an optimal design and operation based on a tradeoff between economic and environmental performance.


1982 ◽  
Vol 19 (04) ◽  
pp. 894-899 ◽  
Author(s):  
J. Haslett

The process {Xn }, defined by Xn + 1 = max{Yn + 1 + αßX n, ßX n}, with αand ß in [0, 1) and {Yn } stationary, arises in studies of solar thermal energy systems. Bounds for the stationary mean EX are given, which are more general and in some cases tighter, than those previously available.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2043 ◽  
Author(s):  
Hai-Chen Zhang ◽  
Ben-hao Kang ◽  
Xinxin Sheng ◽  
Xiang Lu

A series of novel bio-based form stable composite phase-change materials (fs-CPCMs) for solar thermal energy storage and management applications were prepared, using the pomelo peel flour (PPF) as the supporting matrix and poly (ethylene glycol) (PEG) or isocyanate-terminated PEG to induce a phase change. The microscopic structure, crystalline structures and morphologies, phase change properties, thermal stability, light-to-thermal conversion behavior, and thermal management characteristics of the obtained fs-CPCMs were studied. The results indicate that the obtained fs-CPCM-2 presented remarkable phase-change performance and high thermal stability. The melting latent heat and crystallization heat for fs-CPCM-2 are 143.2 J/g and 141.8 J/g, respectively, and its relative enthalpy efficiency ( λ ) is 87.4%, which are higher than most reported values in the related literature. The obtained novel bio-based fs-CPCM-2 demonstrated good potential for applications in solar thermal energy storage and waste heat recovery.


1982 ◽  
Vol 19 (4) ◽  
pp. 894-899 ◽  
Author(s):  
J. Haslett

The process {Xn}, defined by Xn+ 1 = max{Yn+ 1 + αßXn, ßXn}, with αand ß in [0, 1) and {Yn} stationary, arises in studies of solar thermal energy systems. Bounds for the stationary mean EX are given, which are more general and in some cases tighter, than those previously available.


Author(s):  
Nelson Fumo ◽  
Louay M. Chamra ◽  
Vicente Bortone

Integrated energy systems combine distributed power generation with thermally activated components to use waste heat, improving the overall energy efficiency, and making better use of fuels. Use of solar thermal energy is attractive to improve combined cooling, heating, and power (CCHP) systems performance, particularly during summer time since the cooling load coincides very well with solar energy availability. Limitation of the use of solar systems is mainly related to high first cost and large surface area for solar energy harvesting. Therefore, solar thermal CCHP systems seem to be an alternative to increase the use of solar thermal energy as a means to increase energy systems overall efficiency and reduce greenhouse gases (GHGs) emissions. This study focuses on the use of solar collectors in CCHP systems in order to reduce PEC and emission of CO2 in office buildings. By using a base CCHP system, the energy and economic analysis are presented as the contribution of the solar system from the baseline. For comparison purposes, the analysis is made for the cities of Minneapolis (MN), Chicago (IL), New York (NY), Atlanta (GA), and Fort Worth (TX). Results show that solar thermal CCHP systems can effectively reduce the fuel energy consumption from the boiler. The potential of solar collectors in CCHP systems to reduce PEC and CO2 emission increases with the cooling demand; while the effectiveness of solar collectors to reduce primary energy consumption and CO2 emission, and the ability of the system to pay by itself from fuel savings, decreases with the number of solar collectors.


2019 ◽  
Author(s):  
Karolina Matuszek ◽  
R. Vijayaraghavan ◽  
Craig Forsyth ◽  
Surianarayanan Mahadevan ◽  
Mega Kar ◽  
...  

Renewable energy has the ultimate capacity to resolve the environmental and scarcity challenges of the world’s energy supplies. However, both the utility of these sources and the economics of their implementation are strongly limited by their intermittent nature; inexpensive means of energy storage therefore needs to be part of the design. Distributed thermal energy storage is surprisingly underdeveloped in this context, in part due to the lack of advanced storage materials. Here, we describe a novel family of thermal energy storage materials based on pyrazolium cation, that operate in the 100-220°C temperature range, offering safe, inexpensive capacity, opening new pathways for high efficiency collection and storage of both solar-thermal energy, as well as excess wind power. We probe the molecular origins of the high thermal energy storage capacity of these ionic materials and demonstrate extended cycling that provides a basis for further scale up and development.


Sign in / Sign up

Export Citation Format

Share Document