New bounds for the thermal energy storage process with stationary input

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.

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.


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.


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):  
Mohammad Alhuyi Nazari ◽  
Akbar Maleki ◽  
Mamdouh El Haj Assad ◽  
Marc A. Rosen ◽  
Arman Haghighi ◽  
...  

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