Underground Thermal Energy Storage

verfasst von: Kun Sang Lee

Verlag: Springer London

Buchreihe : Green Energy and Technology

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

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Über dieses Buch

Underground thermal energy storage (UTES) provide us with a flexible tool to combat global warming through conserving energy while utilizing natural renewable energy resources. Primarily, they act as a buffer to balance fluctuations in supply and demand of low temperature thermal energy. Underground Thermal Energy Storage provides an comprehensive introduction to the extensively-used energy storage method.

Underground Thermal Energy Storage gives a general overview of UTES from basic concepts and classifications to operation regimes. As well as discussing general procedures for design and construction, thermo-hydro geological modeling of UTES systems is explained. Finally, current real life data and statistics are include to summarize major global developments in UTES over the past decades.

The concise style and thorough coverage makes Underground Thermal Energy Storage a solid introduction for students, engineers and geologists alike.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract

As fossil fuel resources such as oil, natural gas, and coal are increasingly less available and more expensive, many energy conservation strategies become more feasible.

Kun Sang Lee

Chapter 2. Underground Thermal Energy Storage

Abstract

Nature provides storage systems between the seasons because thermal energy is passively stored into the ground and groundwater by the seasonal climate changes. Below a depth of 10–15 m, the ground temperature is not influenced and equals the annual mean air temperature. Therefore, average temperature of the ground is higher than the surface air temperature during the winter and lower during the summer.

Kun Sang Lee

Chapter 3. Basic Theory and Ground Properties

Abstract

Deng (2004) introduced a theoretical background on underground thermal energy systems in his dissertation on standing column wells. The contents in this chapter are mainly based on Deng's (2004) dissertation.

Kun Sang Lee

Chapter 4. Aquifer Thermal Energy Storage

Abstract

In general, groundwater temperatures remain relatively stable at temperatures typically 1–2 °C higher than local mean annual temperatures between depths of 10–20 m. Below these depths, groundwater temperatures gradually increase at a rate of geothermal gradient. As a result, in areas where a supply of groundwater is readily available from an aquifer, a reliable source of low temperature geothermal energy exists.

Kun Sang Lee

Chapter 5. Borehole Thermal Energy Storage

Abstract

If it is impossible to exploit a suitable aquifer for energy storage, a borehole thermal energy storage system (BTES) can be considered. Vertical ground heat exchangers (GHE), also called borehole heat exchangers (BHE) are widely used when there is a need to install sufficient heat exchange capacity under a confined surface area such as where the Earth is rocky close to the surface, or minimum disruption of the landscape is desired.

Kun Sang Lee

Chapter 6. Cavern Thermal Energy Storage Systems

Abstract

Kun Sang Lee

Chapter 7. Standing Column Well

Abstract

A number of ground systems cannot be categorized either as open or as closed. Such a system is the standing column well (SCW) shown in Fig. 7.1, where water is pumped from the bottom of the well to the heat pump. The exiting water is percolated through gravel in the annulus of the well in order to absorb heat. Standing wells are typically 15 cm in diameter and may be as deep as 500 m.

Kun Sang Lee

Chapter 8. Modeling

Abstract

Performance of TES is influenced by various factors such as location, construction type, size, geometry, storage medium, and used materials. Furthermore, TES are integrated in heating and cooling systems with a great variety of system configurations and control and operation strategies. Boundary conditions also influence the energetic and exergetic efficiency of TES. Hence, for a realistic comparison system simulations are required, which include all sensitive parameters (Ochs et al. 2009).

Kun Sang Lee

Titel: Underground Thermal Energy Storage
verfasst von: Kun Sang Lee
Verlag: Springer London
Electronic ISBN: 978-1-4471-4273-7
Print ISBN: 978-1-4471-4272-0
DOI: https://doi.org/10.1007/978-1-4471-4273-7