Gravity-Assisted Melting in Enclosures

Abstract

The gradual depletion of fossil fuels over the past few decades has resulted in an increase in energy costs which can be expected to rise sharply over the next few decades as supplies become scarce. Current worries regarding the disposal of nuclear wastes have caused many countries to put less stress on nuclear energy, and higher air pollution causing acid rain and possible long term change in global weather patterns make the use of solar energy a very attractive option in the long run. Though the amount of solar energy falling on the earth’s surface far exceeds our requirements, the diffuse and unpredictable nature of solar radiation makes it extremely difficult to harness. Efficient energy storage devices are essential if solar energy is ever to be used on a large scale. Considerable research is being done on many different kinds of storage devices like electrochemical batteries, flywheels, compressed air, pumped water storage, etc. However, thermal energy storage devices using phase change materials have some major advantages which make them extremely attractive for certain applications. These include a high energy density of storage and an uniform temperature at which the energy is released or absorbed. Such latent heat thermal energy storage devices can also be used over a wide range of temperatures since different materials can be used as required.