Modeling and Simulation of Solar Chimney Power Plant with and without the Effect of Thermal Energy Storage Systems
No Thumbnail Available
Date
2011-09
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
A solar updraft tower power plant – sometimes also called 'solar chimney' or just ‘solar
tower’ – is a solar thermal power plant utilizing a combination of solar air collector and
central updraft tube to generate a solar induced convective flow which drives pressure
staged turbines to generate electricity.
Several technologies exist that can convert solar energy into electrical energy. The solar
chimney is part of the solar thermal groups of solar conversion technologies. Of these
technologies the solar dish has the highest energy efficiency (the current record is a
conversion efficiency of 30% of solar energy). Solar trough plants have been built with
efficiencies of about 20%. The solar chimney has an efficiency of less than 2%. However,
due to its greater scale and simplicity, the solar chimney may have an economic
efficiency approaching or exceeding that of the other methods.
To improve efficiency of the plant thermal storage system is used. Thermal storage
system improves the power output by re-shaping the profile of the power output. The
most commonly suggested method for creating energy storage is to place extra thermal
mass under the collector in the form of black containers of water.
In this paper both the solar chimney power plants: the plant with and without thermal
storage system are simulated for the case of Afar region using Fluent and the effect of
turbine position is also analyzed. The cost of the power output per kilowatt-hour is
reduced while using the thermal storage system. It also regulates the power output. The
power output increases as the turbine is positioned at higher position but the cost of the
chimney so the plants cost increases very much.
Solar chimneys are very suitable for use in remote communities where there is high solar
energy capacity; such as Afar and Somalia, as a power source for both residential and
industrial use, based on reliability, cost, and operational factors. They can provide a
suitable energy source in many remote areas of Ethiopia, including areas that are not
currently supplied by conventional means.
Description
Keywords
Mechanical Engineering