Chapter 7
Mathematical Modelling of Solar
Updraft Tower
K. V. S. Teja, Kapil Garg and Himanshu Tyagi
Abstract Solar updraft tower power plant is a way to harness energy from the
sun. It is a simple concept which requires low maintenance and utilises land that
is already being used for growing plants, and generates power from it. A prototype
plant was setup in Manzanares, Spain. Numerical analysis on power generation is
performed for a similar plant assuming it is setup in Ropar. By considering losses via
convection and radiation through the top surface of the collector, collector efficiency
is calculated. Two cases arise here, 1. With 100% collector efficiency and 2. Collector
efficiency is obtained after subtracting convection and radiation losses. The influx of
solar radiation is highest in June. Hence, the variation of parameters like temperature,
velocity, power output, efficiency with time of the day is done by taking averages
for the month of June. Next the impact of physical parameters like chimney height,
chimney radius and collector radius are studied on 21st June 11:00 to 12:00. How
each parameter impacts the output of the plant is studied by creating a mathematical
model of the power plant. Methods to improve the power output are discussed.
Keywords Solar energy · Solar updraft tower · Collector · Chimney · Wind turbine
Nomenclature
A
Area (m
2 )
C
Power coefficient for wind turbine, C = 0.45
C p
Specific heat at constant pressure for air (J/kg K), C p = 1007 J/kg K
g
Acceleration due to gravity (m/s
2 ), g = 9.81 m/s
2
G sc
Solar constant (W/m
2 ), G sc = 1367 W/m
2
h
Convective heat transfer coefficient (W/m
2 K)
H
Height (m)
I o
Hourly incident solar energy on an extra-terrestrial horizontal surface (J/m
2 )
K. V. S. Teja (B) · K. Garg · H. Tyagi
School of Mechanical, Materials and Energy Engineering, Indian Institute of
Technology Ropar, Rupnagar, Punjab 140001, India
e-mail: 2018mem1016@iitrpr.ac.in
© Springer Nature Singapore Pte Ltd. 2020
H. Tyagi et al. (eds.), Solar Energy, Energy, Environment,
and Sustainability, https://doi.org/10.1007/978-981-15-0675-8_7
95
Mathematical Modelling of Solar
Updraft Tower
K. V. S. Teja, Kapil Garg and Himanshu Tyagi
Abstract Solar updraft tower power plant is a way to harness energy from the
sun. It is a simple concept which requires low maintenance and utilises land that
is already being used for growing plants, and generates power from it. A prototype
plant was setup in Manzanares, Spain. Numerical analysis on power generation is
performed for a similar plant assuming it is setup in Ropar. By considering losses via
convection and radiation through the top surface of the collector, collector efficiency
is calculated. Two cases arise here, 1. With 100% collector efficiency and 2. Collector
efficiency is obtained after subtracting convection and radiation losses. The influx of
solar radiation is highest in June. Hence, the variation of parameters like temperature,
velocity, power output, efficiency with time of the day is done by taking averages
for the month of June. Next the impact of physical parameters like chimney height,
chimney radius and collector radius are studied on 21st June 11:00 to 12:00. How
each parameter impacts the output of the plant is studied by creating a mathematical
model of the power plant. Methods to improve the power output are discussed.
Keywords Solar energy · Solar updraft tower · Collector · Chimney · Wind turbine
Nomenclature
A
Area (m
2 )
C
Power coefficient for wind turbine, C = 0.45
C p
Specific heat at constant pressure for air (J/kg K), C p = 1007 J/kg K
g
Acceleration due to gravity (m/s
2 ), g = 9.81 m/s
2
G sc
Solar constant (W/m
2 ), G sc = 1367 W/m
2
h
Convective heat transfer coefficient (W/m
2 K)
H
Height (m)
I o
Hourly incident solar energy on an extra-terrestrial horizontal surface (J/m
2 )
K. V. S. Teja (B) · K. Garg · H. Tyagi
School of Mechanical, Materials and Energy Engineering, Indian Institute of
Technology Ropar, Rupnagar, Punjab 140001, India
e-mail: 2018mem1016@iitrpr.ac.in
© Springer Nature Singapore Pte Ltd. 2020
H. Tyagi et al. (eds.), Solar Energy, Energy, Environment,
and Sustainability, https://doi.org/10.1007/978-981-15-0675-8_7
95