1 Introduction to Solar Energy …
9
Chapter 13: Buildings use more than 40% of the total power consumed in India.
Therefore, implementing energy conservation within buildings is of prime concern.
Utilization of passive design parameters, such as Phase Change Material (PCM)
incorporation, for energy conservation in buildings is thus a lucrative option. Incorporating PCMs within elements result in lowering of heat gain and temperature within
the building. A number of simulation and experimental studies on PCM incorporated
buildings, have been carried out. The advancements made in last forty years in the
field of PCMs and their utilization as Thermal Energy Storage (TES) medium for
buildings have been reviewed and presented in this study. This study focuses on
PCM incorporation which is sensitive to its properties and climatic parameters of
the location. Thus, there is a need of benchmarking the PCM for their application in
buildings. Focus is on buildings in tropical hot climatic conditions, where reduction in
cooling load is a challenge. This study lays emphasis on using an appropriate PCM
selection. Thus, phase change temperature forms and important criteria for PCM
selection. Thermal conductivity, specific heat and latent heat are other properties
which must be evaluated before PCM selection and implementation within buildings. The study also encompasses different methods of PCM incorporation being
implemented across the world and have marked advantages and disadvantages of
each followed by their impact in terms of energy savings.
Chapter 14: Metastable supercooled liquid phase change material (MSLPCM)
is prepared by homogeneous mixing of sodium acetate trihydrate (SAT), water and
ethylene glycol (EG) in 92:5:3 weight fractions, respectively. A stainless steel (SS306) triggering disk of size 20 mm (L) × 18 mm (W) × 0.2 mm (T) is fabricated
by engraving of grooves on SS disk for initiating nucleation in heat pack and release
of heat at the time of requirement. The PCM heat pack containing 300 g PCM and
a triggering disk is fabricated using high frequency PVC sealing machine. Thermal
performance of identical PCM heat pack and water pack (300 g water) is carried
out inside temperature history measuring setup at 0 °C ambient temperature. The
temperature of PCM heat pack and water heat pack reduces from 70 to 30 °C in 210
and 48 min, respectively at 0 °C ambient temperature. The heating time of PCM heat
pack is ~4.4 times compared to water heat packs.
The last part of this monograph, (Part V) consists of four chapters deal with the
technological advancements in the field of solar cells. New types of solar cells (DSSC
and OSC, which stand for ‘Dye Sensitized Solar Cells’ and ‘Organic Solar Cells’,
respectively) have the potential to generated electricity at very low cost, however
they require further improvements. The abstracts of each of these four chapters are
as follows.
Chapter 15: Utilization of renewable sources can reduce the impact of increasing
global energy demand on the rate of depletion of fossil fuels. One of the most studied and implemented routes to meet this energy demand is to harvest solar energy.
Among solar-energy harvesting devices, dye-sensitized solar cells have been recognized as some of the cheapest and most environment friendly technologies, since they
do not require high purity of starting materials or advanced fabrication techniques.
A dye-sensitized solar cell is composed of a working electrode, in which the light
9
Chapter 13: Buildings use more than 40% of the total power consumed in India.
Therefore, implementing energy conservation within buildings is of prime concern.
Utilization of passive design parameters, such as Phase Change Material (PCM)
incorporation, for energy conservation in buildings is thus a lucrative option. Incorporating PCMs within elements result in lowering of heat gain and temperature within
the building. A number of simulation and experimental studies on PCM incorporated
buildings, have been carried out. The advancements made in last forty years in the
field of PCMs and their utilization as Thermal Energy Storage (TES) medium for
buildings have been reviewed and presented in this study. This study focuses on
PCM incorporation which is sensitive to its properties and climatic parameters of
the location. Thus, there is a need of benchmarking the PCM for their application in
buildings. Focus is on buildings in tropical hot climatic conditions, where reduction in
cooling load is a challenge. This study lays emphasis on using an appropriate PCM
selection. Thus, phase change temperature forms and important criteria for PCM
selection. Thermal conductivity, specific heat and latent heat are other properties
which must be evaluated before PCM selection and implementation within buildings. The study also encompasses different methods of PCM incorporation being
implemented across the world and have marked advantages and disadvantages of
each followed by their impact in terms of energy savings.
Chapter 14: Metastable supercooled liquid phase change material (MSLPCM)
is prepared by homogeneous mixing of sodium acetate trihydrate (SAT), water and
ethylene glycol (EG) in 92:5:3 weight fractions, respectively. A stainless steel (SS306) triggering disk of size 20 mm (L) × 18 mm (W) × 0.2 mm (T) is fabricated
by engraving of grooves on SS disk for initiating nucleation in heat pack and release
of heat at the time of requirement. The PCM heat pack containing 300 g PCM and
a triggering disk is fabricated using high frequency PVC sealing machine. Thermal
performance of identical PCM heat pack and water pack (300 g water) is carried
out inside temperature history measuring setup at 0 °C ambient temperature. The
temperature of PCM heat pack and water heat pack reduces from 70 to 30 °C in 210
and 48 min, respectively at 0 °C ambient temperature. The heating time of PCM heat
pack is ~4.4 times compared to water heat packs.
The last part of this monograph, (Part V) consists of four chapters deal with the
technological advancements in the field of solar cells. New types of solar cells (DSSC
and OSC, which stand for ‘Dye Sensitized Solar Cells’ and ‘Organic Solar Cells’,
respectively) have the potential to generated electricity at very low cost, however
they require further improvements. The abstracts of each of these four chapters are
as follows.
Chapter 15: Utilization of renewable sources can reduce the impact of increasing
global energy demand on the rate of depletion of fossil fuels. One of the most studied and implemented routes to meet this energy demand is to harvest solar energy.
Among solar-energy harvesting devices, dye-sensitized solar cells have been recognized as some of the cheapest and most environment friendly technologies, since they
do not require high purity of starting materials or advanced fabrication techniques.
A dye-sensitized solar cell is composed of a working electrode, in which the light