3. INTRODUCTION
• Solar Energy reaching the earth is
incredible. By one calculation, 30 days
of sunshine striking the Earth have the
energy equivalent of the total of all the
planet’s fossil fuels, both used and
unused!
• All chemical and radioactive polluting
byproducts of the thermonuclear
reactions remain behind on the sun,
while only pure radiant energy reaches
the Earth.
4. INTRODUCTION
• The surface receives about 47% of the total solar
energy that reaches the Earth. Only this amount
is usable
5. Two categories of Solar
Energy
• Active Solar: A method specifically designed to
acquire energy from sun and move it to where
needed, including:
o Photovoltaic electric power generation
o Solar Thermal power generation
o Active solar heating using solar collectors
• Passive Solar: A design of buildings that
inherently takes advantage of the sun for
daylighting and winter heating, and avoids solar
gain in summer to minimize need for cooling.
6. Passive Solar
• Passive solar architecture has been practiced by people living
in hot regions of the world for millennia, eg. Adobe style.
• A good example of contemporary passive solar architecture
are Auroville
7. While designing
• Latitude, sun path, and insolation (sunshine)
• Seasonal variations in solar gain e.g. cooling or
heating degree days, solar insolation, humidity
• Diurnal variations in temperature
• Micro-climate details related to
breezes, humidity, vegetation and land contour
• Obstructions / Over-shadowing - to solar gain or
local cross-winds
• Landscaping and interiors also play a major role.
8. TOPICS COVERED:
• SUN CHART
• SUN PATH
• SHADED ENVELOPE
• LIGHT PIPES
• BUILDING ORIENTATION
• THERMAL MASS
• TROMBE WALL
• SOLAR CHIMENY
9. SUN CHART
• A Sun chart is a graph of the ecliptic of
the Sun through the sky throughout
the year at a particular latitude.
• Most sun charts plot azimuth versus
altitude throughout the days of the
winter solstice and summer solstice, as
well as a number of intervening days.
Since the movement of the Sun is
symmetrical about the solstice, it is
only necessary to plot dates from one
half of the year.
10. SUN CHART
• The graph may
show the entire
horizon or only
the half of the
horizon closest
to the equator.
Sky view
obstructions can
be superimposed
upon a Sun chart
to obtain the
insolation of a
location.
12. SUN PATH
• South orientation receives maximum solar
radiation during winters which is preferable as
composite climate receives severe winters. East
and West receive maximum solar radiation during
summer.
• West is a crucial orientation because high
intensity of solar radiation is received during
summers.
• Orientation also plays an important role with
respect to wind direction.
15. SHADED ENVELOPE
• All the elements of a building are
vulnerable to heat gains. Proper
shading is therefore a very important
aspect in solar passive building design.
SHADING OF ROOF:
• Shading of roof through design
features like pergolas or solar
photovoltaic panels helps in reducing
the incident direct solar radiation on
the roof surface.
17. SHADING OF WINDOWS:
• Incorporation of shading elements with
windows help in: keeping out the sun‘s
heat, block uncomfortable direct
sun, and soften harsh daylight
contrasts. Shading devices are
therefore necessary to allow glare free
natural light.
• Shading devices for windows and walls
moderate heat gains into the building.
20. SHADING OF WALLS
• Shading walls from direct sun can be one of the
simplest and most effective ways of reducing the
heat load on a building.
Impact of shaded wall:
• In day time use buildings shaded east and west
walls have higher energy saving potential than
insulating the external walls.
• The different kinds of shadings for wall are
explained below:
21. DIFFERENT KINDS OF SHADING
Deep porches and verandas:
• These are excellent at reducing the
solar heat gain in a building because
they completely shade the walls.
•
22. DIFFERENT KINDS OF SHADING
Sun-proof fabric covers:
• For porches, or sails these can be attached to the
building itself, and are a good seasonal solution.
23. DIFFERENT KINDS OF SHADING
Vertical shading:
• Vertical shading is the most advisable
form of shading to cut the intensive
solar heat gains for east and west walls
especially in summer.
25. LIGHT PIPES
• Light tubes or light pipes are used for
transporting or distributing natural or
artificial light. In their application of
day lighting, they are also called as
sun pipes, solar pipes, solar light
pipes, or day light pipes.
• They make it possible to transport
daylight through thick roof structures
and attics. They are easier to install in
retrofit applications than skylights.
27. BUILDING ORIENTATION
• A building must face the south in order
to capture the sun’s energy.
• The long side of the house should be
on an east - west axis.
28. THERMAL MASS
• A material that has thermal mass is one that has
the capacity to absorb, store and release the
sun’s heat energy.
• Its density and levels of conductivity help to keep
the internal temperature of a building stable.
• Objects that have thermal mass have inherent
qualities for both heating and cooling.
29. TROMBE WALL
• The Trombe wall absorbs and radiates
solar heat in the winter, while its mass
keeps the house cool in the summer.
• The Trombe wall is painted black to
absorb the maximum amount of solar
heat.
30. TROMBE WALL-PRINCIPLE
• A Trombe wall combines the principles of thermal
mass and a solarium.
• A trombe wall consists of a sun-facing high
thermal mass wall with vents at the top and
bottom, placed behind insulated glazing with an
air gap in between; together they act as a large
solar thermal collector
32. TROMBE WALL-APPLICATION
• During the day, the air between the glazing and
the thermal mass wall gets heated up and flows
through the vents into the interior space via
convection, thus warming the interior space.
• At the same time the thermal mass wall absorbs
and stores the incident solar radiation.
• During the night, the vents are closed and the
thermal mass radiates the stored heat into the
interior space through conduction and radiation.
33. SOLAR CHIMNEY
PRINCIPLE
• A solar chimney often, referred to as a
thermal chimney is a way of improving
the natural ventilation of buildings by
using convection of air heated by
passive solar energy.
• In its simplest form, the solar chimney
consists of a black-painted
chimney, with a partly glazed surface
area towards the top.
34. PRINCIPLE
• During the day, solar energy heats the chimney
and the air within it, creating an updraft of air in
the chimney.
• The suction created at the chimney's base can be
used to ventilate and cool the building below
through stack effect.
37. LIGHT SHELF-PRINCIPLE
• A horizontal shelf positioned (usually
above eye level) to reflect daylight
onto the ceiling and to shield direct
glare from the sky.
• It will result in a more even light
gradient.
• This indirect light supplements and/or
delays the artificial lighting
requirement and thus reduces energy
consumption
38. LIGHT SHELF-APPLICATION
• A light shelf is a horizontal element installed
within a window to divide it into two sections.
• The light shelf is opaque, with a highly reflective
upper surface and a diffusing white under
surface.
• Generally, the light shelf will split the window
with one third of the glazing above and two thirds
below.
• This will allow reflection of both daylight and
sunlight up on to the ceiling, whilst not
obstructing the view through the window.
