PV Mounting Systems - damon`s solar training

Report
Grid-connect
Session 7a
2/11/2014
DAMON FYSON
1
Grid-connect
Session 3
PV Mounting Systems
The two main types of PV
mounting systems; roof mounted
and ground mounted
Ground mounted are used for
massive ‘green field’ power
station installations
. Typically these systems
generate 60-70 MWp
Roof mounted system are
governed by many regulations,
load bearing, wind loading,
paramount; the PV modules are
installed on fireproof material
predominantly a tin or tiled roof
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Session 3
PV Mounting Systems
AS/NZS 1170.2:2011
Australian/New Zealand
Standard™
Structural design
actions
Part 2: Wind actions
SOURCE: http://www.civicsolar.com/resource/wind-loadcalculations-solar-pv-arrays
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Grid-connect
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PV Mounting Systems
AS/NZS 1170.2:2011
SCOPE
This Standard sets out
procedures for determining
wind speeds and resulting
wind actions
to be used in the structural
design of structures
subjected to wind actions
other than those
caused by tornadoes.
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Grid-connect
Session 3
PV Mounting Systems
Today’s photovoltaic
(PV) industry must
rely on licensed
structural engineers’
various interpretations
of building codes and
standards to design
PV mounting systems
that will withstand
wind-induced loads.
SOURCE: http://www.civicsolar.com/resource/wind-load-calculationssolar-pv-arrays
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Grid-connect
Session 3
PV Mounting Systems
Source: http://www.csiro.au/files/files/pis7.pdf
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Grid-connect
Session 3
PV Mounting Systems
Region A
Most of Australia is
designated Region A which
indicates a Region Basic
Wind Velocity of 41ms.
Region B
Region B indicates a
Region Basic Wind
Velocity of 54ms. Local
authorities will advise if
this applies in the area.
Region C
Region C indicates a Region
Basic Wind Velocity of 57ms
and is generally refered to as
cyclonic. These conditions are
generally limited to norhtern
coastal areas.
Region D
Region D (69ms) almost
never occurs. Only use
this if you know for sure
it is what is required
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Grid-connect
Session 3
PV Mounting Systems
Install PV panels on a tin roof
The following four slides illustrate the main steps
Web: www.powersmartsolar.com.au
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Grid-connect
Session 3
PV Mounting Systems
Install PV panels on a tin roof
Web: www.powersmartsolar.com.au
2/11/2014
DAMON FYSON
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Grid-connect
Session 3
PV Mounting Systems
Install PV panels on a tin roof
Web: www.powersmartsolar.com.au
2/11/2014
DAMON FYSON
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Grid-connect
Session 3
PV Mounting Systems
Install PV panels on a tin roof
Web: www.powersmartsolar.com.au
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Grid-connect
PV Mount orientationing Systems
Session 3
Roof mounting systems allow solar
modules to installed portrait or landscape
orientation
SOURCE renewableheatingcompany.co.uk
Typical rectangular 24v modules 1600 x 800mm may be supported by two
rails either across the long or short side. However many manufactures may
only provide warranty for modules clamped on 1600mm side. Clamping on
the 800mm side may not allow structural integrity of the module to
withstand strong suction force caused by wind blowing over them, buckling
may result with cracks in the glass
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Grid-connect
Session 3
PV Mounting Systems
Integrated
Customers and architects may prefer the look
of an installation where the solar modules
become a integral part or the roof
Source:www.google.com.au/imgres?imgurl=http://www.enviora.com/blogs
/media/blogs/enviora/sunrunpowertiles-
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Grid-connect
Session 3
 PV Mounting Systems
Tiled roof
Normal tiles require a tile hook
that attaches flush to the rafters
underneath the tiles, with a goose
neck design having a protruding
arm for attachment of rail
mounting system
Tile hook for lateral rail connectionSource:Creotecc - Roof Hook CREOFIX
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Grid-connect
Session 3
PV Mounting Systems
Non-Penetrating Roof Mount System
Penetrations to roof structure that uses concealed
fixings may void roof warranty on a ‘Klip-Loc’ roof
these type on mounting bracket may be used.
Source: KlipKlamp Roof Mounts
facebook.com
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Grid-connect
PV Mounting Systems
Session 3
PV Array Row Spacing On a flat roof, raking of the arrays
may be an alternative solution to boost yield, however
Note the
consideration must be given so that one row of modules
shadow
does not cast a shadow on the row behind
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PV Mounting Systems
PV Array row spacing …
‘I need to quote on a PV system on a
flat roof. ‘
The PV modules will be on tilted
frames facing true North to optimise
energy production
How do I calculate the distance
between PV Array rows to avoid winter
mid-day shading ?
Remembering back to high school
math classes there was something
called Trigonometry
source: Clear Energy Council
NOW YOU HAVE A USE FOR IT
for any right angle triangle…
if you know one angle and the length
of any side you can calculate the
length of the other two sides
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Grid-connect
Session 3
PV Mounting Systems
NOTE : This calculation gives the
MINIMUM
row spacing to avoid 10:00am to
2:00pm shading
at the Winter solstice ( ~ June 22 )
PV Array row
spacing …
SOURCE: Clear Energy Council
1. You know the length of the PV module - from the manufacturers data - and you have selected the optimum tilt
angle. e.g. 1600mm and 30°
2. You then calculate height X e.g. Sin Tilt ° = X / 1600 … X = Sin 30° x 1600mm
= 0.5 x 1600 = 800mm
It is recommended that the row spacing avoids shading between 10:00am and 2:00pm at the Winter Solstice ( ~
June 22 ) refer to Table 1 on page 2.
3. the minimum spacing (Y) between rows can now
be determined… Row spacing Y = X x Cos ( azimuth angle ) Tan ( altitude angle )
e.g. The PV array is located in SYDNEY - Latitude 34°S
Azimuth = 31° and Altitude = 26°
Y = X x Cos 31° / Tan 26° = 800mm x 1.757 = 1406 mm
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Grid-connect
Session 3
PV Mounting Systems
PV Array row
spacing …
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Grid-connect
Session 3
How Solar
Trackers Work
Solar trackers help
maximize the sunlight
absorption rate by
minimizing the angle of
incidence at which
sunlight hits the solar
panels. This in turn
improves the conversion
efficiency so the highest
amount of power is
generated from a fixed
amount of sunlight during
the day.
The diagram shows how
solar trackers can move
photovoltaic panels
horizontally and vertically
in order to effectively
utilize sunlight
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PV Mounting Systems
(Image credit: www.solar-tracking.com)
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Solar Trackers Work
PV array tilt angle (0° to 90°)
Source; http://rredc.nrel.gov/solar/calculators/PVWATTS/system.html
For a fixed PV array, the tilt angle is the angle from horizontal of the inclination of the
PV array (0° = horizontal, 90° = vertical). For a sun-tracking PV array with one axis of
rotation, the tilt angle is the angle from horizontal of the inclination of the tracker
axis. The tilt angle is not applicable for sun-tracking PV arrays with two axes of
rotation. The default value is a tilt angle equal to the station's latitude. This normally
maximizes annual energy production. Increasing the tilt angle favors energy
production in the winter, while decreasing the tilt angle favors energy production in
the summer
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Grid-connect
Session 3
PV Mounting Systems
Solar Trackers
The Solar Tracker is a device capable of turning after the Sun, which means
following the Sun’s track from its rising in the east to its setting in the west
Because the Solar Tracker turns after the Sun all day long, the solar panels
are set to face the Sun directly all day long, and so is their performance
substantially enhanced.
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Grid-connect
Session 3
2/11/2014
PV Mounting Systems
DAMON FYSON
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Grid-connect
Session 3
PV Mounting Systems
http://rredc.nrel.gov/solar/calculators/PVW
ATTS/system.html great site for example of
yield
http://www.orer.gov.au/installers/index.htm
l clear energy council
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