Roof-mounted PV in

Cyclonic Areas

• Established in 2007 by Centre for Appropriate Technology (Indigenous Science and Technology organisation)

• Engineering consultancy specialising in project management and renewable energy systems

• Previous projects include Desert Knowledge Australia Solar Centre, Crowne Plaza PV system (304kWp), Alice Springs Airport (235kWp)

• Project managers for Bushlight India project – adapting the Bushlight Australia program for an Indian context with pilot projects in Orissa and the Sunderbans (a cyclone prone area)

Bushlight Australia

• Close relationship with Bushlight, a Department of CAT

• a program installing stand alone PV systems in remote Indigenous communities across Australia

•

•Geboowama•Baas Yard

•Kununurra •Fitzroy Station

•Millibunthurra•Goojarr Goonyool•Jimbilum

•Sandridge

•Fish Hole •Gulburang

•Dingo Spring •Wandangula

•Lingara•Scrubby Bore •Larinyuwar

•Gnylmarung

•Tirralintji•Kulumbulani

•Jingaloo•CAIRNS

•Jabir Jabir•Violet Valley

•DERBY

•Communities with Bushlight RE Systems 2002 - 2011

•Communities where Bushlight has

implemented its Community Energy

Planning Model and established a

Renewable Energy System. •Paradise Farm

•Kapalga

•Galawdjapin Mata Mata•Ji-Bena

•DARWIN

•Katherine

•Kabulwarnamyo •Ji-Marda

•Ji-Malawa•Murrungga

•Bawaka

•Gutjangan

Gurrumuru

•Patonga Homestead

•Chile Creek

•Djugarargyn

•Munget•Maddarr

•Nhulunbuy

• Emu Springs

Mount Catt

•Balma

•Yedikba

•4 Mile

•Yanbakwa

•Mirrnatja

•Kulpa

•Chuula

•Coen

•Puntimu

•Theethinji

•Kewulyi

•Ganiyarrang •Wumajbarr

•WuyagibaWanduWarpaant

•Wada Warra •Penkelthen•Glen Garland

•Broome

•Wanamulyandong

•Yandarina

•Jilayria

•Ngarantjadu

•Bedunburru Balginjirr

•Mt Anderson •Fitzroy Crossing •Kartang Rija

•Birri Williams

•Lametha

•Mingalkala

•Kurlku

•Lul-tju•Blue Bush •Likkaparta

•Gunun Woonun

•Gubbangurru

•Barawoorooga NgapagunpaConnells Lagoon

•Kitty Well Gunbah•Pitulki

•Mungalawarru

•Tennant Creek •Kurraya

•Nguyarramini•10 Mile

•Mount Isa

•Hatches Creek

•Mt Dennison

•Mt Theo •Pulardi

•Petyale •Angula

•Illya Pinu

•Karrinyarra•Alyuen

•MulgaBore •Urlampe

•Mt Eaglebeak

•Irrerlirre

•Warren Creek •New Bore •Corkwood Bore

•Panels Well

•Bushlight RE Systems •Ulpanyali

•ALICE SPRINGS •Ponya

•Undoolya Bore

•Snake Well

Gillen Bore

•Alatyeye•Wanmarra

•Ipolera•Mt Peachy

•Main roads •Ukaka •Arkanta #5 Bore

•John Holland North

•Spring Peak

•Patonga Airstrip •Silver Plains

•Moojeeba

Cyclone Monica

17-25 April 2006

Cyclone Monica

17-25 April 2006

•

•Geboowama•Baas Yard

•Kununurra •Fitzroy Station

•Millibunthurra•Goojarr Goonyool•Jimbilum

•Sandridge

•Fish Hole •Gulburang

•Dingo Spring •Wandangula

•Lingara•Scrubby Bore •Larinyuwar

•Gnylmarung

•Tirralintji•Kulumbulani

•Jingaloo•CAIRNS

•Jabir Jabir•Violet Valley

•DERBY

•Communities with Bushlight RE Systems 2002 - 2011

•Communities where Bushlight has

implemented its Community Energy

Planning Model and established a

Renewable Energy System. •Paradise Farm

•Kapalga

•Galawdjapin Mata Mata•Ji-Bena

•DARWIN

•Katherine

•Kabulwarnamyo •Ji-Marda

•Ji-Malawa•Murrungga

•Bawaka

•Gutjangan

Gurrumuru

•Patonga Homestead

•Chile Creek

•Djugarargyn

•Munget•Maddarr

•Nhulunbuy

• Emu Springs

Mount Catt

•Balma

•Yedikba

•4 Mile

•Yanbakwa

•Mirrnatja

•Kulpa

•Chuula

•Coen

•Puntimu

•Theethinji

•Kewulyi

•Ganiyarrang •Wumajbarr

•WuyagibaWanduWarpaant

•Wada Warra •Penkelthen•Glen Garland

•Broome

•Wanamulyandong

•Yandarina

•Jilayria

•Ngarantjadu

•Bedunburru Balginjirr

•Mt Anderson •Fitzroy Crossing •Kartang Rija

•Birri Williams

•Lametha

•Mingalkala

•Kurlku

•Lul-tju•Blue Bush •Likkaparta

•Gunun Woonun

•Gubbangurru

•Barawoorooga NgapagunpaConnells Lagoon

•Kitty Well Gunbah•Pitulki

•Mungalawarru

•Tennant Creek •Kurraya

•Nguyarramini•10 Mile

•Mount Isa

•Hatches Creek

•Mt Dennison

•Mt Theo •Pulardi

•Petyale •Angula

•Illya Pinu

•Karrinyarra•Alyuen

•MulgaBore •Urlampe

•Mt Eaglebeak

•Irrerlirre

•Warren Creek •New Bore •Corkwood Bore

•Panels Well

•Bushlight RE Systems •Ulpanyali

•ALICE SPRINGS •Ponya

•Undoolya Bore

•Snake Well

Gillen Bore

•Alatyeye•Wanmarra

•Ipolera•Mt Peachy

•Main roads •Ukaka •Arkanta #5 Bore

•John Holland North

•Spring Peak

•Patonga Airstrip •Silver Plains

•Moojeeba

Cyclone Ingrid

6 -16 March 2005

Cyclone Ingrid

6 -16 March 2005

Characteristics of a Cyclone

Picnic Bay Surf Club,

Magnetic Island,

TownsvillePhotograph Courtesy, Ergon Energy

• Legislative considerations for PV installations in

cyclonic and non-cyclonic regions

• Design engineering considerations and

explanation for wind loading on domestic housing

and PV modules

• Practical considerations on the job

Extract from Building Code of AustraliaCurrent Mandatory Requirement

Extract Standards Australia AS1170.2 :2002

Extract Standards

Australia AS1170.2 :2002

Basic Design Wind Pressure, p (kPa) = 0.6 x V2 x {other factors}

where V wind speed in metres/sec

• Terrain Category

• Shielding

• Topography

Site Exposure considerations

No

Partial

Full

• Roof geometry

• Wind discontinuities

• Local pressure factors

• Edge conditions

• Special Features

Structural considerations

Aerodynamic Shape& pressure coefficients

Additional Factors for Roofing

components and PV roof mounted

systems

Table 3 Net pressures coefficients for PV panels based above pitched roofs

Wind tunnel Full-scale BS6399-2 flat canopy roof data

study study (1) (1) (1)

Zone AbZone Bb Zone Cb

Positive pressure +0.83(2) +0.97(2) +0.5 +1.8 +1.1

Negative pressure -0.94(2) -0.73(2) -0.6/-1.3(3) -1.3/-1.8(3) -1.4/-2.2(3)

1. Zone A is the central roof area, Zone B is the side edge areas (parallel to the wind),

Zone C is the windward and leeward edge area.

The width of the edge areas is taken as 10% of the largest plan dimension of the roof.

1. These measurements were given as peak pressure coefficients; to be compatible with

BS6399-2 they have been converted to mean pressure coefficients.

2. The first value is for the case with the canopy fully open beneath; the second value is for

the canopy fully blocked.

Source: BRE Digest Wind Loads on roof-based photovoltaic systems Digest 489

Extract Standards

Australia AS1170.2 :2002

Local Pressure Factors at Eaves, Ridges

and Gable Ends

• Before commencement

• During construction

• Upon completion

Practical considerations

• Before work commencement

1. Check Design Documentation in accordance with BCA and Design Standards

• Assumptions in design documents accord with local conditions, design wind loads,

terrain category

• Review any specific geometric design limitations, hip and minimum edge distances

2. Inspect Building structure

• Record and photograph as –built condition

• Determine any inconsistencies of the design layout with the building geometry

• Alert Engineer to any structural concerns you might have. Existing building and roof

frame, roof cladding, fixings for corrosion, previous damage etc

Practical design considerations

Practical design considerations

• During construction

1. Record and photograph agreed system changes and deviations from the

original design

2. Fixings to building structure and Component connection eccentricities

• Ensure installation methodology is agreed and recorded with the Engineer

• Prevent bimetallic corrosion - Isolate dissimilar materials

• Refer any concerns and latent conditions with the Engineer. They have a duty of

care to ensure any modifications to the existing building don’t compromise its

structural integrity

3. Weatherproofness and securing of cabling and ducting

• Preven ion of future debris build up under modules

Practical considerations

• On Completion

1. Check installation for compliance with Design documentation and agreed

changes before Final Inspection.

2. Record, photograph and sign off Snagging List

3. Archive as-built construction documentation

Conclusion and Questions