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Solar Design Manual 8.qx HydroTemp 7/3/12 6:33 PM Page 1Solar Design ManualAluminum extrusion,a world ofopportunities

Solar Design Manual 8.qx HydroTemp 7/3/12 6:33 PM Page 2Aluminum — The material of the futureAluminum has been described as the “materialof opportunity” and more and morecompanies in the solar industry are realizingthe obvious benefits of using aluminum.A significant benefit of aluminum and thealuminum extrusion process is the almostunlimited opportunity to adapt the shape of theproduct to optimize performance, maximizestiffness and strength, and reduce the numberof parts to assemble and fabricate; all of whichcontribute to lowering cost. The low density ofaluminum can also ease handling andtransportation throughout the supply chain bycreating lighter weight components andassemblies. And, aluminum is highly durable,almost maintenance-free, and 100% recyclable.www.hydro.com/northamerica/solarAs it relates to solar applications, aluminum’sunique properties include: High strength-to-weight ratioVery cost effective, with proper system designExcellent formability and ease of fabricationExcellent electrical and thermal conductivityExcellent resistance to corrosionAttractive surface finishExcellent reflector of light and heatEasy and economical recycling

Solar Design Manual 8.qx HydroTemp 7/3/12 6:33 PM Page 3Table of ContentsSolar applications for aluminum extrusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4PV and solar thermal collector module frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Solar mounting systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Solar inverters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Solar thermal applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5PV solar frame & mounting system design considerations . . . . . . . . . . . . . . . . . . . . . 6IBIS PV mounting structure analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Concentrating Solar Power (CSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10IBIS CSP frame structure analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Solar thermal design considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Aluminum, the green metal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16The properties of aluminum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Aluminum alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Corrosion resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Types of extrusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Extrusion design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Joining options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Anodizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Hydro plant capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29North American resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Solar Design Manual 8.qx HydroTemp 7/3/12 6:33 PM Page 4Solar applications for aluminum extrusionsPV and solar thermal collector module framesPhotovoltaic (PV) and solar thermal arraysdeliver efficient, environmentally-friendlyalternatives to fossil-fuel-based powergeneration. Technological advances have led tolower production and installation costs. Amongthese advances is the use of creative design withaluminum extrusion components in the framestructure and other areas of the solar array.With the number of solar parks androoftop installations increasing, people arebecoming more concerned about the aestheticsand maintenance of the array structure. Ownersand operators are looking to solar as a source ofenergy while remaining as unobtrusive aspossible. Architects desire solar systems thatblend in with the rest of the building andsurrounding area.Extruded aluminum frame structures meet orexceed the strength and flexibility requirementswhile delivering a lower lifetime cost comparedto steel frames, especially with a properlydesigned custom solution. Aluminum alsoprovides a high level of aesthetic appeal throughanodizing or powder coating to achieve thedesired surface finish. And, an aluminum framestructure will remain free of rust and resistantto corrosion for the life of the structure.Long life, simple design, easy installation,and greater aesthetic appeal over the life of thestructure – combined with lower lifetime cost –makes aluminum the metal of choice for solar.Solar mounting systemsSolar mounting systems attach the solar panelarray to either the ground or rooftop forresidential and commercial applications. Forrooftop installations, a variety of frame designsare used depending on whether the system ismounted to a pitched or flat roof.Aluminum ideal for rooftop weight limitationsExisting rooftops typically were not designed tosupport the weight of a solar installation. Butthe low density of aluminum helps to make asolar installation feasible, especially on thoserooftops that simply cannot handle the highweight of a steel frame structure.Aluminum extrusions deliver superiordesign flexibility, high strength-to-weight ratio,excellent corrosion resistance and ease ofhandling and assembly – all of which areessential for a successful commercial rooftopinstallation. These characteristics makealuminum the metal choice for solar framestructures installed on carports, commercialbuildings and home rooftops.4www.hydro.com/northamerica/solarGround installationAluminum extrusions are ideal for PV and CSPconstruction because they provide: Stiffness to maintain reflector geometry at alltimes (CSP) Strength to withstand the dead and live loads Excellent durability and corrosion resistance Ease of assembly Lower Total Cost of OwnershipWith aluminum, you gain a lightweightstructure that is easy to handle, transport, andinstall; a structure which is easy to maintainover a long life and resistant to the corrosiveeffects of weather. Aluminum is especiallydesirable for solar parks constructed overlandfills or other areas where escaping gases orother environmental impacts may corrode steelframe structures.

Solar Design Manual 8.qx HydroTemp 7/3/12 6:33 PM Page 5Solar invertersA solar inverter changes the direct current(DC) electricity produced by a photovoltaicarray into alternating current (AC). AC is thetype of current used in commercial andhousehold electrical applications.Inverter cabinetsInverter electrical components are housed in acabinet that can be produced using aluminumextrusions for a cost-effective and highlyutilitarian result. Aluminum inverter cabinetsare lighter weight and offer greater designflexibility than steel cabinets. Aluminumextrusions deliver a faster prototyping capability.With aluminum extrusions you gain theability to create complex enclosures using twoor more simpler extrusions. You can simplifyassembly and optimize product performancewith aluminum. Select your choice of a varietyof finish options, like anodizing. Certain finishattributes, like decorative grooves, can bedesigned into the extrusion. The end result is alower cost, corrosion resistant, lower weightcabinet that also offers the possibility of addingmore components without adding significantlyto the original weight.Heat sinksHeat sinks are used in inverter cabinets todissipate heat. The efficiency of a heat sinkdepends on its ability to transfer heat quicklyaway from the components that requirecooling. Good heat transfer is achieved byusing materials of high thermal conductivitythat can be shaped to give high surface areas.Aluminum extrusions satisfy all of theserequirements, and can be integrated into thestructure.The extrusion process allows you toproduce components in many shapes and sizessuch as the closely spaced narrow fins requiredin heat sinks for heat dissipation. Incomparison to other materials the combinationof aluminum and shape results in lower costcomponents.Solar thermal applicationsAluminum extrusions offer a variety ofsolutions for solar thermal collectors andconnecting lines. For all absorbers, substitutingcopper tubes with aluminum gives immediatecost and weight advantages.Plate and tube absorbersAluminum offers long life, ease of installation,high strength and low corrosion compared toother tube materials such as copper. Thealuminum alloys used to produce solarabsorber tubes meet or exceed all requirementsfor the solar absorber market with excellentflow rate and heat transfer properties.High performance absorbersUsing aluminum in solar absorbers provides theneeded flexibility to implement novel designsolutions (e.g. combining plate and tube).Micro-channel profiles may be assembled tomanifolds and coated to combine the functionsof heat absorption and fluid transport.Connecting linesWith interest in the use of aluminum inabsorbers increasing, it is natural to extend thisto connecting lines, where the cost advantagesare obvious.Extruded aluminum tubing products havebeen proven for handling hot liquids in theautomotive, trucking, specialty vehicle anddefense industries, among others. Withaluminum tube connector lines, you will takefull advantage of the many proven propertiesof aluminum, including its ability to resistdamage in corrosive conditions, non-magneticand non-sparking, lightweight and highstrength. Aluminum delivers design flexibility,high performance, efficiency, reliability andlow cost.5www.hydro.com/northamerica/solar