Solar Panels Arrays
Innovation and Structural Considerations
With the increased implementation of green-building practices, concepts from the past have been resurrected and are being presented as advancements within the construction industry.
The evolution of solar panels has progressed considerably since the emigrant Californians invaded Oregon in the 1970s with their geodetic domes, "holistic" gardens and Dialing for Dollars with McCormick and his puppet characters, Charley and Humphrey. At that time, solar panels were homegrown - I mean home built - and were used to run the florescent lights, off the grid, nurturing "holistic" gardens in people's garages. They never moved their VWs into the garage - very strange.
Today, solar panels implement a combination of revolutionary materials to drive efficiencies from below 10% to the high teens. SunPower model 215: an individual 32"x62" panel produces 215 watts at 17.3% efficiency.
Current solar panel systems have been refined to "stand off" current roofing material with sufficient attachment to withstand wind uplift loads, while providing adequate ventilation below the panel for maintenance purposes.
Since solar panels are typically installed postconstruction, the additional
2.4 lbs./square foot beyond the existing roofing material weight may warrant evaluation of the current roof structure, reinforced concrete, concrete composite deck, metal pan with foam insulation or wood assembly for its ability to vertically support the added assembly. Also, the added panel weight may increase the seismic lateral loads at the roof level sufficiently enough to exceed the existing shear wall panel capacities and/or wind loads. Solar panels will act as hydrofoils even on flat roofs, creating uplift connection and framing concerns. Thus, within high wind or seismic regions, having a structural review and implementing recommendations by an engineer may be prudent.
COMMERCIAL APPLICATIONS
Solar panel arrays are rapidly appearing within new retail construction as well as existing buildings, which are being structurally evaluated/rehabilitated to accept rooftop-mounted solar panel arrays and associated equipment: control panels/converters.
The electricity produced utilizing the rooftop-mounted arrays are easily powering the interior store lights for thousands of big box stores like Macy's, Lowe's, Target and Walmart; imagine the number of arrays you can put on a 50,000 square-foot box store.
Solar arrays have been recently accepted by commercial building owners without reservation and have been used for green campaigning to customers and tenants. But who wouldn't be bragging about being ecologically friendly, as their rooftop-mounted arrays convert up to 22% of available sunlight into electricity!
TRANSPARENT RESISTORS: NANOTECHNOLOGY
Remember those emigrant-Californians? Apparently, their offspring are now researchers at Oregon State University (excellent school … OK, I'm an OSU '82 grad) and have in the past couple of months collaborated with HP to develop transparent transistor and optoelectronics (thin film), creating a solar energy system that is expected to be twice as efficient and half the cost of traditional solar panels. GO BEAVERS!
Solar energy is present every day (unless you are in Alaska, then you get really long days or really long nights). We have hundreds of millions of accessible square feet of retail rooftops in the USA, which all see the light of the sun. Our task is to effectively and consistently capture this energy resource with rooftop-mounted solar panel arrays while folding it into current designs, architectural and structural, which enable the installation of optional solar equipment.
September 2008 Commercial Edition Issue