Solar Builder

JUL-AUG 2018

Solar Builder focuses on the installation/construction of solar PV systems. We cover the latest PV technology (modules, mounting, inverters, storage, BOS) and equip installers/contractors with tips and tools to make informed purchasing decisions.

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SOLARBUILDERMAG.COM | 35 self-powering starts with a small, 30-watt panel mounted above the motor to provide power to a lithium-iron battery. Eff iciencies in design cascade from there. "Most trackers you run AC power coming into the f ield and don't usually use parasitic power off the modules, so you run AC wire to every drive post in the array," Daniel says. "With self-powered, you eliminate all of that and the switch gear you need to have come into the f ield. This decreases installation and BOS costs signif icantly. It does increase O& M costs a bit, but there's more eff iciency in installation and much less wiring. Before the TCU on the TDP 2.0, you'd have one tracker control unit that serviced 4 tables, which meant you'd be run- ning DC wiring from one TCU to the motors on the other three tables. Added together, that's a decent chunk of DC wir- ing. The TDP 2.0 has one TCU per table mounted directly onto the torque tube under panels and next to the motor. This limits DC wiring to a 3 -ft whip cord from the TCU to the motor. The next tweak was bumping the rotation up to +/- 55 degrees, which analysis shows is the optimal angle for captur- ing that morning and late day production and generating as much revenue as possible. Producing more power late in the afternoon is becoming more important, especially in California with the changing rate structure. "We tried 60 degrees but realized it was such a sharp angle, we weren't going to get much more energy yield out of that design. The 55 degrees is the most eff icient," Daniel says. Still a market for version 1? While the expectation is the TDP 2.0 product will be in demand, there is still a market for the original 60-panel version. The TDP 2.0 is more of a utility-scale space solution, so the original TDP might still be the better route for projects in the 1- to 5-MW range where the economics of a 90-panel array might not pencil out. "For some, 60 works well," Daniel explains. "Lot of farmers in Central Valley understand actuator motors and are comfortable with that design. It's a nice solution in the small C&I DG space, and we don't want to mess with that. We're providing choices." "With a 1,000 volt system, the table sizes tend to be 18, 19, 20 and the math doesn't work as well," Daniel says. "The closer you get to 90 panels, the more eff icient the design is because you're amortizing the cost of the controller and motor over more panels. But if you have say 20 modules in a string, you can put four of those strings on the TDP 2.0, and only get to 80 modules. So you don't get the eff iciency of getting close to 90." The move to 1,500 volt business makes this step up to 2.0 imperative because the string sizes will be 27, 28, 29 or 30 usu- ally, which translates to three strings of 81, 84, 87 or 90. "I don't think we lost deals by not having this, but it certainly opens up more of the market for us," says Steve Daniel, EVP of Sales and Marketing for Solar FlexRack. "People are moving toward self-powered trackers in certain areas, mostly where the sun is reliable and it doesn't get too cold." Second generation tracker the result of slow and steady engineering By Chris Crowell Intersolar Preview See the TDP 2.0 for yourself Tough, reliable, and c o s t - c o m p e t i t i v e , Solar FlexRack intro- duces their new, advanced TDP 2.0 Solar Tracker for com- mercial and utility- scale ground mount solar installations. The TDP 2.0 Tracker's new BalanceTrac design offers more modules per row (up to 90), a rotational range of up to 110° and is compatible with 1,000V and 1,500V crystalline and thin film modules. This solution allows for shorter piles and lower per-unit fixed costs for balance of system savings. The combination of complete project support services and this next-genera- tion technology enables solar power plants to increase energy yield while significantly reducing project risks. The results are cost savings across your solar project budget. Booth 9619

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