Tilt in Action: Meet the Fourth Generation Tracker from AllEarth Renewables 

Not all tracking systems need acres of land. All Earth Renewables offers an alternative to rooftops for those doing residential and small C&I work. Now on its Generation 4 Solar Tracker, AllEarth is building on the strengths and history of the first three generations. Here is what’s changed:

Structure

Made from a single-piece steel tubular axle for a sleeker look and lower part count, the biggest change is in the move from hydraulics to electrical motion actuators for tilt and yaw. “This eliminates dealing with hydraulic fluid,” according to mechanical engineer Tim Hoopes. “The electrically driven Planetary Gear Motors have a helical first stage to minimize noise for smooth and quiet operation.”

For yaw, power to the motor is ramped up and down by a pulse width modulation (PWM) algorithm in the control system to minimize impact loading for smooth operation and long life. Hoopes says this is also more energy efficient with all controls and operation using less than 1 percent of the energy production.

A custom linear actuator is used to achieve the tilt motion. The actuator design uses a large diameter ACME threaded rod for column strength.

RELATED: Why solar is a ray of hope for struggling retail industry

“We have married the strength of the hydraulic cylinder with the reliability of electric drives,” Hoopes says. “The motor is the same as the yaw system for a low part count, and a tilt feedback sensor allows for greater positional accuracy.”

Gen 4 also has continuous operation during a grid power outage. It will always go into wind hold (high wind speed shutdown where the tracker goes flat to survive hurricane force winds) since all controls are run off the 24-volt DC battery backup. The batteries are charged from the tracker PV modules with redundant chargers on two PV strings.

The inverter is mounted lower down on the mast for improved accessibility and wiring. Gen 4 also allows installation of the inverter in locations away from the tracker, which is cool when using a larger three-phase string inverter for combining two to three trackers.

Software

For Generation 3, AllEarth Renewables used a modular approach on the circuit board designs for easier installation and removal in the unlikely event of a board failure. According to Seth Maciejowski, embedded systems engineer, on the internet gateway they use a “call in only” architecture that makes installation on most customers’ networks simple and avoids complicated TCP/IP configuration.

“The fourth generation tracker integrates the communications functions into the tracker using cellular and WiFi technology to put more performance and debugging information into the hands of customers and dealers, and it more closely ties systems to our BRIGHT solar monitoring solution,” Maciejowski says. “We’ve moved to a quieter electric drive system for both yaw and tilt actuators to provide variable speed operation and battery backup for grid outages and off grid applications. Through proprietary hardware, we are able to measure DC string power directly, which will be included in the data stream provided to the BRIGHT solar monitoring solution.”

— Solar Builder magazine

Protection Plan: Everything you need to know to protect a commercial roof during a PV installation

protection

A long-term, problem-free commercial flat roof solar installation starts with knowing about the roof systems themselves and how to keep them protected. This isn’t easy. For one, there is an alphabet soup of acronyms: PVC, TPO, EPDM, SBS, APP, BUR, PUF, PIB, CSPE, EPS and XPS. The roof industry lingo doesn’t seem to make much sense either, such as the difference between mechanically attached (MA) and fully adhered (FA), even though both are essentially screwed down mechanically.

In order to mitigate roof damage during construction, there are a few things we need to know. PVC, TPO, EPDM, PIB and CPSE are all single ply membranes, typically between 3/32 and 1/8-in. thick. They are either fully glued down (FA) to an insulation substrate that is glued or screwed to the structural deck or laid loose over the insulation and “stitched” along the seams with screws to the structural deck (MA).

protection

However, an issue with all single ply roofs is that repeated rolling or foot traffic over the screws and stress plates (used to secure the insulation and/or the in-seam screws and plates) can cause abrasion of the membrane, crushing of the insulation and/or tenting of the screws — all of which has the potential to puncture the membrane.

A concern with FA installations is that the plastic or rubber membrane is glued to the skin or facer of the insulation. Repeated rolling or foot traffic can cause the insulation foam to crush and cause cells of the foam insulation to break directly under the facer, causing a de-facto delamination of the roof. Any of this type of damage could end up causing leaks, roof damage or even blow-off — and ultimately, costly call backs.

In general, roof protection falls into two categories:

  • Temporary protection is the roof safeguard deployed during construction to avoid damaging the roof and is subsequently removed upon completion of construction. Some of these protections are universal among roof types and some are membrane specific.
  • Permanent protection will include slip sheets, separator sheets, walk pads and walkways. These items stay on the roof for the life of the PV system.

protection

Guidelines for temporary protection

Inspect the roof prior to starting work. Ensure there is no damage to the roofing membrane, including punctures and scratches to the surface. Any such damage should be circled and reported immediately so that it may be repaired quickly. Panels must not be placed over damaged areas until the damage is repaired.

Treads on wheeled equipment should be covered or other precautions taken to ensure that gravel embedded in the treads does not create a membrane puncture hazard. Motorized equipment should be limited to those that can start and stop gradually to minimize horizontal pulls on the membrane.

RELATED: Tips for planning your next retail PV project

Avoid damage to the foam board insulation layer below the membrane by:

  • Place all pallet loads on foam board sheets or similar materials that can spread the load without damaging the membrane or insulation below.
  • Protect areas that are frequently traveled with plywood or OSB boards (weighted down whenever necessary to prevent uplift by wind). Also, wherever possible, frequently change the travel path location.

Avoid separation of the membrane from the insulation by placing a layer of spaghetti matting (or similar approved matting material) on areas that will be rolled over more than two or three times. Any damage to the roof must be identified with a clear mark on the roof immediately after it occurs, and it should be promptly reported to the construction manager.

protection

Place all pallet loads on foam board sheets or similar materials that can spread the load without damaging the membrane or insulation below.

Protection procedures

For hoist landing areas and rooftop storage of any material in excess of 15 lbs/sf, use a rigid temporary protection system consisting of sheets of plywood or OSB, applied unadhered on the roof. Fully cover scheduled work areas with loosely abutting plywood sections, and apply dunnage insulation pieces between plywood sections and the roof membrane for heavy access or traffic conditions. Protect the plywood sections from wind displacement. Remove temporary rigid protection promptly upon completion of hoisting, loading or heavy traffic work.

When constructing ramps and work platforms, protect the roofing by arranging pieces of dunnage insulation between the ramp leading edges and all ramp/platform sleeper and support contact points.

Utilize temporary flexible protection consisting of rolls of walk mat material at all traffic lanes, which are essentially any areas subject to repeat or routine movement of personnel or carted materials. Loose walk mat material should be picked up and secured at the end of each day or whenever inclement or windy weather is predicted.

Ensure that the wheel load for rolling equipment does not exceed 15 psi. For example, wheeled equipment capable of carrying 1,200 lbs (combined self weight plus load) should have at least 80 sq in. of wheel contact area. If the equipment distributes the load on four wheels evenly, each wheel should have at least 20 sq in. of contact area. If the contact width is 4 in., the contact length must be at least 5 in. If the area is insufficient, either the load must be reduced or additional wheels must be added. For minor inadequacies, small amounts of air may be released from the tires to increase the contact areas.

protection

Guidelines for permanent protection

Rigid conduit supports, metal ballast trays or rigid racking that sits directly on the roof, or other equipment subject to thermally driven oscillation movement, will require appropriately sized roof material matching slip sheets.

Soft durometer PV racking support pads that are not subject to thermally driven oscillation and have been proven to be compatible with the roof membrane system type, may be — with the approval of the roof manufacturer — installed without slip sheets.

PV system support pads that have not been proven to be compatible in direct contact with the roof membrane (or if movement of the support pads relative to the roof are expected) will require an appropriately sized roof material matching slip or separator sheets.

If the roof is TPO, then the slip sheets are TPO — EPDM for EPDM roofs and PVC for PVC roofs. Slip sheet thickness is typically minimum .060 but material thickness matches above that. For example, .060 slip sheet for a .045 roof, .060 slip sheet for a .060 roof and .090 slip sheet for a .090 roof. The slip sheets can be tack welded, tack adhered or even loose depending on the roof manufacturer.

Upon completion of the PV installation, provide permanent walk pads at areas designated by the roof manufacturer as a location requiring protection. Typical locations include: a minimum 30-in. x 30-in. walk pad installed at all door or ladder access points and all work station locations on rooftop mounted mechanical equipment. Work station locations pertaining to a PV installation may include rooftop mounted inverters or combiner boxes. Additionally, any PV equipment that requires more than monthly service should have a dedicated path of walkway pads from the roof access point to the service-dependent equipment. The walk pad system should consist of the roof manufacturer’s roof-compatible walk pad installed utilizing the roof manufacturer’s recommended method of securement.

Peter Corsi is a consultant for N.B.S. Consultants.


Adhesive Mounting Options

Not a fan of ballast or attachments? Check out some adhesive options

green linkGreen Link introduced a new adhesive/sealant designed for use with its KnuckleHead Rooftop Support System. Green Link Adhesive/Sealant bonds and seals the KnuckleHead Universal Base directly to the roof membrane and is effective on a wide range of roof surfaces. The new adhesive/sealant has been specially formulated to adhere to PVC, EPDM, TPO and Mod Bit, as well as the KnuckleHead base itself, which is composed of glass-reinforced nylon. Green Link Adhesive/Sealant is based on polyether chemistry. It cures by exposure to moisture, so it can be applied to damp surfaces and will not shrink upon curing. It will not discolor from UV exposure, can be applied at temperatures as low as 32°F and is capable of joint movement in excess of 35 percent. It is available in standard 10.1-oz cartridges.

OMG Roofing Products’ PowerGrip Universal is designed to reduce or eliminate ballast in solar racking systems, offering up to 3,300 lbf of tensile strength, 2,500 lbf of shear strength and 2,000 lbf of compressive strength. It’s one of the strongest anchors on the market. Made of heavy-duty cast aluminum, PowerGrip Universal is easy to install, saving time and labor when compared to alternatives. The system transfers the load to the structural roof deck and does not require any membrane welding.

— Solar Builder magazine

The Ultimate SPI Showcase: Here’s what to see at Solar Power International 2017

Big leap for microinverters

APsystems SPI

APsystems will unveil the YC600, a dual-module, smart grid and Rule 21 compliant microinverter at SPI in Las Vegas. A groundbreaking design in microinverter technology, the YC600 will offer the highest peak output power, faster transmission speed and more modules allowed per string than comparable microinverters. A wider MPPT voltage range will result in a greater energy harvest for homeowners.

You’ll want to get the full scoop at booth 1745.

Streamlined Shutdown

Fronius

Fronius is launching a new generation of its Rapid Shutdown Box, which the company says will be the most convenient solution for NEC 2014 (690.12) and NEC 2017 compliance, while enhancing overall rooftop and firefighter safety. The new generation includes two versions: the Fronius Rapid Shutdown Box Duo and Quattro.
“Based on customer feedback, we implemented many improvements into this new generation of our Rapid Shutdown Box,” says Michael Mendik, head of solution management at Fronius USA.

Directly connected to the inverter through the same conduit as the DC homeruns and powered by the array, the Fronius solution minimizes the number of components and eliminates the need for an external power supply. The low-profile design and the multiple mounting options allow for installation underneath the modules, ensuring a clean system look. In addition, the NEMA 4X rating ensures the box is built for severe outdoor conditions. MC4 connectors, spring-loaded terminals and generous wiring space make the wiring a breeze. The Rapid Shutdown Box also acts as a combiner box, removing the need for additional hardware. Booth 3943.

Lightweight, flexible power conversion

Ideal Power

Ideal Power invented a new kind of power conversion architecture that delivers on flexibility, allowing you to enable or disable any features depending on project needs. At SPI, check out its 30-kW Stabiliti Series power converters. These multiport, compact converters are smaller, lighter and dramatically reduce installation costs while increasing return on investment. Ideal Power recently partnered with NEXTracker to implement it in various PV sites throughout North America. Booth 1433.

A top rail clip to rule them all

Heyco solar rail clips

Heyco has been busy this summer, introducing several new clips and wire management accessories for the solar market. Newest to the lineup are the SunRunner 4-2 and SunRunner 4-2U, which are top rail clips for various racking manufacturers such as Unirac, Ironridge, Everest, SnapNRack, Solar Mount and other similar racking profiles. The SunRunner 4-2 and SunRunner 4-2U are suitable for the new Enphase Q Cable. At the booth, you can also enter for a chance to win a Google Home. Booth 4762.

Drive down carport costs

Baja Carports InterSolar 2017 Booth Models

Baja Construction always has a standout booth, and this year its in-house construction team will be installing its signature Baja Solar Support System design, the “Braced Single Post Support,” built with high-tensile light gauge steel to support 24 solar modules (7.8 kW). Included in the structure is an EV Station for the hot red Tesla parked underneath. Meet Baja’s in-house designers, engineers and project managers and also make certain to visit Baja’s sponsored lobby lounge for food and beverages. I’m sure you’re already there. Booth 4155.

Improve your grip strength

Ace Clamp solar mount
AceClamps are factory-assembled clamps with patented design features that allow strong connections to standing-seam roof panels without the use of set screws or any other loose parts that could damage the surface of the roof panel. AceClamp designs have been vibration tested during the development stage and incorporate special locking features to ensure that the bolts do not back out when subjected to vibratory loads from wind flutter and light seismic activity. Booth 809.

OMG Roofing solar mount

OMG Roofing Products has introduced PowerGrip Universal for mounting solar racking systems on commercial roofs. PowerGrip Universal is designed to reduce or eliminate ballast in solar racking systems, so there’s less weight, material handling and labor on the roof. Made of heavy-duty cast aluminum, PowerGrip Universal offers 3,300 lbf of tensile strength, 2,500 lbf of shear strength and 2,000 lbf of compressive strength. It’s one of the strongest anchors on the market. Booth 629.

Solar Connections

The Standing Seam Power Clamp from Solar Connections can attach to virtually any standing seam profile and draws its strength from patent-pending WaveLock Technology with optional two, three and five points of attachment. The top can be custom drilled and tapped to fit any bolt configuration. Offering ease of installation, the Silver Bullet set screws include a rounded bullet tip to maximize strength while also keeping the paint finish and seam free from harm. Additionally, the Standing Seam Power Clamp is available in standard mill finish aluminum material, making it an item you can easily keep in stock when the need arises. Booth 1569.

Reinventing the ground mount

Nuance Energy

Nuance Energy’s patent-pending Osprey PowerPlatform could revolutionize ground-mounted solar projects. This earth anchor foundation system satisfies permitting requirements for virtually any site and soil type without the need for geotechnical reports or special inspections. It eliminates the need for heavy equipment or cement by enabling small, unskilled crews to install the entire platform quickly and easily using only handheld tools. Booth 2108.

Meet the 4G platform

Ginlong Solis inverter

Ginlong Technologies is now shipping its Solis 4G Platform. What you can see at SPI this year in booth 2427 is the Solis-1P(2.5-10K)-4G-US single phase string inverters, with high switching frequency; 2, 3 and 4 MPPTs designs; 97.8 percent peak efficiency (97.5 percent CEC); fan-less NEMA 4X / IP65 design, integrated AFCI; web-based and smartphone app monitoring, all under 44 lbs. The Solis 25K-66K-US three phase inverters are designed for all commercial and utility-scale installations with four MPPT designs and ultra-low start up volume that maximizes energy harvest. Booth 2427.

Five trackers to, um, track

SunLink TTD

SunLink’s TechTrack enables efficient load redistribution and allows the system to handle extreme wind with less steel, fewer foundations and lower cost. Now, TechTrack’s intelligent control system also delivers equally responsive control modes for snow, flood and O&M. The result is system level benefits, visible in SunLink’s Vertex data monitoring system. Rigorous testing to UL3703 further reduces permitting risk. Booth 3319.

Soltec

SF7 is the next-generation horizontal single-axis solar PV tracker from Soltec. Soltec says the SF7 enables up to 5 percent greater MW per acre than other trackers and does that with 54 percent fewer piles-per-MW, 15 percent less parts count and 58 percent fewer screw type connections than leading competitors. SF7 standard features include short tracker site-filling options, unique steep-slope tolerance of 17 percent NS, efficient self-powering and innovative cable management solutions for combining, fusing and protecting PV source circuits more economically. Booth 3640.

Solar FlexRack TDP 2 Turnkey Solar Tracker_2017

Solar FlexRack is launching its TDP Tracker with a new BalanceTrac design to increase energy yield and reduce balance of system costs. This TDP 2.0 Solar Tracker with BalanceTrac, optimized for 1,000- and 1,500-V modules, has greater rotational range of up to 120° and enables more modules per row (up to 90). The robust design delivers autonomous tables that increase site flexibility to maximize land use. Booth 2538.

AllEarth Renewable

AllEarth Renewables is showing off its new Gen 4 tracker which will be self-powered, to guard against the grid going down and will have expanded communication options, such as Wi-Fi, cellular and SD card enabled. It will come as a complete, pre-engineered system for easy, efficient shipping. Booth 626.

Array Technologies

Array Technologies is revealing the results of a recent TÜV Rheinland-backed independent report focused on solar tracker reliability. Array’s latest single-axis tracker, the DuraTrack HZ v3, is often touted for its reliability and lower cost of ownership. Array says DuraTrack HZ v3 is proven to be 300x less likely to experience catastrophic failure during wind events than more stow-reliant, single-row competitors. Booth 2919.

Page two has new on big-time collaborations, products for boosting performance, installing on shingles and more.

— Solar Builder magazine

OMG Roofing’s new PowerGrip aims to reduce need for solar rooftop ballast

OMG Roofing Products has introduced PowerGrip Universal, a rooftop attachment anchor for mounting solar racking systems and other products to virtually any commercial roof. PowerGrip Universal is designed to reduce or eliminate the need for ballast in solar racking systems, so there’s less weight, material handling and labor on the roof.

OMG Roofing

PowerGrip Universal is designed with wind performance in mind and offers up to 3,300 lbf. (13.34 kN) of tensile strength, 2,500 lbf. (11.12 kN) of shear strength, and 2,000 lbf. (8.9 kN) of compressive load strength, making it one of the strongest roof an-chors on the market today.

Made of heavy-duty cast aluminum, PowerGrip Universal units are designed with a base ring that gets secured through the roofing cover and into the structural roof deck, and a waterproof cover plate to keep water from infiltrating the roof assembly.

“This is an exciting development for securely mounting roof-top solar systems,” said Adam Cincotta, PowerGrip product manager for OMG Roofing Products. “Rooftop solar racking has become more prevalent, and until now there has not been an anchor system on the market that offers both the strength and ease-of-installation that Power-Grip Universal provides.”
PowerGrip Universal units are easy to install, saving both time and labor when compared to alternative options. The system is designed to transfer the load to the structural roof deck, and does not require any membrane welding. PowerGrip Universal units are typically installed in less than five minutes.

In addition to commercial solar rack systems, PowerGrip Universal can be used for many other roof mounted items such as pipe supports, step crossovers, raceways, satellite dishes, small antennas and HVAC applications.

2016 Solar Mounting/Racking Guide: Product Showcase

— Solar Builder magazine