We are unable to anticipate every selection an installer might make, but we do know that the Skystream 600 will require larger wire sizes than the Skystream 3.7. Therefore, the new kits will include 1-1/2” (38 mm) PVC electrical fittings instead of the 1” (25 mm) fittings in previous kits.  We will also include 1-1/2” (38 mm) electrical conduit and couplings sufficient to extend beyond the excavation.  This may eliminate foundation construction delays in some cases.

To provide options for the installer, and to accommodate Skystream 3.7 installations, the new anchor rod templates have holes pre-drilled to accept both 1-1/2” (38 mm) and 1” (25 mm) PVC electrical conduit.

Extensive research and testing has led to new specifications and dosages for our fiber reinforced concrete.  Four manufacturers have qualified their fibers for use in our SMarT Foundations: Novomesh 950 synthetic fibers by Propex Concrete Solutions (orderexpress@propexusus.com): TufMax DOT synthetic fibers by ABC Polymer Industries (info@abcfibers.com); Dramix RC-80/60-BN steel fibers by Bekaert Corporation (susan.krausman@bekaert.com); and BASF MasterFiber FF3 steel fibers by Maccaferri, Inc. (www.maccaferri-usa.com). The new SMarT Foundation Drawings specify the required fiber dosages and provide contact information for these worldwide suppliers.  AnemErgonics can also provide fibers in appropriate situations.

We recommend that installers check with their ready-mix concrete suppliers early in the construction planning process, thereby ensuring the greatest flexibility in price and delivery of reinforcing fibers.

SMarT Foundations for Skystream 600 have been engineered to achieve the greatest construction efficiency and the lowest installation cost.  Required excavation depth is 42” (1067 mm) for Southwest Windpower supplied towers and wind speeds up to 120 mph (54 mps).  For greater wind speeds, the excavation depth is 48” (1219 mm). The foundation kits are designed for 120 mph (54 mps) because that is sufficient for 97% of all U.S. installations.For winds speeds greater than 120 mph (54 mps), or for frost depths greater than 42” (1067 mm), the installer is required to fabricate an extension for the Lower Stanchion supplied with the kit.  Details are explained in the new Instruction Manuals.

To accommodate the increased design forces of the Skystream 600, all foundation kits will now be supplied with embedded washers and capturing nuts for the bottom of the anchor rods that are placed in the concrete.

The new SMarT Foundation kits have not yet been approved for seismic zones C, D, E and F. In those rare cases, a design supplement will be required. Please contact your Southwest Windpower sales person at customerservice@windenergy.com or an AnemErgonics representative at info@anemergonics.com.

As a result of considerable research and testing, including third party anchor rod pullout tests and concrete flexural-strength tests, AnemErgonics has developed, in concert with Tower Engineering Professionals (TEP), a “white paper” explaining the benefits of fiber reinforced concrete.  TEP (rglover@tepgroup.net) is authorized to share this information on a need-to-know basis with building authorities who seek clarification when permitting Skystream foundations.

The technology is applicable to most small wind turbines, but the first commercial application will be for Southwest Windpower’s Skystream turbines. Because SMarT Towers will weigh approximately half as much as steel towers, they will be easier to ship, handle and erect with gin poles and lightweight winches.

SMarT Towers will be packaged with SMarT Foundation kits, further reducing the cost of purchase, shipping and logistics. They will be finished with extremely durable, pigmented resin in natural earth tones. An important element of the SBIR research is the accelerated-life test conducted at the National Renewable Energy Laboratory in Boulder, Colorado. Following the successful conclusion of these tests, the first demonstration units were installed in January, 2010.

Concrete anchors are required to connect the tower base flange to the concrete foundation. Our engineers and technicians have invested hundreds of hours researching anchor rod specifications, including materials, corrosion protection, washers, nuts and vibration resistance. They succeeded in designing a system that simplifies installation and significantly reduces price, weight and shipping cost compared to the methods used previously. We use anchor rods threaded at both ends, and our system complies with ASTM F1554 (rods), ASTM F436 (washers) and ASTM A563 (nuts). In keeping with prudent engineering practice and the recommendations of U.S. government agencies, we also supply vibration resistant locking devices. We are proud to use domestic steel in our anchor rods, which are manufactured in the U.S.A.

Anchor rods are shipped in two long boxes, each of which weighs approximately 60 lbs (27 kg). Each box contains four anchor rods and associated nuts, washers and vibration resistant locking devices. Mill certifications are included for the anchor rod material so that installers can choose appropriate installation specifications. All unused materials are either reusable or recyclable.

It is important to note that according to Tower Engineering Professionals “… specification of installation procedures is the responsibility of the turbine or tower manufacturer.” And the U.S. Department of Transportation, Federal Highway Administration says in its Guidelines for the Installation, Inspection, Maintenance and Repair of Structural Supports for Highway Signs, Luminaries, and Traffic Signals that “Proper installation … inspection and testing … of the anchor rods is the responsibility of the foundation contractor.” So please check with the turbine manufacturer for recommended installation procedures.

Anchor rods in their shipping box

There usually is a premium to be paid for HES concrete. However, the “standard” strength of ready-mix concrete from many suppliers is typically 3000 psi to 3500 psi. If this is your situation, the cure time may be much less than 28 days and towers may be installed sooner at no additional cost. AnemErgonics recommends that you discuss this with your contractor and/or concrete supplier when evaluating foundation cost and installation schedule. We also suggest that you require the concrete supplier to provide documentation of the mix strength.

The few parts remaining after foundation construction have several potential uses. The adjustable guy ropes and nail pegs can be used for camping tents or temporary shelters. The ABS and PVC (polyvinyl chloride) parts can be used in plumbing and electrical projects. Cardboard forms and boxes can be reused or disposed in typical recycling operations. And the SONOTUBE™ locator brackets are sheet steel that is also readily recycled. As for our anchor rod system, there is very little remaining after installation.

Our craft paper wrapping is 100% recycled material and can certainly be reused. The cardboard boxes have many reuses and they are readily recycled. Making these choices adds nothing to the cost of our products. It is the responsible thing to do. And we think it is the choice our customers would like us to make.