0211TECpC1:0211TECpC1
3/2/11
2:49 PM
Page C1
0211TECpFPads:0211TECpFPads
2/28/11
2:31 PM
Visit us at: www.haticonsolar.com
Page C2
0211TECpFPads:0211TECpFPads
3/2/11
Visit us at: www.legrand.us/cablofil
9:36 AM
Page 1
0211TECpFPads:0211TECpFPads
2/28/11
2:25 PM
Page 2
Visit us at: SEDPV.com
0211TECpFPads:0211TECpFPads
2/28/11
Visit us at: www.norenproducts.com
2:25 PM
Page 3
0211TECp04:0211TECp04
Contents
3/1/11
12:22 PM
Page 4
+
06
Stetson Wind Project Stetson Mountain, Maine
10 20 26
Getting to know North America’s Leading Geotechnical Contractor
MV/HV Cable Testing – VLF Technology
From Electrical Contracting to Solar Installation: Knowing What You Need To Know
34
NABCEP Alternative Experience Pathway for Qualified Electricians
40
Multi-Contact, serving some of the world’s most demanding applications.
44
Finding your place in the sun
4
The Electric Current March 2011
26
44
PRESIDENT/PUBLISHER Glen Hobson - 205-733-1341 SALES DEVELOPMENT MANAGER Hank Underwood - 205-733-1343 NATIONAL SALES MANAGER Rick Harless - 205-733-1324 CIRCULATION DIRECTOR/WEB DESIGN Jacklyn Hobson CREATIVE DIRECTOR Derek Gaylard ART DIRECTOR David Todd Executive and Advertising Offices 2070 Valleydale Rd, Suite # 6 Hoover, AL 35244 toll free: 866.981.4511 phone: 205-733-1341 fax: 205-733-1344 www.theelectriccurrent.com The Electric Current is distributed free to qualified subscribers. U.S. Postage paid at Birmingham, Alabama and additional mailing offices. The Electric Current is distributed to to qualified owners and managers in the electrical industry. Publisher is not liable for all content (including editorial and illustrations provided by advertisers) of advertisements published and does not accept responsibility for any claims made against the publisher. It is the advertiser’s or agency’s responsibility to obtain appropriate releases on any item or individuals pictured in an advertisement. Reproduction of this magazine in whole or in part is prohibited without prior written permission from the publisher. POSTMASTER: Send address changes to The Electric Current 2070 Valleydale Rd., Suite #6 Hoover, AL 35244 PRINTED IN THE USA
0211TECpFPads:0211TECpFPads
2/28/11
2:26 PM
Visit us at: www.hiokiusa.com
Page 5
0211TECp06-48:0211TECp06-48
Feature
6
3/1/11
12:26 PM
Page 6
+
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
2:26 PM
Page 7
Visit us at: www.jonasconstruction.com
0211TECp06-48:0211TECp06-48
Feature
8
3/1/11
12:26 PM
Page 8
+
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
2:26 PM
Page 9
Visit us at: www.zistos.com/EC.htm
0211TECp06-48:0211TECp06-48
Industry News
3/1/11
12:26 PM
Page 10
+
Getting to know North America’s Leading
Geotechnical Contractor
Wet soil mixing and jet grouting to create a bottom seal to allow the installation of a precast conveyor tunnel below the water table at the Mirant Morgantown coal-fired plant in Newburg, MD.
10
The Electric Current March 2011
Hayward Baker Inc. (HBI) is North America’s leading geotechnical contractor, offering the full range of pre and post construction services for foundation rehabilitation, settlement control, liquefaction mitigation, soil stabilization, groundwater control, slope stability, excavation support, and underpinning. They are ranked #1 Specialty Excavation/Foundation Contractor by Engineering News-Record, year after year. Among the specialty techniques offered by HBI are cement, chemical, compaction, jet, urethane, and soil fracture grouting; dry and wet soil mixing, dynamic compaction, injection systems for expansive soils, rapid impact compaction, rigid inclusions, Vibro systems, Vibro PiersTM, augercast piles, driven piles, Franki piles (PIFs), helical piles, jacked piers, MacropilesTM, micropiles, pit underpinning, soil and rock anchors, anchor block slope stabilization, Gabion systems, Micropile Slide Stabilization (MS3), sheet piles, soil nailing, soldier piles and lagging, polyurethane injection, slab jacking, slurry walls, TRD Walls, and wick drains. Over the past 30 years, HBI’s techniques have been applied to numerous projects, ranging from dam rehabilitation to soil stabilization for major subway construction to seismic retrofit to sinkhole remediation. HBI also has extensive experience with power projects, having performed services for power generating stations of all types. Many ground improvement techniques saw their first use in the United States by HBI. Whatever the geotechnical challenge, chances are that HBI has solved a similar one before. Headquartered in Odenton, Maryland, HBI has over 20 offices across the United States, as well as locations in Mexico, and Canada. Since its inception, HBI has established itself in the forefront of geotechnical specialty contracting, evolving and expanding to meet the increasingly complex needs of the construction community. They are capable of offering full DesignBuild services for virtually any geotechnical construction application, and are able to design and fabricate equipment for specific applications.
0211TECpFPads:0211TECpFPads
2/28/11
2:26 PM
Page 11
Visit us at: www.dhsolar.net
0211TECpFPads:0211TECpFPads
2/28/11
2:27 PM
Page 12
Visit us at: www.nabcep.com
0211TECpFPads:0211TECpFPads
2/28/11
2:27 PM
Page 13
Visit us at: www.pelsue.com
0211TECp06-48:0211TECp06-48
Industry News
3/1/11
12:26 PM
Page 14
+
Dynamic compaction for ground improvement for planned wind towers at Stoney Corners wind farm in McBain, MI.
HBI belongs to the internationally recognized Keller Group, which provides specialty geotechnical contracting services worldwide. German affiliate Keller Grundbau developed the technology and equipment for the deep vibratory techniques of Vibro Compaction and Vibro Replacement that have been instrumental in site improvement both in North America and overseas. All of HBI’s work is conducted in the safest manner possible. Their accident incident statistics are well below the national average as dictated by the Bureau of Labor Statistics. A comprehensive safety awareness and training program for employees, and regular evaluation of job site procedures helps to ensure minimum risk. To their client’s benefit, a safe work environment for their staff and their surroundings is a more efficient one for the job. HBI’s depth of experience and expertise, range of techniques, and the international resources of the Keller Group ensure that clients receive the highest level of quality, service, safety or driven piles may be the solution. However, and value available anywhere in the industry. often the poor soils can be strengthened and stiffened economically to enable the structure GEOTECHNICAL CONSTRUCTION to be constructed on a shallow foundation. TECHNIQUES FOR POWER Ground improvement and grouting techniques GENERATION FACILITIES can effectively address a variety of weak soil Foundation design can pose challenges conditions. Whether designing a foundation which are generally addressed during design prior to construction or a remedial solution to and construction; however, problematic sub- an existing foundation experiencing unacsurface conditions can go initially undetected, ceptable performance, the goal is to identify only to be discovered when they are manifested the most economical foundation system that as foundation problems during construction op- will provide acceptable performance. What follows is a brief explanation of erations, or after the structures are constructed. Initial design for any project should include many of the ground improvement, grouting, a geotechnical exploration by a geotechnical and deep foundation techniques that can efengineering consultant. The geotechnical re- fectively be employed for power sites to alport should include an evaluation of the site low construction on shallow foundations, geological history, soil engineering proper- correct settlement issues, or transfer foundaties (including density, gradation, and mois- tion loads to a competent bearing stratum. ture content), and the in situ strength, GROUND IMPROVEMENT permeability, and compressibility characteristics of each stratum within the influence of Ground improvement methods modify the the planned foundation. When problems oc- in situ soil matrix to increase bearing capacity cur with an existing structure, a similar ex- and/or reduce the risk of liquefaction of granploration is required to determine the cause ular soils during a seismic event. Some methand remediation options. ods use energy (vibratory or impact) to Weak or loose soils can result in a number strengthen the soil, while others use cementiof foundation performance problems, includ- tious binders to strengthen the soil. ing insufficient bearing capacity, excessive total VIBRO PIERSTM (AGGREGATE PIERS) or differential (tilting) settlement, or unacceptable performance during a seismic event (liqVibro PiersTM, also known as aggregate uefaction or excessive dynamic settlement). piers, are short, stiff aggregate piers conWhen the geotechnical exploration at a structed to reinforce fine grained soils and are planned facility location reveals that the sub- only used prior to construction of the foundasurface conditions are weak and compressible, tion. The pier location is initially predrilled for a deep foundation system consisting of drilled soils in which the hole will remain open. In
14
The Electric Current March 2011
soils that cave or collapse, a bottom feed vibrator can be employed. The downhole vibrator is lowered vertically to the designed tip of the pier, typically with a standard crane. Aggregate (new crushed stone or recycled concrete) is then introduced into the hole and is compacted in lifts by repeated penetrations with the vibrator. The vibratory energy from the vibrator densifies the aggregate and any surrounding granular soil. The high modulus pier reinforces the treatment zone. The technique increases bearing capacity and decrease settlement for planned structures.
VIBRO COMPACTION Vibro compaction densifies granular soils using a downhole vibrator probe and is a preconstruction technique. The probe is lowered vertically into the soil, typically with a standard crane. After reaching the bottom of the treatment zone, the soils are densified as the probe is raised. The vibratory energy allows the soil particles to move into a denser configuration. The densification results in a depression at the ground surface unless granular backfill is added during the densification process. The treated soils have increased density, friction angle and stiffness. The technique has been used to increase bearing capacity, decrease settlement and mitigate liquefaction.
DYNAMIC COMPACTION Dynamic compaction densifies soils and fills by using a drop weight on a grid pattern and is a preconstruction technique. The drop weight, typically a hardened steel plate, is
0211TECpFPads:0211TECpFPads
2/28/11
2:27 PM
Page 15
Visit us at: www.meproducts.net
0211TECp06-48:0211TECp06-48
Feature Story
3/1/11
12:26 PM
+
lifted by a crane and repeatedly dropped on the ground surface. The drop locations are typically located on a grid pattern, the spacing of which is determined by the subsurface conditions and foundation loading and geometry. Treated granular soils and fills have increased density, friction angle and stiffness. The technique has been used to increase bearing capacity, and decrease settlement and liquefaction potential for planned structures. In shallow Karstic geologies, it has been used to collapse voids prior to construction, thereby reducing sinkhole potential. Although the process appears simple, experience is required to understand the capabilities, limitations, and risk factors associated with the dynamic compaction technique.
SOIL MIXING Soil mixing techniques mechanically blend soils in place with cementitious material to improve soil engineering properties such as strength and compressibility, and is a preconstruction technique. Soil mixing increases bearing capacity, decreases settlement and increase global stability for planned structures. There are two types of soil mixing: Wet and Dry. Wet soil mixing uses binder slurry to treat soils that have low water content. Dry soil mixing uses binder delivered in powder form to treat soils with high water content. The binder material is introduced to the soil through a hollow rotating pipe that is equipped with cutting and mixing blades. The soil mix product can take the form of individual columns of various sizes, typically in the range of 2.5 to 8 feet in diameter. Columns can be installed as individual elements, as overlapping multiple elements installed with a multiaxis mixing tool, or in the form of a mass stabilization, installed with a specialized blending tool attached to an excavator arm. Because mixed soil provides enhanced bearing capacity and reduced compressibility, the use of the soil mixing technique allows for a reduction in size of the foundation, often reducing the overall construction cost and time.
RIGID INCLUSIONS Rigid inclusions is a ground improvement technique that transfers loads through weak strata to a firm underlying stratum, using high modulus concrete columns, and is a preconstruction technique.. Planned power sites may appear firm on the surface, only to conceal a buried weak soil stratum. Depending on the depth and thickness of the weak layer, it may provide the planned structures with insufficient
16
Page 16
Jet grouting to construct a 60-ft-deep by 60-ft-wide cutoff wall to prevent the Péribonka River from seeping into a diversion tunnel for the new earth embankment hydroelectric dam in Péribonka, Quebec, Canada.
mix the in situ soil as the drill stem and grouting monitor are rotated and raised. Excess soilcrete rises to the surface through the borehole annulus where it is contained. Depending on the application and soils to be treated, one of three variations is used: the single fluid system (slurry grout jet), the double fluid system (slurry grout jet surrounded by an air jet) and the triple fluid system (water jet surrounded by an air jet, with a lower grout jet). Jet grouting can underpin existing foundations and provide groundwater cutoff.
CEMENT GROUTING Cement grouting, also known as slurry grouting or high mobility grouting, is a grouting technique that fills pores in granular soil or voids in rock or soil with flowable particulate grouts. Depending on the application, Portland cement or microfine cement grout is injected under pressure at strategic locations bearing capacity or be the cause of excessive either through single port or multiple port pipes. The grout particle size and soil/rock settlement. A closed-end mandrel is advanced to the void size must be properly matched to permit underlying firm soils. The pipe is then filled the grout to enter the pores or voids. The with a concrete mix with a high internal fric- grouted mass has an increased strength and tion. The end of the mandrel is opened and stiffness, and reduced permeability. The techthe mandrel is extracted. The concrete fills the nique has been used to reduce water flow void created by the mandrel during extraction, through rock formations beneath hydroelecand terminates in an upper strong stratum or is tric dams and to cement coarse granular soils subsequently overlain by a fill relieving platform. to underpin foundations or for support prior to The improved performance results from the re- an adjacent excavation. inforcement of the compressible strata with the CHEMICAL GROUTING high modulus columns. The technique has been used to increase allowable bearing pressure Chemical grouting transforms granular soils and decrease settlement for planned structures. into sandstone-like masses, by permeation with a low viscosity grout, and can be used as GROUTING a preconstruction technique or for remedial Grouting techniques strengthen weak soils situations. Typically, a sleeve port pipe is first by the introduction of grout mixtures into the grouted into a predrilled hole. The grout is insoil with special tooling. The appropriate jected under pressure through the ports on the method is chosen based on the soil proper- pipe. The grout permeates the soil and solidifies it into a sandstone-like mass. The grouted ties and specified requirements. soil has increased strength and stiffness, and JET GROUTING reduced permeability. The technique underJet grouting creates in situ geometries of pins existing foundations where granular soils soil and cement, known as ‘soilcrete’, using a have resulted in excessive settlements or for grouting monitor attached to the end of a drill support prior to an adjacent excavation. stem, and can be used as a preconstruction COMPACTION GROUTING technique or for remedial situations. The soilcrete is significantly stronger than the in situ Compaction grouting, also known as Low soil, and increases the bearing capacity and Mobility Grouting, is a grouting technique that shear resistance. The grouting monitor is ad- displaces and densifies loose granular soils, revanced to the maximum treatment depth. High inforces soils and stabilizes subsurface voids or velocity fluid jets are then initiated from ports sinkholes, by the staged injection of low-slump, in the side of the monitor. The jets erode and low mobility aggregate grout. Compaction
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
2:27 PM
Page 17
Visit us at: www.surgesuppression.com
0211TECp06-48:0211TECp06-48
Industry News
3/1/11
12:27 PM
Page 18
+
grouting can be used for both preconstruction and beneath an existing foundation. Typically, a pipe is first advanced to the maximum treatment depth. Mortar grout is then injected as the pipe is slowly extracted in lifts, creating a column of overlapping grout bulbs. The expansion of the grout bulbs displaces surrounding soils. The surrounding granular soil has increased density, friction angle and stiffness. The high modulus grout column reinforces the treatment zone. The technique has been used to increase bearing capacity, and decrease settlement and liquefaction potential for planned and existing structures. In Karstic geologies, compaction grouting has been used to treat existing sinkholes or to reduce the sinkhole potential in sinkhole prone areas.
FRACTURE GROUTING Fracture grouting, also known as compensation grouting, hydrofractures in situ soil using neat fluid grout. When excessive total or differential settlement occurs to structures founded on fine-grained soils, soil fracture grouting may be the correct solution for releveling and providing long-term support. For foundation applications, soil fracture grouting is most commonly used as a remedial measure to counteract ongoing consolidation settlement in fine-grained soils, or for the pretreatment of marginally stiff, fine-grained soils that might otherwise require the use of deep foundations. A sleeve port pipe is grouted into a predrilled hole beneath the foundation. The grout is injected under pressure at strategic locations through the ports in the pipe. Once the hydrofracture pressure of the soil is exceeded, fractures open up in the soil and are immediately expanded by the subsequent influx of grout. The process results in controlled heave of the overlying soils and foundation.
Driven pipe pile foundations for solar panels, Southeastern U.S. ditions. Micropiles can be installed through holes cored through an existing foundation. After installation the micropiles are bonded or mechanically attached to the foundation. Alternately, micropiles can be installed around the perimeter of the foundation, after which the connection is achieved by enlarging the foundation. Although the highest capacity micropiles typically develop their capacity by bonding into bedrock, significant capacities are achievable by friction bonding into soils. Micropiles are often combined with a variety of grouting or ground treatment to maximize capacities.
DRIVEN PILES Driven piles can be a cost-effective deep foundation system for some sites underlain by loose or soft soils, or mine spoils, which can provide insufficient bearing capacity and excessive settlement. Types include timber, precast concrete, steel H-piles, and pipe piles. The technique is most commonly used for new foundations. The piles can resist compression and tension loads. Driven piles may be slightly battered outward to resist lateral loads. Since driven piles generally do not require predrilling, they can be driven into a contaminated soil profile without producing spoil that can require costly removal.
AUGERCAST PILES
Augercast piles, also known as continuous flight auger piles (CFA), are deep foundation elements that are cast-in-place, using a hollow stem auger with continuous flights. The technique is most commonly used for new foundations. The auger is drilled into the soil and/or DEEP FOUNDATIONS rock to design depth. The auger is then slowly Deep foundations bypass unsuitable soils extracted, removing the drilled soil/rock as and bear into deeper strata to provide the re- concrete or grout is pumped through the holquired capacity. Deep foundation systems re- low stem. The grout pressure and volume must sist the moment couple by compression, be carefully controlled to construct a continuous tension, or bending of the deep foundation pile without defects. Reinforcing steel is then lowered into the wet concrete or grout. The finelements. ished foundation element resists compressive, MICROPILES uplift and lateral loads. Micropiles, also known as minipiles, pin ANCHORS piles, needle piles or root piles, can provide exceptional value, particularly in difficult acSoil or rock anchors increase the uplift cacess situations. In addition to new construc- pacity of foundations. Structures subject to tion, micropiles are often installed to remediate high lateral loads may experience a large problems with existing foundations, or retrofit overturning moment. This loading condition existing structures for changes in loading con- results in a downward load on the downwind
18
The Electric Current March 2011
edge of the foundation, and an upward load on the windward edge. Seismic loading, where applicable, further increases these overturning loads. For shallow foundations, the downward load bears on natural or improved soils. The uplift load can be resisted by the weight of the foundation and additional surcharge placed above the footing. Increasing the mat diameter can also increase the resistance to the overturning moment. When individual piles are utilized for deep foundations, the downwind elements resist the moment load in compression and the windward piles in tension. Foundations supported by a drilled shaft or a concrete cylinder are designed to withstand the moment in bending. The uplift capacity of foundations can be increased by incorporating soil or rock anchors into the foundation system. Soil and rock anchors are tension elements which develop their capacity by bonding into soil and rock, respectively. Anchors are typically constructed by first drilling a 6- to 12-inch diameter hole into a stable soil or rock formation. A high-strength steel bar or strand (cable) is then placed into the hole, and the hole is filled with a high strength cementitious grout. The top of the bar or strand is then attached to the foundation. When the foundation is subjected to an uplift load, the anchor resists the load by going into tension and transferring the load to the stable soil or rock formation. Soon after construction of an anchor, the soil-to-anchor or rock-to-anchor bond can be enhanced by pressure grouting the bond zone. For more information on geotechnical construction techniques, visit www.haywardbaker.com. â?‘ About the author: James Hussin is a director for Hayward Baker Inc., the leading specialty foundation and ground improvement contractor. He can be reached at jdhussin@haywardbaker.com. Go online to www.haywardbaker.com.
0211TECpFPads:0211TECpFPads
2/28/11
2:28 PM
Page 19
Visit us at: www.phase-a-matic.com
0211TECp06-48:0211TECp06-48
Case Study
20
3/1/11
12:27 PM
Page 20
+
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
2:28 PM
Page 21
Visit us at: www.conduitrepair.com
0211TECp06-48:0211TECp06-48
Case Study
22
3/1/11
12:27 PM
Page 22
+
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
2:28 PM
Page 23
Visit us at: www.utlitymetals.com
0211TECpFPads:0211TECpFPads
2/28/11
2:28 PM
Page 24
Visit us at: www.hvinc.com
0211TECpFPads:0211TECpFPads
2/28/11
Visit us at: www.bierermeters.com
2:29 PM
Page 25
0211TECp06-48:0211TECp06-48
Case Study
3/1/11
12:27 PM
Page 26
+
From Electrical Contracting to Solar Installation:
Knowing What You Need To Know By Mike Bauer, SunWize Technologies
Solar mounting requires careful roof attachment and code compliant flashing (photo courtesy of Quick Mount PV)
M
any electrical contractors contemplate diversifying their business to include the design and installation of solar electric systems. Of all the construction trades, electricians are the best candidates to make this move since photovoltaics (PV) are electrical in nature and interconnected with a household’s electrical system. However, there are important differences between electrical contracting and solar installation businesses. This article discusses those differences by first comparing and contrasting a solar installation with a typical electrical contracting business in terms of marketing, sales, administration, operations and finally the installation itself. Next, it describes how the transition into solar can be greatly facilitated by aligning with a support-
26
ive, capable solar wholesale distributor and by utilizing pre-engineered system packages.
fering business mix means that the solar installation business requires more outreach to bring a steady flow of new customers. SOLAR IS MARKETING Solar electric systems are “big ticket”, disAND SALES INTENSIVE cretionary items. They are equivalent to a new Solar installations require more sales and car purchase and usually undergo the same marketing than the typical electrical installations. degree of scrutiny, shopping or “tire kicking”. While both businesses are heavily dependent This is in contrast to an essential electrical reon referrals, solar customers rarely provide a pair, important upgrade or time critical work source of repeat business. In addition, electri- on a larger construction project. The upshot cal contractors often get a significant portion is that PV systems require a greater educaof their jobs working for other contractors, sub- tional and selling effort. Multiple visits to the contracting on projects for general contrac- buyer are often required, competition can be tors for example. Solar installers heated and the sales cycle can be months. In predominately work directly for the end-user the California market as few as one in six to (home and business owners); they seldom ob- eight leads turns into a contract and the cost of tain projects through ongoing relationships that sale can be over $1000 in marketing exwith other contractors. The net effect of the dif- pense. As a result, margins can be thinner than
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
2:29 PM
Page 27
Visit us at: www.sunwize.com
0211TECp06-48:0211TECp06-48
Case Study
3/1/11
12:27 PM
Page 28
+ therefore more involved.
on an electrical project. Unlike electric work, solar electric systems require both consumer education and preparation of the owners to take over the operation of the system (people who lease a system or purchase power from a system installed on their rooftop are exempt from this requirement). They will need to understand the system sufficiently to determine if it is performing properly and to provide the minimal maintenance that it requires (unless the installer provides this as an added service). Finally, the workmanship of solar electric systems by law has to be guaranteed for ten years in many areas. This means that the back-end support of the sale is often longer than in the electrical trade.
SOLAR INVOLVES NONELECTRICAL TRADE SKILLS
Electricians will have to become familiar with DC wiring and grounding as in this disconnect box (photo courtesy of Solar-Fit)
SOLAR IS ADMINISTRATIVELY INTENSIVE Solar installations encompass more paperwork than electrical contracting. While both businesses involve proposals, contracts, drawings and permitting, these documents are generally more involved in solar. For example, proposals contain calculations of estimated energy production, cost savings and financial return. Moreover, solar installation deals in administrative aspects not found in electrical contracting: rebate administration, financing and tax considerations. Many states or utilities have rebate incentive programs that often have applications. In many cases, financing is involved and the installer has to facilitate this process. In some cases, PACE (property assessed clean energy) programs for instance, the solar installer needs to complete a portion of the application and often submits the entire package to the city or county implementing the tax-based financing program. While income tax issues involve no paperwork, the installer does need to understand Federal incentives like the 30% tax credit and whatever State incentives apply (some states like Hawaii, Louisiana, North Carolina and Oregon have their own tax credits).
SOLAR IS CASH INTENSIVE Solar projects involve more cash outlay and cash management than electrical contracting.
28
Modules are expensive (up to $500 each) and inverters cost between $2,000 and $4,000. Materials will comprise about 8090% of the total job cost and can tie up tens of thousands of dollars. In contrast, electrical projects have a much greater labor component, closer to 50% of the job cost. There may be other variables that complicate the management of the cash needed for any given install. In some states like California, down payment is limited by law to $1,000. To be competitive, installers often have to carry the rebate for the homeowner or provide bridge financing (usually through third parties) until tax refunds arrive. Credit terms for materials are typically limited to 30 days.
SOLAR IS LOGISTICALLY COMPLEX While most materials for an electrical project are stocked at the local supply house or involve a very short lead time, solar equipment is different. The industry has been in a period of short supply for over a year and availability of modules and inverters has been an issue. This situation requires the solar installer to plan ahead. and work with a reputable solar distributor.. A national distributor will ship from centralized warehouses in various locations across the county. In addition to lead times, shipping costs and delivery times are involved. JIT (just in time) job delivery is
The Electric Current March 2011
The typical solar installation requires roofing skills and specialty labor. One of the most critical aspects of a residential or commercial rooftop application is the roof attachment and waterproofing. Leaks due to improper flashing (or no flashing at all) are the most common liability in the industry. Sometimes roofing needs to removed and replaced to install the mounting system. A skilled roofer or someone trained in roofing best practices is a critical member of the installation team. Typically a pair of skilled laborers is utilized to install the racking and modules. When trained, they also do the roof attachments and flashing as well. Commercial projects get more complex. Electrical engineers specializing in large scale PV systems are utilized. Structural engineers are also required because of roof loading. Licensed commercial roofing contractors are regularly involved because of the major liability of roof penetrations.
SOLAR INVOLVES ONGOING SERVICE AND SUPPORT As mentioned earlier, solar installations require more service and support than electrical work. Unlike an electrical system, which seldom fails if installed properly, the inverters in solar electric systems contain complex electronics with a life expectancy of about 15 years (vs. 25-30 years for the modules). This means that they will require replacing in the 25 to 30 year life of a PV system. PV arrays are sometimes located in vulnerable areas and can be damaged by objects such as falling tree branches. The need for service and support can provide an additional stream of revenue; many installers are now offering optional monitoring and maintenance services (such as module cleaning) with the installation.
PARTNERING WITH A SOLAR DISTRIBUTOR, A CRITICAL SUCCESS FACTOR The differences discussed above may appear daunting but they can be significantly alleviated by aligning with a supportive, capable solar wholesale distributor. A solar distributor’s business depends in part on new
0211TECpFPads:0211TECpFPads
2/28/11
2:29 PM
Visit us at: www.californiaturbo.com
Page 29
0211TECp06-48:0211TECp06-48
Case Study
3/1/11
12:27 PM
Page 30
+ of trouble, insure a quality system for the end customer, and safeguard the reputation of the industry. They represent the best formula for success for electrical contractors new to the business. System packages also make sense for small and/or low volume electrical contractors who have solar experience. These contractors offer a wide range of electrical contracting services, including solar electric. These businesses do not have the volume to warrant additional overheads in purchasing, engineering, inventory, and logistics. There are also a large number of small operations that operate from their home or a small storefront with limited shop space. These operations sometimes pick Grid-Tie Systems from SunWize Technologies: complete, pre-engineered solar electric systems make entry into solar easy
Select a solar distributor with depth and breadth of inventory tem packages are pre-engineered, documented, complete systems that are ordered with a single part number and available in a wide range of configurations. Pre-engineering means solar contractors are freed from the details of system design and are guaranteed a reliable, proven system. The inclusion of electrical and mechanical drawings translate to less time spent putting together a submittal package for the local building department or obtaining interconnection. Ordering using a single part number saves time in purchasing while off-the-shelf availability minimizes lead time and guarantees everything will arrive at the same time. Hundreds of available configurations assure that the requirements of most installations can be satisfied with a PV system package. System packages are ideally suited to electrical contractors new to the solar installation business. They embed the experience that the SYSTEM PACKAGES, THE BEST novice solar contractor lacks. They allow conWAY TO GET STARTED tractors to focus on the areas where they do Once partnered with a solar distributor, the have experience and can excel: selling and inbest way to get started is by installing system stalling jobs, particularly the electrical portion. packages, sometimes referred to as kits. Sys- System packages help keep contractors out entrants in the market; they are used to and well equipped to support and nurture electrical contractors getting into solar. It is critical to pick the right distributor; at this initial stage, the ability to provide support and customer service trumps price. Solar distributors deliver invaluable pre-sales and post-sales technical support and a range of training opportunities. After service and support, electrical contractors need to evaluate solar distributors in terms of the breadth and depth of their inventory. Critical to success is developing a close working relationship with a single Sales Manager within the solar distributor’s organization. They will be able to utilize their many years of experience to provide guidance and direction in such areas as system design, equipment selection and industry best practices. They will also act effectively as an extension of the electrical contractor’s organization, managing many logistics, watching over orders, networking, advocating and expediting when necessary.
30
The Electric Current March 2011
up system packages right from the freight carriers dock or have them drop -shipped to the customer. In short, system packages save experienced electrical contractors time and money by simplifying their operations. In summary, successful entry into solar installation depends on fully understanding what is involved, finding a good solar distributor partner and easing into installations with preengineered system packages. â?‘
0211TECpFPads:0211TECpFPads
2/28/11
2:29 PM
Page 31
Visit us at: www.dexterchaney.com
0211TECpFPads:0211TECpFPads
2/28/11
4:08 PM
Page 32
Visit us at: www.cementexusa.com
0211TECpFPads:0211TECpFPads
2/28/11
2:29 PM
Page 33
Visit us at: www.ezmeter.com
0211TECp06-48:0211TECp06-48
Feature
3/1/11
12:27 PM
Page 34
+
NABCEP Alternative Experience Pathway for Qualified Electricians By – Ezra Auerbach
n August of 2009 NABCEP announced a new program that would enable journeymen electricians to gain the experience required to sit for the NABCEP exam. This program was called the Alternative Experience Pathway (AEP). Its guiding principle recognizes the extensive knowledge and skill that it takes to earn journeyman electrician recognition and provides a “fast track” approach to these individuals gaining their PV installation experience. In brief, this new pathway allows teams of up to four qualified electricians (journeymen) work together on a PV installation that is done under the supervision of a proctor. Each of the team members will get installation credit for these installs that is unique in the NABCEP Eligibility Requirements – in all other cases only a single individual can get credit for any given installation. At first the program met with some resistance, many seasoned PV installers felt that the AEP would water down the eligibility requirements to take the exam. This is in fact no way the case. The only people who even qualify for this installation experience pathway must be journeymen electricians (or be recognized as a qualified electrician by their AHJ) and they must have a minimum of 40 hours of PV specific training that includes the hands-on installation of two distinctly different PV systems, plus the two system installs that are part of this Alternative Experience Pathway. This means that candidates qualifying to sit for this exam will have participated in a minimum of four PV installs. Don Warfield, Chairperson of NABCEP says, “The Alternative Experience Pathway program enables a large block of otherwise qualified craftsmen to qualify for certification and increase the supply of Certified workers in markets which place high value on certification” Chris LaForge, a veteran solar installer, electrican and advanced PV trainer who works with the non profit solar training organization the Mid West Renewable Energy Association (MREA) agrees, he says; “At the MREA we find that qualified
I
34
The Electric Current March 2011
electricians are building their skill sets quickly and fully meeting the goals outlined in NABCEP’s task analysis. The new pathway will allow us to provide the opportunity for more of our most qualified students to meet the experience requirements to sit for the PV Certification Exam. ” In the past year Alternative Experience Pathway installations have taken place in Texas and Montana. The first round of candidates who completed their training and installations at the Austin JTC took the NABCEP Certified PV Installer Exam in September – and their passing score percentage was higher than the average. In Texas the AEP program has been used in conjunction with a Department of Labor grant to train out of work or underemployed journeymen electricians to play senior roles on PV installation projects. The project is a joint venture between the Austin Texas JATC (Joint Apprenticeship and Training Center) and ImagineSolar – a private PV training company. This unique partnership brings together the combined strengths of a nationally recognized PV centric training organization and the outstanding facilities of a JATC. “We are proud that the solar training roadmap and the state-ofthe-art Solar Field Lab, designed by ImagineSolar, have enabled our members to be approved to sit for the NABCEP Certified PV Installer Exam,” stated Gilbert Ferrales, Training Director for the AEJATC. “None of this would have been possible if not for the Department of Labor Green Jobs Training Grant we were awarded earlier this year. The grant award was the result of our close working partnership with the local workforce investment board, Workforce Solutions Capitol Area, and ImagineSolar.” Response to this program from Electrical Contractors has been equally positive. “ImagineSolar provided not only a pathway to the NABCEP Certification Exam but also in-depth installation experience on cutting edge solar.” said Jack Payne, Owner, B.J. Electric, and a member of the AEJATC Board of Trustees. ImagineSolar starts their students out in an extensive classroom and laboratory based training program that runs 120 hours. In addition
0211TECpFPads:0211TECpFPads
2/28/11
2:30 PM
Page 35
Visit us at: www.aetenergy.com
0211TECp06-48:0211TECp06-48
Feature
3/1/11
12:28 PM
Page 36
+ to theoretical learning the students participate in group installations that includes a wide variety of system types including; AC-coupled bimodal systems, micro-inverters, dual-axis trackers, and cylindrical CIGS modules as well as traditional solar technology. In short the students are exposed to a very wide range of equipment and installation types. After completing the classroom and hands on training the students are broken into teams of four, as a team the complete two installations at the JATC. To ensure that the students are as close as possible to “real world” installation conditions the systems are all inspected and approved (or rejected) by the AHJ. In Austin, incentive payments for PV installations are tied to a requirement to have NABCEP Certified Installers on the job. This project is helping ensure that there is a ready supply of well trained and fully qualified available as solar electric installations become increasingly prevalent. The Montana Electrical Joint Apprenticeship and Training Committee took a different approach to their implementation of the AEP program. Thanks to the dogged determination of Mitch Hegman, the Assistant Training Director at the JATC a community-based installation was located. A team of four electricians, who took advanced PV training at the JATC, worked together to install a PV system on the East Valley Middle School in East Helena, MT. This job provided the electricians working on the project with valuable real-world PV installation experience, which, of course, entailed the odd bit of difficulty – the wrong fasteners for the mounting frame slowed down progress
Visit us at: www.krenzvent.com
36
The Electric Current March 2011
Visit us at: www.arpiusa.com
0211TECpFPads:0211TECpFPads
3/1/11
9:47 AM
Page 37
Visit us at: www.surgepure.ca
0211TECp06-48:0211TECp06-48
Feature
3/1/11
12:28 PM
Page 38
+ progress beyond the permitting process due to structural loading beyond existing roof design – all of this made for valuable lessons in site surveys, permitting and system design.” This 4.48 kW installation of two strings of ten 224 Watts Sharp PV modules is virtually a letter perfect example of the intent of the AEP program because it provided value to multiple stakeholders. Not only did the candidates get the experience they needed to sit for the NABCEP exam they also made a lasting contribution to their community. East Valley students, parents and school staff will long see the benefits offered by solar electricity thanks to this project. The Alternative Experience Pathway installation opportunity is open to all Joint Apprenticeship Training Centers. It offers a great way for qualified electricians who take advanced training based on the NABCEP PV Installer Job Task Analysis to get the experience they need to take the Certification Exam. It also presents a great opportunity for training centers to work with their community and make a positive contribution to the greening of the local electrical grid. NABCEP strongly encourages collaboration between contractors, JATCs, utilities and community groups to use lasting, realworld project for Alternative Experience Pathway installations. For more information on this program readers should contact the author at eauerbach@nabcep.org. ❑
The Alternative Experience Pathway installation opportunity is open to all Joint Apprenticeship Training Centers. while someone was dispatched to the nearest hardware supplier for the correct length screw. The “real world” intervened in the installation a second time. An issue with cabling arose when installing the monitoring system – to address the problem one of the installers had to interface with the IT person at the school. Mitch Hegman says; “This issue is illustrative of the technical problems that can ‘haunt’ installers and lead to unanticipated expenditures of time. In that regard this problem was almost fortuitous with respect to the intent of this program to present some obstacles for the installers to solve.” Mr. Hegman says. “I am very pleased with the performance of the installers. I think we can all agree that these candidates long ago achieved ‘expert’ status in skills such as interpretation of the NEC, raceway installations, conductor sizing, etc. The training throughout this venture however, has been remarkably productive in bringing them to the front edge of PV design and installation.” He continues; “The Middle School was actually the third site selected for the PV system. Both previous locations failed to
Visit us at: www.udevices.com
38
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
2:30 PM
Page 39
Visit us at: www.kvar.com
0211TECp06-48:0211TECp06-48
Feature
3/1/11
12:28 PM
Page 40
+
Multi-Contact, serving some of the world’s most demanding applications. Multi-Contact is a well known manufacturer of precision electrical and electronic connectors and interconnection systems. Multi-Contact’s extensive history and experience in creating cutting-edge electrical connections serves some of the world’s most demanding applications in robotics, test and measurement, military, aerospace, medical, solar energy, power distribution, and many others. MC connectors are designed for high performance and high mating cycles, and they are ideally suited for high-current applications. The renowned Multilam technology was created six decades ago and has been integrated into the complete connector line that Multi-Contact continues to create today. All MultiContact products are built upon this time- tested and proven Multilam band technology. The Multilam is unmatched in terms of low resistance, low insertion forces and reliability. MultiContact also offers both standard and custom connector solutions for all types of interconnect application. Multi-Contact takes great pride in focusing on emerging technologies. MC‘s pioneering history within the solar industry is well documented, mainly because the manufacturing background allowed them to create the very first solar specific connector, dating back to the 1980’s. Multi-Contact’s line of plug connectors for data and power ranges from mini-sized connectors to high-current connectors that are more than capable of carrying several thousand amperes. This background and experience allowed MC to naturally enter the photovoltaic sector, where the MC Solarline is one of the market leaders for connections in cabling systems for all types of solar array systems (MultiContact was the first company to manufacture and offer such a photovoltaic connector product to anyone who wanted one). As MC continued to be the only company offering standard solar connector parts from inventory, they saw the market go from very small specialized niche group of people to inevitably, a huge political interest before any other company was even able to make their first solar connector. Multi-Contact has put forth great effort in making the most reliable and precision quality solar connector possible. Its solar connectors are part of some of the longest standing Solar Arrays still up and running to this day. The proprietary blend of metal alloys along with the Multilam technology, and quality assurance checks and balances, has made the MC Solarline of connectors (including both MC3’s and MC4’s) the solar industry’s strongest and most reliable connectors. MC’s time tested track record speaks for itself. To ensure proper usage and installation practices of MC’s solar
40
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
Visit us at: www.multi-contact.com
2:30 PM
Page 41
0211TECp06-48:0211TECp06-48
Feature
3/1/11
12:29 PM
Page 42
+
connectors, they offer many programs to solar professionals. MC wants to make every MC solar connection as concise and as easy as possible, for the safety for everyone involved. Solar integrators and end users alike can count on MC connections being both reliable and held to the highest safety standards in existence. MC offers an MC3 connector certification program as well as an MC3 and MC4 tutorial video that serves as a step by step guide detailing all the instructions needed to make and assemble these simple yet powerful connections. With quality standard products and custom-designed solutions to meet customer needs, Multi-Contact has a proven track record as a reliable business partner and design pioneer. Multi-Contact credits its commitment to quality and reliability as the secret to its long-term customer relationships. The MC3 and MC4 connectors meet or exceed all county, state, and federal regulatory building codes. Multi-Contact has been certified according to the quality management standard ISO 9001-2008. Multi-Contact’s products comply with county, state, and federal regulatory building mandates and are in compliance with many other safety standards and certifications–notably UL, NEC, IEC and TÜV. Other product certifications include cUL, RoHS, DIN EN, CTS, ESTI, VDE, and many more. Note that such compliance to codes are part
42
The Electric Current March 2011
of the review and approval processes by government job inspectors. Multi-Contact has a very strong global presence; it is part of the Stäubli Group, an international mechatronics solution provider. Being involved with so many different types of innovative technologies helps both establishments stay in tune as well as contribute to many of today’s emerging products. Multi-Contact’s headquarter is located in Switzerland and has sales offices globally, with new offices in Mexico Russia and India. Multi-Contact’s North American Headquarters is based North of San Francisco in Windsor, California. Further production sites are located in France, Germany, U.S.A., and China. Business units operate across Europe, as well as in Asia and throughout the Americas. For further questions or inquiries please contact Brian Pfister at 707-548-4780. ❑
0211TECpFPads:0211TECpFPads
3/1/11
9:47 AM
Page 43
Visit us at: www.solmetric.com
0211TECp06-48:0211TECp06-48
Feature
3/1/11
12:29 PM
Page 44
+
Finding your place in the sun By Peter Hoberg Solmetric Corporation
T
horough site evaluation will not guarantee a successful solar installation, but it can definitely increase the chances. Solar site evaluation can be a key success factor for solar installers. It requires a thorough knowledge of solar fundamentals as well as up-to-date information on the latest tools and best practices. When performing site evaluation, the solar professional needs to gather data, including: • Roof orientation, including azimuth and tilt • Roof area available for solar array • Shade measurements for energy calculations • Conduit and inverter locations If this data is gathered quickly and efficiently, then the time investment is kept to a reasonable level. Perhaps even more importantly, the client is left with a positive impression, and the chances of winning the business are improved. The data must also be thorough, so that all information required to do a system design or proposal is available, without guesswork or without requiring a second site visit. In this article we will discuss some of common site evaluation challenges and some new tools that can help improve the accuracy and efficiency.
SHADE MEASUREMENT TOOL
and tilt are measured continuously, and sun paths for the current location are calculated and drawn on the screen in “Live Preview” mode. As the operator moves, the image updates. This function enables the operator to see where obstructions (chimney, tree, other structure, etc.) will cause shade. By defining a desired “shade-free” window, such as 9am to 3pm yearround, the operator can move to the edge of a shade-free zone, and mark that location on the roof, for example with chalk. When completed, the user can map out an array area that will assure shade free production in this time window. The window can be defined with a start and stop time, and a start and stop month.
MEASURING WHEN METAL INTERFERES WITH COMPASS A compass relies on the earth’s magnetic field to its orientation reading. When using the compass near metal, readings can be distorted in an unpredictable way. In this case, SunEye shade readings can still be taken using a reference heading other than the compass, such as the seam of the roof, or the heading of a far away object. The user can enter the reference direction, and the invalid compass readings are over-ridden.
SOLAR ACCESS “UP THERE” Shade measurements are normally performed using a manual reflecting In many situations, shade measureSolmetric SunEye has integrated fisheye lens and touchscreen user interface. globe, or an integrated automatic apments are required, but access is not proach using a fisheye lens. The autoavailable. For example, n many site matic fisheye lens approach is used by the Solmetric SunEye™, evaluations, it may be difficult to access the exact location of and can offer significant advantages in accuracy and time- the solar array. For example, the roof access may not be ausavings. Shade readings are taken from a specific location on thorized at the time of the evaluation or the proper safety the roof and processed immediately to show solar access per- equipment may not be available. A new building or solar parkcentage, and also the time-of-shade, that is what months, and ing canopy may not be constructed yet, or step ladders may what time of day, surrounding obstructions will cause shade. not reach high enough and scissors lifts or boom lifts can be expensive and complex. FINDING SHADE-FREE ZONES For these situations, the SunEye Extension Kit enables the The SunEye incorporates an electronic compass and level measurements from ground level up to 18 feet. The SunEye is for proper orientation during shade measurements. Direction mounted securely on a plate, then raised up on the telescoping 44
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
Visit us at: www.haywardbaker.com
2:31 PM
Page 45
0211TECp06-48:0211TECp06-48
Feature
3/1/11
12:30 PM
Page 46
+
SunEye Extension Kit enables measurements up to 18 feet above ground level.
•Beware that the images may be one to three years old. Structures may be missing, trees may have grown, etc., both on the property PREPARING FOR SITE VISITS and on neighboring properties. Images represent a useful snapAerial photography is freely shot in time, but it is important to available from Google, Bing or also look for changes and new other sources, and can be an exdevelopments. cellent way to prepare for a site • Resolution may be limited. The visit. By inspecting both overhead quality of imagery quality varies by and oblique (angled) views of the region and over time. Larger onsite you can estimate the roof size roof obstructions such as chimneys and identify trees or buildings or may be visible but smaller ones, other structures that may cause Identify shade-free areas using SunEye window. such as vent pipes, may not be. shading or roof access difficulty. Overall, aerial images provide a great way to prepare for a However, care must be taken when using this information: • Make sure that you have zeroed in on the right building or site evaluation. But they do not replace the need for on-site visual inspection. site. Address information alone cannot always assure that During a site visit, SunEye readings can be located on the the right building or site is identified. I have heard stories of roof and afterwards viewed in Google Earth™. complete solar proposals being prepared for a willing cusWith the right tools and training, effective on-site evaluatomer, but on the wrong house. Sometimes this requires a tion and shade measurements can help increase your chances phone call or two, but it is definitely worth it to avoid the of success in solar. ❑ embarrassment.
pole to the desired level. Measurements are triggered by rotating the pole.
46
The Electric Current March 2011
0211TECpFPads:0211TECpFPads
2/28/11
4:08 PM
Page 47
Visit us at: www.lappusa.com
0211TECp06-48:0211TECp06-48
3/2/11
Advertiser Index
9:34 AM
Page 48
+
Company Name AET Energy ALCAN ARPI Bierer & Associates California Turbo Cementex Conduit Repair Dexter + Chaney DH Solar E- Z Meter HatiCon Solar Hayward Baker High Voltage Hioki USA Jonas Software Krenz Vent KVAR Lapp U.S.A Legrand/Cablofil ME Products Multi - Contact NABCEP Noren Products Northwest Lighting Systems, Co. Pelsue Phase- A- Matic SED Solmetric Sun Wize Surge Pure Surge Suppression Underground Devices, Inc. Utlity Metals Zistos Portable Video Systems
48
The Electric Current March 2011
Page Number 35 BC 36 25 29 32 21 31 11 33 IFC 45 24 5 7 36 39 47 1 15 41 12 3 IBC 13 19 2 43 27 37 17 38 23 9
Website www.aetenergy.com www.alcan.com www.arpiusa.com www.bierermeters.com www.californiaturbo.com www.cementexusa.com www.conduitrepair.com www.dexterchaney.com www.dhsolar.net www.ezmeter.com www.haticonsolar.com www.haywardbaker.com www.hvinc.com www.hiokiusa.com www.jonasconstruction.com www.krenzvent.com www.kvar.com www.lappusa.com www.legrand.us/cablofil www.meproducts.net www.multi-contact.com www.nabcep.com www.norenproducts.com www.northwestlightingsystems.com www.pelsue.com www.phase-a-matic.com www.SEDPV.com www.solmetric.com www.sunwize.com www.surgepure.ca www.surgesuppression.com www.udevices.com www.utlitymetals.com www.zistos.com/EC.htm
0211TECpFPads:0211TECpFPads
3/1/11
12:02 PM
Page C3
Visit us at: www.northwestlightingsystems.com
0211TECpFPads:0211TECpFPads
Visit us at: www.alcan.com
2/28/11
2:31 PM
Page C4