Getting the Highest Solar Module Quality & Performance How and why PTC Ratings work Connecting Renewable Energy to the Electric Transmission Grid
HVDC Technology Optimizing Wind Turbine Controls
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contents Getting the Highest Solar Module Quality & Performance How and why PTC Ratings work Connecting Renewable Energy to the Electric Transmission Grid
Treasury Publishes New Q&A as Year-end Deadline Approaches
Optimizing Wind Turbine Controls Geophysics & Geothermal Exploration
10 PLUS Show in Print features: • Solar Power International • CanWEA 2010 • Geothermal Energy Expo 2010 Conference & Expo
12 On the cover: Canadian Solar announced this 1.12 MW solar installation at the Mineta San José International Airport in May 2010. Cover photo courtesy of Canadian Solar www.canadiansolar.com
Investing in clean energy
Show-in-Print: CanWEA 2010
The Key to Getting the Highest Solar Module Quality & Performance
Connecting Renewable Energy to the Electric Transmission Grid
The Future of Wind Energy
Optimizing Wind Turbine Controls: Isn’t it time to do it?
Benefits of Type Certification for Wind Turbines: Three steps to get started
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Smarter Management of Solar Power Key Benefits of Roll Form Technology
Hydro and Marine energy
Thermostats vs. Hygrostats: Condensation control in electronic enclosures
Geothermal Energy Expo 2010 115 BioPower
Solar Racking, IBC & Taking the Time to Protect Yourself Solar products
Show in Print: Solar Power International
A Turning Point for the Concentrated Solar Power Industry: Delivering bankable energy solutions
departments Solar energy
What You Should Know About Financing a Solar Project in Today’s Market
September / October 2010 Volume 4, Number 5
Case Study: Historic Transmission Project Choosing the Right Wind Turbine Lubricant to Optimize Production Critical Surface Preparation for Clean Energy Applications
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editor's note You’ve likely heard the expression ‘making something out of nothing.’ Well, it seems new research is attempting to do just that. In the ongoing search for renewable energy sources, scientists are trying to harness and harvest electricity out of mid air. Although air would appear to consist of a whole lot of nothing, turns out it is actually full of electrical charges. Presented in a report at the 240th National Meeting of the American Chemical Society (ACS) earlier this year, Fernando Galembeck (a PhD from the University of Campinas in Sao Paolo, Brazil) and his team not only debunked the myth that water droplets in the atmosphere are electrically neutral, even after touching charged dust particles or other liquid droplets, but they also found that water in the atmosphere picks up charges. They proved this by measuring the charge of silica and aluminum phosphate, two common airborne substances. When the air is humid, silica turns negative and the aluminum phosphate gets a more positive charge—knowledge that one day may even be used to solve and control lightening strikes. Moreover, this research of “harnessing hygroelectricity” could eventually be developed into an alternative source of energy. Much like rooftop solar panels, imagine a ceiling of hygroelectricity collectors at home or in the office. “Our research could pave the way for turning electricity from the atmosphere into an alternative energy source for the future,” said lead scientist, Galembeck. “Just as solar energy could free some households from paying electric bills, this promising new energy source could have a similar effect.” (source: www.sciencedaily.com) At a time when the economy is still recovering (or reeling, depending on how you look at it), affecting jobs and project financing, and oil spills continue to hit the news (with yet another, smaller rig exploding into in the Gulf of Mexico at the beginning of
September), it’s nice to imagine a future where something as significant as energy could be made, seemingly, out of nothing. This issue, we focus on many positives including the bankable energy solutions solar power and, especially, the Concentrated Solar Power (CSP) industry are now beginning to offer; the future of wind energy, including the world’s largest wind energy project or contract ever signed by a US utility, the Alta Wind Energy Center (AWEC) in California, which will have the capacity to generate 1,550 megawatts of renewable energy; and, the promise of geothermal exploration. We also look at legislation, from the ARRA cash grants to the recently proposed rules for the reduction of boiler emissions by the US Environmental Protection Agency, which, at first sound quite environmentally progressive. However, they do not differentiate the growing biomass heat industry or biomass-fueled heating systems (be sure to check out page 122). As I imagine a near-perfect future, I leave you with a letter from one of our readers. I realize I’m circling back to the BP oil spill (discussed at length in my note last issue), but building the future takes time, and all of us: I enjoyed reading your editor’s note from the July/August 2010 edition of NACE. It’s amazing to me, but I do feel many people aren’t (in spite of all the coverage) really taking in just how destructive an event this oil spill is. Your numbers show it, and, more importantly, your note tells us all how to get involved. I think that last point is sorely lacking from all the talk that comes from Washington, BP, and the President himself. Time to write a letter to my congressman, or check out www.matteroftrust.org. ~ Bill P. There’s a quote that goes, “When it comes to the future, there are three kinds of people: those who let it happen, those who make it happen, and those who wonder what happened.” ~John M. Richardson, Jr. Remember to get involved.
news bites Facts about wind energy’s emissions savings In an attempt to set the record straight in the battle between facts about wind energy and fossil fuels, the American Wind Energy Association’s (AWEA) recent data and analysis have demonstrated that the emissions savings from adding wind energy to the grid are even larger than had been commonly thought. In addition to each kWh of wind energy directly offsetting a kWh that would have been produced by a fossil-fired power plant, new analysis show that wind plants further reduce emissions by forcing the most polluting and inflexible power plants offline and causing them to be replaced by more efficient and flexible types of generation. Read more at www.awea.org/newsroom/pdf/08-27-10-Wind_and_emissions_response.pdf. AWEA | www.awea.org
Tool to connect the solar supply chain The International PV Equipment Association (IPVEA), an independent, non-profit organization of manufacturers and suppliers of photovoltaic fabrication equipment and related raw materials, introduces the PV Matrix, an innovative new solar supply chain tool. The IPVEA Matrix illustrates and links the complete PV Value Chain. Located online, the tool is designed to provide a central source of information to connect the solar industry. The PV Matrix separates solar technology into four main segments: silicon, organic, R&D, and installation and power generation. Each segment expands to show categories within that technology. For example, silicon expands to raw material to wafer, wafer to cell, and cell to modules. From there, each subsection further breaks down. This is beneficial because it simplifies technology and allows visitors to find specific information and locate key suppliers. Visitors and suppliers can both work and interact with other companies. Companies listed on the PV Matrix can also improve their networks, as well as company sales, profile, and exposure to the PV industry. Additionally, the Matrix provides customizable microsites where visitors can view image libraries, data sheets, white papers, product brochures, videos, and more.
DOE funds algal biofuels research The US Department of Energy (DOE) announced the investment of up to $24 million this past summer for three research groups to tackle key hurdles in the commercialization of algae-based biofuels. The selections will support the development of a clean, sustainable transportation sector—a goal of the Department’s continued effort to spur the creation of the domestic bio-industry while creating jobs. Developing cost-effective renewable transportation fuels is a key component of the Administration’s strategy to cut greenhouse gas emissions and move the nation toward energy independence. “The United States must find effective ways to hasten the development of technologies for advanced biofuels made from algae and other renewable resources to reduce our need for foreign sources of oil,” said Assistant Secretary for Energy Efficiency and Renewable Energy Cathy Zoi.
Check it out at www.matrix.ipvea.org.
The three consortia selected for funding are: • Sustainable Algal Biofuels Consortium (Mesa, Arizona); • Consortium for Algal Biofuels Commercialization (San Diego, California); and • Cellana, LLC Consortium (Kailua-Kona, Hawaii).
International Photovoltaic Equipment Association (IPVEA) | www.ipvea.org
Department of Energy (DOE) | www1.eere.energy.gov
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Treasury Publishes New Q&A as Year-end Deadline Approaches By Leah S Karlov & Joanna Grossman
he year-end deadline is quickly approaching for new renewable energy projects to start construction to qualify for the federal cash grant in lieu of the 30% investment tax credit. Because renewable energy projects receiving cash grants must reach certain development milestones (including site control, procurement arrangements, locking in funding, and environmental reviews) before breaking ground, a great deal of attention is focused on what it means to start construction for purposes of meeting the year-end deadline. In addition to earlier guidance, on June 24th, 2010, the US Treasury published a series of questions and answers (the “Q&As”) clarifying what it means to start construction for purposes of the cash grant.
Section 1603 of the American Recovery and Reinvestment Act of 2009 provides cash grants to owners (and, in some cases, lessees) of solar, wind, and certain other renewable energy projects, the construction of which begins by December 31st, 2010. Construction is treated as having begun when either: 1) physical work of a significant nature has begun; or 2) costs have been paid or incurred that satisfy a 5% safe harbor. Physical work of a signiﬁcant nature
Probably the most important news in the Q&As is a warning that “Treasury will closely scrutinize any construction activity that does not involve a continuous program of construction or a contractual obligation to undertake and complete within a reasonable time, a continuous program of construction.” Treasury provided this warning in the context of acknowledging that laying the foundation for a single wind turbine generator will satisfy the requirement construction has commenced for a 50-turbine project. The warning is equally applicable to solar and other renewable energy projects. Consequently, project sponsors and investors may be more inclined to rely on the 5% safe harbor to avoid the risk construction delays could preclude cash grant eligibility. The Q&As provide additional examples of what constitutes physical work of a significant nature while, at the same time, clarifying the boundary between eligible electrical generation equipment and ineligible transmission assets. For example, the Q&As clarify that physical work on a transformer that steps up the voltage of electricity produced at a facility is considered physical work of a significant nature because such equipment is specified energy property. In contrast, work on a transmission tower does not count as physical work of a significant nature because transmission equipment is not specified energy property. Another example addresses roads built on the construction site. Roads integral to the qualified facility (e.g. onsite roads that move materials to be processed and roads to operate or maintain the facility) are specified energy property. Starting construction on these integral roads will satisfy the commencement of construction standard. However, roads that provide access to the site and roads used solely for employee and visitor vehicles do not constitute specified energy property and, consequently, commencing construction of those roads cannot be counted as beginning construction. Similarly, clearing land or erecting fences does not qualify as physical work of a significant nature; nor does dismantling an existing facility to build a new one. Work carried out pursuant to a binding contract with a third-party contractor or component vendor may count if the work commences after the contract is entered into. Work performed on inventory of a supplier produced or manufactured before the contract was entered into cannot be counted as physical work of a significant nature. If a binding written contract is entered into with a supplier that produces the same goods for multiple customers, the contractor must be able to demonstrate when the work began with respect to the particular property that will be delivered to the applicant. For this purpose, the supplier may use any reasonable and consistent method to allocate work between customers.
Leah S. Karlov is Of Counsel in the Tax Department of Milbank, Tweed, Hadley & McCloy LLP.
Joanna Grossman is an associate in the Tax Department of Milbank, Tweed, Hadley & McCloy LLP.
Five percent safe harbor
Under the 5% safe harbor, commencement of construction is deemed to occur when more than five percent of the eligible property costs have been paid or incurred. Without elaboration, the Q&As states that the 5% safe harbor will be satisfied when five percent or more of the total cost of eligible property is paid or incurred. Costs incurred for ineligible property such as perimeter fencing, transmission and interconnection, buildings, employee parking, and other ineligible property will not count. In general, costs are not treated as incurred for purposes of the 5% safe harbor until purchased property or services are delivered or title to the property passes to the applicant (the so-called “economic performance” rules). When relying on the work of a contractor to satisfy the 5% safe harbor, the applicant may treat costs as paid or incurred when costs are paid or incurred by the contractor. Applicants may also include costs paid or incurred by a supplier that is manufacturing property or components for the applicant pursuant to a binding written contract. As with the physical work of a significant nature standard, costs must be incurred after the binding written contract is entered into, and must be reasonably allocated to the specified energy property of the applicant. The ability to treat costs incurred by a supplier as if they were incurred by the applicant only applies to those contracting directly with the applicant. Consequently, costs incurred by a component supplier to a contractor will not be treated as incurred until the components are provided to the contractor (not as the costs are paid or incurred by the supplier). Treasury has also clarified that the cost of components will be treated as having been incurred when title to the components is transferred to the applicant, even though components may be stored at the manufacturer’s premises. Additionally, the Q&As reiterate it is not sufficient to show an applicant reasonably expected costs incurred by December 31st, 2011 to exceed five percent of the project costs. Rather, the costs incurred must be equal to or greater than five percent of the actual total cost of the specified energy property. If a project includes multiple units of specified energy property (e.g., multiple wind turbine generators) and less than five percent of the cost of the eligible property in the entire project has been incurred before year’s-end, an applicant can elect to treat the project as including less than all the units of property and apply for a cash grant on that lesser number. What’s next?
At this point, developers and lenders are rushing to get construction of their projects started to meet the December 31st, 2010 deadline. As for alternatives, legislation has been introduced in Congress to provide a refundable 30% tax credit with respect to qualified projects the construction of which commences before January 1st, 2013, and which are placed in service before specified termination dates. Though, in some respects, the refundable credit would provide greater flexibility than the cash grant program, a significant drawback is the tax refund could be delayed. Instead of being paid within 60 days following submission of a completed application, as is currently the practice with the cash grant, the tax refund would not be paid until some time after the due date of the applicant’s tax return for the tax year in which the property is placed in service. At this point, we are assuming that for purposes of applying the commencement of construction requirement of the proposed legislation, the existing guidance and Q&As would remain applicable. Milbank, Tweed, Hadley & McCloy LLP | www.milbank.com
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What You Should Know About Financing a Solar Project in Today’s Market
Pioneer Union Elementary School District’s solar farms qualified for an estimated $2.8 million in accelerated depreciation and federal tax incentives, and another $1.4 million in cash rebates through the California Solar Initiative (CSI) program.
By Wim Goethals
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quiet, yet critical, evolution is taking place within the financial landscape for solar projects. During the last year, financing conditions improved as more investors and banks stood ready to bankroll solar photovoltaic (PV) projects. On the other hand, this positive effect was somewhat dampened by incentive levels dropping faster than anticipated or, in some cases, those incentives being suspended or even eliminated altogether. One thing is clear: expect to see a flurry of activity in the last quarter of 2010, as everybody tries to get the maximum amount of megawatts in the ground ahead of the federal grant expiration. Despite this uncertainty, securing the financing for these PV projects might not be as difficult as it was one to two years ago. There are several reasons why investors and banks have fallen in love (albeit not passionately) again with solar PV. First and foremost, photovoltaics truly are a proven technology. The first solar installations implemented decades ago are still functioning and producing ahead of budget. Secondly, this proven technology also happens to generate very stable, predictable, and transparent cash flows—a critical characteristic that every investor appreciates and values. Lastly, and perhaps in response to the subprime credit excesses of the recent past, the financial community values the concept of deploying capital in projects that return a tangible benefit to society. Nevertheless, there are obvious downsides to investing in solar PV, specifically in the United States where no Feed-in-Tariff (FIT) exists. Having made the decision to explore renewable energy, most customers do not buy a PV
installation on a balance sheet, but rather opt for a Power Purchase Agreement (PPA) under which a specialized company will buy and finance the installation for them, and sell the electricity output back at a pre-agreed price. Compared with a typical solar PV project in Germany, or in the Canadian province of Ontario (or any other region with a FiT in place), there are two considerable downsides to this approach when it comes to financing the installation. First, and most obviously, we are no longer talking about government-backed cash flows with a little bit of production risk. PPA-financings are non-recourse loans exposed to corporate credit risk. Secondly, and probably more importantly, there is no such thing as a standard PPA. Combined with the plethora of state and local incentives out there, this means that any serious investor will have to go through a lengthy due diligence process before committing a single cent to a project. Given the comparatively small amounts of money involved in solar PV financings (e.g., a 500 kWp installation requires around $2 to $2.5 million), this means investing a huge amount of intellectual capital on a per dollar basis. This complexity is frequently underestimated by people new to the industry (or new to the US market). Inexperienced project developers or integrators all too often bring “unfinanceable” PV projects to investors. In reaction, during the last year, investors have been channeling more and more of their dollars toward the “institutional” developers, seeking a sense of security in these companies because of their size, proven track-record, and strong balance sheets.
Going on the Offensive: Understand what impacts ﬁnancing decisions
Going on the offensive should not, however, discourage new entrants or small developers. As the old sports adage goes: sometimes the best defense is a good offense. Such an approach begins by understanding the top drivers that impact how—or if—a solar project gets financed. Doing so means asking some tough questions. For example: Does the project actually “pencil out?” When financing a solar PV project, investors will assume corporate credit risk, energy production risk, project documentation risk, and tax risk. They will expect to earn a little bit more than just the Treasury rate (or a corporate bond for that matter). It is important to be realistic. Is the PPA a financeable contract? This is the tricky one. Since a significant part of the value of the incentives is taxdriven, care has to be given that these tax benefits end up with the party that can use them. Retain legal counsel to make sure the PPA respects all the rules and regulations regarding pricing of these contracts, buyout options, and other service components. Is the customer financeable? In essence, through a PPA, you’re financing the customer. In general, the customer will need to be investment-grade or better. How financeable is the EPC contractor and technology? The partner actually installing the PV system and guaranteeing the successful function and performance over the contract’s lifetime must have a proven track record of success and a strong balance sheet. Experienced developers put their contractors through a rigorous partner screening process using criteria such as: • Has the company implemented this type of project before? • Are the company’s projects still operating as they should? • Does the company have the financial strength and wherewithal to see the project through to the end? • Does the company share the same values and business strategies? With any one of the above components missing or out of synch, it would be difficult to obtain financing for a solar project in today’s market. Yet, the evolution continues. Any realistic developer or investor knows that there are no federally mandated, nationwide incentives on the horizon. With that knowledge, the solar energy landscape in the US will belong to
those individuals and companies willing to embrace the complexities of solar financing on a state-by-state basis—in each case performing the relentless, but wholly necessary due diligence so that the resulting solar PV projects deliver solid financial benefits and, arguably, more importantly, establish a base of clean, renewable energy.
Wim Goethals serves as Head of Finance Americas for Enfinity America Corporation. Enfinity finances, develops, builds, operates, and maintains commercial solar energy systems. Enfinity America Corporation www.enfinitycorp.com
A Turning Point for the Concentrated Solar Power Industry Delivering bankable energy solutions By Jayesh Goyal
he potential for the concentrated solar power (CSP) industry to generate electricity has been discussed for years, but the ability to deliver on that potential has never been as good as it is today. The International Energy Agency reported in May 2010 that CSP could provide 11.3% of global electricity by 2050. Meanwhile, the market for CSP plants is expected to grow by 20% annually over the next decade, reaching an estimated installed capacity of more than 20 gigawatts by 2020. States like California and nations like Australia, India, and South Africa are establishing bold renewable energy goals that can only be met with significant input from CSP technologies. Clearly, there is a vast global market for CSP. However, the industry is at a turning point. Many large projects have been announced and power purchase agreements (PPAs) have been signed, yet there have been numerous delays and cancellations, and difficulties in obtaining project financing are creating roadblocks. The key to capitalizing on the market opportunity lies in the ability to get projects financed, and that requires CSP companies to deliver on price and performance promises. Essentially, from a lender’s perspective, the key questions relate to reliability, cost, and performance as follows…
How reliable is the technology?
Demonstrating the reliability of CSP technology is essential. Actual operating plants with historical performance data are the best proof point. Certifications by credible and independent entities are essential to reinforce the claims made by technology players. For example, AREVA Solar has used its Kimberlina plant to demonstrate the reliability of its Compact Linear Fresnel Reflector (CLFR) technology, resulting in the company becoming the first solar steam boiler manufacturer to receive the “S” Stamp Certification from the American Society of Mechanical Engineers. Getting this kind of third-party certification would have been impossible without having a field installation producing electricity daily. Other CSP firms like eSolar and BrightSource have also built demonstration plants to prove their technology. A prudent approach to reducing risk is to build progressively larger plants so magnifying their scale is not as daunting. The success of these relatively smaller projects reassures traditionally risk-averse utilities that a technology is ready to provide reliable service in today’s market. For example, the successful implementation of solar steam augmentation at the Liddell Power Station in Australia gave the Australian government enough confidence in the technology to commit funding toward a 44 MW booster project at the coal-fired Kogan Creek Power Station. Proving reliability greatly increases the chance that such projects will be funded. Does the price provide a good return?
Numerous large projects have been announced in the past several years, but they haven’t always come to fruition. Many projects secure PPAs at prices that make the returns on the project marginal, so any unforeseen cost increases make the project unviable. This industry problem is what Greentech Media Research analyst Brett Prior pointed to in his recent posting, “A signed PPA isn’t enough. Why? Economics.” Prior states: “Many of these PPAs have prices that won't allow for a reasonable return for the equity investor (8% to 9% unlevered, or 13% to 16% levered) and, as such, they likely won't be able to attract the funds required to build the project.” Companies need to be realistic about their pricing outlook and build in contingencies for cost and schedule overruns. PPAs are important, but success as an industry will be measured by an ability to provide high-performance installations at 12
The Kimberlina Solar Thermal Power Plant in Bakersfield, California is the first new CSP plant to come online in California in nearly 20 years, and the first in the US to utilize Compact Linear Fresnel Reflector (CLFR) technology.
This 9 MW solar steam system boosts power at the coal-fired Liddell Power Station in New South Wales, Australia, making it the world’s first solar/coalfired augmentation facility in the world. a competitive price. Put simply, can we deliver? The answer: yes. We’ve seen the photovoltaic sector lower costs as technologies have advanced and the supply chain has been streamlined. The same trend is expected in CSP as more plants get built and large industrial players bring their supply chain and scale efficiencies to these projects. This will allow firms to provide market-competitive pricing with assured returns for the investor. Who is guaranteeing delivery and performance?
Unsteady financial markets and uncertain tax policies have led to a situation where many projects, even when they get private financing, are structured in such a manner that the room for error and the chances for a safe return are slim. To put this in perspective, since 2002 slightly more than 50% of renewable projects have either been delayed or cancelled, according to the California Public Utilities Commission. After ‘transmission,’ ‘financing’ was cited as the top barrier to development. Since there are market and technology risks that could jeopardize returns, CSP companies need to be able to offer customers credible schedule and performance guarantees. Because many CSP companies are start-ups, they do not have the strong balance sheet needed to provide credible guarantees that would enable them to secure project financing. That is why some CSP companies are seeking to pair their technology with the financial backing of large, industrial players. In March, AREVA purchased the CSP start-up Ausra to form AREVA Solar. Similarly, Siemens purchased Israel’s Solel in October 2009, and Alstom recently announced a minority stake in BrightSource. The financial backing of these major players is needed to signal to power customers that CSP projects can provide safe returns on an investment. In the end, credibility based on execution and financial strength will likely be the critical factor for success in the industry. As project financing shakes out, it’s anticipated the market will be dominated by a few strong players that can successfully answer investors’ make-or-break questions. Jayesh Goyal is the VP of North American Sales for Mountain View, California-based AREVA Solar, Inc. AREVA Solar, Inc. | www.areva.com
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Solar Racking, IBC & Taking the Time to Protect Yourself By Wolfgang Fritz
he US market, once the leader in solar energy manufacturing and development around the world, has recently lost its lead. However, energy experts in Europe predict the US will likely surpass Japan and Germany in solar power market share in years to come, making it the largest photovoltaic (PV) market on the globe. In fact, despite a rocky economy in 2009, the US PV industry still managed to expand by 38% in installed capacity while total installed cost of solar systems dropped by 10%. The design of mounting systems for solar installations of all types should follow the latest building codes to provide owners, investors, insurance companies, and municipalities with security that the systems will be safe over the lifetime of the structure. Unfortunately, the codes have not been able to keep up with the rapid development within the industry; thereby, leaving designers with a lot of room for interpretation and uncertainty. Rigorous structural analysis of the racking systems cannot only ensure stakeholders of the integrity of a system, but also yield significant potential for optimization, as well as cost savings. In the United States, the governing body for all structural design pertaining to buildings is the International Building Code (IBC). At the moment, the 2006 Edition is still widely used in the building industry while the 2009 Edition was recently issued. With specific regard to minimum design loads for buildings and other structures, the IBC refers to the American Society of Civil Engineers (ASCE) Standard 7. This standard addresses the calculations of design loads for dead, wind, and snow loads, which are generally the most common for solar power installations in the majority of states within the US. In order to perform the design in accordance with IBC, the following questions have to be answered first: In which state is the system located and in what municipality or zip code will it be constructed? These questions are very important as wind and snow conditions vary significantly throughout the United States. Is the system roof- or ground-mounted? For roof-mounted structures, the PV system is generally considered a component of an existing building; whereas, for ground-mounted structures, the PV installation is consid-
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HOLDS TWO FRAMED MODULES
SPACING & SUPPORT RAIL HOLES FOR WIND DAM OPTION BALLAST TRAY
Is the site located on the seashore, on open fields with scattered obstructions, or in a forest or a city center? Depending whether or not the approaching wind will encounter obstructions before meeting with the structure has a big influence on forces exerted on the system, and even snow accumulation around solar panels. Once all questions are answered, the design work can begin. The wind speed can now be converted into a wind pressure and factors for wind direction, gust effect, structure height, exposure, terrain, and structural importance have to be applied. The magnitude of these coefficients also depends on the size of the installation. ASCE 7 provides charts and tables to aid in the design, but the decision of which graph to use is in part left to the designer. After the wind loads are determined, they have to be combined with the snow and dead loads using load factors provided by the IBC. Each member has to be designed separately taking into account its geometry, location within the system, and material properties. The structural analysis will then yield forces that have to be transferred to the underlying building structure in case of roof-mounted installations, or to the soil for ground-mounted arrays. In the latter case, soil tests, including tests for corrosion potential, need to be performed to ensure a safe and economical design that can endure a design life of 20 to 30 years. The building code also allows for the use of wind tunnel tests to assess the wind loads on structures such as PV systems on roofs. Seeing that solar power systems on roofs have become popular only in recent years, wind tunnel tests can be very useful to assess loads on the systems if they are performed correctly. While the code provides requirements how they should be performed, it is often hard for a building or for permit officials to determine whether or not the assumptions made are appropriate. For wind tunnel tests to be adequate and code compliant, they have to be performed using a boundary layer model, which accounts for variations in wind speed with height and models turbulent wind conditions as found around building structures correctly. The most common wind tunnel tests used in the car industry employ only laminar flow regimens, which are not representative of conditions around buildings and generally yield lower design forces. Building officials need to be aware of the various tests available to make an educated decision about structural design calculations provided by designers. Solar PV installations represent a large investment for developers and owners of systems. Rigorous structural analysis in support of the design of these systems in accordance with the local building codes provides stakeholders of PV systems with BOOTH 1625 the necessary security that the system will be safe over its entire lifetime. It is very important for owners of systems and building officials to request detailed structural analysis to ensure a safe design over the lifetime of the structure, so the potential for failures of systems during extreme weather events, as well as the impact to life and property can be minimized. Officials, developers, and owners should not hesitate to ask the racking manufacturer for detailed calculations in addition to standard verbiage letters stating that the codes were followed. After all, any failure of a system will not only result in potential loss of property, investment, and human INTERLOCKING SYSTEM life, but will inevitably also taint a still young but fast growing industry as a whole. SET SPACING BAR SEISMIC RATED EDPM PADDING
Wolfgang Fritz, Ph.D., P.E. is the vice president of engineering for Schletter Inc. Schletter Inc. | www.schletter.us
Modular Solar Racking for Ground and Roof Mounts SEPTEMBER/OCTOBER 2010
Next on the list of information needed are the surroundings of the project site.
SOLAR RACKING FOR ROOF MOUNTS
FLIP UP FEATURE
ered a building itself. The way wind influences the system and, hence, the design forces are very different in either case. The building code clearly prohibits the designer from assuming a component to be designed as a building itself unless it is over 700 ft2, which is generally never the case for a roof-mounted solar installation.
419.267.5240 EXT. 1148
Solar thermal solutions Solar Skies Mfg. is now offering a full line of stainless steel, high-performance storage and drain back tanks and components. The tanks are: SRCC OG300 certified; easy to install and maintain; available with or without heat exchangers; made of a durable outer shell for rust and impact resistance; environmentally safe and CFC-free; and, offer water blown insulation. Solar Skies Mfg., LLC manufactures solar thermal collectors and distributes solar tanks and components for both residential and commercial use. The SRCC-rated collectors and solar tanks are offered in a multiple of series and a wide range of sizes. To ensure they continue to offer valued services and products to customers, Solar Skies has relocated to a 40,000-square-foot facility, designed to support lean manufacturing principles, which ultimately deliver greater value and turn-around time. Solar Skies | www.solarskies.com
Solar converter step-up transformer Pacific Crest Transformers offers the SPSU photovoltaic solar converter step-up transformer, ideal for connecting solar farms to the electricity grid at large-scale solar power installations. Reliable and efficient, the SPSU is uniquely designed for the additional loading associated with non-sinusoidal harmonic frequencies often found in inverter-driven transformers. An innovative system of multiple windings reduces transformer costs and minimizes transformer footprint by combining the step-up function to fewer transformers than other systems. The SPSU model features circular windings that spread the radial forces evenly over their circumference and have cooling ducts throughout the coils, eliminating hot spots that lead to premature breakdown and transformer failure. Coil end blocking with heavy duty three-gauge steel bracing and proprietary pressure plates contains the axial forces exerted during a fault condition. These forces can cause telescoping of the coils, shortening transformer life. Designed and constructed to meet and exceed earthquake standards, the SPSU PV solar converter step-up transformer also incorporates a variety of fluids, including less flammable fluids required for enclosed applications. Pacific Crest Transformers www.pacificcresttrans.com
solar energy PV coating technology & vacuum solutions Oerlikon Leybold Vacuum presents the UNIVEX research and experimental coating system, along with their new DRYVAC pump systems. The full-line vacuum portfolio supports all manufacturing processes within PV applications in the rough, medium, high, and ultra-high vacuum regime. Pumping technologies, systems, and services include components, standardized systems, and fully customized vacuum solutions. The product range comprises oil sealed rotary vane and piston pumps, dry compressing and oil-free pumps, vacuum boosters, turbomolecular, oil diffusion and cryogenic vacuum pumps, as well as standard and customized research coating systems. From the research stages of PV and nano technologies, Oerlikon Leybold Vacuum offers customers optimized vacuum solutions, driving down cost of ownership and enhancing production reliability and profitability. Oerlikon Leybold Vacuum www.oerlikon.com/leybold | www.leyboldchampion.com
Micro-inverter for monocrystalline & polycrystalline PV modules
GLOBAL EXPERTISE DELIVERED LOCALLY RSA is the world leader in renewable energy insurance. With renewable energy teams based in more than 20 global operations we speak your language and can deliver protection at every stage of development, from the initial planning stages through to construction and operation. Talk to your insurance broker about RSA’s renewable energy products and expertise or find one online at www.rsagroup.ca.
Direct Grid Technologies, LLC has announced a new series of OEM grid-tie micro-inverters that mate to a variety of monocrystalline and polycrystalline type modules. The DGM-S250 offers a power output of 250 watts, and the DGM-S460 offers an unprecedented 460 watts. Similar to its predecessor, the DGA Series, the DGM Series units use Direct Grid’s unique closed-loop MOSFET planar architecture, which offers high power and excellent thermal management—resulting in unparalleled efficiency and reliability. The DGM-S250 is designed to mate with a single 60 cell 210-240 watt module while the DGM-S460 is suited to mate with a two 60 cell 210-240 watt modules. For original equipment manufacturers, power tracking voltage inputs can be modified to suit custom maximum power point ranges. The SMART DGM Series also includes Echelon communication that permits each micro-inverter in the network to communicate with a remote access node. Power data, temperature, diagnostics, and unique identification code are routinely collected from each micro-inverter, and this network communication provides theft deterrence. The resulting data can be graphically presented to end-users for easy system monitoring. Certifications targeted for the DGM Series will include UL1741/IEEE1547, VDE 0126, FCC Part15, and CE. Direct Grid Technologies, LLC www.directgrid.com
© 2010. RSA is a registered trade name of Royal & Sun Alliance Insurance Company of Canada. “RSA” and the RSA logo are trademarks used under license from RSA Insurance Group plc.
Solar combiner conﬁgurator Bentek Solar offers manufacturing and engineering solutions for complex electro-mechanical and power distribution systems for the semiconductor and solar industries. The company recently launched the Bentek Solar Configure-To-Order (CTO) Solar Combiner Configurator. The Bentek Solar CTO configurator simplifies the configuration and quoting of custom CTO solar combiners. This tool has been designed to meet the needs of the marketplace for fast, accurate response to system designs and costs for complex components, and provides quotes to customers within 24 hours or less. Bentek Solar | www.benteksolar.com
Will your module last? Put it to the test. Encapsulation for semiconductor & solar applications Greene, Tweed is continuing to enable the next generation of semiconductor and solar technology, expanding their ProTechna encapsulation capability to provide the ultimate level of protection in critical applications. ProTechna safeguards sensitive components, eliminating direct exposure to damaging conditions such as temperature, plasma, chemical, and abrasion. This enhanced protection minimizes harmful particulation, extends operational service life, and maximizes production capabilities. As part of the company’s portfolio of OpTegra integrated solutions, Greene, Tweed’s ProTechna capability offers custom solutions that solve critical environmental challenges to maximize production. Their engineers evaluate each customer application, providing technical expertise to select the material and design a solution with the ultimate level of protection and performance for critical components. From process doors to chamber lids and gates, ProTechna shields components from aggressive chemical and thermal attack in semiconductor and solar production. ProTechna also enables multiple components to be integrated into a single-part solution. This part count reduction simplifies installation, as well as reduces inventory and maintenance costs. Greene, Tweed | www.gtweed.com
Your company may be a market leader, but are your products ready for the long haul? One sure way to know is to employ Atlas testing products and services designed specifically for the solar energy market. With our proprietary Atlas 25PLUS Comprehensive Test Program, we can determine how PV modules will stand up to UV, salt spray corrosion, moisture, heat, freezing temperatures and extreme outdoor conditions. Put the elements to work for you and gain a reputation for reliability and durability. Visit www.solardurability.com today to request a free white paper on the Atlas 25PLUS program.
Introducing the new Atlas XR360 PV Module Weather Durability Testing System Combining the advancements in environmental chamber and xenon solar simulation technology, the XR360 comes in three models with capacity to test more than 90% of current PV modules. • Chamber is equipped with four high performance water-cooled xenon arc lamps • Full climatic functionality • Expanded capability to run IEC environmental tests
North American Clean Energy
The Key to Getting the Highest Solar Module Quality & Performance How and why PTC Ratings work By Alan King
he Standard Testing Conditions (STC) ratings provided by solar module man- Conditions that manufacturers report and, therefore, more indicative of the real ufacturers have long been the solar industry’s de facto method of identifying a amount of solar energy a module will generate. There is a growing perception that, given module’s anticipated electrical output. However, the test that most accurately because of the STC test’s highly controlled environment, STC ratings over-report reflects the electrical output of a given module is that performed under PVUSA and under-deliver electricity output. This inaccuracy concerns solar module purTesting Conditions, known as PTC ratings. chasers and project designers who want to invest in modules that deliver the maxiIn California, PTC ratings are required for modules to be eligible to receive mum amount of energy and fastest ROI. PTC ratings are typically approximately California Energy Commission (CEC) incentive funds through the California Solar five percent lower than STC ratings, and are increasingly used by project developInitiative, and can be a factor in determining the amount of rebates a system owner ers to model the expected power output of systems. receives. PVUSA Test Conditions measure a solar photovoltaic (PV) module’s The California Public Utilities Commission (CPUC) and the California Energy power output at atmospheric conditions that more closely resemble true solar and Commission (CEC) began administering the California Solar Incentive (CSI) climatic variable conditions than those simulated by Standard Testing Conditions. A program in 2007. The CEC created a performance-based system of incentives to higher PTC rating indicates higher actual on-site solar energy production per-watt determine the amount of rebates to which a given installation is entitled. CEC installed, which leads to faster return on investment. In the 1990s, a group of public and private corporations To learn more about PTC ratings, collaborated with the US government to create a national visit: http://adsabs.harvard.edu/abs/1995pgec.rept...... cooperative research project called Photovoltaics for Utility Scale Applications (PVUSA), whose purpose was to assess the viability of utility scale PV electric systems and new PV To learn more about PTC ratings for companies and modules, visit: technology. PVUSA developed a rating methodology for PV www.energy.ca.gov/2008publications/CEC-300-2008-007/CEC-300-2008-007-CMF.PDF module performance evaluation and performed its first tests at a University of California, Davis solar farm that was conFor a list of modules that qualify for CSI rebates, go to: structed by PG&E in 1986 and sold to the California Energy http://www.gosolarcalifornia.ca.gov/equipment/pvmodule.html Commission in 1997. The test objectives were: 1. Evaluate the performance, reliability, and cost of promising PV modules and balance-of-system (BOS) components side-by-side at a single location; assess PV system operation and maintenance in a utility setting; 2. Compare US utilities’ hands-on experience in designing, procuring, and operating PV systems; and, 3. Document and disseminate knowledge gained from the project. Although initially designed for utility scale installations, the PVUSA rating method has become a PV rating standard for solar modules in a variety of applications (including residential and commercial), and is now required to enter the California Energy Commission’s rebate program. PVUSA’s Testing Conditions collect data on a module’s power output for a designated period of time under conditions of 1,000 Watts per square meter solar irradiance, 20° Celsius air temperature, and a wind speed of one meter per second at 10 meters above ground level. The solar industry considers these test conditions to be more reflective of real-world solar and climatic conditions than the Standard Test
rebates are awarded based on the expected performance of the specific installation to ensure that California proportionally rewards PV systems that provide maximum solar generation. Per CSI requirements, solar generating equipment and modules must be PTC-rated and listed by the CEC and, at least, have a 10-year warranty to be eligible for incentive payments. California has been a leader in the solar industry and is currently the only state to which PTC ratings are directly pegged to incentives. The California Energy Commission’s decision to reward top-performing systems (as measured by their PTC ratings) has benefited California’s solar industry because it ensures that system owners get the greatest energy production per rate-payer dollar. Higher-quality solar installations deliver better power performance in the field, which directly translates to higher rebates in California that help end-users manage costs. Alan King is the vice president of sales for the United States Division of Canadian Solar, Inc. Canadian Solar | www.canadian-solar.com
High efficiency by 3-Level Topology 650V 3-Level-Modules with PressFIT-Technology Infineon‘s new family of 3-Level Inverter modules offers significant advantages for designing highly efficient UPS and solar inverters. the three level inverter proves to be an attractive candidate for low and medium power low voltage applications which require high switching frequencies, complex filtering and high efficiency like double conversion UPS and solar inverters. Integrating all elements of a phase leg into one module optimises stray inductance and handling efforts. ■
30A - 400A/650V modules
Low inductive design High reliability due to PressFIT Optimized thermal performance RoHS compliant
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Infineon Technologies Industrial Power, 1050 Route 22, Lebanon, NJ 08833 Phone: 908-236-5600, firstname.lastname@example.org
[ www.inﬁneon.com/highpower ]
Thermostats vs. Hygrostats: Condensation Control in Electronic Enclosures Energy savings alone are enough to justify the decision By Gary Silk
Condensation: An overlooked cause of failure
Condensation causes electrical and electronic components housed in enclosures to fail prematurely. At up to 65% relative humidity, the probability that condensation will form remains low. Condensation can be eliminated, however, by keeping the environment inside an enclosure at a temperature of as little as 9° F (5° C) higher than that of the ambient air. The warmer the air, the more water vapor it can contain. When air cools it can no longer hold the water vapor it contains, and reaches what is called the “dew point”—where condensation occurs. Outdoor equipment in renewable energy applications such as grid-tie matching inverters, pitch and yaw control controls for wind turbine applications, and tracking
control systems for solar applications are particularly at risk as condensation occurs with the shift between daytime warming and nighttime cooling. Even indoor systems can be susceptible to the formation of condensation through humidity and temperature variations. Enclosure heaters and controls
Heaters are typically applied to enclosures that house electronics for two reasons: 1. To keep the electronics above a safe minimum operating temperature, typically 32° F or 0° C; and, 2. To control condensation from forming on electronic components. Heaters should be operated by control devices such as thermostats, hygrostats, or a combination device called a hygrotherm.
Thermostats vs hygrostats
The following focuses on condensation control while comparing the use of thermostats and hygrostats to determine which control device is best for controlling condensation. Heating requirements of a typical application
One representative application is solar tracking controls. Typically, a NEMA 4 enclosure houses the tracker control system. Enclosure sizes vary, but a common size is 36" H x 24" W x 10" D. Engineers wanting to develop one product solution that can be applied throughout North America must design the thermal management system to handle ambient temperatures as low as -40° F (-40° C), and dew points in the high 70° F range. Common practice is to keep the interior of the enclosure at or about 40° F (4° C). To maintain the enclosure interior at or above 40° F (4° C), in this example, a heater with at least 700 watts of heating power would be required. This same heater also has enough capacity to control condensation. To isolate the condensation control aspect of the thermal management system, it is necessary to focus on the operation of the heater only at temperatures above the minimum safe operating temperature of 40° F (4° C). Controlling condensation using a thermostat
To use a thermostat to control condensation, it would have to be set at the high 70° F range. For this example, a temperature of 77° F (25° C) has been chosen. The heating power required to raise the interior temperature of the enclosure, from the base heating level of 40° F (4° C) to 77° F (25° C), is approximately 335 watts. Only when the dew point is actually at 77° F is the 335 watts of heat really needed. Since the heater will be energized at all temperatures up to and including 77° F, the energy and heater life are being wasted at all times when the dew point is below 77° F. Assuming the heater runs 50% of the time, the basis to determine how much energy is used and the cost of that energy can be established. This correlates to a total of 4380 hours of an 8760-hour year the heater will be operating—due to the thermostat being set at 77° F (25° C) versus 40° F (4° C). Using the required 335W of heat and the current average cost of energy in the US, which is about nine cents per kilowatt hour, approximately 1467 kilowatt hours of electricity is used per year to eliminate condensation incidents at a total annual cost of about $132 per tracking system controller. 20
Controlling condensation using a hygrostat
A hygrostat switches a contact energizing the heater based on a relative humidity set point. If a hygrostat is set to 65% R.H., the heater will only have to raise the interior of the enclosure 9° F (5° C) to prevent a condensation event. Again, assuming the heater is running 50% of the time, relative humidity will be above 65%* and the heating power required to raise the temperature by 9° F (5° C) is only 81 watts. Using the same numbers from the above example (4,380 hours x 81 watts = 355 kilowatt hours), at the same nine cents per kilowatt hour, means the cost of controlling condensation using a hygrostat would be about $32 per year. Compared to the $132 per year using a thermostat, this yields a cost savings of about $100 per year. Although the hygrostat is about four times the cost of a thermostat, the increased cost is made up very quickly from the energy savings. Cold winters & humid summers
In many geographic areas of North America, the temperature gets colder than the electronics minimum safe operating temperature, and opposite season dew points above 65% are common. In these areas, a dual-function hygrotherm is the optimum control device. A hygrotherm combines the functions of a thermostat and a hygrostat, so that the same heater will be energized either when heat is required due to low ambient temperatures or when the relative humidity is high enough to cause a condensation event. Conclusion
Hygrostats are a much more energy efficient control device for ensuring control system enclosures remain condensation free. *Assuming relative humidity will be above 65% half of the time is a very conservative estimate. Assuming relative humidity was above 65% for a lesser percentage of the time, which is more realistic, would result in the cost savings associated with using a hygrostat being even greater as the heater would be energized less than 50% of the time. STEGO, Inc. | www.stegousa.com
Second-generation micro-inverter In 2010, Delta Energy Systems started development of the next-generation micro-inverter known as the SOLIVIA .25 M. The SOLIVIA .25 M micro-inverter, expected to ship in Q2 2011, is an exciting addition to the existing SOLIVIA line that includes four new high-efficiency grid-tie inverters for the North American market. Several key benefits become apparent for the SOLIVIA .25 M: they are very compact and easily installed directly within a solar module frame; each unit serves to convert a single solar module’s DC power to grid compliant AC power eliminating the need for expensive DC disconnects and combiner boxes; and, each unit offers per-module Maximum Power Point Tracking (MPPT), which leads to greater efficiency and greater energy harvest from the complete solar array. The SOLIVIA .25 M will have a nominal output power of 250 watts and be oriented to 250 watt poly- and mono-crystalline modules. The micro-inverter is targeted to have a high CEC efficiency of 95.5% and a target MPPT efficiency of 99.9%. The micro-inverter will feature an enclosure protection class of NEMA 6/IP67, and operate in a wide temperature range of -25° C to +85° C, making it ideal for installation in protected outside areas. Delta Energy Systems (Germany) GmbH | www.solar-inverter.com
Ultrasonic reciprocating coating system Sono-Tek Corporation is currently highlighting their ultrasonic coating equipment, including a high-speed ultrasonic reciprocating coating system, HyperSonic. The HyperSonic system is designed to coat large area solar glass (up to 122cm) with uniform, thin-film anti-reflective coatings. SonoTek’s ultrasonic coating technology applies an optimum anti-reflective layer, maximizing the light available for conversion and increasing transmission over the sun’s incident angles. Traditional CVD and PVD for solar glass coatings are expensive, slow batch manufacturing processes. Pressure nozzles are capable of spraying anti-reflective suspensions; however, they have critical process limitations. Significant overspray and clogging, along with poor deposition control and inconsistent uniformity are major drawbacks to pressure nozzle technology. Sono-Tek’s ultrasonic nozzles are able to overcome these limitations with minimal bounceback and overspray, non-clogging performance, and uniform thin-film coatings. The benefits of ultrasonic coating include the ability to control thickness of deposition, drop size control (by varying nozzle frequency), and tight drop distribution resulting in precise, uniform deposition. Ultrasonic nozzles are ideal for spraying nanosuspensions, commonly used in anti-reflection coatings, as the continuous ultrasonic vibration of the nozzle deagglomerates particles and keeps them evenly suspended in solution. Sono-Tek | www.sono-tek.com
Smarter Management of Solar Power By Darren Hammell
he sun is not always shining. On a second-by-second basis the sun is more difficult to predict than the wind. A passing cloud can take a one-megawatt solar array from 100% down to 10% capacity in a couple of seconds, whereas blowing wind tends to drop off more gradually. Fortunately, the sun is also predictable. It will rise in the morning and reach its peak intensity close to when the electric grid is struggling the mostâ€”hot summer days in the late afternoon and evening. Although many believe grid-tied photovoltaics are already a cost-effective investment for society and societyâ€™s electrical needs, it would certainly be better if those pesky solar problems of unpredictability and intermittency could be solved. Though doing so will take effort by all industry stakeholders, there are already some ways to integrate a commercial-scale solar array with buildings and the electric grid to the benefit of the system owner and the grid as a whole.
Integration with on-site generators
When the grid goes down, a solar array shuts off. Many sites, particularly agricultural, have diesel generators that will turn on to provide backup power, but the array will
Storing todayâ€™s energy for tomorrowâ€™s use.
Princeton Power Systemsâ€™ solar array installation at Princeton University
sit idle. This type of installation, which covers almost every commercial-scale installation, adds intermittency to the solar equationâ€”the electric grid reliability itself. It is possible to integrate arrays with on-site generators, allowing the array to continue operating when the grid goes down, but many customers arenâ€™t aware that this is an option. Integrating solar with on-site generators can save fuel and money while increasing a customerâ€™s positive perception of their solar system, all at a nominal cost.
Industrial motor/generator system
Load curtailment | Peak shaving
0DGHLQWKH86$ Sun XtenderÂŽ batteries are the original â€œAGMâ€? (Absorbent Glass Mat) battery adopted by the U.S. Military.
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Trimming backloads during a gridâ€™s peak usage times provides clear benefits to the electric grid and, as time-of-use pricing becomes prevalent, provides economic benefits to the user. Noncritical loads can be shut off at peak times, or heating and cooling loads can be shifted earlier or later to minimize energy consumption during certain times of day. Load curtailment does not have to be simply â€œon or off.â€? Imagine a variable speed motor drive that dynamically controls the speed of a pump or fan to reduce its energy use when there is less power coming from the array. By combining these two functions, the load profile of the motor can be completely flattened, saving money and supporting the electric grid. Energy storage