By JOrn Brembach
Market Trends in Solar Energy
The sun’s radiance is one of the most abundant energy sources known to mankind. If we could harness and store all the energy the sun shines on the Earth in just one hour, we would have enough to power global electricity consumption for a whole year. Photovoltaic (PV) panels convert solar energy directly into electricity, which can be used to power connected devices in locations distant from the nearest electricity infrastructure, such as powering road signs and in third-world applications for irrigation pumps, but another is for direct feed-in to the electricity grid.
PV manufacturers, investors in solar energy and the officials who authorize government subsidies have good reasons to be optimistic about buoyant growth in the solar energy sector for years to come. Presently, direct conversion of solar energy to electricity by Photovoltaic (PV) cells may only represent a small fraction of generating capacity worldwide at 0.1%, but the International Energy Agency (IEA) PV technology roadmap 2010 predicts this will rise to 5% by 2030 and reach 11% by 2050.
Of course, surveys and projections from recent years may need revising upwards following the Japanese nuclear disaster in March 2011, which has already provoked sweeping policy changes in many countries and is accelerating the switch to renewal energy sources after popular anti-nuclear campaigns and, as an example, subsequent government reversals on extending reactor lifetimes in Germany.
As a consequence of this constantly increasing growth, the cost-effectiveness of PV systems is gaining rapidly in importance. The main parameters which affect the investment’s profitability are capital cost, subsidies available and economic lifespan.
High Initial Investment
PV systems represent an environmentally sound, robust, reliable, and thoroughly tested technology, complete with a long lifetime. Investors often draw more attention to the profitability of the investment rather than focus on ecological benefits, but despite considerable upfront capital costs, subsequent operation and maintenance costs are relatively low and the return on investment derives from a combination of reduction in the electricity consumption of an installation to which the system is connected and sales of feed-in energy to a power utility.
For PV systems, around 70% of the capital costs are related to the initial purchase of the PV modules themselves. This means the payback time of the whole system is mainly determined by the initial power output, power degradation and the lifetime of the module. The economic viability of a PV system over its lifetime is partly conditional on the attention paid to the specific physical requirements of solar modules, such as tilt angles, operative temperatures, shadow-makers, mechanical load and other conditions.
As the production of PV systems accelerates and the technology becomes more efficient, economies of scale are expected to bring the capital cost of PV modules down. In the meantime, a combination of government subsidies, cheap loans and tax relief can offset some of the capital costs, but these typically demand stringent certification to reduce the risks involved. The structure and payback time from feed-in tariffs also has a major impact on the economics of PV uptake and this varies from country to country.
Obvious investment risks include failure of the solar modules well before the end of projected life spans, perhaps due to the failure of a minor individual component. That is why thorough and specific testing for safety and performance is necessary to guard investments.
PV Systems Standards and Safety Tests
Performance testing focuses on efficiency and durability, so for example, power efficiency, UV resistance, resistance to breakage caused by persons, objects or adverse weather conditions such as hail and so on are all measured.
Compliance with regulations such as European Union directives RoHS and EC 1907/2006 (REACH) is considered very important and PV systems can also certify for conformity with these pieces of legislation.
When PV modules are to be utilized under severe weather conditions, investors require additional performance certifications and guarantees, including for example, ammonia resistance, heavy snow load or desert resistance. In addition, if the PV module is to be installed in a coastal region, tests against salt mist corrosion resistance are also highly recommended.
In terms of electrical safety, PV systems are subject to IEC 61730, which defines the safety standards for all module technologies, IEC 61215 is specific to polycrystalline silicon modules and IEC 61646 covers thin film modules.
Safety tests verify critical features of PV modules, including dielectric resistance as well as resistance to current surges and leakages. Other safety critical components that undergo rigorous testing include access to elements under tension, grounding, and the measurement of insulation for both humid and freezing conditions.
Photovoltaic Module Certification
The recent rapid growth of testing laboratories testifies to the importance of quality, safety and proven performance in the manufacture of PV modules. Certified PV modules reach the market with both a proven lifespan and the guarantee of a lack of defects that could potentially have a detrimental effect on performance.
The CB program was developed by the International Electronics Committee System for Conformity Testing and Certification of Electrotechnical Equipment and Components (IECEE), to simplify the global trade with electrical products and to ensure mutual recognition of testing reports and certification between the participating countries and certification organizations.
CB certification is recognized by all CB Scheme member countries and often offers a shortcut to other national approval marks. Thus risk mitigation is increased through CB certification and in addition, a CB certified PV module can enjoy the good reputation and greater market access that the CB Scheme offers to CB qualified products.
Differences in North America
As Canada and the U.S.A. do not fully accept IEC 61730 for product safety, PV modules destined for these markets need to follow the local UL 1703 standard for electrical safety. For PV modules the major difference between the two standards is that UL 1703 also requires a fire test, during which a module is set on fire to envisage how the fire will spread based on the composition of module cells. Furthermore, certification to UL 1703 can only be performed in the U.S.A. or Canadian labs accredited by the Occupational Safety and Health Administration (OHSA). Harmonization of the IEC and UL electrical safety standard is a constant topic of discussion both within the industry and between governments, but there is little chance of it happening soon.
However, in February 2010, the Solar America Board for Codes and Standards recommended the adoption of IEC quality standards for all modules purchased in the U.S. marketplace. The aim of this initiative is to improve the quality and reliability of the photovoltaic technology in the U.S. marketplace.
This effort takes initial steps in providing a foundation for the protection of consumers and businesses alike from unknowingly buying poor quality Photovoltaic (PV) modules, including those rejected by testing and certification officials in other countries. Both the European Union and Asia already require this testing on all photovoltaic technology sold in their markets.
This is a first step in developing a sustainable marketplace for renewable solar technologies. It is in the market’s long-term best interest to take basic steps to prevent poor quality solar energy equipment from flooding the U.S. market.
Protecting PV Systems Means Assuring Quality
Surprisingly for a country not known for its sunny weather, Germany is currently the second largest in terms of solar energy generation worldwide after Spain and sports a large number of manufacturers. The SGS Solar Test House in Dresden, Germany, is a particularly fine example of expertise in PV module testing services. SGS also has PV testing laboratories in all key locations and markets worldwide; all are ISO 17025 accredited and offer the full range of PV testing and certification services.
Power inverters are covered by IEC 62109-1 and SGS-CEBEC offers safety testing for these as well as large PV systems. SGS can also offer certification for ‘connection/disconnection from grid’, ensuring voltage fluctuations remain within required limits when connection is made to networks of medium voltage. Through its SSC (Systems and Services Certification) division, SGS also verifies electrical installations that have adopted or added photovoltaic systems or have undergone other such major adaptations.
Certifying the Investment
Although voluntary, module certification has become a must for PV manufacturers, as buyers want to make sure their substantial investment is worth it and will pay off over time. The importance of certification is reflected not only by the high number of certifications sold in Europe and the U.S.A. but also by the growth of the module qualification business in Asia. Certification standards are constantly being reviewed in industry working groups to improve testing requirements that eventually lead to more efficient modules. The third edition of the crystalline modules standard will most probably be published this year and updates to the thin-film module standard are currently under discussion.
Certification of solar systems benefits manufacturers, contractors, consumers, and government agencies by establishing credibility and acceptance. Standardized methods for measuring product performance and durability as well as certification standards serve as a rational basis for qualification for tax credit programs and help manufacturers to produce high quality PV modules and increase their market share through an increase in good reputation. The manufacturer’s initial investment can thus be made both profitable and secure.
Although solar module qualification consists of some very tough tests that challenge manufacturers to do their very best, the future of this industry seems to be very bright.
Jorn Brembach joined the leading testing and certification company, SGS (www.sgs.com/ solar) in 2003. As Business Manager in Photovoltaics, he holds the civil engineer degree as well as an Executive MBA.
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