Photovoltaic (PV) energy, the conversion of sunlight to electricity, was discovered in the late 1830s, followed by usable PV cells developed in the early 1950s. Despite its history, only recently has the U.S. solar market really started to take off. Driven by the volatility of energy prices from traditional sources such as coal, gas and fossil fuels, the push to advance solar energy use reminds us of the critical need to mitigate certain risks that come with progress in innovation – research and standards are two ways to help do that.
Today, solar is the fastest growing energy source in the U.S., helping to power homes, businesses and utility grids. Last year was a record-breaking year as the market grew by 76 percent, according to the Solar Energy Industries Association (SEIA). As the overall price to install solar continues to decrease due to lowering manufacturing and material costs, it is becoming even more attractive to consumers and businesses. However, perhaps most importantly for increased adoption, the solar industry must ensure PV systems are a sound investment.
Often, PV system buyers plan for a 20-year service life. Product reliability plays a crucial role in the overall PV energy cost profile and return on initial investment – related to both higher and more consistent power output and the need for fewer, less frequent PV panel replacements. Through conducting research and developing new and improving standards and testing methodologies for solar products, the use of such tests that look for potential induced degradation (PID) susceptibility, for example, will help manufacturers better understand the performance of their module.
PID is a severe threat to PV module reliability because it can result in a power loss of nearly 100 percent in modules at the end of a system string (a number of PV panels aligned in series), sometimes in just one month. Creating an established scientific test procedure that is easier and less costly to screen modules for PID helps enhance PV reliability, as well as promote PV adoption.
Testing PV Technologies
PV technologies began with the use of treated crystalline silicon operating as a semiconductor to generate a flow of direct current electricity when exposed to light. Although crystalline silicon is still used by the majority of the industry, newer thin film polymer and semi-conducting molecule PV technologies are evolving, allowing PV use in products such as flexible roofing applications.
While there is no shortage of sunlight, there are shortcomings with some PV products on the market today. It is important for the PV industry to develop a unique and proven PID testing method, particularly one that is innovative and comprehensive in the way it assesses PID susceptibility. When testing is conducted in accordance with precisely defined protocols, it ensures more objective and reproducible results from subsequent PV module testing. Conducting PID testing with appropriate standards, helps ensure more objective and reproducible results from subsequent PV module testing.
Ensuring Reliability
Overall, renewable energy is helping to advance markets and industries, along with everyday adoption of such technologies like never before. There is greater demand for innovative energy generation, distribution, management and usage. This is a transformative age with new technologies and product developments arriving at an incredible pace. However, all innovation is met with emerging risks, and mitigating these risks is most important to allow for further innovation.
The use of solar energy can create a more efficient and productive world. But this cannot occur without putting safety, performance and reliability in the spotlight – achieved through fundamental discovery, progressive testing methodologies, equipment, and procedures, integration of software and innovating standards. Instilling a highly scientific, multi-faceted engineering discipline into research, development, design and manufacturing of products worldwide encourages safer and higher performance PV systems.
The PV industry is projected to install an additional 400 to 600 gigawatts of PV capacity by 2020 as the underlying costs of PV energy are expected to drop by an estimated 10 percent per year. As long as the industry can ensure reliability, solar energy will continue to push forward as a clean, renewable source of energy utilized widely by consumers and businesses.
Evelyn M. Butler is UL’s global business development director for its energy and industrial systems division, which includes PV / Solar, wind, inverters, generators, biofuels and traditional fuels. She has been with UL for 23 years in conformity assessment, quality registration services, sales/marketing and industry management roles, focusing the last eight years, on developing UL’s renewable energy businesses; representing UL in conferences, tradeshows and industry events and often speaking on the role of conformity assessment and standards in the industry value chain.
Ken Boyce is UL’s technical manager for energy technologies. In this role he oversees standards development and technical operations for PV / Solar, wind, inverters, battery, biofuels, and other renewable energy equipment and systems. Ken has over 25 years of experience in global safety engineering across a wide range of industry sectors. Ken is a frequent speaker at global technical conferences, author of technical papers, and leader in the standard and code communities. Ken was recognized as a charter recipient of UL’s Distinguished Member of Technical Staff and is a Registered Professional Engineer.
UL is a global independent safety science company with more than a century of expertise innovating safety solutions from the public adoption of electricity to new breakthroughs in sustainability, renewable energy and nanotechnology.
