Reliability and Safety
DOE solar reliability and safety research and development (R&D) focuses on testing photovoltaic (PV) modules, inverters, and systems for long-term performance, and helping investors, consumers, and companies predict long-term performance. PV reliability research is a priority for many in the solar industry, from project planners to members of the financial community to manufacturers. Reliability R&D within the SunShot Systems Integration activities focuses on:
- Identifying reliability issues in PV modules, power electronics, and PV systems in the field and their associated failure mechanisms
- Developing reliability tests and standards that correlate accelerated lifetime tests with component and system lifetimes for different regions of the country
- Providing industry with tools, protocols, test data, and analyses to support the development of safer and more reliable PV components and systems.
Quantifying long-term performance and reliability helps accelerate PV market penetration by improving customer confidence and enabling manufacturers and project developers to better understand and predict product performance, degradation, lifetime, long-term performance, and associated costs for operations and maintenance.
DOE funds projects at national laboratories that enable solar companies to demonstrate reliability as a key aspect of technology development. These activities leverage DOE's investments in PV test equipment, facilities, and research at the national laboratories.
National Laboratory R&D
National laboratory reliability and safety R&D is being performed in the following areas:
Predicting Service Life for PV Modules
The National Renewable Energy Laboratory (NREL), with funding from DOE, is developing methods to predict service life for PV modules.
Working with the International PV Module Quality Assurance Task Force, this project is developing a set of accelerated stress tests that will lead to a quantitative prediction of module service life in a variety of climates for different PV applications. Specific goals include:
- Developing the necessary accelerated stress tests to provide quantitative predictions for specific failure mechanisms for crystalline silicon, thin-film, and concentrating PV (CPV) modules
- Incorporating test sequences into an approved International Electrotechnical Commission (IEC) standard
- Identifying failure modes for new SunShot PV technology modules with recommendations for accelerated stress tests that can duplicate those failure modes
- Developing a "PV Module QA Manufacturing Guideline" as a PV-specific International Organization for Standardization (ISO) 9000 standard
- Harmonizing module safety tests
- Developing a draft IEC standard for the electronics integrated in PV modules.
This effort is a systematic study of PV module failure modes. Study participants include a large number of reliability scientists and engineers from around the world. This work will provide the basis for predicting PV module service lifetime.
Providing methodologies for quantitatively comparing the expected performance lifetimes between different commercially available module technologies will allow investors to better evaluate which module types to purchase for their systems. It will also reduce risk in the selection of modules, therefore reducing the cost to finance those systems.
PV Systems Reliability
Sandia National Laboratories, with funding from DOE, is working to increase PV system reliability.
Sandia is taking a systems approach to PV reliability, availability, and safety and contributing to the reliability of modules, inverters, and the integrated system through these specific focus areas:
- Operations and maintenance (O&M) standardization
- Arc-fault and ground-fault issues at the system level, moving from detection to prevention
- Interconnect reliability applicable to modules, junction boxes, inverters, and balance of system (BOS) connectors
- Inverter reliability and capacitor lifetime predictions.
This effort will develop new O&M standards and protocols, new arc-fault and ground-fault mitigation strategies, and new failure analysis assessments that can be implemented in proactive O&M protocols.
PV reliability and safety are critical to:
- Accelerating solar deployment by demonstrating safe, long-lived, predictable power generation systems
- Reducing the time from development to commercialization by developing, validating, and standardizing design for reliability methods, accelerated test protocols, and reliability analyses
- Fostering collaboration for utility-scale solutions by developing standard O&M practices for optimizing performance and reducing operating costs, which will encourage data sharing and provide system lifetime data that will lower risk-related investment costs to utilities and their financial or insurance backers.