Grid-forming, Reliable, Efficient, Affordable, and Transformerlessly-grounded Photovoltaic-storage System (GREAT PVs)

Solar energy is a clean, sustainable source of energy that can increase energy independence and community resilience, strengthen domestic generation of energy, and reduce carbon emissions. Many homes in the United States can achieve net-zero-electricity-consumption from the utility with residential solar systems. However, traditional photovoltaic inverters in solar energy systems are designed without supporting the grid. This is not a problem when the penetration level is low, but it is when the penetration elevates. There are also issues related to fire risks, safety, reliability, cost, size, weight, and efficiency. This project (Phases I and II) will develop a photovoltaic-storage inverter that behaves as a virtual synchronous machine to support the grid, while significantly reducing fire risk, cost, volume, and weight, and improving safety and reliability, through the holistic integration of patented power electronics and control technologies for the U.S. residential solar market, tapping into a $4-billion annual market. The resulting product is targeted to be 70 percent lighter, 75 percent smaller, 4.5 percent more efficient and 23 percent cheaper against the average of two closest competing products. Phase I (9 months) will be focusing on developing a functional hardware prototype with advanced grid-support and hardware features, such as black-start, grid-forming, transformerlessly-grounded operation for reduced fire risk and improved safety, fault ride-through, islanding detection, etc. Phase II (15 months) will be focusing on improving efficiency and reducing weight/size/cost to meet the performance targets, and developing a 6kW commercial, UL-certified product that is ready for low- volume manufacturing in late 2022 and mass manufacturing in 2023 in the United States. The resulting product is expected to revolutionize the residential photovoltaic-storage market and set new standards for the industry with advanced functions and features. Operating photovoltaic-storage systems as virtual synchronous machines will harmonize the solar-grid relationship with improved grid stability, resiliency and reliability, which removes a technical challenge that hinders the large-scale utilization of solar energy. One such unit will enable an average US home to achieve net-zero-electricity- consumption from utility while providing grid support, eliminating 8.5 tons of carbon emission a year. The targeted weight/size reduction also means reduced usage of natural resources and transportation for unnecessary weight, making contributions to sustainability. The product’s black-start and grid- forming capabilities will enable fast power recovery after natural disasters. This offers significant social benefits to communities at an affordable price without building large infrastructure, a challenge that prevented Puerto Rico from powering 150,000 homes six months after Hurricane Maria. The fire safety of rooftop solar has emerged as a big concern after it was reported that Tesla solar panels ignited atop seven Walmart stores and one Amazon warehouse. The proposed product will significantly reduce the fire risk of solar systems from the root. The mass manufacturing of the products in the United States will create many new jobs and contribute to economic prosperity because of the estimated $4-billion annual market. The targeted cost reduction and efficiency improvement will benefit home owners through reduced up-front investment, increased generation, and lowered levelized cost of energy. While this project takes the residential solar market as a strategic market entry, the technology is scalable for behind-the-meter and grid-scale solar energy systems as well as other distributed energy resources. The support of this project will considerably accelerate commercializing Syndem’s patents for large-scale deployment of renewables.