The POWER Interview: New Solar Technology Increasing Efficiency, Power Density

The use of distributed solar photovoltaic (PV) systems is growing as more homeowners and businesses take control of their energy needs and look for ways to make their electricity supply more reliable and cost-effective. These systems, typically sited on rooftops of residential and/or commercial and industrial buildings, parking garages, or other buildings, are benefiting from technology advancements that are making solar power more efficient. As more solar energy equipment is installed, and more frequently paired with energy storage systems, costs are expected to come down as electricity production increases. New Mexico-based BayWa r.e. in one of the leading companies in the solar energy sector, providing consulting services, financing, market intelligence and more to groups aligned with solar power. David Dunlap, vice president of Product Strategy at BayWa r.e. Solar Systems, provided POWER with insight into the company's work. Dunlap joined BayWa r.e. in 2016, after 16 years in residential construction management, where he implemented green building technologies and renewable energy systems at an award-winning design-build firm in Santa Fe, New Mexico. [caption id="attachment_212178" align="alignright" width="271"]

David Dunlap[/caption] Dunlap also worked with Honeywell Building Solutions, where he developed energy retrofit project solutions in the public sector. He currently leads BayWa r.e.'s product strategy and partnership relations with top-tier solar and storage equipment manufacturers. POWER: What are some newer, more-efficient solar panels being used for rooftop solar or distributed solar power generation?Dunlap: Recent advancements in solar technology have focused on improving efficiency, reducing degradation, and lowering temperature coefficients. Traditional P-type mono PERC cells, which were once dominant, have nearly reached their technology limits. As a result, there's a shift towards N-type (TopCon), heterojunction (HJT) and back contact cell technologies. These innovations are opening up new possibilities for higher efficiency and denser solar panels, addressing the challenge of increasing power density within limited rooftop space. POWER: What are some newer mounting structures and/or installation techniques for distributed solar?Dunlap: In terms of mounting structures and installation techniques, the industry has largely converged on best practices. One notable trend is the adoption of self-sealing, deck-mounted solutions for asphalt shingle roofs, as they offer advantages over traditional flashing solutions. These solutions are not only more reliable but also quicker to install. While there haven't been revolutionary breakthroughs, the focus is on refining existing practices for efficient and risk-minimized installations. POWER: What are some newer charge controllers and inverters for distributed solar installations?Dunlap: Charge controllers as a separate device are primarily used in off-grid battery-based systems. However, in the context of solar-plus-storage grid-tied systems, the emphasis is on creating seamless ecosystems. Manufacturers are integrating PV inverters, energy management technology, and battery storage into a unified platform, all working within the grid-connected home. This integration ensures compatibility and simplifies the overall system, allowing for efficient energy production and storage, as well as the advantage of net metering and grid connection all on one communication and management platform. We may be seeing a potential shift back to string architecture with a clear focus on cost/labor savings as the core benefit. Newer relevant market entries may challenge established expectations around pricing vs. performance (while reliability still remains paramount). POWER: How is distributed solar power generation serving the electric vehicle charging market? What are some of the best battery energy storage systems to pair with distributed solar?Dunlap: Currently, there's limited integration between distributed solar power and electric vehicle (EV) charging. EV chargers are often connected directly to the grid without integration with solar systems. However, the ideal scenario is to have EV charging integrated into a single energy management ecosystem alongside solar and storage. This setup would enable bidirectional energy flow, allowing energy to be transferred between the car, the home, and the grid as needed. Regarding recommended battery energy storage systems, the focus should be on integrated solutions that work seamlessly with the entire PV and storage ecosystem rather than specific battery brands. The key is to ensure that the EV charger is part of a holistic energy management platform that can efficiently utilize and manage energy from various sources. POWER: What new technologies are being studied now to support future distributed solar power generation?Dunlap: The future of distributed solar power generation lies in a combination of technological advancements and policy changes. While technology will continue to improve and make solar more accessible and cost-effective, it's equally important for policymakers and regulators to support the transition to clean energy. Integrated systems that combine solar, storage, and EV charging will likely become more widespread. The key is to create a regulatory framework that encourages and facilitates the widespread adoption of distributed solar power, making it more accessible to homeowners and businesses alike.U.S. trade policy combined with investment in domestic manufacturing will play a part in this as well, either isolating us from global technology initiatives, or protecting and growing our domestic capabilities for the same.

Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).