Raghu Belur, Enphase Energy

Establishing a New Product Class

In March 2006, Raghu Belur and former Cisco colleague Martin Fornage launched Enphase Energy. Since then, Enphase has proven the viability of microinverter-based PV systems and brought the benefits of module-level dc-to-ac conversion to the industry. An analysis of CSI data revealed that, in 2010, Enphase microinverters held more than 13% of the market share in residential installations with capacities up to 10 kW, up from 5.3% in 2009. For small commercial systems ranging from 10 to 100 kW, Enphase secured 9.3% market share in 2010, up from just 3% in 2009. Enphase has shipped more than 500,000 units to date, and it has announced plans to triple production capacity by year-end 2011. Raghu holds an MS in electrical engineering from Texas A&M University and an MBA from the Haas School of Business.

SP: What drove you to transition from the computer networking and telecommunications industry to solar, and how did your past experiences assist in the successful launch of Enphase Energy?
RB: Martin and I were working on highefficiency power-supply technology and advanced communication systems for telecommunications equipment when Martin decided to buy a PV system for his home. Upon seeing the inverter equipment used in PV systems, we immediately thought we could create a better solution. Specifically, if we could design an inverter at the individual module level, we could use lowvoltage, low-power technology and semiconductor-based designs to increase performance, reliability and intelligence, while at the same time create a path to continued cost reduction. Essentially, we saw the opportunity to bring some of the concepts of Moore’s law to PV inverters. [Moore’s law identifies a long-term computer hardware trend where the number of transistors that can be placed inexpensively on an integrated circuit doubles approximately every 2 years.]

SP: In the late 1990s, microinverter products from NKF Electronics and Ascension Technologies failed to gain acceptance in the PV marketplace. From a product engineering perspective, what enabled Enphase to succeed where earlier attempts had failed?
RB: In trying to understand why past technologies had not succeeded, we concluded that they had failed in four key areas: efficiency, reliability, cost and lack of a systems-level approach. The main cause of all these problems was that product developers were attempting to follow the designs of existing central inverters, with the intention of simply making them smaller. Martin and I knew this wouldn’t work, so we built a microinverter from the ground up, integrating cutting-edge power electronics with digital control and intelligence. We also took a different approach by thinking at the system level—every microinverter would incorporate built-in data acquisition and networking technology to make the whole array smarter and more connected. We’ve devised ways to use automotive- and military-grade semiconductors and components in our system without dramatically affecting its cost or size. Our semiconductorbased approach provides a significant advantage over central inverters. We can build more reliable systems and simultaneously increase functionality and lower costs.

SP: Many PV integrators view microinverters as a solution for residential and small commercial installations but not for larger commercial projects. Are you developing products for the commercial sector?
RB: The majority of our installations are residential and small commercial. However, we are seeing significant demand for larger commercial installations as system integrators see the improvements that microinverters deliver to ROI. We are very focused on increasing our presence in this market through further innovations targeted at the needs of large commercial systems. Our system-level approach means that we develop completely integrated solutions. This calls for both hardware and software advancements for large commercial installations. On the hardware side, we will be releasing our 3-phase 480 V product soon, which allows for larger branch circuits and greater BOS savings. The software component is critical as well because commercial systems require different capabilities, including support for O&M, reporting and system analytics.

SP: Does Enphase have specific programs or training to assist integrators in deploying microinverters into larger commercial systems?
RB: Yes, we are building our staff specifically for commercial projects, and it’s one of our fastest-growing areas. Today we work with our installer partners during all phases of site development, from technical support during presales to detailed review of line drawings. We also have dedicated sales staff on both coasts focused on large commercial integrators and EPCs. Soon we will be introducing targeted training materials such as best practices for commercial-scale microinverter system design and installation.

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