Tom Kapucija, Director of Marketing, Microsemi

Please tell us a little about Microsemi.

Microsemi Corporation is a leading designer, manufacturer and marketer of high performance analog and mixed-signal integrated circuits, RF subsystems, and high reliability semiconductors. A diverse product portfolio supports a wide variety of market segments such as Defense & Security, Medical, Mobile and Connectivity, Display and Lighting, Industrial and Commercial Avionics as well as the Solar PV industry with its discrete and power modules for Solar inverter offerings. The companys semiconductors address system level performance and reliability by managing and controlling or regulating power, and enabling protection against transient voltage spikes. Microsemis products include individual components as well as integrated circuit solutions that enhance customer designs by improving performance and reliability, battery optimization, reducing size, Bill of Material (BOM) costs or protecting circuits. The principal markets the company serves include implanted medical, defense/aerospace and satellite, notebook computers, monitors and LCD TVs, automotive and mobile connectivity applications.

Recently, Microsemi introduced the worlds first solar bypass solution capable of increasing power generation efficiency in PV solar module applications. Could you explain the technology and its applications in detail?

The Microsemi LX2400 IDEALSolarTM bypass solution is an integrated circuit solution based on technology developed by Microsemi in conjunction with Spelsberg ELS, an expert in connection systems for photovoltaic modules, and Fraunhofer Institute for Solar Energy (ISE), the largest solar energy research institute in Europe. The LX2400 implements the Microsemis patented CoolRUNTM technology, which increases power-generation efficiency and significantly reduces operating temperatures while slashing the operational expense, reliability problems and associated warranty costs of traditional Schottky diodes.

Microsemis LX2400 will be used in junction boxes supporting both existing and next-generation high-power solar modules serving industrial, commercial, and solar Power Purchase Agreements (PPA) applications.

With the lowest forward voltage drop and power dissipation in a bypass solution, the LX2400 is the first of its kind to address thermal reliability, operational cost, and power-generation efficiency challenges that are common in solar installations. The device operates with negligible heat generation, resulting in a temperature rise of only 10 ℃(typical). It is designed with Microsemis high-reliability, 40-year design rule methodology to enable support for industry warranty requirements and extreme environment survivability. The LX2400 is fully functional from -65 ℃ to +165 ℃, passes 1.4 Joule lightning tests and is compliant with IEC61215, Section 10.18.

By adapting and refining our expertise in satellite PV module applications, where high reliability is a must, we have developed a solution that can provide system operators with improved profitability, a faster break-even time, and improved energy efficiency.

Please introduce some of your recent technological breakthroughs.

Microsemis CoolRUNTM technology consists of a number of innovations to reduce the heat generation when the bypass diode is functioning as well as being able to operate without a replenishment or hiccup cycle. Since our forward voltage drop during operation is 90% less than typical solutions now on the market, our heat generation (or power dissipated when the diode is in its forward mode of operation i.e., bypassing a shaded string) is 10% of that generated by the commonly used solutions on the market. This directly translates into improved reliability and robustness and longer life. The technology is also scalable for the next generation of solar modules (i.e., panels) where the string currents are expected to increase to 12 A and beyond while maintaining low forward voltage drops and power dissipation.

What is your prospect for the solar industry in terms of PV installation?

The solar market continues to grow at a strong pace, creating additional opportunities to expand our technology to new markets. According to market research firm Gartner ("Gartner Says U.S. Solar PPA Industry Growth Will Create New IT Revenue Opportunities," December 2009), "the U.S. solar power PPA market will grow to reach an estimated US$8 billion in new PV solar power generation installations by 2013, up from an estimated US$700 million in 2009." Microsemi will continue to offer products for the solar PV industry with the LX2400 as a key example of our ability to provide unique solutions that enable improvements in operational expenses as well as performance and reliability.

As for conversion efficiencies, how far do you think they can be pushed?

Conversion efficiencies have a number of factors such as the cell efficiency of converting photons to electrons, the module efficiency, the inverter efficiency, and the ability to optimize the overall system by integrating diagnostics/monitoring capabilities. Due to the scale of some installations, Incremental or even small improvements in the efficiency of any given component can lead to significant system level improvements. A lot of the future system level improvements will be governed by photon to electron conversion efficiencies improvements by the cell and module manufacturers. The inverter efficiencies are already very high and a 1% increase in efficiency of an inverter is quite a bit less than a 1% increase in the efficiency of a cell or module (e.g., A cell efficiency increase from 20% to 21% is an absolute increase of 5% whereas a 1% efficiency increase in the inverter from 95% to 96% is only an absolute increase of 1.05%).