TECHNOLOGYENERGY
Solar Bypass Diodes: Then and Now
The needs of the solar industry are changing fast and companies need to become aware of technolgies and ideas that can give them an advantage. Many tend to focus on panels and efficiencies but this is only part of the equation along a growing value chain. Shawn A. Fahrenbruch, Principal Engineer at Microsemi’s Analog Mixed Signal Group discusses the concurrent changes that have occurred in solar bypass diodes providing another piece of the PV jigsaw.
T
he solar industry is rapidly changing. Not only is cell efficiency making steady gains, but the users’ demands are increasing as well. These changes have opened the door to innovations in technology and business models in surprising ways. With these changes, comes a new emphasis on operations and maintenance costs. A recent disruptive change is the introduction of “Individual Solar Module Performance Monitoring” solutions. This technology, which is currently deployed, will highlight previously unrecognized field failures of bypass diodes.
In the book “The Innovator’s Dilemma”, Clayton Christensen illustrated the nature of disruptive technology very effectively and his lessons can be extended to the solar arena. In any industry, technology evolves predictably until a point is reached where further advances require heroic efforts. Occasionally, the industry gets disrupted by radically different technology or changes in consumer patterns and the race to market continues on a more aggressive metric of acceptance. A common signature of disruptive technology is that (initially) it has worse price/performance than what exists when measured by traditional metrics of acceptance. But as the “added-value” of the new technology is recognized, the market moves onto an even more demanding metric of acceptance. Using this idea, fig 1 illustrates the progression of the solar industry.
The original usages for solar systems were for “off-
grid” systems. Solar energy charged battery banks and, often, the batteries were fully charged by 11 a.m. Early adopters were interested in the metrics of “sun-to-electricity” efficiency and reliability. Next in the evolution came the advent of “grid-connected” systems. There were hassles with local permits, but today the advantages of the “on-grid” system, by all metrics (even cost), have attracted a whole new market of residential users that enjoy watching their electrical bills drive backwards toward zero (or below) while still employing the utility grid when cloudy.
Changing dynamics
The solar industry has now come to a crossroads. The metrics of efficiency, reliability, and installation
Fig: 1 Solar industry progression
21
www.solar-pv-management.com Issue VI 2010
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64