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Solar Energy International presents “Understanding the Solar Business – an insider’s guide to success”

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Understanding the Solar Business an insider’s guide to success.

Learn the secrets of success in the competative solar industry from an industry insider. This presentation will help you … View Full Article »


Thanks to all that participated in my workshop at Solfest 2010 in Ukiah.

To download a pdf version of the Starting a Solar Business presentation Click this link

Solar training options have exploded in the past 2 years. Learn the key elements to selecting or developing a quality solar training programs.

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Maintaining quality in a rapidly growing solar training market

Certification – why it matters

Certificate or Certification?

This has been a point of confusion in the solar industry. Learn the difference between a certificate and certification. Understand the factors that define legitamacy in certification, and review the benefits that certfication brings to system owners, practitioners, employers, and the industry.

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Certification – why it matters

Flat vs. Tilted Arrays

flat array                      tilted array

One of the most unfortunate mistakes made in PV system design is the flat mounted array.  You should ALWAYS mount modules in a tilted configuration. Lets explore the benefits of the tilted array…

1) More power production results from better sun angle - Modules tilted up toward the southern horizon in the northern hemisphere (or towards the north in the southern hemisphere) will produce considerably more power than modules that are flat.

2) Sheeting of rain water promotes module cleaning - Tilting your array promotes sheeting of rain to clean the modules.  Flat modules are a wonderful catch basin and turn into a a shallow puddle every time it rains.  An even bigger problem can result  View Full Article »

Shade mitigation products like micro-inverters and energy maximizers are the hottest new products in solar.enphase

Enphase micro-inverters provide a convenient solution for dc-ac conversion, shade mitigation, and module level power production monitoring.  Micro-inverters convert DC to AC power at each and every module in the array.  This eliminates the difficult process of string sizing and reduces the problems related to more dangerous high voltage dc strings.

tigoThe Tigo Energy Maximizer dc-dc power optimizer offers shade mitigation, module level mpp tracking, module level production monitoring and they work with any string inverter (SMA, KACO, Fronius, PV Powered, Xantrex etc..).  An additional important benefit of dc-dc power optimizers is they cut the string voltage down to module level voltage if the AC power is lost.  This means that when your main breaker is off, the high voltage strings drop to module level voltage making pv system servicing easier and safer. View Full Article »

The devastating effects of shade

Even small amounts of shade can cause MAJOR power interruption in a solar array.

If you shade only one cell in a module you will likely see a 33% power reduction from that module. If you shade a row of cells in one module, you will see a devastating 90% power reduction. The even bigger problem is that every module in the series string will see the same power reduction.  So when that chimney casts a shadow over one row of cells on the last module in a string of 13, you lose 90% of the power to ALL 13 modules

Most experienced site assessors use the Solmetric Suneye or Solar Pathfinder to determine shading problems before determining how large an array can be mounted in the desired location.

Micro-Inverters (like Enphase) and energy maximizers like the Tigo system can help minimize the power loss due to shading, but solar pros agree that every effort should be made to ensure ALL modules are shade free between the hours of 9AM and 3PM.

ps. even shadows from power lines and bird poop (especially pigeons!) can cause a noticeable power reduction.

The history of residential solar photovoltaics

The history of residential solar photovoltaics (solar pv) is closely connected to the “back to the land” movement that started in the late 1960’s. These “back to the land” migrations attracted hippies that were intent upon living off the land. They were focused on wise resource management due to frugal finances, and they were focused on sustainability due to a respect for natural resources. The popular hotspots in this “back to the land” movement included Northern California, central Oregon, the Ozarks, and the Rockies. These hippie havens produced many solar pioneers in the 70’s and 80’s that would make a major contribution to the development of the PV market.

Here are a few of the stories of the characters that colored the history of the solar PV movement.

david_katz1David Katz (AEE Solar CEO & founder) grew up in Maryland and attended the University of Maryland in the early 70’s. After getting his degree in Electrical Engineering he continued to operate the business that helped finance his college education – Volkswagen Beetle mechanic. His mother was not too thrilled that her son who had just earned his degree in Electrical Engineering was continuing to wrench on Beetles, so unbeknownst to David, she submitted an application on his behalf to the Federal Government, and wouldn’t you know… View Full Article »