STC vs PTC Panel #’s

STC versus PTC – what do the numbers mean?

STC stands for Standard Test Conditions. These are measured under lab conditions of 1000W per sq meter of “sunlight” with a standard spectrum etc. It is a nominal or name plate value. For instance, a Phono Solar 240 Watt panel is 240Watts (STC). An array made from 10 of these panels is considered 2,400Watts (STC). When talking about the array size, the STC number is always used. It is a handy way of comparing arrays to each other, etc.

PTC stands for PVUSA Test Condition. This is much closer to real world conditions. The PTC value is used by California to figure your rebate. A Phono Solar 240 Watt panel is 217.5W (PTC)

Some blogs and websites are defining PTC as “Performance Test Conditions” but this is simply wrong. Oh by the way, PVUSA stands for Photovoltaics for Utility Systems Applications. To makes matters more complicated, it is originally called Photovoltaics for Utility Scale Applications. 

Go Solar California www.gosolarcalifornia.com tells us:

PTC refers to PVUSA Test Conditions, which were developed to test and compare PV systems as part of the PVUSA (Photovoltaics for Utility Scale Applications) project. PTC are 1,000 Watts per square meter solar irradiance, 20 degrees C air temperature, and wind speed of 1 meter per second at 10 meters above ground level. PV manufacturers use Standard Test Conditions, or STC, to rate their PV products. STC are 1,000 Watts per square meter solar irradiance, 25 degrees C cell temperature, air mass equal to 1.5, and ASTM G173-03 standard spectrum. The PTC rating, which is lower than the STC rating, is generally recognized as a more realistic measure of PV output because the test conditions better reflect “real-world” solar and climatic conditions, compared to the STC rating. All ratings in the list are DC (direct current) watts.

Neither PTC nor STC account for all “real-world” losses. Actual solar systems will produce lower outputs due to soiling, shading, module mismatch, wire losses, inverter and transformer losses, shortfalls in actual nameplate ratings, panel degradation over time, and high-temperature losses for arrays mounted close to or integrated within a roofline. These loss factors can vary by season, geographic location, mounting technique, azimuth, and array tilt. Examples of estimated losses from varying factors can be found at: http://rredc.nrel.gov/solar/codes_algs/PVWATTS/system.html.

Ambassador Energy Celebrates!

Another 100kW farm deal.  Inspired the Bunny Hop from some of the AE employees! http://www.youtube.com/user/ambassadorenergyinc

Train for NABCEP EL Test

Ambassador Energy offers the training and the test!  Add this incredible credential to your resume and win more jobs!  Click above on the AE Training tab or  Click here for information and to register for the next class!

AE excited about PACE opportunities

Murrieta, CA, home to Ambassador Energy, is part of 15 cities in WRCOG which will participate in their area’s version of PACE/AB811 financing. The program is allocating $300 million to home and business owners who want to add solar PV to offset high energy costs and “go green”. “We are anxiously awaiting news from WRCOG [...]

AE at Western States Roofing Expo

Ambassador Energy just returned from their third consecutive exhibit at the Western States Roofing Expo in Reno, Nevada. Thanks to all of our clients and prospective clients for stopping by! Click here for the full story!

AE gives NABCEP EL Test!

ISPQ accredited Ambassador Energy has facilitated its first Intro to Solar PV class and proctored the NABCEP EL test to its graduates.  Ambassador Energy offers high-level training and expertise through its NABCEP certified employees and trainers, and is one of only seven companies in California to proctor the NABCEP EL test at the conclusion of [...]

Press Release – Ohio AE Agency May 2011

Ambassador Energy’s first Authorized Agency in Ohio, PowerSource Energy Management, overcomes obstacles to ace their first residential solar photovoltaic (PV) system. After their four-day Solar Photovoltaic training at Ambassador Energy’s training facility in Murrieta, CA, PowerSource Energy Management quickly hit the ground running, selling and installing their first solar PV system near Cincinnati, Ohio. Not [...]

Seven AE Agencies Graduate from Training!

Murrieta, CA (PRWEB) October 1, 2010 — During the week of September 21st through 24th, 2010, Ambassador Energy experienced record attendance in its New Agency Training in Murrieta, CA, where they host their monthly proprietary four-day intensive solar photovoltaic boot camp-style training, led by NABCEP certified Steve Fulgham, the company’s CEO. In this training alone, [...]

US Solar Market To Grow Tenfold by 2014

Solarbuzz: Published: July 26, 2010 California, United States — Despite a challenging domestic economic environment, the U.S. solar market grew 36% in 2009, according to the United States PV Market 2010 from Solarbuzz. This growth was, however, not nearly as strong as the region’s 62% growth in 2008. On a global scale, the country was [...]