Colorado Solar is owned and operated by Best Buy Solar Inc. a privately held company located in Talent, Oregon. We are the nation's largest high volume dealer of alternative energy products.

We've been in business for 11 years, with more than fifteen thousands of satisfied customers throughout the US and abroad and have been selling alternative energy systems long before "Y2K" and the current "Energy Crisis". Unlike the many companies who in the last few months have jumped on the energy crises bandwagon with little or no expertise, you can count on us to give you the service and support that you deserve.

When shopping for a solar electric system for your home or business, make sure that the dealer that you are speaking with is quoting you in actual PTC rated kilowatt hours per day. We have noticed several dealers that are listing only CTC kilowatt hours per day which are not real world numbers. Make sure when comparison shopping that you are comparing apples to apples. Insist upon receiving an actual system PTC rating which includes the efficiency rating of both the modules and inverter. Colorado Solar always posts real world performance with every system we sell and will back that up in writing !

STC in an acronym for "Factory Standard Test Conditions" which is 1,000 watts per square meter solar irradiance, 1.5 Air Mass and a 25 degrees C. cell temperature. PTC is an acronym for "PV USA Test Conditions" which were developed at the PV USA test site at the University of Davis, California. The PTC rating represents a more real life condition of 1,000 watts per square meter solar irradiance, 1.5 Air Mass, and 20 degrees C. ambient temperature at 10 meters above ground level and wind speed of 1 meter per second.

The ambient temperature rating is a better standard than factory conditions because silicon solar cells average about 20 degrees C. above ambient temperature in the real world, cell voltage drops as temperature increases. A module's power output in real life conditions is lower than the power measured at the factory where cell temperature is maintained at a controlled 77 degrees F. (25 C).

Cell voltage drops about 0.08 volts per degree C. in environments which exceed 25 degrees C. Thus, an STC rating of 17 volts can actually become a PTC rating of 15 or 16 volts. Using Ohm's Law, volts times amps is equal to watts which equals power, so a reduced voltage, means reduced watts.