There are several different options available when it come to installation. The main requirement is that the system be installed according to the National Electric Code or NEC Code. The State of California will allow the home owner to do his or her own installation, but California and other states have adopted a much more stringent system to rate real world performance of solar panels. This rating system assigns what is known as a PTC (PVUSA Test Conditions) rating to each solar panel that is approved for use in their rebate programs.

This rating system was developed to test and compare PV systems as part of the PVUSA (Photovoltaics for Utility Scale Applications) project.

The PTC rating, which is lower than the STC (Standard Test Conditions) 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.

California and other states have adopted a much more stringent system to rate real world performance of solar panels. This rating system assigns what is known as a PTC (PVUSA Test Conditions) rating to each solar panel that is approved for use in their rebate programs.

This rating system was developed to test and compare PV systems as part of the PVUSA (Photovoltaics for Utility Scale Applications) project.

The PTC rating, which is lower than the STC (Standard Test Conditions) 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.

According to the California Energy Commission's rules, you will lose 15% of your rebate if you install a system without using a licensed contractor. There is no special license required, you will need to pull your own permit with your local municipality and your system will need to be inspected. On the other hand if you hire someone to do the installation, he or she will need one of the following licenses: An active A, B, or C-10 license or C-46 license. We can recommend several C-10 licensed electricians that have plenty of experience in the installation of solar electric systems. We can also refer you to individuals who posses C-10 licenses that can act as a consultant, should you choose to do the work yourself, but just need a little advise.

One word of warning though ! We receive phone calls almost daily, from individuals and companies who want to get into the solar electric business and want to their buy components from our company. The calls range from individuals with absolutely no experience in solar or electrical work, to companies who have have done electrical work but have no experience in solar. If you're shopping around be careful ! Using a C-10 licensed electrician is fine but most electricians have little experience with DC circuits or especially experience with programming or using inverters, Charge controllers, metering etc. All of the C-10 licensed electrician that are on our recommended list have been specially trained in these important areas. And you can count on them to provide you with a safe, professional installation.

Off Grid Solar, Inc. is owned and operated by Off Grid Solar, Inc. a privately held company located in Victorville, California. We are the nation's largest high volume dealer of alternative energy products.

We've been in business for 8 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. Off Grid Solar, Inc. 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.