As you can see by this image,of the solar pathfinder, I don't have a great look at the sun. The sun provides the maximum power between 9 AM and 3 PM. In the summer, late spring and early fall, this roof has sun between 9 and 3. The trees to the south cast shadows in the winter, late fall and early spring.

Most inverters are wired to a string of panels. As the shadows pass over each panel, the power from the entire string of panels is reduced. To maximize the power from this roof, I chose to use the Enphase inverters. Each panel has it's own inverter and the power I can generate is maximized.

My goal was to reduce our power bill to $0/month. This system should provide about 83% of our current annual power. The biggest power users at our house are the electric water heater, well pump and the irrigation pump. We heat our house with wood from our wood lot and the wood stove has a Holly-Hydro-Heater that heats most of the hot water we use in the winter. The irrigation pump is used only in the summer months to water our garden.

The local electrical utility company, PSREC, is a cooperative and began a rebate program for solar a couple of years ago. Last year PSREC was providing a rebate of $2.60 for every watt of installed PV (PTC) with a cap of $6,000. With this rebate and the 30% tax credit, the cost of this system was reduced almost in half. If you look at this system as an investment, the return on this investment, over 30 yesrs, is over 7% per year. If you factor in inflation and rising utility costs, the return on this investment is even higher. PSREC is currently charging about 14.75 cents per kWh. The cost per kWh with this grid-tied PV system, over 30 years, is about 7.5 cents per kWH. All things considered, the best return on this investment is the satisfaction of knowing that we are producing almost all of our own electrical power with just the sun that happens to fall on our roof.

I purchased this system from Wholesale Solar. I looked at pricing from several other companies and found that WSS was very fair in their costs for an entire system. The thing I liked best about WSS was the service -they helped me figure out what would work best in my situation. The company is large enough to get good pricing, but small enough so that, when you call, they know who you are and are very helpful.

I have found that the Solar Pathfinder is a tool that gives an accurate look at how much sun is available 12 months out of the year and breaks down the potential sun each month throughout the day into 1/2 hour increments. It is important to make sure the pathfinder is adjusted to true south and is level. It is also important to look at all four corners of the potential array site.

To find out how much power can be generated at a potential site, it is helpful to use the software, the "Solar Pathfinder Assistant", to prepare a shade analysis report. To complete the report you must take a digital picture of the solar pathfinder at each of the four corners of the proposed solar array. You can then import these images into the Pathfinder Assistant program and do a digital tracing of the shade line of each of the four images.

You enter your zip code, that brings in the data for your location from the closest weather station with the sites insolation potential (how much average annual sun is available using historical weather data). Enter the brand, size and number  of the proposed panel(s) and inverter(s). This information brings in effciency data about your proposed equipment. You also enter the tilt or pitch of your proposed array as well as the azimuth (orientation to true south). This information helps the Pathfinder Assistant develop a more accurate efficiency de-rate factor (this data can be adjusted manually where needed - as an example, Enphase inverters can be adjusted for no mis-match and little-to-no DC voltage loss).

This information is then compiled into a multi-page report. I've found these reports to be as accurate as the data that was entered into the program. Our utility company now requires a shade analysis report when there is a potential for shading of the proposed array.

Before you buy a system, it is nice to know how much power you can actually produce at a site - not just how much you hope you can produce.

glad to see your pictures are working now, the install looks great