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My Experience Hooking Up Rooftop Solar Electric Panels


Hooking Up Rooftop Solar Panels. My Experience

The moment of truth came today. A technician working for the solar energy company visited our home today to do a pre-inspection test and then turned on our new 3 kilowatt rooftop solar panel electric system. After flipping three switches our meter began to slowly spin backwards. It was wesome! As the air conditioner unit kicked in the meter began to creep slowly forward and then as a cloud passed over it resumed its usual forward speed. As the cloud passed by and the central air unit turned off, the meter resumed spinning backward, "reversing" our electric bill. This month we're actually looking forward to our electric bill to see how much of a difference the system will make. The system we've installed is supposed to generate about $40 worth of electricity per month and since our bills run around $120 it will give us about a third of our electricity, carbon free. As electricity rates go, (as they have done reliable for the past 20 years,) up the value of the monthly solar generated power should also go up.

Getting to this point was a bit of an ordeal. The city that I live in in, Austin, Texas offers a very generous rebate for solar power systems, covering almost a quarter of the cost. In addition to the city rebates there is a $2000 federal rebate that we'll get when we file our taxes at the end of the year.

The first step was the site evaluation by the city. Instead of an on-site inspection, an engineer in an office somewhere simply clicked on Google Earth, looked at a photo of our roof and checked if it faced the right direction or had any trees shading it. As it turned out, our home was just within the parameters, with its south to west facing roof, and we were approved. Next the solar company sent out their estimator who measured our roof and inspected our electrical system. He mentioned that our shingles were quite loose and that it was quite possible that we'd be needing a new roof in a couple of years. When I asked him what the cost was to come and re-install the solar panel system was he told me it would be about two thousand dollars, possibly more.

I Guess We Need A New Roof?

We had been considering switching to a metal roof for some time, for the insurance discount and fire safety as well as energy savings, so we decided to go ahead and replace our asphalt shingle roof with a standing seam metal roof at a cost of $8500. The insurance discount for having a more fire resistant roof would be around 20% so we would eventually get our money back, and we wouldn't have to worry about the solar panel system having to be removed for another 30 years.

After the roof was installed, which was a terrible, noisy affair, the solar power company arrived and began installing the panels. Each panel array has six brackets and there are nine panels total. The contractor sealed each roof penetration with a high tech sealant guaranteed to last twenty years or more, so we shouldn't have to worry about leaks.

After the panels were installed they ran conduit down to the electric meter and installed an electrical disconnect box and the inverter which converts the energy from the panels into AC current. I personally wanted them to place the inverter, a costly piece of equipment, inside the garage, so that it would be sheltered from the heat of the sun and to protect it from damage. The installer insisted on placing it on the outside of the home, requiring less wiring, so we reluctantly agreed. The complete installation process took about one week, from start to finish.

Our total cost for the solar energy system, out of pocket, was $5,400, not including the cost of the metal roof. We expect to see payback from our investment in about eight years or less, especially with rising energy costs. My wife and I are very happy so far with the system. It reminds us of when we lived on a sailboat in the Caribbean and solar panels provided much of our energy. It is too bad that more cities around the nation are not offering similar rebate programs. If more people purchased photovoltaic solar energy systems for their homes, it is very likely that the cost of solar panels would fall because of increased demand.

Update: Four Years Later, What We Would've Done Differently

I'm updating this article as we are now four years down the road from our solar panel installation date. We don't have any regrets about installing the system, however we do wish that we'd done more research. At the time we were installing our system we had the choice to choose a type of solar panel that worked more efficiently on hot days. As solar panels heat up, they typically become less efficient, as counter-intuitive as that may seem. Electricity flows best through cooler conductors, and on days when we had temperatures over 100 Fahrenheit, our power output dropped noticeably.

The second regret that we have is that we didn't go a bit bigger. A three kilowatt system was affordable at the time, however we could've supplied most of our home's energy needs had we gone to 6 kW.

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Another regret we now have is having gone with the first company that we contacted. Had we shopped around, we could have saved aroud $1,000 on our system and possibly avoided some other problems, which I'll discuss next.

Although the installation went fairly smoothly there was one issue with the installation that caused us some problems, and forced us to file a complaint against the installer. About a year after the solar panel installation we noticed water dripping down from the ceiling above our fridge, just after a heavy rain. I went up into the attic and traced the leak to where one of the wires for the panel entered the attic from the roof. When the roof dried off, I got a ladder and went up to inspect the hole, and found that instead of using the proper type of flashing and "boot" around the conduit, the installer had simply caulked around it with silicone. As the roof expanded and contracted with temperature, a crack developed, allowing water to pour in. It was very shoddy, amateur type work, and something that a more experienced installer would've never done.

A third issue that we had with the system was the placement of the inverter. The installer placed the inverter (device which convert's the panel's DC energy to AC), on the sunniest side of the house. Over time the intense heat began to cause the display to crack and fade, as well as to operate hotter than normal. We had no way of checking, but the extra heat most likely made this part of the system less efficient as well.

Lastly, we based our decision to invest in the system on a set of "payback" calculations shown to us by the solar installer. The estimated payback time for our investment was shown to be around 8 years, based on rising energy costs. It was forecast that by four or five years from installation, that we would be paying 18 cents per kilowatt hour. What happened in reality was that the wind energy industry in Texas grew exponentially during that time, providing so much cheap energy that power companies scrambled to build transmission lines and find markets for it. Our actual charge per kilowatt hour remained the same, even with inflation averaging around 2% per year. It only affected our payback time frame by a couple years, however it shows that these types of calculations can be based on incorrect assumptions.

Overall, we're glad we decided to go with a rooftop solar panel system, yet we wish that we had done just a bit more research and comparison shopping.

© 2008 Nolen Hart

Comments on May 04, 2012:

this is all the rage where I live - we ordered our solar panels but the company went bust! People here say solar has pushed the price of electricity up for people who DONT have solar because electric companies have got less market share Is it inevitable Good read doodlebugs - I would really be interested in an update further down the track

Nolen Hart (author) from Southwest on October 25, 2011:

Since this hub was published we have hooked up a second PV system at my mother in law's home. It provides 100% of the energy her home uses.

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