<p>This topic has come up over the years so I thought that I’d add my personal experience. Now that we’ve complete our first year with a PV system mounted on our roof our annual electric bill was lowered by about $1200. The system cost about $12,000 (after tax credits) so I figure that’s a 10% tax free ROI. I did size the system with maximum financial return in mind (i.e., I didn’t try to replace 100% of our electric usage, only 70-80%) and we live in a sunny part of California, but that return makes it a good investment in my opinion.</p>
<p>How long does the system last?</p>
<p>Our system is warranted for 49 years, I believe. Our bill is now $17 every month. We got a system to produce more electricity than we expected to use and get the max 65% rebate refund. Our net cost of our small system was about $5000. We probably saved well over $600 or 12% return. Since our system
Was installed, we have never owed nor paid more than $17, which the electric company requires for us to remain connected to the grid. :). When we go over one or two months, its offset by the amount we regularly produce over the amount we use. </p>
<p>If we need to reroof in a decade, the system can be removed and reinstalled for $500 of so.</p>
<p>Different components have different projected lifespans. The panels themselves are guaranteed for 25 years, and experience with PV panels indicates that while their production will taper off slowly they will continue to generate electricity indefinitely. The other parts - mainly the inverter which converts the direct current generated by the panels into 220V AC -are guaranteed for 10 years, and periodic replacement every 10-15 years is a reasonable expectation.</p>
<p>Great job Kluge!</p>
<p>I hope you will consider buying a Volt and charge it from home. You will be able to stick it to the oil companies as well as coal mining companies.</p>
<p>Kluge, Himom,</p>
<p>What is the room temp setting for your HVAC during the summer? Have you experienced roof leaks under the solar panels?</p>
<p>Krlilies, I deferred my solar installation until after I installed a new comp. shingle roof - no leaks last winter. </p>
<p>The panels are on the south-facing part of our roof and it seems that the house doesn’t heat up as much (or stay hot as long in the evening) as it used to. Also, we like fresh air and around here things generally cool down to the 50’s or low 60’s at night even in the middle of summer, so we typically open all the windows at night, then close up in the morning. As a result, even when the outside temperature is over 100 during the day, our house won’t usually hit 80 until late afternoon even without AC - and that’s only on the second floor. So we generally only run our whole-house AC 5 to 10 times a year. I did install a small one room unit in my second floor, south-facing office and occasionally cool just that room down a bit without turning on the entire house system.</p>
<p>Razorsharp - since I started working out of my home office most days I don’t drive enough miles for a new car to pencil out. I’m driving an old Toyota with 200+K miles on it and don’t put enough miles on it to kill it. Economically and ecologically the sensible thing to do is just to keep driving it. Now, if I still commuted 60 miles RT every day, you might be on to something.</p>
<p>We had our roofer inspect our roof just before we installed, and he said we have at least 10 more years of life on our roof. We have not had any leaks ever, including since installing PV 1.5 years ago. My brothers have all had PV installed and none of them have leaks either, nor our many friends who have installed PV. </p>
<p>There are different warranty lives available, depending in what panel and inverters you choose. We chose the 25 or 40 year panels and inverters, I believe (hard to remember but it was the longest available at the time). As long as it lasts a few decades, we will be pretty happy. Our system was installed a few years after two of my brothers. Most of the systems switched from just having one or two inverters to having one per panel. They did have some components and panels rated for 10 or so years. </p>
<p>They also installed software so they and we can monitor how much electricity is produced in real time and get a monthly report from the software and electric company. Our neighbor got their PV system years before us and also have never had leaks nor paid more than the minimum $17 to remain on the electric grid.</p>
<p>We don’t have any A/C, but are flirting with the idea of installing it, as its been so hot recently. Mt sibs with A/C got enough panels that they can run it as often as they like and still not pay for electricity. One bought a Leaf and loves not paying for gas. We all bought a bit more than we needed, as we figure our electricity needs may increase over time and its easier to get it all at the same time than piecemeal.</p>
<p>Thanks for the tips Kluge and Himom particularly the condition of the roof and whether it is south-facing.</p>
<p>Yes, our roof naturally has a south-facing portion that is wholly unobstructed by vegetation or neighbors. That is where the panels were installed. The south-facing solar water heater panels sometimes are shaded by the neighbor’s tree, but the PV panels are totally exposed to the sun from early morning and generate a lot of electricity. We have a high R rating because our area gets a lot of sun. My brother gets even more sun and has a higher R rating.</p>
<p>Our neighbors just re-roofed last week; they’re installing PV now. They are like us and normally have a very low electric bill but prefer it to drop to $17/month rather than ranging from $75-150/month. Others we know had bills ranging from $200+ to $500 and more; they had larger systems installed and are happy for reduced bills. Electrical prices in HI are among the highest in the nation per kilowatt, as are our gas prices.</p>