Most solar panels are warranted to last 25 years, but this rating is assuming sunlight is hitting the panels 24 hrs a day. Since they'll actually only be receiving about eight hours of sunlight a day, you can assume they will last three times longer than what they're rated for about 75 years!
Every home is unique, as is every home's energy usage. There are limitless configurations you can install! One of the beauties of solar power is the fact that it is modular and can be added over time. There are also numerous state and federal incentives to offset the installation of solar panels.
Solar panels will generate electricity whenever any form of sunlight is hitting them. They just aren't as efficient overcast days, so they won't generate as much power. Though it's still safe to say they will generate considerably more power than roofing shingles will.
Since solar panels have no moving parts or active ingredients, they don't require much maintenance at all. A periodic cleaning and inspection of the system's connections are all that's required. Suffice to say the typical kitchen sink needs more maintenance than our solar panels.
Solar panels can also be mounted on a rack in any open area with an unobstructed view of the southern sky. They can even be mounted on a tracking system (called a heliostat) which moves the panels to face directly into the sun, drastically increasing their efficiency. Keep in mind that a heliostat does have moving parts, increasing its need for maintenance and original purchase price.
You may be thinking of solar thermal systems, which are entirely different than photovoltaic solar panels. Photovoltaic panels generate electricity, so if your home is heated by electricity, then yes solar energy would be used to power your heating. However, most homes in the Tri-State area burn natural gas or fossil fuels to provide heat, which is typically more efficient than using electricity for heating. If you are currently heating with natural gas, propane, oil or wood, you would have to convert your heating system to electricity in order to heat with the energy generated by solar panels.Most air conditioning units are powered by electricity, so yes, the electricity provided by your solar panels will cool your home. As an added bonus, consider this; most electricity used for cooling is consumed during the middle of the day when solar energy is most abundant!
There are many variables involved in this calculation. A few factors include: the cost of energy; the rate of inflation; and electrical power consumption. Typically systems will pay for themselves in five to twelve years. The real return on your investment is much more than an economic one. By reducing our demand for fossil fuels, we are not only reducing our reliance on electricity and the aging distribution grid, but we are gaining independence along with peace of mind from being better stewards of our natural resources as well as our finances. This is difficult to put a price tag on.
*We just want to note for the above information that we are not accountants and that the specifics for how you can apply these tax credits should be discussed with your professional tax advisor.