Is It Right For You?

1. Does your roof face the sun?

2. Are there any shadows from trees or high building surfaces? Will the area remain un-shaded in late November?

3. Will there be any future shading problems over the next decades? Do I have any sun rights?

4. What is your average monthly electric bill?

5. How old is your roof?

6. Do you have a large enough service panel to handle the system?

7. Is there room to install solar panels on the ground or on other buildings on your property?

If your roof faces directly south, you would have optimum solar collection. If your house faces southeast or southwest, you would lose 6% solar collection capability. If facing east or west, you would lose 20% of solar collection capability. You can counter this loss by increasing the size of the system.

To calculate the size of your own solar system using LIPA's solar estimator, click here.

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Shading has a large impact on system performance. Small shadows on PV modules cause large drops in performance of the system. When laying out a roof installation, allow for room around roof vent pipes, dormers and chimneys to name a few.

Tree branches – even without leaves – leave enough shadow to cause serious degradation in system performance. Many systems have shadow problems in December and January – this could be acceptable to some degree because the losses during these sunless months are minor and will result in no more than a 7 % loss overall in a yearly average. This loss has to be added to the above “off angle losses” for the true system performance. As a rule, the closer the shadowing object, the greater the power loss due to the smaller opportunity for scattered light to enter the shadowed area. Return to the top.

Keep in mind that trees grow, and neighbors can build on their property. Your town might have a "pyramid law" that can help prevent construction or trees from encroaching on your solar access. Return to the top.

Knowing your average monthly electric bill is extremely important to understanding your solar electrical needs. To get a copy of your annual kilowatt usage in a LIPA service territory, call LIPA at 1-800-490-0025. Have your account number ready. Return to the top.

Is your roof less than 5 years old? It's much easier and less costly to replace a questionable roof than it is to remove and replacing solar panels.

Do you have a single layer of shingles on the roof? For example, the town of Smithtown requires no more than one layer of shingles when installing solar.

What is your roof made of? Standard composite shingles are easiest when installing solar. Cedar shingle roofs require additional supports which increases the cost. Flat roofs require ballasted mounting systems or additional hardware, which adds to the cost of the installation. Return to the top.

Generally speaking, a 100 amp service panel will handle up to 4,000 watts of solar. A 150 amp service panel will handle up to 6,000 watts of solar. A 225 amp panel will handle up to 10,000 watts of solar. Return to the top.

Ground mounted and pole mounted systems are sometimes a cost-effective alternative to mounting solar on a roof.

Mounting solar panels on a garage roof which is in the sun can also be cost effective. The power from the solar modules can be connected to the garage sub-panel, which is already connected to the main panel on the house. Return to the top.