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Frequently Asked Questions
Please take a look at our frequently asked questions below.
What is solar electricity?
Solar electric or photovoltaics (PV) technology converts
sunlight directly into electricity. You may be more familiar
with PV cells as solar cells that power watches and calculators.
But PV can do much more. It can provide electricity for your
home and provide the opportunity for you to take advantage of
net metering. back to top
Why use PV?
The sun generates enough clean energy in one day to provide a
year’s supply of energy for your home. Why not tap into this
abundant resource of clean energy? PV preserves the earth’s
finite fossil-fuel resources-coal oil, natural gas-and reduces
air and noise pollution associated with those energy sources.
Recent technological breakthroughs, combined with LIPA’s
incentive program and New York State’s Tax Credit program, have
greatly reduced the cost of PV ownership. PV system reliability
and durability are outstanding - typical PV systems may last 40
years with minimal maintenance.
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How does solar electricity or “PV” systems
work?
Photovoltaics, also known as “PV,” produce electricity from the
sun. The solar “cell” is the basic building block of PV
technology. Solar cells are wired together to form a PV module.
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PV systems begin with the solar module. Modules gather solar
energy in the form of sunlight and convert it into direct
current (DC) electricity. The more sunlight they receive, the
more electricity they produce. Solar modules are the heart of
the PV system. In essence, they are the power generators.
To convert DC power to alternate current (AC) power, the type of
electricity used in your home, a device called an inverter is
used. Depending upon the size of the PV system, inverters may be
mounted by the PV manufacturer right on the back of a PV module.
Inverters may also be wall-mounted separately from the PV
system, but within close proximity to the solar panels.
This type of inverter’s location can be in the basement,
attic or garage. If an excess of electricity is produced through
the PV system, the power will flow back through your meter for
distribution back to LIPA’s grid system. This is known as “net
metering". back to top
Can I "net meter" solar electricity back to
LIPA?
LIPA will give retail credit to solar customers who feed excess
electricity back to the utility’s grid. Known as “net metering”,
this utility policy is implemented by letting the homeowner’s
electric meter spin backwards.
Learn more about Net Metering.
How does Net Metering work?
Thanks to New York State’s “net metering” law, enacted in 1997,
New York residents can now use solar power to literally turn
back their LIPA meter, and sell excess energy production back to
LIPA.
Your electric meter spins forward when electricity is flowing
from LIPA into your home. The meter spins backward when power is
flowing from your home back to LIPA. That is, if more
electricity is generated through a PV system than your home
requires, the excess energy flows back to LIPA’s electric grid
system, which turns your electric meter backwards. At the end of
the month, you are billed only for net consumption - the amount
of electricity consumed less the amount of electricity
distributed back to LIPA’s grid. back to top.
What happens if the sun doesn’t shine?
Your PV system will continue to produce electricity during
cloudy weather, although the total amount will be reduced. Power
will automatically be provided through LIPA at night or during
inclement weather.
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What does a typical PV panel look like?
A typical PV panel consists of solar cells connected
electrically to form a module that can measure two to four feet
wide and four to six feet long. Some solar modules look just
like traditional roof shingles. Many interconnected PV modules
are called an array. back to top
Is my home right for a PV system?
A PV system needs unobstructed access to the sun’s rays for
most, or all of the day, throughout the year. PV panels are
relatively unaffected by changing weather. In fact, some PV
cells actually work better at colder temperatures. PV modules
are angled to catch the sun, not snow, so any snow that does
collect melts quickly. To maximize the energy production of
photovoltaic electricity, PV systems are installed on a southern
exposed roof and mounted parallel with the roof at a 35
degree roof pitch with no shading. However, roofs that face east
or west may also be acceptable. PV panels should have their
surfaces exposed to the sun’s rays for most or all of the day,
with minimal or no shadows from trees, chimneys and gables
between 9 AM and 4 PM. back to top
Home Energy Efficiency and PV
An energy efficient home means you can install less PV. Every
dollar on energy efficiency in the home saves $20 on your PV
electric panels. To become energy efficient in the home, use
compact fluorescent light bulbs, which use 75% less energy than
the equivalent incandescent. A 15 watt compact fluorescent will
produce as much light as a 60 watt incandescent. Also look for
energy saving appliances (clothes washers, refrigerators, room
A/C, dishwashers. Refrigerators before 1990 are power hogs!
LIPA’s Programs can help you become more energy
efficient in the home.
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How does shading affect my PV system?
Proper placement of your Photo Voltaic (PV) system is critical
to the success of the PV systems output. Having even one cell in
a PV module in the shade, especially during the best sun hours
of the day, can decrease the output for the entire module and
possibly the entire system.
Since the shaded cell is not producing any moving electrons,
it acts like an open circuit to the entire string. This is
similar to having one Christmas tree light burned out in a
string of lights. No current can flow!
When looking to place your PV system, please watch for any
type of shading. Shading can include trees, chimneys, TV
antennas / satellite dishes, dormers of the house.
Step 1- Review your roof for good access to the
sun. Does the area for PV system receive full sunlight with
no shading?
Step 2- If you have 100% of sunlight on a south
facing roof, you have an ideal roof for PV, although east
and west facing roofs are very good also. If there is
shading on your roof, consult with a person trained on PV.
This could be a PV contractor from LIPA’s Web site, the Long
Island Shines Web site, or from the telephone book.
Another option is to use LIPA’s Solar Pioneer Web site,
follow the link to “Building Your Own PV System” which is the
Clean Power Estimator tool. Click on the link of “Click for
Obstruction Analysis”. This link will help determine the impact
from the shading. A Solar Pathfinder is a tool commonly used by
a contractor to determine the impact of the shading on your
potential PV system. Please note: Eligibility for LIPA’s rebate
can be denied by improper installation of PV system. Improper
installation includes orientation and shading. back to top
Can my home accommodate a PV system?
The amount of space needed by a PV system is based on the output of
the PV system and the type of PV system installed. Most residential
systems require as little as 50 square feet (for a small “starter”
system) up to as much as 1,000 square feet for larger systems. A
typical two-kilowatt system could occupy approximately 200 square
feet. If your location limits the physical size of your system, you
may want to install a system that uses more efficient PV modules.
Greater efficiency means that the module uses less surface area to
convert sunlight into a given amount of electric power.
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Estimated Roof Area Needed in Square Feet
|
PV Module Efficiency* |
PV Capacity Rating,
watts (in bold) |
| |
100
|
250
|
500
|
1,000
|
2,000
|
4,000
|
10,000
|
100,000
|
|
4
|
30
|
75
|
150
|
300
|
600
|
1,200
|
3,000
|
30,000
|
|
8
|
15
|
38
|
75
|
150
|
300
|
600
|
1,500
|
15,000
|
|
12
|
10
|
25
|
50
|
100
|
200
|
400
|
1,000
|
10,000
|
|
16
|
8
|
20
|
40
|
80
|
160
|
320
|
800
|
8,000
|
* Although the efficiency (percentage of sunlight converted to
electrical energy) varies with different types of PV Modules
available today, higher-efficiency modules typically cost more. So,
a less efficient system is not necessarily less cost-effective. -
The Vermont Renewable Energy Resource Center.
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How much PV will I need?
As a starting point, you might consider how much of your present
electricity needs you would like to meet with your PV system.
For example, suppose that you would like to meet 50 percent of
your electricity needs with your PV system. You could work with
your PV provider to examine past electric bills and determine
the size of the PV system needed to achieve that goal.
You can contact LIPA by calling 1-800-490-0025 and request
the total electricity usage, measured in kilowatt-hours, for
your household over the last 12 months (or consult your electric
bills if you save them.). Ask your PV provider how much your new
PV system will produce on an annual basis (also measured in
kilowatt-hours) and compare that number to your annual electric
demand to get an idea of how much you will save.
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Calculating Electricity Bill Savings for a
Net-Metered PV system
Energy From the PV System
Determine the
size of your PV system in kilowatts (kW). This value
represents the "kW of PV" input for the equations below.
Based on Long Island’s geographic location, the "Energy
Production Factor" is 1,273.
To estimate the annual energy produced by your system,
use the following equation:
Energy from the PV system = (kW of PV ) x (Energy
Production Factor) = kWh/year
Divide this number by twelve if you want to determine
your estimated monthly energy reduction.
Energy Bill Savings
To estimate the annual energy bill savings from your
system, use the following equation:
Energy bill savings = (Annual kWh/year ) x
(Residential Rate) = $/year saved
(The residential rate in the above equation should be
in dollars per kWh; for example, the rate of 20 cents
for kWh is input as $0.20/kWh.)
For example, a 5 kW PV system on Long Island (assuming a
residential rate of .20 cents per kWh) would provide the
following:
Energy from the PV system = 5kW x 1,273 = 6,365
kWh/year.
Energy Bill Savings = 6,365 kWh/year x $.20/kWh = $1,273.
Do I need to be concerned with the condition
of my existing roof?
A PV system can be installed on any well-structured roof.
Typically asphalt shingles are easiest to work with, while slate
is the most difficult. If your roof is older and needs to be
replaced in the very near future, you may want to replace it at
the time the PV system is installed to avoid the future cost of
removing and reinstalling your PV system. PV systems are also
available that integrate PV cells into the roofing materials
themselves. This allows the roof itself to act as the PV
collecting device and serves as an excellent option when
replacing a roof or designing and/or building anew home. One
benefit of an integrated PV system is its ability to offset the
cost of roofing materials. back to top
How much does a PV system cost?
The total cost of a PV system includes the PV system and
installation. Your PV system’s cost will depend on a number of
factors, including system size and the energy efficiency of your
home, whether the home is under construction and whether the PV
is integrated into the roof or mounted on top of an existing
roof. The cost also varies depending on the PV system rating,
size, manufacturer, retailer and installer. Small-scaled PV
systems with built-in inverters that produce about 600 watts of
power may cost about $10 per watt ($6,000). These small systems
will offset only a small fraction of your electricity bill. A
2-kilowatt system that will offset the needs of a very
energy-efficiency home may cost $8 to $10 per watt
($16,000-$20,000). At the high end, a 10-kilowatt system that
will completely offset the energy needs of many conventional
homes may cost $7 to $8 per watt ($70,000-$80,000). These prices
of course, are just rough estimates, and your costs will depend
on your system's configuration, your equipment options and other
factors. back to top
Remember, LIPA’s current Solar Pioneer incentives can
significantly reduce the cost of purchasing a PV system. In
addition, New York State’s tax credit can reduce your
overall costs much further.
LIPA’s Solar Pioneer Program offers you, direct
incentives of $3.50 per watt towards the installation of a
PV system up to 10kW, or a maximum rebate of $35,000.
In addition, you can take advantage of:
- Net Metering. Homeowners can use solar power to run
their LIPA meter backwards and sell excess energy
production back to LIPA;
-
New York State’s 25% tax credit towards the
total cost of a PV
system, with a maximum credit of
$5,000. If your tax credit is
greater than the amount
of tax you owe New York State, the balance will not be
refunded to you. However, any credit amount in excess of
the tax due can be carried over for a maximum of up to
five years.
- A 15-year real property tax exemption through
New York State's Real Property Tax Law for solar
systems installed in New York State.
The following is an example of what a 5 kW PV system
would cost:
| 5 kW PV system including contractor
installation at $7.50/watt: |
$37,500.00 |
| LIPA's PV Rebate at $3.50/watt: |
17,500.00 |
| Cost to Customer: |
20,000.00 |
| New York State's Solar Tax 25% Credit
(Capped at $5,000) |
5,000.00 |
| Net Cost to Customer |
15,000.00 |
| Federal Solar Tax 30% Credit (Capped
at 2,000) |
2,000.00 |
|
Final Net Cost to Customer: |
13,000.00 |
What are the property tax benefits for
purchasing a PV system?
Enacted in 1990, The
New York State Real Property Tax
Law provides a 15 year real
property tax exemption for solar systems constructed in New York
State. The intent of the law is to encourage the installation of
solar systems and ensures property owners that their real
property taxes will not increase as a result of the installation
of a solar system.
Who can I contact for more information on PV?
For information about LIPA’s Solar Pioneer Program, please call
LIPA’s Energy Infoline at 1-800-692-2626. LIPA can provide you
with a wealth of information to help you better understand how
to put the sun to work for you. back to top |
Clean Energy Initiative
