1.
Why
should I consider buying a photovoltaic (PV) system?
- A
PV system reduces or eliminates the amount of electricity
you purchase from your utility (electric service)
provider.
- A
PV system can save you money on your electric bill and act
as a hedge against future prices increases.
- The
electricity generated by a PV system is clean, renewable,
and reliable.
- You
can reduce the load on your community's utility grid.
- You
can provide additional electricity for the grid when you
generate more than you use during the day, when
electricity demand is highest.
2.
What
is a solar electric (photovoltaic) grid-tied PV system, and
how does it work?
- Photovoltaic
(PV) technology produces direct current (DC) electricity
by collecting electrons freed by the interaction between
sunlight and the semiconductor materials in a PV cell.
- The
DC power from the PV modules (panels) is converted to AC
power by the inverter, which is then back-fed to the AC
load panel.
- Depending
on the PV output and household load, the power is either
used by the house and/or back-fed to the utility grid (for
a credit).
- See
CBS
TV News Video Coverage (Click on Play-> Local
Homes, Businesses Use Solar Energy To Cut Costs)
3.
What
is required for installation? That is, do I have a good site
for PV?
- An
unshaded area with clear, unobstructed access to the sky
- Buildings,
trees, or other vegetation should not shade your site.
- South-facing
roof exposure is best, but roofs facing east and west may
be OK.
- Modules
can be mounted on the roof (8/12, 34o pitch is
optimal for grid-tie), wall, pole, or ground rack.
- If
a rooftop is not available, your PV system could be
mounted on the ground.
- Access
to electrical load (breaker) panel
- Interconnection
agreement with utility company
4.
What
can I expect photovoltaic startup costs to be?
- Grid
tie system (roof mount) costs about $9/watt, installed, or
$18.000 to $20,000 for a 2 kW system.
- Grid
tie with battery backup costs about $13/watt, installed.
- Off
grid with battery backup costs about $13/watt, installed.
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5.
How
efficient and effective is solar (photovoltaic) power?
- PV
modules vary in efficiency from approximately 8 to 18%.
6.
How
much energy will a PV system produce?
- For
most areas of northern Illinois, a roof-mounted PV system
on an 8/12 pitch (34o) will produce approximately 1300
kilowatt-hours per kilowatt of installed PV.
- Other
production estimates can be found using PV
Watts Estimation Tool
on the NREL website.
7.
What
should the size of my PV system be?
- You
can match the size of your system to your electricity
needs and budget.
- Modules
produce approximately 12 to 15 watts/sq. ft.
8.
How
much of my electrical usage will a PV system offset?
- Add
up your total kilowatt-hours used per year from your
monthly electric bills.
- Divide
this amount either by 1300 kWh/yr for northern Illinois or
by using the PV
Watts Estimation Tool
on the NREL website to determine the amount of PV watts
required.
- Example:
| Annual
Usage |
|
1kW
System Output |
|
System
Capacity |
|
3,900 |
/ |
1,300 |
= |
3
kW installed |
... or 3 kW installed PV for approximately 100% of your
electrical requirements.
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9.
What
do I need to know about connecting my PV system to my local
community's electric grid (utility company)?
- You
will need to enter into an Interconnection Agreement with
your local utility, which will address the terms and
conditions under which your system will be safely
connected to the grid.
- The
agreement will specify the metering arrangements (called
Net Metering), which will allow you to "bank"
any surplus electricity your system generates on the
electric grid.
- Excess
electricity might be generated during the day when your
system produces more electricity than you need, in which
case your meter will run backwards to record the
amount of electricity banked on the grid. You can also use
an equal amount of electricity later without incurring any
additional cost.
- If
you use more electricity from the grid than you have
banked, your utility will charge you annually for the
difference.
10.
How
long can I expect it to take for me to get a return on my
investment?
- Simple
rate of return varies upon system cost, incentives applied
and green tag credits, and range from approximately 15 to
30 years.
11.
What
state and federal grants, rebates, or other incentives are available
that encourage the use of renewable energy?
12.
Is it possible to finance a PV
system for my home?
- The
best way to finance a PV system for your home is through a
mortgage loan that includes a primary mortgage, second
mortgage, or home equity loan secured by your property.
- If
mortgage financing is not available, look for other
sources such as conventional bank loans.
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