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Are
you thinking about generating your own electricity?
Here
is some useful information that can help you decide if
investing in a solar electric system is right for you.
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What is a
solar electric or photovoltaic system?
Solar electric or photovoltaic (PV) systems use the sun's
energy to make electricity. PV technology produces direct
current electricity by collecting electrons freed by the
interaction between sunlight and the semiconductor materials
in a PV cell.
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Why should
I consider buying a PV system?
A PV system reduces or eliminates the amount of electricity
you purchase from your utility or electric service provider.
A PV system can save you money on your electricity bill
and act as a hedge against future price increases.
The electricity
generated by your PV system is clean, renewable and reliable.
You help your community by reducing the load on the utility
grid and you can provide additional electricity for the
grid when you generate more than you use during the day,
when electricity demand is highest.
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Do
I have a good site for PV?
Your site must have clear, unobstructed access to the sun.
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. If a rooftop is not available, your
PV system can also be mounted on the ground. |
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What should
the size of my PV system be?
You can match the size of your system to your electricity
needs and budget. The average household in California uses
about 6,500 kilowatt-hours (kWh) per year. If your usage
is typical of the average household, a system in the 3 to
4 kilowatt (kW) range would be adequate to meet most of
your electricity needs. To estimate the best system size
for your home or business, examine your electricity usage
for the last 12 months and apply this easy formula.
A system with
a capacity of 1 kW can produce about 1750 kWh per year.
Divide your annual electricity usage (in kWh per year) by
1750 kWh to get the system size (capacity in kilowatts)
that would meet most of your electricity needs. If you want
your PV system to meet half of your electricity needs, then
you should size it to meet half of your annual electrical
usage.
Or you can offset
only a small portion of your electricity bill with a single
PV panel. If you size your system larger than your average
electricity needs, for example to meet your highest electricity
needs on summer afternoons, your system would generate more
electricity than you could use during the rest of the year.
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How much mounting space do I need?
A small PV system can use as little as 50 square feet. A larger
system, to meet the needs of a typical household, would use
between 300 to 600 square feet. As a rule of thumb, 100 square
feet of PV panels produces about one kilowatt of electricity.
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Are there any special features I should consider?
An inverter is needed to change the direct current (DC) power
from the solar panels into alternating current (AC) electricity
to power your electrical devices and to be compatible with
the electric grid. Batteries can provide back-up power for
your home or business in case of grid outages, but they also
increase your costs. |
Are
there any financing programs available?
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. A list of companies that finance
PV systems can be found on the Consumer Energy Center website
at
www.consumerenergycenter.org.
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What do I
need to know about connecting my PV system to the grid?
You will need to enter into an Interconnection Agreement
with your utility. This agreement addresses the terms and
conditions under which your system will be safely connected
to the grid. The agreement also specifies the metering arrangements
(called Net Metering). Net Metering allows you to ³bank²
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. Your meter would simply
run backwards to record the amount of electricity banked
on the grid. You can 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. (Please
refer to the Energy Commission's ABC's of Net Metering for
more information.)
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How do I
find a PV retailer?
The California Energy Commission provides a list of PV retailers.
You should also check with the California Solar Energy Industries
Association (see address below). Retailers either can provide
installation or can refer you to installation contractors
in your area. Try to find a company located in the area
where your system will be installed. Price is only one factor
when selecting a PV company and/or contractor.
Here are some other considerations:
- Does the company
have experience installing grid-connected systems?
- How many years
has the company been in the business of installing PV
systems?
- Does the company
use licensed California contractors?
- Does the company
have any judgments or liens against it?
- Will the company
provide references of previous customers?
- If you get
more than one bid, make sure that the bids are for the
same system.
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