| Answers
to Common Questions
Who are the primary users of
solar energy?
Recent years have seen rapid growth in the
number of installations of PV on to buildings that are
connected to the electricity grid. This area of demand
has been stimulated in part by government subsidy programs
and by green pricing policies of utilities or electricity
service providers. The central driving force though
comes from the desire of individuals or companies to
obtain their electricity from a clean, non-polluting,
renewable source for which they are prepared to pay
a small premium.
What are Photovoltaics?
Photovoltaic devices, or solar cells, convert sunlight
directly to electricity. It is an attractive alternative
to conventional sources of electricity for many reasons:
it is silent, non-polluting, and renewable; it requires
no special training to operate; it is modular and versatile;
it is extremely reliable and virtually maintenance free
(with no moving parts); and it can be installed almost
anywhere. The customer pays only for the system; the
fuel is free.
Photovoltaic cells are made of a semiconductor material,
usually silicon, and produce an electric current in
the presence of light. Individual cells are combined
to create modules that produce a specific amount of
peak power. The modules, in turn, can be combined to
create arrays that produce larger amounts of power.
These arrays can be sized to meet the power requirements
of the particular application.
Does a solar energy system
offer significant environmental benefits?
Yes. Solar electric systems have an operating life of
over 25 years, and spare the environment from thousands
of tons of harmful emissions, by avoiding the production
of electricity generated from traditional fossil-fuel
burning power plants. These emissions include nitrogen
oxides, sulfur dioxide and carbon dioxide, which are
major contributors to smog, acid rain and global warming.
What is passive solar heating
and cooling?
Buildings designed for passive solar and daylighting
incorporate design features such as large south-facing
windows and building materials that absorb and slowly
release the sun's heat. No mechanical means are employed
in passive solar heating. Incorporating passive solar
designs can reduce heating bills as much as 50 percent.
Passive solar designs can also include natural ventilation
for cooling. Windows are an important aspect of passive
solar design.
Proper building orientation, so the longest walls run
from east to west, allows solar heat to enter the home
in winter, while allowing in as little sun as possible
during summer. Shading and overhangs also reduce excessive
summer heat, while still permitting winter sun.
What's the difference between
passive and active solar?
Passive solar uses building and site elements and natural
processes to accomplish a given task (comfort, water
heating, air movement, etc.) with no, or minimal, mechanical
and electrical equipment. Active solar utilizes
mechanical and electrical equipment.
I have a 2500 sq. ft. home.
How much will it cost to power it with solar?
Unfortunately there is no per square foot "average"
since the cost of a system actually depends on your
daily energy usage and how many full sun hours you receive
per day; And if you have other sources of electricity.
To accurately size a system to meet your needs, we need
to know how much energy you use per day. If your home
is connected to the utility grid, simply look at your
monthly electric bill.
Solar technologies are cost-effective
in many niche applications today, for example, the use
of photovoltaics at remote installations not on the
power grid. A solar energy system's cost can also be
reduced by Federal, state, and local tax incentives
and other financial support. Additional cost reductions
are possible through the use of state-implemented net
metering options. Financing assistance can, in some
cases, reduce the cost of solar energy systems to the
point where monthly payments for the system are less
than the savings on the monthly energy bill.
What is the "payback"
on my system?
This is an often asked question . If we bought a car
based solely on financial payback we would all be driving
the cheapest form of transportation available. Solar
electricity is the least expensive, most reliable clean
source of energy available. The cost of your grid electricity
does not subsidize the air and water pollution it creates.
The cost of these things in the long view are immeasurable.
A single 75 watt solar panel will prevent 7000 pounds
of carbon dioxide from being emitted into our atmosphere
over its lifetime. What is the value of independence?
One of the things our customers appreciate more than
anything else about their alternative electric systems
is that feeling of independence they get when grid power
goes down and their neighbors homes are all dark. These
and many other things contribute to the unforeseen payback
we experience off the grid which really is rarely taken
into consideration.
Is it possible to retrofit
my turn-of-the-century home for solar energy?
Yes. Solar PV modules can be retrofitted on
to a pitched roof above the existing roof-tiles, or
the tiles replaced by specially designed PV roof-tiles
or roof-tiling systems.
I am building a home in a remote
location, away from power lines. Would this project
be a candidate for a solar energy system?
Photovoltaic Systems are frequently the preferred solution
for homes which have no access to the electricity grid.
These solar systems are configured to meet power needs
less expensively than extending the grid to reach your
location. Remote homes in sunny locations can obtain
reliable electricity to meet basic needs for lighting
(using energy efficient fluorescent lamps) and radio
or television with a simple PV system comprising a PV
panel, a rechargeable battery to store the energy captured
during daylight hours, a regulator (or charge controller)
and the necessary wiring and switches. Such systems
are often called "solar home systems" or SHS
for short.
What is the Million Solar Roofs
Initiative?
Million Solar Roofs is a federal initiative to install
solar energy systems on one million U.S. buildings by
2010. President Clinton announced the initiative on
June 26, 1997 in a speech before the United Nations
Session on Environment and Development. The initiative
includes two types of solar technology: photovoltaics
that produce electricity from sunlight and solar thermal
panels that produce heat for domestic hot water, space
heating, or heating swimming pools. |