| City
Residential homes |
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 programmes (especially Japan
and Germany) and by green pricing policies of utilities or
electricity service providers (e.g. in Switzerland and the
USA). 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.
In these grid-connected systems, a PV System supplies  electricity
to the building and any day-time excess may be exported to
the grid. Batteries are not required because the grid supplies
any extra demand. However, if you want to be independent of
the grid supply you will need battery storage to provide power
outside daylight hours.
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. If you are
planning to put a PV system on to a building and have it connected
to the grid supply there are likely to be local regulations
that need to be met, and permission required from your utility
or electricity service provider. The level of credit for any
exported electricity will vary depending on local schemes
in place.
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| Holiday
Properties |
Photovoltaic Systems are frequently the preferred
solution for holiday 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.
The size of the PV module and battery is designed to provide
enough power and storage to meet peak energy requirements
- this is called "sizing" the system. . All systems
with battery storage should use solar batteries of the right
design and specification for the system, car batteries will
not do! Also, high quality compact fluorescent lamps are available
with good lifetimes; poor quality lamps will blacken quickly
and their light output will drop off. The quality of the regulator
is a key factor in the reliability of the overall system.
The PV modules are usually mounted on a pole, or on the roof.
In this application, 50 to 100W modules would probably be
required although smaller panels of 10 to 15W might provide
sufficient power for the most basic single lamp system.
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| Central
Power Stations |
Central Power applications use solar energy
in the same configuration that a Utility would utilize a major
power station. This is distinctly different from the other
applications on this page, which are known as "distributed
power" or power distributed in small aggregate amounts
of power, usually close to the point of use of the electricity.
Central solar power generation plants have been installed
in Italy, US and Spain, for example. However, all these plants
are "pilot" in nature. Central solar plants may
be attractive under certain conditions, but they do not capitalize
on the competitive strengths of solar PV in terms of its flexibility
of location (i.e. being located close to the customer) and
its ability to be installed incrementally. |
| Other
Recreational Applications |
Solar Power is frequently used in consumer product applications
which require small amounts of energy (like calculators).
Another frequent use is for Recreation Vehicles (RVs) and
Boating to recharge the battery for recreational use activities.
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|
| Industrial
Applications |
|
For many years, Solar Energy has been the power supply of
choice for Industrial applications, where power is required
at remote locations. This means in these applications that
solar power is economic, without subsidy. Most systems in
individual uses require a few kilowatts of power.
The examples are powering repeater stations for microwave,
TV  and
radio, telemetry and radio telephones.
Solar energy is also frequently used on transportation signalling
e.g. offshore navigation buoys, lighthouses, aircraft warning
lights on pylons or structures, and increasingly in road
traffic warning signals. Solar is used to power environmental
and situation monitoring equipment and corrosion protection
systems (based on impressing a current) for pipelines, well-heads,
and bridges or other structures. As before, for larger electrical
loads it can be cost effective to configure a hybrid power
system that links the PV with a small diesel generator.
Solar's great benefit here is that it is highly reliable
and requires little maintenance so it's ideal in places
that are hard to get to.
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| Water
Pumping, lighting, heating in the Developing World |
|
Apart from off-grid homes, other remote buildings such as
schools, community halls, and clinics can all benefit from
electrification with Solar Energy. This can power TV, video,
telephony and a range of refrigeration equipment, which
is available to meet World Health Organisation standards
for vaccine refrigeration, for instance . Rather than base
Solar power generation on individual dwellings, it is also
possible to configure central village power plants that
can either power homes via a local wired network, or act
as a battery charging station where members of the community
can bring batteries to be recharged.
PV Systems can be used to pump water in remote areas e.g.
as part of a portable water supply system. Specialized solar
water pumps are designed for submersible use (in a borehole)
or to float  on
open water. Usually, the ability to store water in a tank
means that battery power storage is unnecessary. Large-scale
desalination plants can also be PV powered. Larger off-grid
systems can be constructed to power larger and more sophisticated
electrical loads by using an array of PV modules and having
more battery storage capacity.
To meet the largest power requirements in an off-grid location,
the PV system is sometimes best configured with a small
diesel generator. This means that the PV system no longer
has to be sized to cope with the worst sunlight conditions
available during the year. The diesel generator can then
provide the back-up power, but its use is minimised during
the rest of the year by the PV system, so fuel and maintenance
costs are kept low.
Solar
energy can also power area lighting to enable more outdoor
activities after dark or improve security, and to illuminate
signs or advertising boards.
|
| Commercial
buildings |
On an office building, atria can be covered
with glass/glass PV modules, which can be semi-transparent
to provide shaded light. On a factory, large roof areas have
been the best location for solar modules. If they are flat,
then arrays can be mounted using techniques that do not breach
the weatherproof roof membrane. Also, skylights can be covered
partially with PV.
The vertical walls of office buildings provide several opportunities
for PV incorporation. The first is as a "curtain wall system"
that constitutes the weather barrier of the building. The
second, as a "rainscreen overcladding system" where there
is an underlying weather barrier that provides the insulation
and sealing of the building.
The third option is to create sunshades or balconies incorporating
a PV System. Sunshades may have the PV System mounted externally
to the building or have PV cells specially mounted between
glass sheets comprising the window. |
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