Glossary; Design And Implementation - Viessmann Vitovolt 200 Technical Manual

4.2 Design and implementation

Proceeding systematically during the
installation of a mains−connected
photovoltaic system
simplifies the design phase; careful
preparation saves time during the
assembly and installation.
Some detailed questions are part of the
daily routine for an expert contractor,
others are new territory for experts too,
where mains−connected photovoltaic
systems are concerned.
Steps leading to a solar power station
1. Information and consultation
2. Designing and sizing the system
3. Checking, whether planning permission
is required.
In most cases solar heating power
systems do not require planning
permission, provided they are installed
on pitched roofs or are integrated into
the roof surface. However, local
planning regulations (local area plan)
and regulations in connection with
listed buildings may deviate from this
standard. An enquiry at your local
planning office will provide the
necessary information.

4.3 Glossary

AC current
Current which constantly alternates its
direction. Conventional AC current
changes its direction 100 times per
second (50 Hz) and provides a rated
voltage of 230 V.
Amorphous solar cell
Thin−film solar panel made from
non−crystalline (amorphous) material, e.g.
silicone, vacuum metallised onto glass or
stainless steel film, saving materials.
Conventional energy sources
Fossil fuels, such as coal, mineral oil,
natural gas and uranium.
Cost−covering payment
Annually determined energy generation
costs for solar power according to an
energy−efficiency calculation for the
current year of construction, as issued by
the Strompreisaufsicht
Nordrhein−Westfalen. This term has its
origin in the support concept by the same
name of the Aachener
Solarenergie−Fördervereins.
Diffused radiation
Non−directional sunlight, diffused by
clouds, particles, etc.
VITOVOLT
4. Creating an offer and clarifying the
financing and any funding options.
5. Installing and connecting the system to
the grid.
6. Commissioning and instructing the
user.
7. Operating and checking yield, fiscal
matters.
Planning checklist
Clarify the following questions before
designing and building a mains−
connected photovoltaic system:
H Where should the panels be installed
(pitched roof, flat roof, wall,
freestanding)?
H On what base should the panels be fitted
(material of roof cover, type of wall
cladding)?
H Establish the inclination and orientation
of the panel array (inclination in degrees,
deviation from south).
H How large should the system be
(available surface, budget)?
Direct radiation
Direct sunlight which hits the earth's
surface without diffusion.
Electron
In physics, the electrical current flow is
explained by the movement of electrons.
The electron is an atomic particle which
carries the electrical charge (model).
Energy
Electrical energy is measured in watt
hours (1000 Wh = 1 kWh), which should
not be confused with the momentary
power watt (W) or the peak power watt
peak (W ) or kW .
p p
Energy return time
Energetic "amortisation time", during
which the photovoltaic system generates
that amount of energy, which was
required for its manufacture.
ENS
Safety circuit for network monitoring of
the inverter. The abbreviation "ENS"
means: Two pieces of independent
equipment for monitoring a network with
associated switching devices, wired in
series.
4.2 Design and implementation
H Will the panels be shaded (antenna,
balcony, chimney, trees, neighbouring
building)?
H How can the cables be routed inside the
building (dormant chimney, supply duct,
existing electrical ducts, cable channel
on the building exterior, e.g. along a
gutter pipe)?
H How should the inverter be installed
(freestanding, under the roof, in the
cellar)?
H Is a meter slot available or can such a
space be created without too much effort
within the meter box (e.g. utilisation of a
space for a tariff time switch or position
an existing tariff time switch
"piggy−back" onto a meter)?
H Who is the responsible power supplier?
Feed−in remuneration [in Germany]
The local power supply company must
buy power and pay a minimum price
(payment) in accordance with EEG
regulations.
"Garden hose" effect
Many solar cells are wired in series in a
photovoltaic system. If a solar cell or part
of a solar panel is covered up (e.g.
through shading), the current flow will be
reduced at that point, which acts like a
kink in a garden hose. Various technical
data relating to solar panels too have this
effect: the weakest link (panel) determines
the maximum output.
Generator wiring chamber (GWC)
Junction box where the cables of the
solar generator are brought together. In
addition, safety elements for panel lines
and to protect against lightning excess
voltages are integrated; frequently a
switch is also included.
Global radiation
The volume of energy as total from direct
and diffused radiation
2
to 1 m of horizontal surface.
4.3 Glossary
generally relates
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