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Renewable
Energy Systems
 This
is the self-proclaimed future of energy production. For industry to
remain sustainable in the future, the need to switch to a renewable
source of energy is inevitable.
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( Solar Resource Map: The darkest areas are the most effective
areas for solar power )
Smaller
operating renewable energy systems offer power in remote locations
where grid energy is expensive or unable to be connected.
Portal solar cells can be used to power laptops in the field.
Small wind turbines are of sufficient power for sailboat
navigational systems. The use of these systems is limited to
the ingenuity of the installer. Renewable systems can also be used
to supplement grid power for added savings. Many states are
now passing net metering laws to encourage and fund such
installations for distributed generation of energy.
Tech Power Systems is staying at the
front of this and other emerging technologies. Consult with
our knowledgeable staff too see if a Renewable Energy System is
right for you.
All systems are custom fitted to your
facility's power and system requirements.
Solar
Panels
Sunwize Solar Panel SM
Series -
50 to 110 Watts, provide the
highest power density and have the longest service record.
Intelligent module deliver optimum
power under reduced light conditions.
PowerMax® solar cells form the heart of these modules. These cells
make optimum use of the module surface area. Thanks to their square
shape, they are highly efficient and still provide the maximum power
possible even under low light levels or poor weather conditions.
The specially hardened front glass has excellent light transmitting
properties and protects the module against most adverse
environmental conditions such as hail or ice. The solar cells are
laminated in EVA (ethylene-vinyl acetate) between a multi layer rear
film and the front glass. This permanently laminated assembly
protects the cells against moisture and ensures electrical
insulation. A torsion-resistant module frame made of anodized
aluminum guarantees particularly high mechanical strength.
SM 50
 SM 50H
 SM 55
 SM110
Click on Images above to
view specs in PDF format
Call for pricing and sizing configurations
for all of our other product details
SP Series -
75 to 150 Watts, Shell's most popular modules, provide a medium
range power density.
ST Series - 5 to 38
Watts, use PowerMax® thin film technology to deliver battery charge
power levels in low light situations and are ideal for specialized
telemetry applications.
Solar Cell
Technology
How a Photovoltaic
Cell works
A solar cell is made up of a number of layers. The critical two
layers of the cell are the middle two, one of which is known as
n-type semi-conductor and the other as p-type semiconductor. It is
at the junction of these two layers that the cell generates
electricity.
Semi-conductors
are special electronic materials that are used in computers and
other electronic devices. They are called semi-conductors because
they conduct poorly when compared to metals, but they conduct very
well when compared to insulators. They fall somewhere in the middle.
Semi-conductors
have two special properties that are essential to the solar cell's
ability to make electricity:
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When light is absorbed
within a semi-conductor, electrons are freed by the
semi-conductor.
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When dissimilar semi
conductors are joined at a common boundary, a fixed electric field
is usually induced across the boundary.
So how does the cell generate electricity? When light enters the
solar cell and is absorbed in the semi-conductor sandwich an
electron is freed. If this electron is close enough to the boundary
of the two semi-conductors, it is swept across the boundary by the
fixed electric field. The movement of the electron across the
boundary causes a charge imbalance in the semi-conductors. The semi
conductors naturally want to get rid of this charge imbalance.
However, the electric field prevents the electron from recrossing
the boundary, so if it is to return, it must travel via an external
circuit - thus we have electricity! (because electric current is the
flow of electrons through a wire)
The outermost
layer of the cell is a cover glass. This is designed to protect the
rest of the structure from the environment. It is attached to the
rest of the cell with a transparent adhesive.
When sunlight passes through the glass and the adhesive, it
encounters an anti-reflection (AR) coating. This coating is also
transparent. It is designed to reduced the amount of sunlight
reflected by the cell. Without the AR coating, the s olar
cell acts like a mirror, reflecting up to 30% of the light hitting
the cell. The AR coating minimizes this reflection off the cell,
reducing reflection losses to less that 5%, so that as much sunlight
as possible is available for the cell to use to make electricity.
For the solar cell
to be useful, there must be some way for the electricity it produces
be passed to the outside world. This is the purpose of the front and
back contacts. Their function is to carry the electrical current
produced by the cell.
The current
generated by the light hitting the solar cell flows from all parts
of its surfaces, so it is important that the contacts reach
everywhere on the cell. Ideally, to reduce losses caused by the
current having to travel any distance across the surface of the
cell, we would like to cover the whole of the top and bottom
surfaces of the cell with the contacts. However, if we did this, the
top contact would block the sunlight and the cell wouldn't work. As
a compromise, the top contact is usually made of thin fingers of
metal that reach most of the cell and only block a small portion of
the light. The bottom contact is not in the way of the light, so it
can be a sheet of metal.
As long as light
shines on the cell, we get electricity. Light comes into the cell
and gets absorbed. Electrons are freed and pushed across the
boundary by the electric field. They pass through an external
circuit and return to their starting point.
( Solar Panel and Wind Turbine combination equipment ) →
This happens as
long as light shines on the cell, so how come the cell never wears
out? Because the sunlight provides the energy input. Just like
sunlight provides the energy for plants to grow, it also provides
the energy for solar cells to produce electricity.
Wind Turbines
Find
Out About How the Turbine Works
This aerial view of a wind power plant shows how a group of wind
turbines can make electricity for the utility grid. The electricity
is sent through transmission and distribution lines to homes,
businesses, schools, and so on.
These three-bladed wind turbines are operated "upwind," with the
blades facing into the wind. The other common wind turbine type is
the two-bladed, downwind turbine.
So how do wind turbines make electricity? Simply stated, a wind
turbine works the opposite of a fan. Instead of using electricity to
make wind, like a fan, wind turbines use wind to make electricity.
The wind turns the blades, which spin a shaft, which connects to a
generator and makes electricity. Utility-scale turbines range in
size from 50 to 750 kilowatts. Single small turbines, below 50
kilowatts, are used for homes, telecommunications dishes, or water
pumping.
Look at
the Wind Turbine Close Up
Wind
Turbine Glossary
Anemometer:
Measures the wind speed and transmits wind speed data to the
controller.
Blades:
Most turbines have either two or three blades. Wind blowing over the
blades causes the blades to "lift" and rotate.
Brakes:
A disc brake which can be applied mechanically, electrically, or
hydraulically to stop the rotor in emergencies.
Controller:
The controller starts up the machine at wind speeds of about 8 to 16
miles per hour (mph) and shuts off the machine at about 65 mph.
Turbines cannot operate at wind speeds above about 65 mph because
their generators could overheat.
Gear Box:
Gears connect the low-speed shaft to the high-speed shaft and
increase the rotational speeds from about 30 to 60 rotations per
minute (rpm) to about 1200 to 1500 rpm, the rotational speed
required by most generators to produce electricity. The gear box is
a costly (and heavy) part of the wind turbine and engineers are
exploring "direct-drive" generators that operate at lower rotational
speeds and don't need gear boxes.
Generator:
Usually an off-the-shelf induction generator that produces 60-cycle
AC electricity.
High
Speed Shaft:
Drives the generator.
Low Speed Shaft:
The rotor turns the low-speed shaft at about 30 to 60 rotations per
minute.
Nacelle:
The rotor attaches to the nacelle, which sits atop the tower and
includes the gear box, low- and high-speed shafts, generator,
controller, and brake. A cover protects the components inside the
nacelle. Some nacelles are large enough for a technician to stand
inside while working.
Pitch:
Blades are turned, or pitched, out of the wind to keep the rotor
from turning in winds that are too high or too low to produce
electricity.
Rotor:
The blades and the hub together are called the rotor.
Tower:
Towers
are made from tubular steel (shown here) or steel lattice. Because
wind speed increases with height, taller towers enable turbines to
capture more energy and generate more electricity.
Wind Direction:
This is an "upwind" turbine, so-called because it operates facing
into the wind. Other turbines are designed to run "downwind", facing
away from the wind.
Wind Vane:
Measures wind direction and communicates with the yaw drive to
orient the turbine properly with respect to the wind.
Yaw Drive:
Upwind turbines face into the wind; the yaw drive is used to keep
the rotor facing into the wind as the wind direction changes.
Downwind turbines don't require a yaw drive, the wind blows the
rotor downwind.
Yaw Motor:
Powers the yaw drive.
Tech Power Systems is staying at the
front of this and other emerging technologies. Consult with
our knowledgeable staff too see if a Renewable Energy System is
right for you.
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