Transcript Solar panels - Rosalie Forest Eco Lodge

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SOLAR AND WIND ELECTRICITY WORKSHOP
THE FIRST RULE OF GOING RENEWABLE
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CONSIDER YOUR CONSUMPTION
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One of the most important things to remember when
considering going solar is your consumption. The more
you use, the more you need to spend on your system.
Change your light bulbs to compact fluorescent bulb,
switch off lights and appliances when out, make sure
the fridge shuts properly, and try not to use big power
things like irons and hairdryers. If you can manage
without these you can save thousands of dollars.
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Solar panels / wind turbine/hydro
Charge controller
Batteries
Inverter
THE GOLDEN RULE – ALWAYS
CONSIDER YOUR CONSUMPTION
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There are two main ways of using solar energy to
produce electricity. These are through the use of
solar cells and solar thermal technology.
Solar cells are photovoltaic cells that turn light into
electricity. Solar cells are used in two main ways.
They are used in homes small, electrical items, like
calculators, and for remote area power supplies,
like telephones and space satellites. They are also
used on a larger scale to supply electricity through
energy companies and authorities, and have even
been used to a limited extent in the development
of solar-powered vehicles.
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Solar thermal technology uses heat gained
directly from sunlight. The best known use of
this technology is in solar water heating.
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Photovoltaic cells (PVs or solar panels) are a very
different technology from solar water heating, and use
light to generate electricity. They are particularly well
suited to sites where a grid connection would be
difficult or expensive or that are only used in the
summer. For an independent power supply, solar
works well with wind as there is a good balance of
both over the year. Solar electricity, like electricity from
other renewable energy sources, doesn't produce
carbon dioxide or harm the environment.
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there are no moving parts to fix so they are relatively
easy to install and maintain
they can be sited in town or countryside and are not
restricted in the way that wind and hydro-power
systems are
they can replace other roofing materials, for example
tiles. The cells are embedded in a flat, waterproof
material to form 'modules', which make ideal cladding
material for walls and roofs
they need not take up any additional land space.
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Solar photovoltaic panels are made up of
silicon cells which are surrounded by electron
molecules and connected together by wires.
The photon rays from the sun hit the electron
molecules and break them away from the
silicon cells, pushing them along the wires.
Everything in front is a positive charge, and
everything behind is a negative charge. The
positive current is electricity
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Solar panels / wind turbine/ hydro
Charge controller
Batteries
Inverter
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Most solar panels and wind turbines make 12
volt electricity, and most systems use batteries
to store the power, so that once the sun goes
down, there is still power available to use.
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However, the first stop for the power, after it
travels down the wires from the panels or
turbine, is the CHARGE CONTROLLER.
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The positive charge from the panels or turbine
passes down the wires to the controller. This
has to a sensor which knows when the batteries
are full, and switches off the current from the
panels. When there is space available in the
batteries, it opens and allows the current to
pass freely once more.
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Thus preventing OVERCHARGING which
shortens the life expectancy of batteries.
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The 12 volt power passes through some wires and
is then stored in batteries until it is required.
The average renewable energy system makes 12 or
24 volt electricity, and the average person uses
either 110 volts or 220-240 volts, depending on
where in the world they live.
So to use the energy stored in the batteries in an
average home it has to be converted to a useable
voltage, 110 or 220-240. This is done very simply
by using a power inverter (similar to a
transformer), which converts the current to the
desired voltage.
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From there you have normal electricity, exactly
as if it was from the local electricity supplier,
just as useful; just as dangerous.
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Nature provides the earth with more energy
each minute than the world consumes in one
year. It seems a waste not use a bit of it at
least!!
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Small portable solar powered generators are now
available at low cost for small homes with minimal
power consumption. They range form 300 watt
units to 1500 watt units, and are very practical for
small isolated locations. The disadvantage is that
the system cannot be greatly expanded like the
standard system now in use here and at 3 rivers.
These systems work out at around US$1000
including tax and shipping.
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Solar panels / wind turbine/
hydro
Charge controller
Batteries
Inverter
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One of the most important things to remember
when considering using renewable energy is
your consumption. The more you use, the more
you need to spend on your system. Change
your light bulbs to compact fluorescent bulb,
switch off lights and appliances when out,
make sure the fridge shuts properly, and try
not to use big power things like irons and
hairdryers. If you can manage without these
you can save thousands of dollars.
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Wind turbines are simple and low
maintenance. Once installed they need very
little attention. Basically they act instead of, or
as well, solar panels, and are wired in exactly
the same order of basic components as the solar
panels. An excellent solution to the changing
weather problem is a solar / wind combination
system.
When it is sunny you get good charge from the
solar, and when the wind blows the batteries
will charge.
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Also, once the sun goes down, your batteries
get the opportunity to re charge at night too,
thus being much more reliable. A wind turbine
works just like a hydro turbine, or car
alternator, except that it uses wind to turn the
propeller instead of water of an engine.
Wind turbines operate on a simple principle.
The energy in the wind turns two or three
propeller-like blades around a rotor. The rotor
is connected to the main shaft, which spins a
generator to create electricity.
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Wind turbines are often mounted on
a tower to capture the most energy.
At 100 feet (30 meters) or more
above ground, they can take
advantage of faster and less
turbulent wind.
Wind turbines can be used to
produce electricity for a single home
or building, or they can be
connected to an electricity grid
(shown here) for more widespread
electricity distribution.
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The Air-X has a charge controller which can manage
any battery bank size from 25 to 25,000 amp hours.
Periodically, battery charging is cut for a few
milliseconds to check if the batteries are full. Therefore
the lifetime of the batteries will be extended and
overcharging is not possible as the turbine will slow to
an almost complete stop when the batteries are full.
The Air-X wind turbine is so quiet and simple to use it
is practical to fit it to the rooftop, greatly reducing
costs, but ideally you should fit it to a pole (with an
outside diameter of 1.5"). With carbon fibre blades,
aircraft quality aluminium alloy castings, and only two
moving parts, there is little to go wrong.
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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.
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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.
Brake: 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.
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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.
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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.
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Wind speed is affected by many variables. In
the picture below, wind speeds are
approximated and are depicted in miles per
hour (MPH), using a standard wind sock.
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The Xantrex C Series offers the C35, C40 and
C60 controllers which can handle 35, 40, and 60
amps of DC current. These can be used as solar
charge controllers or load controllers or load
diversion controllers.
PREVENTS OVERCHARGING
PREVENTS POWER BACKFLOW
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Pure sine-wave inverters produce in many
cases cleaner electricity than normal utility
power from your local electric company and
should be used when operating AC motors for
long durations such as: pumps, refrigerators
compressors etc...
The machine converts the power to a useable
240 volts or 110 volts..
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Our system is using 8 x Trojan L-16 deep cycle lead
acid batteries. This sis where the power is stored,
until you are ready to use it.
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Although most systems use the main four
components, there are two that are not always
necessary. If you are using all 12 volt
appliances, an inverter is not required as the
power is already at 12 volts.
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Solar footpath lights are a stand alone 12 volt
system. They each have their own solar panel,
built in charge controller, which recharges the
batteries inside daily. There is a built in sensor
which turns the light on at night and off again
the morning. They light down to show the
way, but do not spoil the view of the night sky.
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There are a few systems that do not require
batteries..
A solar powered pump for example, can have a
direct feed from the panels and controller to
the pump, when the sun is up it pumps, when
the sun goes down it stops, thus avoid the need
for power storage and therefore batteries
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One of the most important things to remember
when considering going renewable is your
consumption. The more you use, the more you
need to spend on your system. Change your light
bulbs to compact fluorescent bulb, switch off lights
and appliances when out, make sure the fridge
shuts properly, and try not to use big power things
like irons and hairdryers. If you can manage
without these you can save thousands of dollars.
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SPREADSHEETS
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THANKS FOR COMING TO THE DOMINICA
INTERNATIONAL ECOFEST 2009.
JEM WINSTON
 MANAGING DIRECTOR
ROSALIE FOREST ECO LODGE
 [email protected]
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