Q: What is a grid tie inverter?
A: A grid tie inverter
is an inverter which takes the direct currents produced
by the generator of a wind turbine and convert it to
a form which can be directly exported to the electricity
grid network. The benefits of this is that the owner
can directly utilise this energy in his normal household
usage and offset his electricity bills.
Q: What happens if I do not
use all of the electricity that is being produced? Is
this energy stored?
A: Well any surplus electricity
that is not utilised will be directed back into the
grid network. Unlike a battery charging system, this
energy is not stored but is sent to other users on the
electricity network.
Q: Why
do we not use a battery charging system instead?
A: The many reasons for
not wanting to use a battery charging system. Batteries
can only store a limited amount of energy, have a finite
operational life which is very dependent on the usage
pattern. Batteries are expensive when they are required
to store alot of energy. The added stage of using a
battery charger and the charging and discharging of
the batteries reduces the overall efficiencies of the
system. Batteries tend to operate under low voltages
and this also reduces efficiencies due to the high currents
present and require expensive thick cables to operate.
In addition, batteries contain a lot of environmentally
unfriendly chemicals which we would all like to avoid.
Q: So will we be paid for the
surplus electricity that we produce.
A: This depends very much
on the local regulations and policies. Many countries
are strongly encouraging its citizens to be reduce their
energy demand and even incentivise them to produce surplus
in order to reduce the damands placed on the generation
companies. Many places are already putting schemes to
meter any excess electricity produced and to pay the
owner for it. Check with your local utilities for more
information. In any case, if all the electricity generated
is used within the household, then this can be considered
as the utility company paying the owner back for the
amount of energy he would have otherwise had to buy
from the utility.
Q: Can we use a PV inverter
on a wind turbine system?
A: Technically, this is
possible, however, it would be not ideal to do so as
these are two very different applications with different
characteristics. Just as one would not take a Formula
1 race car to go rallying racing, you would not want
to use a PV inverter for a wind turbine because the
requirements for a wind turbine are much more demanding.
Q: So
what is different between wind and solar generation
systems?
A: Solar systems have
been developed for a source which is relatively stable,
the sun's rays do not change in intensity very suddenly
and usually is present for around 8-12 hours a day.
A PV inverter does not have to react quickly to sudden
changes unlike for a wind turbine where winds gusts
all the time and the inverter has to be ready to capture
that energy quickly. Solar inverters can afford to shut
down at night but wind turbine inverters have to stay
on for much longer as one can not predict when the winds
will be blowing.
Q: What
about using your wind turbine grid tie inverter on a
PV system?
A: Although our grid tie
inverters have been optimised for use with a wind turbine
system, we have a version of the inverter which has
special control algorithms which perform the necessary
Maximum Power Point Tracking for use with a PV system.
Due to our wide operating input voltage range, we can
adapt our unit to suit more systems than many other
PV inverters.
Q: Is there anything unique
about Ginlong's wind turbine inverters?
A: We have been designing
inverters which optimise the energy capture for wind
turbines and have developed new and patent pending algorithms
which outperform other systems at the moment. Some of
these control schemes have already been put in use in
our production units and others are in the final stages
of testing before being released in the market.
Q: I
am a manufacturer and would like for you to customise
your unit to suit my turbine. What can you do for me?
A: We always welcome wind
turbine manufacturers to contact us for customisation.
Currently our units are designed such that manufacturers
can perform some of the customisation by themselves.
Please contact us for more details.
Q: Where
would you normally mount the inverter unit?
A: We have specially designed
this inverter unit to be mounted indoors near the distribution
unit so that the owner can easily monitor how much power
the wind turbine is generating. We have designed the
look of the unit to be pleasent and not occupy too much
area. The unit has been designed to be very quiet without
the need of any fans to disturb the occupants.
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