solar panels increase in efficiency and new technology drops the price
and the way solar panels are installed there is going to be a huge amount
of energy that has to be modulated. Solar inverters take care of this
process, allowing solar panels to produce as much power as possible.
In the past these inverters were very large, a household inverter was
about the size of a refrigerator. Their main purpose is to convert the
direct current (DC) power that is generated from the panels into grid-friendly
alternating current (AC). New inverter designs have made the units much
smaller, but having many micro solar inverters connected to each array
is actually much more efficient than having one large unit.
There are a lot of factors that can affect a solar panel’s efficiency.
Shade, dust, debris, and other obstructions greatly reduce its power
output. With one inverter, all the power is run through each panel before
it gets converted to usable electricity. This means that a solar array
is only as powerful as its weakest panel. With multiple small inverters,
panels that are exposed to direct sunlight do not have any of their
charge weakened by panels that are obstructed or in the shade. This
means that no energy is lost due to inefficient panels, each panel can
produce as much electricity as possible and convert it AC power.
These micro solar inverters are used in conjunction with a maximum
power point tracking algorithm, or MPPT at every module. It is a small
computer that tracks how much power each panel is generating and determines
how much power to take from each panel. If there was only one of these
devices it would track the weakest panel and determine that as the desired
power, even if other panels are producing much more on other parts of
the array. This results in a huge loss of efficiency. These micro-inverters
can increase electricity yields by 25% when compared to a single solar
inverter. The information they collect can also be sent to a website
or home computer for custom adjustments, although the inverters are
very accurate without any manual setting.
Another advantage to having multiple inverters is that if one fails
the system still functions. If only a single large inverter is being
used a malfunction can lead to a complete loss of power. Single inverters
are large, hot and noisy, while micro-inverters have completely eliminated
those characteristics. Installations can easily be expanded over time,
almost every type of panel is compatible with micro-inverters and with
the addition of an MPPT can produce its maximum power all the time.
Since each panel can produce power at their maximum voltage it is possible
for mismatched panels to be used together. With one inverter all the
panels have to have the same rating, if one is lower every panel will
only produce that amount of power. That has been a huge limiting factor
for installing solar panels, each panel has to match perfectly with
the next one for maximum efficiency which can drive the cost up and
limit the size of the array from future development.