How are micro-inverters different than central inverters?
In a home solar system using a standard central inverter, solar panels are
typically connected together in a series that produces one burst of power.
This electricity is sent into the central inverter, which is often installed inside a
garage. Micro-inverters, on the other hand, are much smaller, and designed
to be attached to each solar panel on your roof. The current from each panel
is directly converted and sent into your home.
A big advantage of using micro-inverters is that if one panel becomes shaded, or blocked by snow or leaves, it won’t affect the rest
of the array. In a setup where solar panels are attached in a series, the panels act like one unit; if one panel performs 10% less
efficiently, they all will. If there’s a manufacturing defect in one panel, or anything else goes wrong as the panels age, the whole
array will be affected. Micro-inverters eliminate this problem because every solar panel is independent, and if there’s any small
problem with one of them, the rest of the panels will still continue to pump out power normally.
Central or “string” inverters also come in limited power ratings. Solar arrays come in all sizes, based on the needs of your unique
house. Because the size of central inverters is limited, you may end up having to pay for one that’s much bigger than you actually
need. Micro-inverters can be customized to the exact number of solar panels that you have
Micro-inverters also take less space; since they’re up on the roof, you won’t have to find room in your garage. Central inverters
sometimes require cooling fans that can be noisy. Because micro-inverters run at lower power points than central inverters, they
also have the advantage of requiring less additional equipment. Cooling fans can be eliminated, large transformers are no longer
necessary, and other parts can be smaller.
Micro-inverters are also considered more reliable than central inverters. They have longer warranties (usually 15-25 years, versus
5-10 years for central inverters). Because they handle less power and produce less heat, they can last longer. Because they help
whole system working at its best.
Approximately 5%-30% of collected energy is lost or wasted while an inverter converts DC power from solar PV to AC power.
Inverter efficiency is vital to the solar PV system efficiency because central or string inverters determine both the amount of DC
energy collected from a solar array and the demand placed on transformers and capacitors to complete the process.
panel(s) instead of an entire solar array. The overall effect reduces the need for large transformers, large electrolytic capacitors,
and eliminates the need for fans (as cooling loads are much lower).