Why all inverters are not created equal
If you’ve read our blog How does solar energy actually work, you know you’ll need an inverter as part of your solar installation.
Not quite sure what that is or why you need it? You’ve come to the right place.
What’s the difference between DC (direct current) and AC (alternating current) electricity?
AC and DC are different types of current flow in a circuit.
The direct current (DC) electric charge only flows one way, therefore delivering a steady voltage or charge. However, this steady charge is generally of a low voltage, meaning it’s not all that useful for larger appliances.
Alternating current (AC) periodically changes direction. This means the voltage in AC circuits also regularly reverses because the current changes direction. In fact, it changes direction about 50-60 times per second. That’s a lot of energy.
AC electricity is used in most homes and businesses and you may be wondering why because DC seems a lot simpler than AC.
Two main reasons:
- AC works at high voltages and can even be increased using a transformer far more easily than DC, and;
- AC is cheaper to transmit over long distances. This makes electricity accessible to everyone.
So, how do we turn all that DC energy into AC? We use an inverter.
How does an inverter work?
A solar inverter is one of the most important components in the solar power system. The device converts the variable direct current (DC) output of a photovoltaic (PV) solar panel into alternating current (AC) electricity. The inverter is highly efficient transferring about 90% of the energy.
This AC electricity is then fed into your home or business to power your appliances.
Different types of inverters
There are three different types of inverters:
• String Inverters
• Microinverters, and;
• Power Optimisers
String Inverters
The most common solar panels but these days, considered dated technology.
Panels are ‘stringed’ together, connecting to a single inverter, making them very cost effective. Works well for installations that have full, consistent sun exposure. However, the array is only as effective as its least exposed panel meaning they’re not a good choice for shaded roofs or roofs facing in several directions.
Microinverters
Installed on each panel or integrated into the panel itself. As the panels aren’t linked, each panel will use solar energy to the max, even if other panels are shaded.
Power Optimisers
While not technically inverters, they’re a great compromise between string inverters and microinverters. Like microinverters, they’re installed on or integrated into each panel. But they don’t convert DC to AC instead sending it to a string inverter, effectively optimising the system by reducing the effect of those pesky shaded panels.
Power optimisers can also be the solution to a complex install.
