And while solar panels are a crucial part any solar system, they’re not the only component required. In fact, for a user to truly be able to utilize the solar power created by panels, the energy needs to go through a solar inverter.
Simply put, a solar inverter converts direct current (DC) electricity into alternating current (AC) electricity. This is important as solar panels generate DC electricity, but regular households, businesses and appliances require AC electricity to run. So without the inverter, you’re essentially creating an abundance of solar energy that you can store (if you have a solar battery), but can’t actually use. For this reason, the solar inverter is often considered the ‘gateway’ of a solar system.
So that’s the quick explanation. But to fully understand just how indispensable a solar inverter is, we need to look at how the whole solar energy process functions.
Let’s start from the start! The process of collecting solar energy starts with the solar panels. When the sun shines on your solar photovoltaic (PV) system, electrons within the solar cells start to move around, which produces direct current (DC) energy. Circuits within the cells collect this, converting energy from the sun into electrical power. Throughout the day (weather permitting), these individual panels continue to collect this power, producing DC electricity and combining it. It’s then sent off to the solar inverter!
The solar inverter receives this DC electricity, converts it, then sends the converted power off to the fusebox. When the switchboard receives this AC electricity, it can then be delivered to the home or business to power all of the appliances as necessary. From the fusebox, excess power is then either sent to a battery storage system or back into the grid, depending on the user’s usage and system set-up.
Unlike solar panels, which are mounted on the roof, the solar inverter is placed on the wall outside your home or in a garage or laundry. This is to protect it from the weather, as well as ensuring close proximity to the power board. For best performance, an inverter should always be in the shade.
Yep! There are three main types of solar inverters; stand alone inverters, grid-tie inverters and battery back up inverters.
A grid-tie inverter is converts DC electricity into an alternating current (AC) that is suitable for injecting into an electrical power grid. In order to inject electrical power efficiently and safely into the grid, grid-tie inverters must accurately match the voltage and phase of the grid sine wave AC waveform. Grid-tie inverters are designed to shut down automatically upon loss of utility supply, and do not provide backup power during utility outages. Grid-tie inverters are used between local electrical power generators: solar panel, wind turbine, hydro-electric, and the grid.
Battery backup inverters are solar inverters which are developed to get energy from batteries and manage the energy charge it got from the battery through the onboard charger, and brings the surplus energy to your utility grid. These battery backup inverters are able to supply alternating current (AC) power to selected areas which require energy during a power outage. They are required to be installed with anti-islanding protection. Islanding is a process where grid tie inverters are fooled that a utility grid is still functioning even if it has been turned off. It takes place due to load circuits that resonate in the electrical system.
Stand alone inverters are a type of solar inverter designed for systems that are typically isolated. This includes remote stand-alone applications or off-grid power systems with battery backup – and is utilised when the inverter draws its DC power from batteries charged by PV solar and converts it to AC power. Usually these do not interface in any way with the utility grid, meaning that it does not require anti-islanding protection.
There are many different sizes available for solar inverters. The size required is dependent on the size of the solar panels installed. For example, a 5.0kW solar power system would require a solar inverter of similar or larger capacity. In general, as a minimum, the inverter needs to be able to handle the maximum power that your solar power system can generate. Physically, grid connected inverters come in a variety of shapes, sizes and weight. The smallest solar inverters are around the size of a business suitcase, while the bigger inverters are more like a large overseas travel bag.
Some inverters also give you basic monitoring functionalities, however these capabilities are fairly limited. Most inverters have display lights indicating whether the unit is on, off or in standby. They can also have displays that indicate the amount of energy (kilowatt hours) you have produced in the past 24 hours and the amount of electricity (kilowatt hours) you have produced since the unit was installed. To access this information you unfortunately have to physically inspect the unit.
To see exactly what solar power you’re using, and when you’re using it, an intelligent energy management system will grant you remote monitoring and is set up to help you get the most out of your solar power system.
While solar panels have no moving parts and can be expected to continue working past 25 years, inverters are arguably the most likely part of the solar system to fail. Depending on the brand, they need regular replacement every 5-10 years. carbonTRACK will let you know if there is a problem with your system’s inverter – and you can set reminders to look into replacing it before the warranty is set to expire to head off problems before they happen.
It is clear that the inverter is crucial for the conversion of the energy collected from the panels to a power source that can be used continuously in your home. The solar inverter works as a middleman, and without it, the power collected by the panels would be worthless.