What Exactly is a Solar Inverter?

Nearly all inverters carry out the same function, to convert DC to AC electricity and indeed solar inverters are no different.

Solar inverters are required because solar panels generate DC electricity so your renewal fuel electric system will need to convert this to AC – the voltage that pretty much every electrical device in the home or office operates on.

When you think about inverters and solar power it is important to recognise that essentially there are two main types of solar system.

The first is connected to the grid, often referred to as being grid-tied, and second works independently and is not connected to the grid. This type of system is usually referred to as being (off-grid). These two different systems use different kinds of inverter.

The grid-tied inverter allows the DC voltage to be converted into AC voltage for consumption either straightaway or alternatively, it can be 'sold' back to the grid. Of course, in these instances the equipment must comply with the strict regulations that are imposed by the utility companies themselves.

An example of this would be that a grid-tied inverter must generate AC voltage of a strictly sinusoidal form.

Another of the key features of the grid-tied versions is that for the safety of technicians in that they stop operating when there is a grid failure.

Obviously, this prevents anyone working on the network from getting an electric shock – hence why the equipment must meet strict criteria.

As we described earlier, off-grid equipment can be considerably different. For instance, in the case of an off-grid solar system it is possible that it will not have an inverter if DC loads only are to be powered.

Whilst this is unlikely, it is conceivable.

With no connection to the grid network, off-grid inverters are subject to far fewer rules and regulations because, as the name suggests, they have no connection with the grid.

Depending on its size, a photovoltaic system could comprise either a single inverter or multiple ones.

Like pretty much everything, both concepts have their pros and cons. The vast majority of modern inverters come with a feature known as Maximum Power Point Tracking which allows the solar panels to generate electricity at their maximum capacity.

The concept of inverters is certainly not complicated and there is nothing mysterious about them. However, they are expensive and generally very bulky especially the higher powered or industrial versions.

Understanding the type of inverter that you need is important and essentially you only need to know a couple of points.

If you do your research and know your stuff, you will feel confident talking to a solar vendor. If you are looking to buy solar panels, the vendor is likely to want to know the following points:

• How to estimate 'AC power rating' – the key parameter of any inverter
• What to be aware of when selecting an inverter with MPPT feature
• In what circumstance a single inverter is not sufficient