Looking for a solar system, or upgrading an existing system? An inverter is a device that converts energy from a solar panel into usable energy for your home. It is often the most difficult part of the solar system of the house, and often the first part of the failure.
There are cord inverters, microinverters, hybrids, and power optimizers: each has its advantages and disadvantages, so how do you filter through quotations and complaints and choose the ones that are best for you? We guide you through the models and brakes so that you can ask your manufacturer specific questions and find the best solution that suits your home and budget.
What makes a solar inverter?
The inverter box on the wall, or sometimes on the roof, absorbs direct current (DC) generated by solar photovoltaic (PV) panels and converts to alternating current (AC) for use in your home’s electrical circuits. It is often the hardest part of the solar PV system and unfortunately, it is also the most difficult part to start.
Types of inverters
Regardless of the type, the mainverters must be a Clean Energy Council (CEC) approved and must meet the Australian standard AS 4777. All major brakes are good in this regard, but if your manufacturer provided you with a type you have never heard of, ask. In order to ensure that the CEC is approved.
- String inverters – the most common choice for most homes
- Microinverters – good for part of the shade
- Hybrid inverters – one unit for connecting panels and batteries
- Battery inverters – connecting the battery to an existing system
- Power optimizers – another option for dealing with shaded panels
What is the inverter size I need?
What size inverter you need depends on the size of the solar panel array.The inverter size is measured in kilowatts (kw) and is the maximum amount of energy generated by the sun that the inverter can handle.
Methods of calculating inverter size
The large 1200 watt micro inverter output power must be approximately 75% of the power resolar array.
- Or, indicated by another method, the array frequency can be up to 133% of that inverter capacity.
- This law is regulated by the CEC, and solar PV systems must comply with their own rules in order to obtain stcs (Small-scale Technology Certificates, a rebate scheme or rebate applicable to a solar panel system).
Where should the solar inverter be installed?
Cable, hybrid and battery inverters should be installed on shaded walls, usually near the main switchboard. Mainverters are designed for outdoor use and usually protect against the elements, but do not like extreme heat; it can affect their performance and life.
If your inverter cannot be installed in a shady area, your system should encourage mounting awning on it. Specialized awnings are available. In some cases, a house that is resistant to weathering may also be needed.
Also consider safety. String inverters can be a test for an experienced thief if they are in an easily accessible area. Stealing is rare but rare. Placing it behind a fence or locked area with a gate is ideal. Some models have anti-theft locking devices built-in.
Your Micro inverter should last about five years – and it will usually pay for itself at that time – but wisely it should last ten years or more.
Inverter warranty usually lasts 5 years, but get a 10 year + warranty cover which may extend the life of the unit. For example, solaredge offers a 12-year warranty and Fronius offers a five-year free warranty for an additional five years if you register the product over the air.
Extra guarantees are usually available but you will usually pay extra. We do not usually recommend an increased warranty for most products, but for peace of mind, it may be worth considering your inverter, especially if you can afford one at a lower price.
Finn Peacock from solar quotes looked at inverter manufacturer support for customers who had a problem with their inverter but could not get help from the first installer, for example, because the installation is no longer in business. The good news is that almost all types have stated that it will help consumers in these cases and support direct warranty claims.
Glen Morris from Smart Energy Lab in Victoria points out that whatever your system (including the inverter) has already paid for itself, as it usually does after five years or so, is not a risk if your inverter fails out of it. Warranty period. While it is completely impossible to go without solar for a while and pay for a new inverter, you may find a better, more cost-effective inverter than you could a few years ago.