The electricity produced by solar panels is DC (Direct Current). This electricity must be converted to match the type of electricity that it is intended to power. The inverter is a box which connects between the panels on your roof and your electrical switch board. It converts the DC electricity from your solar panels to 240V AC; suitable for use by the appliances in your home.
Inverters are the work horse of any Solar PV System, however not all solar inverters are equal. The quality of an inverter is not always about the country of manufacture. Rather, it has everything to do with not only the design and efficiency of the unit but also the quality control processes and the financial stability of the manufacturer.
There are a huge number of inverter brands, types and sizes being sold in Australia today. We have done all the hard work for you and selected the best brands for you to choose from.
Below is a brief outline of the main types of inverters you should consider when deciding on a new system.
An off-grid inverter is very different from a grid-connected inverter. If your home is already connected to the electricity grid, this is not the inverter for you. When there is no electricity available from the local utility (Grid) for whatever reason, you are able to create and store your own electricity using an off-grid or Stand Alone inverter. A dedicated off-grid system will require a number of additional components. Solar Panels for generation, Batteries for storage and a charge controller at a minimum. This controller is usually built into an off-grid inverter on the DC side. Off-grid systems must be sized correctly and can usually be backed up with an alternative power source such as a generator.
To power a building in Australia the panels DC power must be converted to 240 Volts AC (Alternating Current) to match the Grid supplying all properties. This function is performed by a device called a Grid Tie Inverter. The output of the Inverter is connected to the buildings Main Switch, meaning that the electricity will now power the loads in that building.
When you produce more electricity than you are using, the excess is sent back on to the grid. A new Bi-Directional Meter is required so that the excess electricity can be counted. This excess (Feed-In) appears as a credit on your power bill, earning you a healthy return! This system will reduce the amount of electricity you bring in (Import) from the Grid during daylight hours and it will also contribute towards the reduction of your total bill.
String Inverters require a number of panels connected together in series to generate enough power to turn it on. All panels in each string need to be facing in the same direction and angle. The number of strings in a system depends on its particular specifications. String inverters will have either 1 or 2 MPPTs. Each MPPT can have one or more strings facing in different directions and different panels to the other.
Pros: Most common and best value due to lowest cost per watt,
Cons: Come in sizes (may limit future expansion),
We recommend and install these String Inverters.
As the name suggests, micro inverters are much smaller than string inverters. There is one inverter for each panel. Located under the panel they can be attached to the rail or directly to the panels frame. The main reason for using micro inverters is if the array will be subjected to partial shading. Solar Panels should never be installed where they will be significantly affected by shading and micro inverters will not fix large amounts of shading. Micros also work best when more than 2 directions are required.
Pros: Greater performance under shade, A/C power from the roof to Meter box, No inverter at Meter box, Can be added to 1 panel at a time.
Cons: Around 10 - 20% more expensive.
We recommend and install Enphase Micro Inverters.
A Hybrid Inverter is a Grid Tie Inverter with the added ability to connect and control a Battery. When a Battery is connected to a Hybrid Inverter it can send the electricity produced during the day to the Battery. A meter is connected to the electrical loads supply so that the Inverter knows what the buildings current requirements are. A Hybrid Inverter can then be programmed so that during daylight hours it will only invert the exact amount of electricity required to power the buildings loads. All excess solar generation is sent directly to the battery.
All Batteries store DC electricity only. As Solar Panels also produce DC electricity, a Hybrid Inverter is made with the battery controller on the DC side. This means that there is no need to invert the electricity to store it. As day turns to night, the controller begins to draw electricity from the battery to match the loads. This is known as DC Connect between the Inverter and the Battery. The main advantages of this system are that it is all contained in the one unit and it is very efficient due to the electricity being inverted only once.
Pros: Best way to connect a battery.
Cons: More expensive than standard inverters.
. Hybrid Inverters We recommend and install these
These are the brands which we recommend and install:
SolarEdge DC optimized inverters overcome traditional concerns to offer more energy, better maintenance, and enhanced safety.
SolarEdge allows strings of uneven lengths, modules in multiple orientations and different roof facets in a single string and modules in shaded areas. Module-level performance monitoring & remote maintenance. 2%-25% more energy from the PV system depending on site issues. Extremely effective where partial shade is an issue.
As a leading global specialist for photovoltaic system technology, SMA is setting the standards today for the decentralized and renewable energy supply of tomorrow.
More than 3,000 SMA employees in 20 countries have devoted themselves to this task. Our innovative solutions for all photovoltaic applications and our unsurpassed service, offer our customers worldwide greater independence in meeting their energy needs.
Efficient, reliable, high power inverters form the heart of any PV system. In the development of PV inverters, Fronius has thought out new technologies, searched for innovative solutions, and has found completely new answers. The result: Highly functional mains-connected inverters, which interact optimally with all solar modules.
Register your string inverter and get a 10 year warranty for free until December 31, 2017.
ABB has one of the widest portfolios of solar inverters ranging from small micro-inverters and three-phase string inverters up to megawatt-sized central inverters. This extensive range of solar inverters is suitable for the smallest residential photovoltaic (PV) systems right up to multi-megawatt PV power plants.
ABB solar inverters utilize over 40 years of experience and advances made in inverter and power converter technology that have contributed to ABB becoming a world leader in power converters.
Enphase microinverters operate independently, so each panel performs to its fullest. One shaded or dirty panel won't affect the rest of the system. Burst technology lets microinverters produce more at dawn, dusk, and in low-light conditions, for a longer solar day.
Because they function independently, microinverters are inherently more reliable: there's no single point of failure in a microinverter system. If one panel goes down, the others won't go down with it. An all-AC system also means no high-voltage DC power on your roof.
Sungrow Power Supply Co., Ltd. a high-tech enterprise engaged in development of power supply equipment for renewable energy especially solar PV and wind power, provides grid-connected PV inverter, wind power converter, technical consultancy, system design and other relevant services.
Founded in 1997 by Dr. Renxian Cao, Sungrow has become one of the leading manufacturers in the world PV inverter industry.