The solar inveter is a critical element in any solar power system. It is the heart of the solar system in many ways in that it has 4 primary functions:
- The inverter converts the d.c. electricity produced by the solar panels into ‘useable’ a.c. electricity – by usable, we mean that this electricity can be consumed in our homes and if there is any not used by our houses appliances then the balance will be sent back to the Queensland electricity grid for a ‘credit’ on our power bill – the amount of credit determined by the feed in tariff.
- The solar inverter will (in virtually all modern inverters), employ M.P.P.T. or maximum power point tracking techniques to maximise the V.I. (voltage times current) curve of the solar panel output throughout the day. This is very important in getting the most ‘bang for buck’ from the solar panels themselves.
- Safety Function: It is absolutely critical that if the electricity grid ‘goes down’, for example if their is an electrical fault at a sub station or is strong Brisbane storms cause power lines to come down etc, that the inverter stops feeding power (produced by the solar panels) back onto the electricity grid. If linesmen were working on the grid and the inverter continued to ‘feed’ power back to the grid, then this would obviously be a very hazardous situation for the linesmen.
- Solar Power Monitoring Function: Again, most modern inverters will allow you to monitor the output from your solar panels system. This monitoring can be fairly simple, as in an L.C.D. display on the inverter, displaying real-time energy production figures, to extremely sophisticated monitoring systems that can transmit data on your systems energy production, via radio frequency links for download onto a personal computer or laptop in your home. This allows you to monitor seasonal fluctuations in your systems performance and very importantly, confirm that your system is working correctly.
Critical Issues for Inverter Selection In Brisbane
In our view, the most important issues when looking at solar inverter selection in Brisbane are:
- Reliability – Brisbane has extremely hot summers. The electronic design of the inverter, its heat-sinking and possible fan-cooling are factors not to be overlooked. The number one factor in inverter failure, like most electronic devices is heat.
- Long term warranty support for the inverter. This is fairly self explanatory – if the inverter fails in 6 years time, will the warranty be honoured? What is the warranty?
- Efficiency – Top line inverters are reaching efficiencies of 98% plus. Low efficiency inverters are simply wasting power produced by the solar panels – not good!
- Ease of use and quality supporting documentation. As discussed above, most quality invertrs have monitoring ability. This must be easy to understand and use. Many inverters come with software for loading onto your p.c. to allow for display, storage and reading of inverter data.
Below is a reasonably good video from Power One, Aurora. Their inveters are widely used in Brisbane (we are not endorsing them and are not affiliated with them).