Hybrid inverters vs Solar only inverters
What are the differences, in regard to the role they play in a energy market ?
There are ‘Solar-specific’ inverters and ‘Hybrid’ inverters that are also called Off-Grid, Bi-directional or multi-powered inverters.
Solar Only inverters are designed to only convert Solar DC Voltage into AC Voltage, for either consumption or export into state grid.
Hybrid inverters on the other hand are bi-directional, some give the option to manage energy from several sources like Batteries, Solar, Wind, Aqua generation, few inverters have an AGS function, this feature Automatically Starts a Generator & imports energy, before going to the State Grid for power, if it's an on-grid inverter.
We recommend that you purchase a Hybrid inverter that has an "Uninterrupted Power Supply" (UPS) function, then when ready all you will have to do is plug them in, meaning that Batterys when installed the energy from the batteries will instantly kick-in with no disruption to the power supply when the State-grid fails or solar stops Generating.
By law all on-grid inverters should have Anti-islanding Protection, it is an important & sophisticated safety feature built into all grid connect inverters, the monitoring circuits detect the loss of grid power in fractions of a second, and switches off the ability to Export energy to protect linesmen working on the power lines kilometres away.
Inverter-Islanding or Anti-Islanding are both operation modes that relates to a System that operate in isolation from the electricity Distribution network, e.g. State Grid. NB: Retailers are NOT Distributors!
Meaning that Your Solar, Aqua & Wind Turbines connected to the State Grid in parallel mode, means they can both generate power independently in the event of a grid power outage, however is is more complicated ...For more information Click here to Read More!
Will a solar system work during a state grid blackout ?
Short answer: No. As a typical grid connected solar only system will automatically shut down by the Inverters Energy Management System if there is a blackout. That is a legal requirement as it protects the grid workers, from power feeding into the state grid lines they are working on.
Long answer: As stated above, a Solar Only grid connected system can feed power into the state-grid and must shut down in a blackout. This means that even if the solar panels are pumping out DC power, this is not being converted by the inverter and therefore not available for use in the building.
The Solution: A Hybrid Inverter with energy management systems that can allow the system to work on a stand alone basis during blackouts. These are often incorporated with Energy Storage Systems.
Ideally the correct sized battery bank will supply the building's full power needs, even if the solar array is not producing enough power at that time.
The critical system is an energy management system that will shut down any feed into the grid during a blackout, while allowing the solar power generated to feed the current use. Typically, these systems prioritise the use of power generated. First priority is to feed the current usage. Second priority is to charge the batteries. Finally, excess power is exported to the grid. A good system will recognise a blackout and not allow export for that time.
Hybrid inverters converts and directs solar power to where it is needed, and when it is needed, the Battery Management System (BMS) of all Hybrid inverters is smart circuitry that automatically converts excess energy to charge the particular battery technology used.
We recommend purchase a Hybrid inverter even if Battery's are not yet integrated, as if/when you decide to install batteries, Hybrid inverter allow you to simply wire (plug&play) the Batteries in.
Some Hybrid inverters have Automatic Generator Start (AGS) function that Starts & Stops a fuel Generator to Blackout-proof a premises, these are usually in UPS (uninterrupted power supply) off-grid inverters, whereby the inverter can be programmed to automatically start & stop if the State Grid goes down or the batteries get low, this function can be programmed to suit your needs.
When batteries are installed, commonly the GenSet would only be used in extended periods of bad weather, there the generated energy will firstly power your premises while the excess energy will be Charging your batteries at the same time, that is a double win situation, as usually a generator will only need to be operated for short periods, as Hybrid inverters utilise the built-in Charge Control circuit to float or rapidly charge the Batteries to a pre-set level, then the Generator will automatically be switch off, once the Battery bank reaches the pre-set charge level you set.
If you already have a Solar Array and looking to upgrade your energy independence by adding Battery storage, a "Solar Only inverters" will Not charge your batteries, you should replace your solar inverter (keep as spare) with a UPS Hybrid Inverter, it is obviously better & simpler to install a new Hybrid inverter with all those features incorporated, rather than purchasing several separated items, each drawing additional energy !
If you are going to purchase Batteries, we strongly recommend you purchase the largest Battery bank your budget/finances can afford, as an Inverter is the heart of a micro grid, that simply converts your battery DC voltage into AC voltage into either single or three phase power. Remember: It is easier to add additional Solar panels to increase your energy Generation anytime, than increase your energy storage capacity!
Without a doubt Energy Storage is the Foundation stone of energy independence, allowing you to create the best self sufficient Micro-Power-Grid possible!
NB: We recommend a 5kW be the smallest inverter to install, as that will cover all residential energy demands, in Australia a 5kW inverter is commonly the maximum size allowed when exporting energy/power into the state grid, unless you have upgraded to 30kW three phase wiring coming into your premises from your distribution company.