{"id":80809,"date":"2024-01-04T09:34:53","date_gmt":"2024-01-04T00:04:53","guid":{"rendered":"https:\/\/www.solarquotes.com.au\/blog\/?p=80809"},"modified":"2025-12-19T14:41:01","modified_gmt":"2025-12-19T05:11:01","slug":"battery-less-backup","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/battery-less-backup\/","title":{"rendered":"Solar Backup Without Batteries: Revolutionary or Ridiculous?"},"content":{"rendered":"

\"Battery-less<\/p>\n

Solar newbies are often bemused as to why their rooftop solar shuts down during a grid outage. It seems counterintuitive, given that the idea of an alternative power supply is to generate electricity separately from the grid.<\/p>\n

Installing a home battery<\/a> is the obvious solution to keeping your lights on during a power cut. However, the cost of batteries<\/a> puts them out of reach for many people.<\/p>\n

A handful of solar inverters offer a seemingly magic backup power solution: backup power without a battery during a grid outage.<\/p>\n

It sounds too good to be true, and you know what they say about that.<\/p>\n

This article will highlight some inverters with this feature and explain their limitations. We’ll also discuss why it’s rare and whether you should even bother about it in the first place.<\/p>\n

Why Does An Inverter Shut Down During An Outage?<\/h2>\n

All solar inverters<\/a> are not equal. The one thing they have in common, and their primary function, is to convert DC (direct current) from solar panels<\/a> or batteries into AC (alternating current), which is usable for household appliances. That’s where the similarities start and finish.<\/p>\n

“Grid-following” inverters are the most common type used in grid-connected systems. Their AC output is designed to synchronise with the electric grid, ensuring the generated electricity is in phase with the grid’s electricity. The inverter typically shuts down when there’s a blackout or a power outage.<\/p>\n

All inverters must disconnect from the distribution network whenever the supply is disrupted. If your inverter kept putting electricity into the grid, it could electrocute lineworkers who are trying to get you back on line.<\/p>\n

Backup With A Battery<\/h2>\n

Adding a battery can provide backup capability during a blackout. There are many configurations and levels of battery backup available. However, in all cases, the inverter must still be able to disconnect from the grid during an outage.<\/p>\n

In this scenario, the type of inverter used depends on the system’s setup. It could be either a hybrid inverter or a battery inverter. These inverters can switch modes \u2013 from being connected to the grid to operating independently as a backup. Once switched, the inverter provides a steady voltage and frequency, but only to a limited extent, powering emergency circuits from the battery. During this time, it remains disconnected from the main power grid<\/p>\n

Can Solar Panels Supply Power During An Outage?<\/h2>\n

Yes, sometimes they can, but a battery is a crucial component. The battery has storage capacity and acts as a buffer. Relying on solar panels without a battery to power your appliances is skating on thin ice.<\/p>\n

Most inverter manufacturers don’t offer “backup without batteries” as a feature, and even when possible, they certainly don’t make a song and dance about it. I think it’s for good reason. They don’t want to be setting you up for disappointment and damaging their brand in the process.<\/p>\n

Stating the obvious – solar panels only generate power in the daylight. So that’s about 50% of the time you will be sitting in the dark. Also, their generation capacity changes instantaneously. The available power to supply loads is as variable as the weather. One minute, it’s there; the next, it’s gone. Is that what you call “backup power”?<\/p>\n

Some electronic devices can be damaged by being switched off and on repeatedly over a short period, and many electric motors and compressors simply won’t start up without enough capacity to support their inrush current. One could argue that for the low-powered devices where this may not be an issue, you could spend your money more wisely for so-called \u201cbackup\u201d.<\/p>\n

So, having poo-poohed the concept of “backup without batteries”, without further ado, in no particular order here are some inverters I’ve found that will do it. There are most likely more to add to this list, but they’re keeping their heads low. Please let me know if I’ve missed any.<\/p>\n

Inverters With “Battery-less Backup” Available In Australia<\/h2>\n

Fronius GEN24 Plus<\/h3>\n

Fronius<\/a> hybrid inverters offer two levels of backup. “Full backup” requires a battery and “PV Point” (battery optional). You’d be hard-pressed to find the word “battery” mentioned in their PV Point blurb, but I dug deep. The following is an excerpt from the freely available installation and commissioning document entitled “Application Guide PV Point Fronius GEN24 Plus Series”:<\/p>\n

“The PV point represents the basic emergency power function of the GEN24 Plus series and is integrated as standard ex-factory. It is a socket that is only supplied in case of grid outage based on the currently available PV generator power (or available battery). The switch happens automatically by the inverter and doesn’t require any additional grid separation components. Every important single phase consumer in the household up to 3 kW can be supplied by the PV point. A PV point installation does not (necessarily) require battery storage \u2013 an installation of a storage unit is optional.”<\/p><\/blockquote>\n

\"Fronius

Fronius PV Point – this graphic shows a European socket powered from the PV Point. The Australian version requires an electrician to hard-wire a socket outlet from the inverter to make it work. You’ll also need to provide an RCD (type A 30 mA), so add that to the bill.<\/p><\/div>\n

Delta E5<\/h3>\n

The Delta<\/a> E5 is another hybrid inverter that offers a battery-less backup feature. The datasheet states a capacity of up to 3600 VA when in “standalone mode”. It will also need a separate distribution panel with RCD protection for backup loads.<\/p>\n

“The stand-alone function of the Hybrid E5 inverter allows the owner to use the battery to power critical loads when the grid is not available. This function will activate automatically during a power outage, although the E5 also has a button to manually switch the system to stand-alone mode. The inverter is still able to enter stand-alone mode even when the battery is not connected, as long as there is sufficient PV production to power the loads.”<\/p><\/blockquote>\n

The video below demonstrates how the Delta E5 can “deliver your solar power to your home during a blackout without a battery” or maybe just heat up last night’s spaghetti leftovers for lunch on a good day.<\/p>\n