What extended power outage teaches us about backup battery power

Recently, after the severe weather event that hit Victoria on 9th June the ABC wrote an article comparing how a few different battery installations performed.

https://www.abc.net.au/news/2021-07-03/battery-power-dandenong-ranges-tesla-agm-grid/100264988

This article pointed out the importance of when purchasing an energy storage battery that it is fit for the purpose that you want it to provide.

Just like many people don’t initially realise that solar arrays don’t operate if the power is disconnected, battery storage systems don’t always work either.

This is fine if you just want a battery energy storage system to provide some load sharing but if you want power when the grid is disconnected the battery has to be capable of being used in an off-grid situation and it has to be wired to allow for this. This usually means the battery inverter is wired in before your solar inverter so that the complete battery and solar PV energy system can operate independently from the grid.

The type and size of your battery system is also important and how much of a battery systems capacity is actually useable. With lead acid and AGM batteries, generally only 30 – 50% of the batteries capacity is useable which means you will need a larger system capacity overall. Also as lead acid and AGM batteries tend to degrade over time and with use this needs to be taken into account when sizing your energy storage system.



Many people purchase solar arrays and /or add energy storage batteries to an existing system in the belief that this will protect themselves against power outages.

However solar arrays on their own won’t do this as they are disconnected when the power goes out to make sure no power inadvertently gets transferred back into the grid to cause problems with anyone working on the lines.

The same applies to some batteries. To continue to have power when the grid goes down you need to have a battery that is “capable of” and “configured to” be able to work independently from the grid.

Also to preserve power when the grid goes down you need a battery that won’t be impacted by water or fire as many lithium-ion batteries can explode if still having charge when they are subjected to water damage.

When people look at purchasing a battery storage system one of the reasons is to provide power when the grid fails as often happens in extreme weather events (which are becoming more frequent). These power outages can last from a few minutes to several days or even weeks and may only happen occasionally or can be a fairly frequent occurrence depending on where you live.

What appliances you want to cover and for how long will have a bearing on the type and capacity of any battery system you purchase.

At one end of the spectrum you may only want to cover a critical circuit of refrigeration and lights and maybe one power point for charging phones etc. for a couple of hours. The other end of the spectrum is to cover all loads of the house for several days. If you want to cover all loads of the house you will need more battery capacity and also large enough inverter capacity to cover running several appliances at once.

Some battery systems can be programmed to always keep a percentage of your battery in reserve in case of a power failure (the SoNick energy storage system will do this). Again, this can determine how much battery capacity you need to cover daily running loads as well as a predetermined reserve battery capacity.

This also highlights the need for resilient local microgrids that are designed to withstand the possibility of power outages. Lithium-ion batteries and lead acid batteries may not be suitable in these situations as they may catch fire and explode themselves when subjected to water or high temperatures which only makes the power situation worse.

Local microgrids are designed to cover a limited area and may consist of a number of individual battery installations or a centralised battery system and power supply. Usually, these systems are charged by solar PV but can also incorporate wind, bioenergy units or hydro depending on the local conditions. All energy generation can be stored locally and distributed according to individual house or community building needs using software programs.

With a SoNick or molten salt battery system you can guarantee power supply, even if grid power goes down and the switchover is instantaneous so you may not even realise the switch to battery power has occurred.

If you would like to know more about getting safe, reliable and recyclable battery storage for your own home or business visit us at http://quantum.GridEdge.com.au or contact us at admin@gridedge.com.au

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