EPS (Emergency Power Supply) Solar Systems

Most Solar Panel systems include a storage battery, but a common question remains - "How can I get my Solar system to work if the power goes out, and how can I use my solar battery in a power cut?"

EPS (Emergency Power Supply) is the key to getting your panels to process power in an outage. Here are the serious technical details regarding EPS and your solar system.

What is EPS and what does it stand for?

EPS stands for ‘Emergency Power Supply.’  Essentially, it means the ability of a Solar PV System to automatically or manually switch over to power your home from your battery storage system in the event of a power outage is referred to as emergency power supply. 

EPS (Emergency Power Supply) explained

In the event of a power outage, EPS functionality allows a home or business owner to access the power stored in a battery. In the event of a power outage, these features can be used to keep certain appliances in your home, or even the entire house, powered.

Generally, EPS means you can only use the energy from your batteries. You will require certain panels with extra safety functionality for them to work in a power outage.

A standard set-up solar system will not keep working in a power cut.  This is because the flow of electricity will change when working on EPS or power will not flow normally to/from the grid. Once the power cut ends and the grid comes back on, the uneven flow of electricity could create potential energy differences that cause an electrical explosion. Essentially, you could damage your solar system, your house, or even yourself if you were nearby. This is why it's important to have things safely set up using EPS sockets.

Certain types of EPS systems and inverters will allow you to safely use your panels in a power cut.

Basically, without EPS, if power is somehow successfully restored and your panels are running, since they are not “in sync” with the frequency of the grid, the system may explode.

How can you get a solar system with EPS functionality?

Generally, we focus on backup battery storage with EPS functionality as your source of power. 

Essentially, EPS allows solar system users to run their household appliances via their battery storage system in the event of a power cut.

When might you need battery backup?

Extra wiring and EPS setup will be an additional cost to your solar system. Check if you realy need EPS backup with some of these common uses:

You frequently suffer from power cuts in your area and you:

• Have a lot of food in your fridge/freezer you’d be worried about losing due to a power failure
• You work from home and need to ensure you can access the internet or use a computer all day
• You have medical equipment running that could fail and stop running without backup power

What options of EPS for solar systems are there?

There are a few options for emergency power supply, both automated and manual. 

Option 1 - Easy automatic sockets

This is a low-cost upgrade to any solar PV system that allows the inverter to immediately disengage from the grid and connect to your socket in the case of a power outage. This is handy for powering smaller needs like charging a phone or lighting.

Option 2 - Easy automatic circuits

This would typically keep lighting and perhaps also the fridge running in the event of a power cut. Again in the event of a power cut and after a short delay, these circuits will become automatically powered by the battery system, not the solar panels. Automatic circuits require a fair bit of extra wiring for safe capabilities.

Option 3 - Slightly trickier manual whole house backup

With a fair bit of extra wiring, you can power your whole house with backup storage power. Unlike the other options, you’ll have to manually switch over to backup power.

In the case of a power outage, a homeowner may manually turn down all high-power loads and activate a full-house switch, allowing your home demand to be supplied straight from your batteries. This is accomplished by redirecting the incoming grid connection and the primary consumer unit through the battery system instead.

Option 4 - Automatic entire-house backup

An off-grid solar system can be set up to power your complete home, with or without a grid connection. These solar PV systems can handle large loads and instantly switch to battery energy in the case of a power outage. This transition is smooth, but you’ll need a huge battery to support the home's demand, which can be pricey.

Option 5 - Automatic entire house backup with off-grid capabilities

Even if the grid connection is lost, the battery inverter isolates the entire home in a whole house off-grid system.

Unlike other alternatives, which are limited by your storage capacity at the moment of grid failure, this sort of solar PV system can power your home as long as there is sunlight, providing complete off-grid capability.

How is EPS installed?

Contrary to common assumption, many solar batteries do not provide a backup supply right out of the box. If your inverter lacks the necessary hardware, you must attach an automated contactor or manual changeover switch to your hybrid inverter in order to add EPS capabilities to your solar panel system. You will also need to build a new external earth as well as a fused down distribution board to link out the circuits, depending on the earthing layout of the property and how the grid is removed.

Get an EPS solar system for your home.

Contact us today to talk to a solar specialist about your home.