In a world of volatile fuel prices, rising electricity bills, and grid instability caused by extreme weather, more and more people are switching to solar. And, in the process, working to gain their energy independence.

Hoymiles hybrid inverters are designed to put power back in people’s hands by giving them access to a reliable source of backup power – so they can make smarter, safer solar energy use a reality.

While most inverters only convert DC solar power into AC power that is consumed by house appliances, hybrid inverters can also convert AC power to DC power. This means that, with a hybrid inverter, you can integrate batteries into your solar system to provide power backup. Hybrid inverters can also connect with a diesel generator, forming a complete off-grid system in case the grid goes down.

A hybrid inverter system uses multiple energy sources. To achieve the best results, you’ll need to make wise decisions on how and when to mobilize each of these energy sources.

Hoymiles hybrid inverters offer three modes, so you can always make the best choice for your energy use. The three modes are: Self-Consumption Mode, Economic Mode (TOU), and Backup Mode.

Now let’s explore exactly how the system operates in each of these different modes, and when you should use each one.

Self-Consumption Mode
In this mode, the system will prioritize making sure you have enough energy to meet the needs of your home, rather than storing electricity in the battery or feeding power to the grid.

In the daytime, when your PV modules start to work and generate solar power, your system will first focus on meeting the demand of your home appliances. Then any surplus energy will be stored in the battery. When the battery is fully charged or reaches the maximum charge power, any excess energy can be “sold” to the grid. You can also set a power export limit, as required by your grid operator, to control exactly how much of your excess energy is fed back into the grid. The catch here is that not all places allow you to feed power to the grid, so you always need to check your local regulations.

After the sun sets, your battery – which was fully charged during the day – will begin discharging to support the energy needs of your home. When your battery starts running low, the grid will kick in to supply your demand. But note that in this mode, your battery cannot be charged from the grid at night – you will need to wait until your PV modules start working again the next day to recharge it.

The rule of thumb is that in Self-Consumption Mode, the system always tries to use solar power first, minimizing your reliance on grid power.

Economic Mode – also called Time of Use (TOU) mode – allows you to squeeze the most benefit from peak-valley electricity price schemes.

With Economic Mode, you can decide how much grid power you want to use during peak hours, off-peak hours, and partial-peak hours, controlling when your battery charges and discharges. You can also set specific time periods for using grid or solar power based on the days and seasons to form your own power usage scheme.

In practice, this means that, if solar power is unavailable, you can switch to battery power during peak hours when electricity prices are high. You can also sell any surplus power to the grid to get more compensation.

During off-peak hours (mainly at night when PV stops working), your battery will then start to charge using lower-priced power from the grid. The caveat is that some countries, like the United States, forbid using grid power to charge batteries, so make sure you check local regulations.

As you can see from the diagram, your battery’s state of charge (SOC) fluctuates throughout the day; you’ll use battery power during peak hours and charge the battery during off-peak hours.

Let’s look at a real-life scenario to see how exactly this mode works. Let’s say peak hours are from 8 am to 9 pm, and off-peak hours are from 9 pm to 8 am.

Backup Mode
This mode is used in areas that experience frequent power outages. It works in a similar way to Self-Consumption Mode. The only difference is that you need to set a backup power SOC (state of charge) – a limit on how much your battery is allowed to discharge before switching to other power sources. This makes sure the battery does not run out of power and you always have a backup to rely on.

For example, if you set the SOC to be 70%, your battery will not discharge below this limit, ensuring you have the power required to supply critical loads in case of power outages.