What is a hybrid inverter?
A hybrid inverter is an all-in-one unit that combines both a solar inverter and a battery inverter. This enables the preservation of surplus solar power in a battery setup for individual utilization.
Hybrid inverters function like typical grid-tie solar inverters but can operate in various modes depending on the application. One of these modes is battery backup mode, which provides limited backup power during a blackout.
Hybrid inverters can operate without a battery. They function similarly to a grid-tie solar inverter. They send any excess solar energy to the grid.
Hybrid inverters are a cost-effective and easy-to-install option for combining solar and battery storage. They are easier and less expensive than off-grid inverter systems because they have all the needed features in one unit. However, experts do not usually recommend them for permanent off-grid installations because of some limitations.
Do hybrid inverters cost more than regular solar inverters?
Hybrid inverters cost more than regular solar inverters because they are more complex and have additional parts. For instance, a typical 5kW solar inverter is priced approximately at $1200, whereas a 5kW hybrid inverter has a price tag nearer to $1500. Standard 5kW off-grid inverters, on the other hand, cost around $2500.
Many households may need to change or upgrade their switchboards to have backup power. This can increase the overall installation cost.
Hybrid inverters carry a higher price tag than standard solar inverters. However, they offer greater cost efficiency and are easier to install compared to independent off-grid inverters.
Understanding the Functioning of Hybrid Inverters
Hybrid inverters are advanced devices. They operate in different modes. The modes depend on how much power the household is using. They also assess the need for backup power.
Hybrid inverters work like regular solar inverters by converting solar panel DC power into AC power for your home.
The system subsequently uses any excess solar energy to charge a linked battery. Hybrid inverters require an external energy meter. This meter, also called a CT meter, measures the amount of power used by the household.
This meter indicates when there is surplus power available for charging the battery. It also gives information on the amount of power being consumed. The inverter can then utilize the battery to power household items as needed.
Most hybrid inverters can function in four primary modes when configured.
- Grid-tie mode: Functions like a standard solar inverter when connected to the grid (no battery).
- Combined Mode: Accumulates surplus solar power throughout the day for utilization in the evening, enhancing self-reliance.
- Standby Mode: Functions as a regular solar inverter when the grid is operational and seamlessly transitions to emergency power mode during a grid failure.
- Independent operation: Functions like an off-grid converter, utilizing surplus solar power to charge the battery and energize loads in the absence of a grid connection.
Just a handful of hybrid inverters are engineered for off-grid solar systems and possess capabilities to initiate and operate a backup power supply, like a generator when necessary.
Hybrid inverters are a good option for homes that want to use solar power and batteries to be more self-sufficient. They allow you to stay connected to the grid while also avoiding frequent power outages. For a side-by-side evaluation of hybrid inverters and battery storage systems, consult our comprehensive comparison charts for hybrids and batteries.
Three primary categories of hybrid inverters
- Standard hybrid inverter for solar energy storage
- Combined inverter for storing solar power and providing emergency backup energy
- Energy Storage Systems for Batteries (ESSB)
Some hybrid inverters do not come with backup power capability as standard and may require additional optional backup boxes and equipment to provide backup power during a blackout.
Energy Storage Systems for Batteries (ESSB) are essentially hybrid inverters with an integrated lithium battery in one complete package, typically about the size of a refrigerator. However, like many appliances, different features and functions make the various BESS systems on the market unique.
Emergency Power Source
For a hybrid inverter to serve as an emergency power source, it needs to possess the ability to disconnect from the grid during a power outage and utilize battery power to maintain crucial household circuits. Most modern hybrid inverters include a ‘grid isolation’ feature built-in, but some models do not. These models cannot operate in backup or off-grid mode without an additional backup box or emergency power supply (EPS) to enable this functionality. If there are no worries about grid stability, these basic hybrid inverters can be a budget-friendly option.
Advanced hybrid inverters can work in backup mode indefinitely and even run completely off-grid if the electrical needs are manageable and there is enough sunlight year-round. However, for off-grid solar systems that need to power an entire house, it’s recommended to use dedicated off-grid inverters and high-capacity batteries. These systems are designed to handle the high continuous and surge power ratings required for running a whole house completely off-grid.
Critical circuits are essential power circuits that can be easily supported during a power outage, including lighting, cooling units, TVs, and computers. To support an entire house, a more powerful AC or DC-linked multi-mode inverter or a dedicated off-grid system is usually required.
Off-grid vs. Hybrid Inverters
Most modern off-grid inverters, also known as multi-mode inverters, are highly advanced and powerful. They can operate with or without a grid AC connection and provide instantaneous backup in case of a blackout. These inverters are capable of backing up large loads such as air conditioners, pumps, and heaters. Many advanced multi-mode off-grid inverters have high pass-through power capacity, meaning there’s no need to separate critical and non-critical loads.
Hybrid inverters, on the other hand, are designed primarily for grid-tied systems with battery backup capabilities. They can operate in multiple modes, including grid-tie mode, hybrid mode for storing excess solar energy, and backup mode during grid outages. Hybrid inverters are more suitable for households that want to maximize self-consumption of solar energy and have backup power capability but do not necessarily need to operate completely off-grid.
Off-grid inverters are more suitable for applications where complete independence from the grid is required, and they offer robust backup capabilities for larger household loads. Hybrid inverters are ideal for grid-tied systems with the flexibility of battery storage and backup power, but they may not provide the same level of independence and backup power capability as dedicated off-grid inverters.