Solar Panels, Inverters and Batteries: How They Fit Together

 

A home solar system can sound complicated at first because there are several different pieces of equipment involved. Solar panels, inverters, batteries, meters and the electricity grid all play different roles.

In practice, the basic process is quite simple.

Solar panels generate electricity, the inverter converts it into electricity your home can use, and a battery can store any suitable excess generation for later. If the system is connected to the grid, your home can also import electricity when needed and export surplus solar energy.

Understanding how these main components work together can make it much easier to compare solar systems and decide what your home actually needs.

 

 

What are the main parts of a home solar system?

Most residential solar systems are built around three main components: solar panels, an inverter and, if required, battery storage.

Solar panels are responsible for generating electricity from sunlight. The inverter makes that electricity usable within the home. A battery adds the ability to store electricity rather than having to use or export it immediately.

Not every solar system needs a battery, but every conventional home solar system needs panels and an inverter.

 

 

What do solar panels actually do?

Solar panels contain photovoltaic cells that convert sunlight into direct current electricity, commonly called DC electricity.

The amount they produce changes throughout the day depending on factors such as sunlight, weather, roof orientation, shading and the size of the solar array.

When conditions are good, the panels may generate more electricity than your home is using at that moment. At other times, such as early morning, evening or overnight, they may produce less than your household needs or none at all.

This changing generation is why the other components of the system are important.

 

 

What does a solar inverter do?

The inverter is one of the most important parts of a solar system.

Solar panels produce DC electricity, but most household appliances use alternating current, or AC electricity. The inverter converts the electricity produced by the panels into a form that can be used around the home.

In simple terms:

Solar panels generate the electricity → the inverter makes it usable → your home consumes it.

The inverter also helps manage how electricity moves through the system.

Depending on the setup, it can help determine whether solar generation is being used by the house, supplied to a battery or exported to the electricity network.

There are different types of solar inverters, and the right option depends on the design of the system. For most homeowners, however, the important thing is not the technical difference between every inverter type, but whether the inverter is suitable for the solar array, battery plans and future energy needs of the property.

 

 

Where does a solar battery fit in?

A solar battery gives you somewhere to store electricity that your panels produce but your home does not need immediately.

Without battery storage, excess electricity from a grid-connected system can generally be exported to the electricity network.

With a suitably configured battery system, some of that electricity can instead be stored and used later.

For example, solar panels may generate strongly around the middle of the day while nobody is home. A battery can store some of that generation so it is available during the evening when household electricity use may be higher.

This does not mean every solar installation needs a battery. Whether battery storage makes sense depends on how and when you use electricity, what you want from the system and your budget.

Our Solar Batteries Explained guide looks at battery storage in more detail.

 

 

How does electricity move through a solar system?

For a typical grid-connected home, electricity moves automatically depending on how much solar power is being generated and how much electricity the house needs.

During the day, solar generation is available to supply the home’s electricity demand.

If the panels are producing more electricity than the house is using, the surplus may charge a battery or be exported to the grid.

If the panels are not producing enough electricity to meet household demand, additional electricity can be supplied from a battery or imported from the grid.

At night, when solar panels are not producing electricity, the home will normally use stored battery energy if available or draw electricity from the grid.

You do not need to manually change between these different sources. The solar system manages the flow of electricity automatically.

 

 

Do you need a battery for solar panels to work?

No, solar panels can work perfectly well as part of a grid-connected system without battery storage.

During daylight hours, the home can use electricity produced by the panels. When more electricity is needed than the panels are producing, the property can continue drawing power from the grid.

Any suitable excess generation can also be exported.

A battery simply changes what the system can do with some of that surplus solar electricity.

This is why it is useful to think about solar panels and battery storage as related, but separate, decisions.

 

 

What happens when your solar panels produce too much electricity?

If the home is using less electricity than the panels are generating, the extra electricity becomes surplus solar generation.

With battery storage, that electricity may be used to charge the battery.

If there is no battery, or the battery has reached its available capacity, surplus electricity may be exported to the grid where the system and connection allow it.

We explain this process in more detail in What Happens to Excess Solar Energy?

 

 

How does the electricity grid fit into the system?

For most New Zealand homes with grid-connected solar, the electricity network remains an important part of the overall setup.

Solar does not mean the property suddenly becomes disconnected from the grid.

Instead, the two work together.

Your home can use solar electricity when it is available and draw electricity from the grid when additional power is required. It can also potentially send excess solar generation back into the network.

This is different from an off-grid solar system, where the property needs to meet its electricity needs without relying on the public network.

We cover those differences separately in our guide to Grid-Tied vs Off-Grid vs Hybrid Solar Systems.

 

 

Why does solar system design matter?

The individual components are important, but they also need to work properly together.

Installing more panels, a larger battery or a higher-capacity inverter does not automatically mean a better solar system.

The right setup depends on things such as your household electricity use, when that electricity is consumed, the available roof space and what you want the system to achieve.

Someone wanting to reduce daytime grid consumption may need a different setup from someone who wants to store more electricity for evening use or improve their level of energy independence.

That is why understanding your household energy use is an important step before deciding on equipment.

 

 

Bringing the solar system together

A home solar system is essentially a group of components working together to generate, convert, manage and potentially store electricity.

The panels capture energy from sunlight. The inverter converts that energy into usable household electricity. A battery can store electricity for later, while the grid can provide additional power when required and receive suitable excess generation.

The best combination depends on the property and the people using it.

Current Generation can assess your electricity use, property and goals to help determine what type of solar setup is appropriate for your home. Get in touch with us today for a free quote.