The highly anticipated and award-winning Fronius Gen 24 is finally available on the French market. The Fronius Gen 24 is essentially a new battery-ready inverter or hybrid inverter. Fronius provided me with a preliminary model of the Gen24 which I tested for several months. In this article, I will first introduce the features of the Fronius Gen24 and explain how it manages to accomplish what many hybrid inverters cannot. Next, I'll reveal what really sets the Fronius Gen24 apart: its build quality. Keep reading or watch my summary in the video below.

WHAT CRITERIA TO CONSIDER FOR A HYBRID INVERTER AND BATTERY ?

It is essential to note that not all hybrid units are designed the same. Here are some key things to look at:

• Battery-Free Backup Option: Ideal if you plan to go solar now and add a battery later.
• Solidity and guarantee of the brand (a guarantee is only useful if the brand is reputable).
• Interoperability between different brands.
• Battery capacity. Do you have enough storage to last overnight?
• Excess solar production. There is no point having a large capacity battery if your solar production is not enough to fill it.
• Transition duration. How quickly does it change from grid-connected mode to outage mode?
• Operation in the event of a breakdown. How do the inverter and battery react during a power interruption?
• AC integration. The ability to use your existing solar installation to power your new battery. But before we dive into the details of batteries, let's explore the systems that work without them.

BACKUP WITHOUT BATTERY: THE PV POINT OF THE GEN24:

BATTERY-FREE EMERGENCY SOLUTION – GEN 24 POINT HP FUNCTION

With the Gen24 model from Fronius, you can benefit from a power supply even in the event of a breakdown, without the need for a battery. Fronius aptly named this feature “Solar Point”. I prefer to call it “Battery-Free Backup”.

However, the PV POINT function has its limitations. It only works when the sun is present and cannot power your entire home. Thus, a dedicated socket is installed either near the inverter or in your home, which is only activated in the event of a breakdown. If such a situation arises, an extension cord will be necessary to plug in your fridge.

The PV POINT function has a maximum capacity of 3000w. If your solar installations generate at least this power, you could easily power a fridge, a freezer, recharge a mobile, use a PC and there would still be margin. It would even be possible to use an electric frying pan, a toaster or a kettle, but not at the same time.

Some see PV POINT as a simple gimmick. In my opinion, this is an interesting development. It offers a partial solution to outages without having to invest massively in a battery. It is this feature of the Fronius Gen24 that appeals to me the most. It offers a cost-effective backup solution now, while being ideally suited for adding a battery in the future.

WHAT IS “BATTERY READY”?

The term “battery ready” is often misused. Although it is possible to connect a Tesla Powerwall to any inverter, this does not mean that the inverter in question is "battery ready." This term should be reserved for DC-coupled battery inverters. What is the difference ? Check out my article on the differences between AC and DC coupled solar batteries. The Fronius Gen24 is a true “battery ready” inverter, perfectly suited for a BYD battery.

WHO IS BYD?

Build Your Dreams. This is not a joke, this is the meaning of BYD.

You would think that BYD owns the bustling city of Shenzhen. The electric buses and taxis that dominate the roads are all BYD vehicles. Everywhere, billboards and buildings display this hopeful acronym. Then there is Mr. Warren Buffet, the most successful investor of the 20th century. In 2008, Buffet invested heavily in BYD by acquiring 24,6% of this company specializing in batteries and electric vehicles. Today, BYD is the world's largest electric vehicle manufacturer.

BYD is a massive company, with remarkable battery expertise and backed by Mr. Buffet. But what about the BYD & Fronius combination?

FRONIUS AND THE BYD SOLAR BATTERY

In an ideal world, I would have a Fronius battery coupled with a Fronius inverter. If a problem arises, it would clearly be attributable to Fronius. However, Fronius chose to no longer produce its own battery and instead partner with BYD. Therefore, in the event of a failure, whose fault is it?

The combination of solar batteries and inverters from different brands has always been a thorny subject in the sector. This is a problem that Fronius has seriously studied. However, in order to make the battery more affordable, Fronius decided not to put its brand on a third-party battery. They preferred to partner with a recognized battery manufacturer and opted for BYD.

I'm not particularly a fan of this brand combination. However, I'm pretty confident that I won't find myself in the middle of a dispute if there are warranty issues. Let's look at the technical details to determine if it's worth the effort.

THE ASSOCIATION OF FRONIUS WITH THE BYD SOLAR BATTERY

Ideally, I would have liked a combination of a battery and an inverter both from Fronius. So, in the event of a problem, the responsibility would clearly lie with Fronius. However, Fronius made the decision to set aside its own battery to collaborate with BYD. So, in the event of an anomaly, who is responsible?

The harmonization between solar batteries and inverters of different brands has always raised questions in the industry. Fronius is well aware of this. However, in order to offer a more economical solution, Fronius has abandoned the idea of ​​directly associating its name with a battery. Instead, they looked for a strong partnership with a renowned battery manufacturer, and their choice fell on BYD.

This mix of brands leaves me perplexed. However, I'm hopeful that I won't get caught in a whirlwind of accusations if there are any warranty issues. Let's dissect the technical aspects to see if this association is worth the detour.

BYD BATTERY WARRANTY :

BYD HV batteries come with a 10-year warranty or a warranty based on “total energy used”, whichever comes first. This total energy used guarantee does not allow you to complete a full cycle every day for 10 years, but rather about 82% of that capacity. After a decade, the battery will retain approximately 60% of its original capacity. It's a pretty standard warranty for a battery, and the terms and conditions seem pretty reasonable.

BYD BATTERY SIZE OPTIONS :

It's not enough to choose any Fronius Gen24 inverter and any BYD battery and hope they work together. It is essential to take into account your excess solar energy. The pairing guide below shows how long it will take to charge your BYD battery to its maximum charge rate. It is important to note the clear reduction in the charge/discharge rate between a 10kWh battery and one of 11kWh.

SWITCHING TIME OF THE FRONIUS GEN 24 INTO EMERGENCY MODE:

The Fronius GEN24 & BYD solution works during a power outage. This is something to keep in mind if you're considering less expensive battery options. However, in the event of an outage, it is necessary to automatically disconnect your home from the network. (You wouldn't want your battery to power every house in your neighborhood. Likewise, you wouldn't want to endanger the person trying to repair damaged power lines.)

Now let's compare Fronius to Victron. Victron opts for slightly different methods to ensure that you do not endanger the ENEDIS technician upstream:

A Victron Multiplus has a built-in automatic switch (a contactor) to disconnect your home from the network. This means that your home backup circuits are constantly operating via the Victron inverter. During a power outage, Victron's internal contact opens to disconnect your emergency circuits from the network. As soon as it disconnects from the grid, the inverter creates its own grid (using stored energy from your battery) and continues to operate. Failover takes less than 20 milliseconds. This is an imperceptible power interruption to the lights.