Technological advances and cost reductions
In recent years, solar energy has established itself as a reliable and accessible solution, even becoming a must-have for people living off-grid. Thanks to technological advancements and falling costs for critical components, such as solar panels, batteries, MPPT controllers, and inverters, investing in a solar system has never been more affordable.
However, many users continue to base their choices on outdated advice or equipment, often influenced by preconceived ideas or ill-informed recommendations. The DIY neighbor, Facebook groups, or even the local battery seller can sometimes be misleading, which can lead to inefficient and expensive installations. After personally making some of these mistakes, here we share our experience to help you make informed choices.
The 48 V, an informed and economical choice
If you are planning a solar installation in 2025, opting for a 48V system is now the best decision, both technically and economically.
Indeed, 48V (rated 51.2V) is no longer strictly reserved for the residential market for various reasons.
The essential role of the inverter in your solar system
The inverter is at the heart of any solar system. Its main function is to convert the energy produced by the solar panels (direct current, DC – Direct Current) into alternating current (AC – Alternative Current), compatible with household electrical appliances. This conversion is not trivial: it largely determines the energy efficiency of your system.
A good modern inverter today offers optimized performance with minimal losses, which was not the case even ten years ago. I invite you to consult specialized sources, to better understand its technical functioning. Also, don’t confuse off-grid inverter, microgrid inverter, and hybrid inverter. The Gospower company has written an interesting article on this subject that we invite you to consult: The difference between on-grid inverters and off-grid inverters.
The 12 V, an outdated choice
In the 2000s, almost all solar systems were based on 12 V. Various factors explained this choice.
- Equipment availability: 12V inverters and batteries were widely used and were often the only affordable choice
- Cost of copper cables: The cables needed to carry 12V current were inexpensive
- Simplicity of systems: 12V installations were easy to understand and put less pressure on limited budgets
- Limited efficiency of UPSs: UPS consumed a lot of energy, sometimes forcing users to invest in devices that operated directly on 12V to reduce energy losses
However, 12V systems had significant limitations. Their low voltage resulted in a high current, which required thicker and more expensive cables. They also lacked flexibility for scalable systems to meet the growing needs of users over time.
The decisive advantages of 48V in 2025
With the technological advancements and the falling cost of the essential components we discussed earlier, 48V is now a much smarter choice than 12V for solar installations.
- Reduced cable costs : Higher voltage means lower current for the same power. This allows for thinner and less expensive cables to be used, while minimizing energy losses due to the Joule effect.
- Increased system efficiency : Modern 48 V inverters offer excellent efficiency, even in continuous operation. Unlike older generations, these devices keep conversion losses at negligible levels.
- Simplicity and standardization : With a 48 V system, there is no longer a need for two separate circuits (DC and AC). The inverters can operate 24/7, making installations comparable to those of grid-connected homes.
- Scalability : 48V systems are designed to withstand easy expansion. Whether you want to add solar panels or increase your storage capacity, the existing infrastructure adapts without major changes.
- Adapted to new technologies : 48 V lithium batteries (rated 51.2 V) have become the standard, with unmatched performance in terms of durability, capacity and cost. A single battery may be enough for a complete system, reducing the footprint and simplifying installation.
One notable exception: the Van Life
For those who adopt a nomadic lifestyle, like the Van Life, 12V systems are still a good choice. Most vehicles operate with this voltage, making it easy to integrate 12V systems for on-board devices and accessories such as LED lights, heating systems, water pumps, refrigerators, or many other devices.
However, even then, a 48V hybrid system can offer benefits for more power-hungry devices, thanks to DC-DC converters like the Victron Orion 12-48.
Why not go beyond 48V?
A question then arises: Why not go for 120 V or more?
Although technically possible, this option remains unviable in 2025 due to the limited availability and high cost of compatible equipment.
This is because 120V or higher systems require more sophisticated inverters and converters, which are often much more expensive than their 48V equivalents. In addition, they place high demands on safety, as increased voltage increases the risk of electric shocks and makes installation more complex.
In addition, 120 V equipment is often designed for fixed residential environments, which makes it less suitable for the specific needs of stand-alone solar systems. For example, the standby or low-load power consumption of 120V devices is generally higher than that of low-voltage equipment, which reduces overall energy efficiency, especially in contexts where energy must be used optimally, such as off-grid.
Today, 48 V is an ideal alternative: it offers enough voltage to power energy-hungry devices, while maintaining reasonable currents, which reduces energy losses and cable costs. This voltage has also become a standard in modern lithium batteries, simplifying the integration and maintenance of systems.
In summary, while 120V or higher systems are possible, their cost, complexity, and lack of adaptability make them a less relevant solution for mobile or off-grid applications in 2025. The 48 V is the most balanced choice, combining performance, safety and cost-effectiveness.
In conclusion
Switching to a 48V solar system is a smart move in 2025, both to maximize energy efficiency and reduce installation costs.
This configuration offers exceptional flexibility and adapts to the growing needs of users, while greatly simplifying system design and maintenance.
Don’t let outdated ideas or uninformed advice influence your choices. Educate yourself, compare options, and call on enlightened professionals to design a solar system adapted to your current and future needs.
By choosing a 48 V configuration, you are relying on modern, proven and scalable technology that perfectly meets the requirements of off-grid systems. This choice not only ensures optimal performance but also peace of mind, knowing that your installation will be durable, reliable and ready to integrate the technological advances of tomorrow.
