With the increasing importance of renewable energies and the growing need for a reliable power supply in remote regions, so-called off-grid photovoltaic systems are enjoying increasing popularity. These systems, also known as island systems, make it possible to generate and use clean and sustainable solar power independently of the public power grid. In this guide, you will learn how off-grid photovoltaic systems work, what advantages they offer and which components are necessary for their operation.
What are off-grid photovoltaic systems?
Off-grid photovoltaic systems are solar power systems that operate independently of the public power grid. In contrast to grid-connected systems (on-grid systems), which feed excess electricity into the public grid and can also draw power from there, off-grid systems are self-sufficient. They supply themselves entirely with energy generated by solar modules and often stored in batteries. This independence makes off-grid systems particularly attractive for remote areas where there is no access to the power grid, such as mountain huts, holiday homes, boats or rural regions.
How off-grid photovoltaic systems work
The main component of an off-grid photovoltaic system is the solar module. This converts sunlight into direct current (DC) using the photovoltaic effect. However, since most household appliances run on alternating current (AC), an inverter is needed to convert the direct current into alternating current.
A key feature of off-grid systems is the storage of the electricity generated. Since sunlight is not continuously available, especially at night or in bad weather, a battery storage system is required to temporarily store the excess energy. This stored energy can then be used when the solar system is not producing any energy or is producing too little energy.
The system is complemented by a charge controller that monitors the battery voltage and ensures that the batteries are not overcharged or deeply discharged, which can significantly extend their lifespan. In addition, the charge controller prevents voltage fluctuations that could damage sensitive equipment.
Advantages of off-grid photovoltaic systems
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Independence from the public power grid: The most obvious advantage of an off-grid system is complete independence from the central power grid. This makes these systems ideal for remote areas where connecting to the public grid is either impossible or expensive.
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Sustainability and environmental friendliness: Off-grid photovoltaic systems use solar energy, a renewable and clean energy source. They do not produce harmful emissions and thus help to reduce the carbon footprint.
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Cost savings in the long term: While the purchase and installation of an off-grid system may initially incur higher costs, in the long term the ongoing electricity costs that would arise if connected to the grid are eliminated. Especially in regions where the grid connection is expensive or unreliable, off-grid systems often pay for themselves within a few years.
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Reliable power supply: In remote areas or in regions that are frequently affected by power outages, off-grid systems offer a reliable source of energy. Even in emergencies or natural disasters, the power supply remains stable, which is particularly beneficial for critical applications such as medical facilities.
Components of an off-grid photovoltaic system
In order to operate an off-grid photovoltaic system efficiently, several essential components are required:
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Solar modules: The solar modules are the heart of the system. They convert sunlight into electrical current. Monocrystalline modules generally offer higher efficiency, while polycrystalline modules are more cost-effective.
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Battery storage: Since the electricity demand does not always match the availability of sun, battery storage is essential. Lithium-ion batteries are the most common choice due to their longevity and efficiency, but lead-acid batteries are still commonly used.
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Inverter: The inverter converts the direct current generated into alternating current, which is needed to run household appliances and electrical systems.
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Charge controller: The charge controller protects the batteries from over- or deep-discharge and regulates the charging process to ensure maximum battery life.
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Generator (optional): In areas with highly variable weather or in high-power applications, a diesel or gasoline generator can be useful as an additional power source to avoid power shortages.
Areas of application
Off-grid photovoltaic systems are an attractive solution, especially in remote areas or areas with poor infrastructure. Typical areas of application are:
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Cabins and holiday homes: In remote holiday homes or mountain huts that are not connected to the public power grid, off-grid systems provide a reliable power supply.
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Agricultural businesses: In remote agricultural businesses, off-grid systems can be used to supply irrigation systems, warehouses or work equipment.
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Boats and mobile homes: Off-grid systems are also ideal on boats or mobile homes for generating independent power on the go.
Conclusion
Off-grid photovoltaic systems offer an environmentally friendly and reliable solution for power supply in remote areas. By using modern technologies such as efficient solar modules, long-lasting battery storage and intelligent charge controllers, these systems can ensure a stable energy supply without the need for a connection to the public power grid. Off-grid systems are an economical and sustainable alternative to conventional power supplies, particularly in rural or remote regions, but also for leisure activities such as camping or boat trips.