Solar systems can be installed not only on house roofs or balconies , but anywhere electricity is needed. This means you can also supply power to your garden shed, even if it has no electrical connection, or equip your tiny house with a solar system. These are known as off-grid systems, which can be installed without a connection to the mains. An off-grid system consists of three to four components, which must be adapted depending on the location and electricity requirements. We will now take a look at what these components are and which ones you should definitely not do without.
The most important element is the solar module [1]. These modules consist of photovoltaic cells that convert sunlight into direct current. The amount of energy generated depends directly on the quality and capacity of the module, as well as the amount of sunlight hitting it. Without the solar module, no solar electricity can be generated.
An often underestimated but crucial component of an off-grid system is the charge controller [2]. This device monitors the battery's state of charge and regulates the charging current from the solar module to the battery. Why is the charge controller so important? Without it, there is a risk of overcharging, which can not only damage the battery but also pose safety risks. An overcharged battery can lose power, become prone to failure, and in the worst case, even be damaged. In addition, the charge controller minimizes the risk of short circuits and overheating, which increases the safety of the entire system.
The battery [3] acts as an energy storage and supplies electricity when the sun is not shining. High-quality batteries are crucial for a reliable power supply. An off-grid system can also work without a battery, but in that case, the electricity cannot be stored and can only be consumed directly. For example, you can run the pond pump in summer when the sun shines during the day. However, if you want to illuminate your garden in the evening or use your garden tools on cloudy days too, you need storage for the solar electricity.
Another component of an off-grid system is the voltage converter [4], also known as an inverter. This converts the direct current stored in the battery into the alternating current required to operate electrical devices. This makes it possible to use the stored energy for various applications. For example, you can connect a string of lights or a garden tool directly there.
Overall, these four components – solar modules, charge controller, battery, and voltage converter – form the heart of an off-grid solar system. Each component serves a specific function, and their cooperation is crucial for the efficiency and longevity of the system. The charge controller plays a key role in particular by protecting the battery and thus ensuring the reliability and safety of the entire off-grid system. Therefore, a charge controller should under no circumstances be omitted if you are aiming for a powerful and sustainable solar solution. The size of the system depends on the consumers that are to be connected to it. The more high-power devices that are to be connected, the larger the solar modules and the battery must be. This ensures that there is always enough electricity available, even when the sun is not shining.
How to determine your consumption
First, determine the expected daily consumption. You can find this out by identifying all the devices you use during the day and the duration of use (hours per day). Add the wattage of the individual devices and multiply the total by the expected operating hours:
Consumption (W+W+W+W...) x Duration (h) = Total (Wh)
Add 10-30% to this total as a power reserve (low sunlight hours, general system loss). Based on this result, the right system for your needs can be selected.
The required watt peak (Wp) of a solar module can be converted into watt-hours (Wh) as follows:
Wp x 4 = Wh/d or Wh/d : 4 = Wp
You calculate the battery capacity as follows:
Daily energy requirement (Wh) x autonomous days x depth of discharge factor + 30% of the power requirement as a reserve
This requires some experience, and our experts are, of course, at your disposal with precise calculations, valuable tips, and guidance for individual advice plus a quote.
