A photovoltaic system for the garden enables electricity supply – even if there is no connection to the power grid. In gardens with a power grid connection, electricity costs can be reduced thanks to a PV system. The PV system can, for example, be mounted on the roof of a garden shed or a lawn.
A garden is mostly used when a particularly large amount of solar power can be generated: in the spring and summer months and on sunny days. This is one of the reasons why more and more garden owners are choosing to install a photovoltaic system in their gardens. Depending on the size of the system, solar power can be used to operate individual lighting elements, pond pumps, and larger electrical devices.
This article presents the advantages of solar systems for the garden and important information for planning and selecting a suitable photovoltaic system.
Solar systems for the garden have these advantages
The solar systems that come into question for gardens are divided into photovoltaic systems – these generate solar power – and solar thermal systems that are used to generate heat.
If a garden is not connected to the public power grid or is not supplied with hot water, a solar system can use electricity or hot water. In particular, small solar systems for allotment gardens are very easy to install and put into operation.
Due to the long service life of solar systems, cheaper solar power can sometimes be generated for the garden or heated drinking or pool water – or even to operate a heater in the garden house for decades.
Both solar thermal and photovoltaic systems can be used effectively in the garden since a garden is typically used when the solar power yield is greatest. Solar systems set up in gardens are usually used exclusively for self-consumption.
Why it makes so much sense to use solar power in the garden
Electrical devices should be operated not only in residential buildings but also in most gardens. If you set up a photovoltaic system in the garden, you have a 230 V power source suitable for typical household electrical appliances. These include, among other things:
- Kitchen appliances such as coffee machines, kettles, etc.
- large electrical appliances such as refrigerators, televisions, or lawnmowers
- Lighting (e.g., fairy lights)
- Charging stations for batteries, such as for electric garden tools or e-bikes
- Permanently operated devices such as pond pumps
Photovoltaic systems for the garden are usually designed as off grid solar systems. This means that they work completely independently of the power grid.
Photovoltaic systems do not have to be cleaned often, are also low-maintenance, and work reliably over long periods – for example, even when the garden is not used during the winter months. During these times, the solar power generated in the garden can also be used to operate an alarm system. Since many burglaries naturally occur at night, a power storage unit is strongly recommended, which supplies the solar power generated during the day to the alarm system at night.
How are photovoltaic systems set up in the garden?
There are different ways to set up photovoltaic systems in the garden. Typically, the solar modules are permanently installed, for example, as a photovoltaic system on a garden shed or a tool shed. The roof of a carport in the garden is also an option for installation. In fact, portable solar panels for camping can also be used for garden solar systems.
However, there is also the option of attaching solar modules to a facade, for example, to the wall of a garden shed.
In addition, a photovoltaic system can be set up free-standing in the garden. For this purpose, special elevations are placed on a terrace or lawn on which the solar modules are mounted. Free-standing solar modules have the advantage that they can be optimally aligned so that the system generates the greatest possible yield at the specific location.
However, it should be noted that solar modules placed on the ground are more likely to be exposed to shading than solar panels on a roof. In addition, the solar modules reduce the area that can be used for gardening. However, they also offer the opportunity to grow plants that do not tolerate direct sunlight.
Finally, there are also portable solar generators for the garden. If the demand for solar power in the garden is quite low, such mobile PV systems are a conceivable option. In this case, the solar modules are hung on a wall, for example, or rolled out on the ground in the sun.
How big should a photovoltaic system be for the garden?
In principle, a photovoltaic system for the garden should always be dimensioned so that it works as much as possible to cover needs. Then the efficiency is greatest.
If a radio, small lighting elements, or a small pond pump are only to be operated from time to time, or if batteries for garden tools are to be charged during longer absences, then the corresponding power requirement can be covered with a small garden photovoltaic system, which has a power output of significantly less than 1,000 W.
On the other hand, if powerful electrical devices such as a refrigerator or even a lawnmower are to be operated, the system must be larger. This applies in particular when the power requirement cannot be covered step by step over a long period – as is the case with rechargeable batteries that are to be charged – but a large amount of power is required in a relatively short time.
To determine the system size or output, the power requirements of all devices to be operated must be added up and then generously rounded up so that the requirements can also be covered on cloudy days. On the other hand, it is advisable to rely on energy-saving devices for consumers, such as small 12-V cooling devices, such as those available in camping supplies. In this case, however, a transformer is still required.
Important: If very powerful devices are to be operated, it is worth taking a critical look at the inverter of a PV system. This component must also be suitable for the desired overall performance.
Last but not least, the size of the photovoltaic system in a garden is also limited by the available area. The roofs of gazebos and sheds often do not offer much space. However, a solar system on the roof can be supplemented by free-standing panels on the lawn.
Important information for setting up a photovoltaic system in the garden
The yield of a photovoltaic system depends on the solar radiation at the location. In principle, the yield from systems in southern Germany is slightly higher than those in northern Germany. The orientation of a photovoltaic system also affects its yield. If you set up a photovoltaic system in the garden, you should choose the placement and orientation so that the sun’s rays hit the solar modules almost vertically for as long as possible during the day.
Especially with solar systems in the garden, trees, and shrubs can provide shading. When planning, it is therefore important to ensure that the solar modules are not placed under trees. In the case of permanently installed systems, not under young trees that will grow in the future.
During the summer months, the yield of a garden PV system is higher than in winter. Little or no solar power is produced in the evening and at night. Here, a power storage system can be worthwhile as a supplement to the PV system. It stores excess solar power that can be released and used at different times. However, in the rarest of cases, home storage is worthwhile. Operators of garden photovoltaic systems usually rely on simple car batteries.
Important: Note restrictions and registration
A photovoltaic system for the garden is usually so small that no building permit is required.
Completely independent of this. However, there is an obligation to register the system just like a balcony power plant if it feeds electricity into the grid. The registration must be made via the market master data register and must take place within one month after commissioning. In some municipalities, the land use plan must also show a garden photovoltaic system. Further information is available from the respective municipality.
Finally, it should be noted that some garden colonies restrict photovoltaic systems for horticultural aesthetic reasons. It is advisable to ask the management of the respective colony before installing a photovoltaic system in the garden.