e.systeme21 GmbH

Your personal photovoltaic system is the heart of your sustainable and ecological energy supply within your own four walls and the first step towards independence. You produce and consume your own electricity. The sun provides this electricity free of charge. Increases in electricity costs are then a thing of the past. In addition, a solar system is a personal financial investment. Not only do you save money, you also earn money by feeding the electricity you don't need into the grid.

With your photovoltaic system, you produce electricity when the sun is shining. However, you are rarely at home when the sun is shining. Wouldn't it be nice to use the electricity you produce yourself in the evening? This is exactly where battery storage systems come in: Electricity storage systems store your unused electricity so that you can use it when you need it. Even a power outage won't be a problem in the future, because we have the right storage system for you. Whether you invest in a storage system directly together with the photovoltaic system or afterwards - we are guaranteed to select the right one for you based on your electricity requirements, your photovoltaic system and your needs.

Electric cars are part of the energy transition. In future, you will be able to charge your car with electricity that is available via your charging station. With your own wallbox, you can charge your car not only safely and conveniently, but also much faster than at a socket - without taking up too much space! Whether on a parking space with a stand or hanging on the wall in the garage: there are a variety of installation options for every space requirement. Contactless identification using an RFID card ensures that only you can charge your electric vehicle at the charging station. Access is also possible with a key via the key switch. It is particularly advantageous to integrate the charging station into your photovoltaic system. The wallbox is used to charge your car battery with solar power. This allows you to drive with 100% green electricity and completely CO2-free. From individual solutions in your own garage to shared charging infrastructure with several charging points. With our all-round service, we offer you a wide range of services: Planning - installation - commissioning - maintenance - billing - operation.

In future, the entire energy supply will be electricity-based. The photovoltaic system will not only be used for normal power supply, but also to support your heating system. The air conditioning system will also be supplied by your PV system. Various heating systems such as heat pumps, heating rods or infrared heating are common forms of electric heating. The photovoltaic system is the ideal energy supplier for your heat supply. In the future, your electricity can even be converted into hydrogen and stored for the long term so that it can be used for heating purposes at any time. Save on expensive heating costs with green electricity! We will find the best solution for you to make even better use of your own energy.

Since the beginning of May 2023, e.systeme21 has been installing a large-scale PV power plant with a total output of 4.7 MWp on the hall roofs of the Ladenburger company in Bopfingen.

The entire installation will cover three large roofs with trapezoidal sheet metal roofing and one large flat roof. With a number of 11,191 modules and a total area of over 22,500 m², this will be one of the largest PV roof systems whose solar power is primarily used in a company. Based on the annual and daily electricity requirements, the experts at e.systeme21 have developed a system concept that is ideally suited to the company.

The number of high-performance inverters has been set in relation to the total number of solar modules in such a way that solar power is produced even in very weak daylight. Even when the sun is high in the sky in summer, only the maximum amount of solar power required by the company is produced. The PV system therefore follows the electricity demand as it is needed in the company during the day. This PV system therefore achieves the greatest efficiency, both energetically and commercially. This requirement is demanding in itself. However, before the initial commissioning, the responsible grid operator, Netze-BW (ODR), only allowed a feed-in power of 30 kW into its medium-voltage grid, to which Ladenburger is connected, despite the high production output of 4.7 MWp. In fact, this is a so-called zero feed-in!

However, the ODR only allows the connection with the full feed-in power if it can be proven that the feed-in power will be reduced to the permitted value of 30 kW within a period of 800 ms (800 milliseconds = 0.8 seconds!). To this end, e.systeme21 will establish a certified process that safely enables precisely this curtailment. In addition, a redundant safety shutdown will be provided to stop the feed-in in the event of a possible failure of the curtailment.

As these processes have to be verified in conjunction with a Class A system certification in accordance with the VDE-AR-4110 application rule, e.systeme21 immediately commissioned an accredited company to carry out the work when the order was placed, having already worked with them successfully and in a spirit of trust on previous projects. As the direct current cables of the PV system components are routed to two central collection points, steel crossbeams were installed between the relevant halls to support the cable trays for these cables. The cables are laid separately for positive and negative polarity in these cable trays and in the cable ducts on the traverses. This virtually eliminates the risk of fire due to possible short circuits between the cables.

The particularly long DC cables have a cross-section of 10 mm² instead of the usual 6 mm². This reduces losses on the lines by 40%. As a result, around 120 km of DC cables with a cross-section of 10 mm² are being laid in this project. All module strings have a length of 19 modules. This eliminates the possibility of confusing different string lengths and the DIN measurements immediately reveal any deviating string lengths.

In addition to these purely electrotechnical requirements, extensive safety aspects in general and as a wood processing company in particular also had to be observed. For example, fire compartments must be observed. Hence the wide strips between the PV modules and the hall sections, as can be seen on the already completed partial systems on Hall A. The partial systems must also not exceed certain contiguous total areas in order to prevent the risk of fire spreading.

In addition, esysteme21 has appointed its own health and safety coordinator (SiGeKo) who, in consultation with Ladenburger's safety specialist, constantly coordinates the work on the construction sites with regard to hazards for the fitters and Ladenburger employees, so that accidents are prevented and personal injury is avoided.

The safety of the firefighters was also taken into account. The cables above the trusses are routed through fire department control boxes. These can be switched off either centrally from the fire alarm control panel or decentrally at each relevant traverse. This allows the emergency services to carry out their extinguishing operations safely. It is even possible to safely tear down traverses if this is necessary for the success of the extinguishing operation.

When solar companies want to show their customers what is technically possible, they sometimes come up with extremely innovative solutions. One such example is the commercial property of e.systeme21 GmbH: with the help of photovoltaics, hydrogen and battery storage, it is completely energy self-sufficient. The company is now also offering this option to industrial and commercial customers.

Since 2013, e.systeme21 has been planning, installing and maintaining photovoltaic systems of all sizes. The range of services is rounded off by energy efficiency measures for commercial customers as well as hydrogen generation and storage. The company with 20 employees from Ulm initially expanded its existing building with 360 square meters of office space and 300 square meters of storage space and renovated it to make it more energy-efficient. In addition, the parking areas and the rest of the site were cleared of asphalt and unsealed as a climate adaptation measure and then paved with new, water-permeable paving.

The new energy solution includes an 80 kilowatt photovoltaic system on the roof and on the façade and a battery storage unit with 80 kilowatt hours. The battery serves as a short-term storage unit, which can be used to cover demand in summer, and it stabilizes the power for the electrolyser. This is because the electricity generation supplies an electrolysis plant with an initial output of ten kilowatts, which produces hydrogen, then compresses it and uses it to fill hydrogen tanks.

The hydrogen can then be converted back into electricity using a fuel cell over the winter or during periods of low solar radiation. The waste heat from the fuel cell and electrolysis supports the heating and hot water supply.

Heating is otherwise provided by a heat pump and a new type of hydrogen dark radiator. These radiators are used in the warehouse and emit a large proportion of the heating energy in the form of radiant heat, similar to infrared radiators. Energy self-sufficiency also includes mobility. Employees can charge their electric vehicles directly with self-generated renewable electricity at three charging stations.