Energy storage as an independence solution

The use of an energy storage system as an independence solution

Types of battery storage and their characterization

There are the following storage systems available on the market, like primarily Li-ion batteries and lead batteries. In addition, there are other types of storage, such as salt water batteries or redox flow batteries that are offered.

A storage battery is basically characterized by the following parameters:

  • Nominal capacity (kWh): The nominal capacity expresses the maximum amount of energy that is theoretically stored in the battery. It does not correspond to usable capacity.
  • Usable capacity (kWh): The usable capacity is the capacity actually available during operation, taking into account the depth of discharge.
  • Efficiency: The efficiency is the ratio of withdrawn to supplied energy.
  • Service life, number of full cycles: The number of full cycles indicates the number of possible loading and unloading of the storage tank up to a defined loss of useful capacity (usually 20% to 30%). The service life of a memory is determined by its number of full cycles.
  • Depth of discharge: The depth of discharge of a storage system indicates how much the storage system can be discharged without reducing the service life of the battery.

The number of full cycles, efficiency and depth of discharge can vary with different cell types and the same nominal capacities. The storage price per kilowatt hour takes these differences into account and thus makes the systems easier to compare. There are currently over 320 systems on the market from a total of approx. 30 manufacturers in the current market overview of the available storage units from C.A.R.M.E.N. e.V. to find.

Link: Market overview of battery storage systems 2019

The design of the PV system with storage

The decision to invest in a PV storage system is largely determined by the profitability of the investment in the storage system and the associated system technology. PV systems are especially economical if they are designed according to consumption.

The profitability results from the savings achieved through the electricity not drawn from the grid. It therefore depends heavily on the development of electricity prices and the remuneration for the electricity fed into the grid. The electrical consumption and the associated load profile are the most important input information for the design of the PV system including storage.

In order to be able to compare the economic efficiency of the storage systems, the investment costs for the storage system and the electricity generation costs (denotes the costs that are necessary for the conversion of energy from another form of energy into electricity) for the electricity generated by the PV system must be added to the Storage price per kWh can be converted.

The degree of self-sufficiency and the proportion of self-consumption

The degree of self-sufficiency and the proportion of self-consumption are important parameters for describing a PV system. The relationship between the degree of self-sufficiency and the proportion of self-consumption is also shown in the tool: PV storage system. The proportion of self-consumption indicates how much of the electricity generated by the PV system is used: the higher the proportion of self-consumption, the less electricity is fed into the grid.

The degree of self-sufficiency, on the other hand, describes how high the proportion of electricity consumption is that is covered by the PV storage system: the higher the degree of self-sufficiency, the less electricity is drawn from the grid.

A pure PV storage system with 100% self-sufficiency for power generation is usually not economical. As a rule, independence from the power grid is only achieved in connection with other system technology, such as a CHP unit. There are also systems on the market that integrate seasonal hydrogen storage together with a fuel cell and an electrolyser into the building's energy supply and thus enable an independent energy supply.

How you benefit

  • You will receive practical advice on system definition
  • An extensive preliminary measurement for system design
  • You do not have to write any funding applications
  • You will receive a grant of up to 40% as investment support

What we offer

  • An extensive analysis
  • Economic efficiency assessment as a basis for decision-making
  • One contact person from system design to installation

Background from the experiences

In all of our projects with an energy storage system, energy costs were reduced by 15 to 60 percent. The savings are based on the use of the storage system, but also on the optimization of the load profile.

With our experience from over 10 years of management consultancy, we advise you competently and in an implementation and solution-oriented manner.

We would be happy to advise you on all your questions about energy storage:

Contact details

Höper Technical Consulting

Kasseler Strasse 91
68305 Mannheim

Owner/ CEO: Dipl. Wirtschaftsing. Hans-Nico Höper

Tel.: +49 174 33 10 438