Custom-made Energy Storage


Enabling a company's energy transition by combining façade-integrated photovoltaics with a VARTA battery storage

Project Facts


Project Volume
100.000-500.000 EUR

Applied Financing Solutions
Private Equity

Project Dates
Start: 2018
In operation since/from: 2018

The Story

In a metal-processing company such as Mayer, it is natural that high levels of power will be consumed. For environmental protection reasons and in order to cut costs, the company’s management is making great effort to supply the production processes with renewable energy as far as possible. When the site was due for expansion in 2018 with a new administrative building, a new concept was thus implemented which combines a photovoltaic installation integrated into the façade with a VARTA lithium ion energy storage system.

The building-integrated photovoltaic installation has an output of 90.3 kWp and achieves an average annual yield of around 810 kWh/kWp. By contrast, anticipated consumption of electric energy is around 460,000 kWh. The newly installed lithium-ion storage facility, VARTA flex storage 36/75, has a charging and discharging output of 36 kW and a useful capacity of 75 kWh.

On average, this combination of PV installation and storage facility produces one kilowatt hour of electricity for 12 cents. The Mayer company thus not only has become more independent from future electricity price increases; it also expects revenues of around 396,000 euros within 25 years and a return on investment in approximately 13 years.

Success Factor | Hero Moment

The core of the applied concept is a modern energy storage facility on a lithium-ion basis, which significantly increases local energy value and in so doing enables the machine manufacturing company to operate efficiently. Since the output and capacity of the modular system can be cascaded, the system could be tailored to fit local conditions. VARTA was responsible for simulating and designing the combined storage system.

VARTA Storage GmbH, Germany

Other Involved Stakeholders
Mayer Group, WALTER konzept

Contact Mail


Photovoltaics, Energy Storage

Terminated Emissions
59 tons CO2e per year

Comparable to the annual CO2 absorption of
472 trees

Hard Facts
73 MWh annual energy savings per year
€ 16.000 Annual cost savings per year