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Demonstrating reliable energy system options convinces B2B customers

EnBW Contracting

EnBW Contracting plans future-oriented energy supply concepts for the housing industry with Polysun.

When it comes to energy, more and more business customers are turning to an experienced specialist offering a contracting partnership. The reason is obvious: an optimized energy supply concept and the long-term predictability of energy costs are more than ever the decisive keys to success. Because these two factors provide customers with security and thus competitive advantages on the market.

EnBW Contracting GmbH has adopted this approach and is leading the way innovatively. The wholly owned subsidiary of the energy group EnBW Energie Baden-Württemberg AG (EnBW) offers customers reliable solutions tailored to individual project characteristics.

EnBW Contracting focuses on supplying energy to industrial customers, municipalities and the housing industry. Demand-driven energy supply concepts and professional operational management enable this target group to concentrate on its core business.

Olaf Kleineschallau, Team Leader Planning & Realization at EnBW Contracting, and his team are responsible for the planning of these energy concepts, from the initial idea to the comparison of options to the detailed planning of the best solution and the subsequent realization of the plants. In view of the increasing complexity of projects, there was a greater need to supplement the self-programmed design programs, which had been steadily optimized over the years, with a standard software solution. Olaf Kleineschallau explains, “As a supplement, we were looking for a tool that could handle multiple energy technologies and always provide us with the best possible option for the customer.”

After an evaluation phase with various software solutions and extensive tests in real operation, EnBW Contracting decided on Polysun from Vela Solaris.

The solution
For the application field “residential area from 100 residential units” with efficiency standard KfW 55, different supply options with gas, air-to-water and earth-to-water heat pumps as well as solar thermal were defined in the Polysun software. These templates are now used right from the start. As requested, the experts at EnBW Contracting can also use the software from Vela Solaris for the most complex simulations. For example, they use it to design PV in combination with battery storage for own consumption optimization and simulate the combination of different heat generators from different sources – earth, water, sun, air.

The result
EnBW Contracting’s customers have a specific useful energy requirement for which they can obtain combined supply variants in every conceivable form.

“For example, solar energy use in combination with other energy sources,” says Olaf Kleineschallau. “No matter whether it’s a complex interconnection, different energy sources for heat pumps or even solar thermal energy – we can plan what seems conclusive to us and our customers with Polysun.”

“We also very much appreciate the competence of Vela Solaris’ technical support, which is always available to us very quickly. This allows us to continue working quickly,” adds team leader Olaf Kleineschallau.

Key points

At a glance

  • Customer: EnBW Contracting GmbH
  • Sector: Energy supply contracting in the form of the provision or supply of heat, steam, cooling, compressed air, electricity from CHP and the operation of the associated facilities, with particular emphasis on renewable energies
  • Location: Stuttgart


  • Increasing need to supplement the self-programmed design programs, which have been continuously optimized over the years, with a standard software solution.
  • It must be possible to map all technologies, especially the combination of different energy technologies.
  • It must be possible to show the best possible option transparently.


  • Polysun Designer
  • Service Vela Solaris: Creation of standardized energy system templates for use in Polysun.


  • Special use cases of different energy sources for heat pumps and use of solar thermal energy can be solved with Polysun.
  • The reliability of the calculated options is guaranteed
  • EnBW Contracting convinces its customers by showing valid simulated options and a supported recommendation for the best option.

Contact us to learn more about what our software Polysun and our simulation experts can do for you!

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