PV plant repowering made easy with Sunny Design

In wenigen Klicks zu höheren Erträgen – Anlagenmodernisierung mit SunnyDesign

Improved performance, better availability of spare parts and use of the latest technologies as well as analysis and monitoring tools: There are many arguments in favor of modernizing existing PV power plants. However, the complexity of such a project scares many system operators off, but a repowering project does not have to be labor-intensive. The Sunny Design web portal provides an easy way to create a modernization plan for your own PV power plant in just a few clicks.

Ready for the future: repowering brings PV systems up to date with the latest technology

PV power plants that were installed during the solar boom just after the turn of the millennium are gradually getting rather long in the tooth. Their output is decreasing, warranties are expiring and spare parts from manufacturers that have fallen victim to market consolidation are no longer available. Older devices and modules no longer satisfy the demands of future-proof energy generation due to rapid advances in technology. An even more important point is that as output wanes, operating costs rise. This natural aging process poses an existential question for power plant operators: dismantle and build anew or refurbish? The most economical solution is repowering, which involves replacing old modules and/or inverters with modern, efficient devices that represent the state of the art. Modernizing in this way can improve the performance of a PV power plant considerably, extend its service life, increase efficiency and availability, reduce operating costs and boost yield. During a repowering project is also an ideal time to incorporate battery-storage systems, for example.

What is more, a modernized PV power plant also opens up new income opportunities through the provision of grid management services, for example. And last but not least, the operators benefit from a renewed limited factory warranty.

Repowering enables PV power plants to deliver better performance once more and reduces operating costs.

Despite these benefits, many shy away from the effort involved in a repowering project. This is mainly because they fear that replacing components is too complicated. But the Sunny Design Web portal provides a simple way to obtain an overview of the options for repowering, free of charge.

SMA Repowering for large scale PV power plants

Sunny Design: generate a repowering plan at the touch of a button

Repowering projects can actually prove time-consuming if you have to consider whether each individual component is to be replaced. The Sunny Design Web portal simplifies this process considerably and, after just a few keystrokes, provides a repowering design that can be implemented immediately.

1. To achieve this, operators create a digital twin of their existing PV power plant. Based on the system data entered, the online tool identifies the best inverter for that specific power plant configuration. In the course of this process, users can choose between automatic and manual design. With a manual design, users choose between various SMA inverters based on maximum efficiency. In the case of an automatic design, the portal suggests three options.

Particularly important for older PV power plants: if the box next to “Consider only current PV modules” is unchecked, a large number of older modules will also be available to choose from on the drop-down menu.

2. In the next window, the web tool will show the efficiency of the power plant. The simplified cost entry calculates the saving on the basis of key data that have been entered. With the detailed option, operators can also record each cost item individually and have the annual yield calculated on this basis.

3. In the summary, users receive a quotation for a modernized system design that they can then implement with professional support from the SMA Repowering team.

Sustainable repowering: replace only what needs replacing

The repowering configuration for PV power plants in Sunny Design Web works independently of the original inverter manufacturer. The portal compares the key parameters of the existing system with the SMA portfolio and proposes a modernized system design with high-performance SMA inverters.

The rule of thumb for repowering is to replace only what needs replacing. If the power plant’s reduced performance is down to the inverter, the original design of the power plant will remain unchanged as far as possible. The aim of Sunny Design Web is to always retain as many components as possible for further use. Important criteria such as DC and AC voltage are predefined in this case. The nominal/feed-in power must not be changed in the course of modernization either.

The key features of the Sunny Design repowering calculation:

  • All modules can be selected in any configuration. In designing their PV power plants, operators can choose the modules that are used in their systems. The portal offers a variety of older PV modules for preselection. If a particular module is not included, the user can simply add it.
  • The user is free to choose the string configuration of the system, e.g., the number of modules in a string, the number of strings per field, etc.
  • Selection between automatic and manual designs: on the basis of the inputs, the web portal automatically suggests the most suitable inverter. But power plant operators can also manually select a particular inverter. The system then evaluates how this fits in with the specified system design.


Do you operate a PV power plant and want to find out whether and, if so, how modernizing your system will pay off?

Click here to go to Sunny Design Web


Shyam Lohidakshan

Product Manager SMA Repowering Solutions

“With the SunnyDesign web portal, power plant operators can quickly and clearly analyze whether and how modernizing their project is paying off. During implementation, they benefit from the professional support of our repowering team.”


5/5 - (1 vote)
  1. Ulf
    Ulf says:

    I like Sunny design. Where can I find more information on which factors are included in the energy yield calculation? E.g are bypass diodes contemplated when a shadow moves over a panel vs its position portrait/landscape? A less inclined panel will clean it self less by rain. Is this a factor that is weighed in? Wind at a certain location will cool the panels better. Is this weather data included? And so on. The manual does not provide this information.

    • Christiane Keim
      Christiane Keim says:

      Hello Ulf,

      Thank you for your kind feedback.
      Please get back to our SMA Service as we need more detailed information for further support.

      Sunny regards

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