Eco Stor: Online calculator determines energy transition storage requirements

From pv magazine Germany

If the energy transition in Germany is to succeed, storage will be needed. There is widespread agreement on this, but the question is how much storage capacity do we need and which additional reserve power plants are necessary. Eco Stor has developed an online tool for this purpose. It allows anyone to run through future models and scenarios and determine the storage capacity required. It is now available to the general public free of charge.

Eco Stor's online tool is a “storage dashboard” that can be used to simulate the various future expansion scenarios based on real load and generation data. The main aim is to show how much reserve capacity will still be needed for the remaining “Dunkelflaute,” or “dark doldrums.” The phases in which neither the sun shines nor the wind blows are regarded as a bogeyman for the energy transition.

The dark doldrums, also known as the dark lull, is defined as a continuous period of more than 24 hours in which the feed-in of renewable energy is permanently below a threshold of 50% of the electricity demand. Such times in which less than half of the electricity demand is covered by photovoltaics and wind power occur primarily in the winter months.

Using the online calculator is self-explanatory, according to Eco Stor. There is also an online helper available that provides information on the most important steps.

The basis for generating the most realistic assumptions possible is the generation and consumption data from 2020 to 2023. From these initial values, you can then select how much photovoltaics or wind power will be installed in the future. Assumptions can also be made about how much short-term storage capacity is available or about electricity consumption. The result then shows the remaining supply gap and how many reserve power plants are required in the event of an emergency. The modeling is based on certain simplifications, Eco Stor notes. Regional network bottlenecks or cross-border electricity trading are not taken into account. The latter in particular will probably replace some short- and long-term storage needs in the future.

Overall, the tool can provide assistance on how the energy system needs to be further developed in the future so that short-term storage correlates with an increasing share of PV and wind power. Eco Stor can also be used to ensure that the energy transition is implemented cost-effectively in the long term, i.e. that an electricity system can be implemented in an economically optimized manner. Indeed, the real key question, Eco Stor stresses, is how to achieve a CO2-free electricity supply at minimal cost.