Germany’s solar sector is undergoing a crucial period of transformation, driven by recent regulations such as the Peak Solar Energy Law, which seeks to improve the integration of photovoltaics into the electricity grid. However, its impact on market expansion and project profitability remains a topic of debate.

In a conversation with Strategic Energy Europe, Carsten Körnig, General Manager of Bundesverband Solarwirtschaft e.V. (BSW), analyses the regulatory changes, challenges in grid infrastructure, and the remarkable growth of energy storage in Germany in 2024.

Impact of the Peak Solar Energy Law on Photovoltaic Expansion

The new regulation aims to increase the flexibility of renewable energy integration and improve the efficiency of the electricity system. However, its effect on solar expansion remains limited.

“The amendments seek to remove obstacles to the expansion of solar energy and storage, but they will not significantly impact the pace of new photovoltaic installations,” explains Körnig.

One of the most debated aspects is the elimination of the feed-in tariff during periods of negative electricity prices. According to the executive, this measure will not significantly affect the profitability of projects, thanks to a compensation mechanism that extends the remuneration period to 20 years.

“Systems that do not receive tariffs during negative price periods can compensate for this loss over their operational lifespan, ensuring financial stability for operators,” he states.

Greater Grid Connection Flexibility: A Solution to Bottlenecks?

Another key regulatory change is the introduction of flexible grid connection agreements, allowing for better utilisation of existing grid capacity and reducing the need for costly expansions.

“The new regulation facilitates the connection of larger generation capacities at existing grid points, optimising infrastructure use and reducing the need for expensive expansions,” says Körnig.

This measure is particularly relevant for photovoltaic projects with storage, as it enables better management of midday solar generation peaks and the redistribution of energy during peak demand hours.

60% Feed-in Limit: Impact on Small-Scale Projects

One of the most controversial aspects of the new law is the 60% limitation on energy feed-in for new installations without intelligent metering systems (iMSys). This could impact the profitability of smaller projects that lack storage.

“For those installing batteries or consuming their own production, the impact will be minimal. However, systems that operate without storage and rely entirely on feeding into the grid could see a reduction in revenues,” warns Körnig.

A study by HTW Berlin estimates that curtailment losses due to this limitation range between 1.1% (for east-west oriented installations) and up to 9% (for south-facing systems without storage). However, the majority of new photovoltaic systems in Germany are now installed with battery storage, significantly mitigating this impact.

Energy Storage Expansion: 50% Growth in 2024

The energy storage sector has experienced unprecedented growth in Germany, with a 50% increase in installed capacity in 2024.

“The number of residential battery storage systems grew by 580,000 units, reaching a total of 1.8 million,” says Körnig. This trend is mainly driven by the profitability of self-consumption, as stored solar energy reduces dependence on grid electricity.

The expansion is not limited to residential projects. In the commercial sector, the number of installed storage facilities increased by 60%, reaching 38,000 units with a total capacity of 1.4 GWh.

Additionally, large-scale storage systems (over 1 MWh) have seen the highest growth rate. In 2024, 100 new large-scale storage facilities were commissioned, adding 0.8 GWh of capacity—double the growth recorded in 2023.

The Future of Solar Energy in Germany: Challenges and Opportunities

Solar energy currently accounts for 15% of Germany’s electricity consumption, solidifying its role as a key pillar of the energy system. However, challenges remain in accelerating the transition and improving photovoltaic integration into the grid.

According to Körnig, the main challenges include:

1. Increased investment in storage to manage solar production during low-demand hours.
2. Faster grid connection processes to reduce time and costs for new projects.
3. More favourable regulations for self-consumption, removing barriers to small-scale profitability.

“Germany’s solar sector has proven its ability to adapt and grow, but it is crucial to continue implementing measures that encourage investment in storage and improve grid infrastructure,” concludes Körnig.

With these strategies, Germany could continue leading the energy transition in Europe, strengthening its model based on renewable energy and efficient storage solutions.