Renewable energy potential in Japan and Germany

This briefing paper examines the renewable energy potential of Germany and Japan across three technology areas: solar photovoltaic (PV), onshore wind, and offshore wind. Drawing on existing national and international studies, it analyses theoretical, technical, and practical potential levels for each country, highlighting both opportunities and the constraints that limit the realisation of these potentials.

Both countries demonstrate the technical capacity to cover their entire electricity demand through renewable sources. Germany benefits from favourable onshore wind conditions and a balanced solar PV landscape, while Japan holds immense potential – particularly for solar PV and floating offshore wind – though practical deployment remains constrained by mountainous terrain, spatial restrictions, and regulatory complexity.

Offshore wind presents a particularly stark contrast: Germany's practical expansion is largely bounded by its comparatively small marine area, whereas Japan's vast exclusive economic zone offers technical potentials that far exceed its governmental targets and projected electricity needs, with floating wind technology essential to unlocking this resource.

The analysis reveals that, despite differing potential structures, both countries face analogous challenges in translating technical potential into deployed capacity. Continued innovation in policy frameworks, technology, and stakeholder engagement will be critical for both countries to fully realise their renewable energy ambitions.