During a winter anticyclone, a 5x increase in solar generation is unlikely to help. 5 x 0 = 0. Right? In summer, however, this would lead to massive overproduction. The grid physically won't be able to absorb this volume.
A 10x increase in battery storage will provide about 280 GWh of capacity. Germany's winter consumption is roughly 1.2–1.5 TWh per day. That means the 10x scaled batteries could power the country for less than 5 hours.
As for biogas and hydro, it depends on how you look at it. Betting on biogas/biomass doesn't really work at a utility scale in practice. The energy density of biomass is abysmally low. Replacing baseload generation with biogas would require converting a critical amount of arable land from food to energy production. Who is going to give that up?
There's a problem with hydro, too. Germany has no room to scale hydro generation. All the available valleys are already flooded.
"The utmost amount (46%) of wood pellets comes from the Baltic countries (Latvia and Estonia) and 30% from the USA, Canada and Russia.6 Estonia and Latvia have steadily been the primary exporters of biomass to Denmark, mainly in the form of wood pellets and wood chips."
https://noah.dk/Biomass-consumption-in-Denmark
https://www.eubioenergy.com/2025/03/13/no-smoke-without-fire...
So Denmark replaced lot of imported fossil fuels with imported wood.
Could we scale this form of energy generation to energy requirements of China, India?
Germany plans massive expansion of imports of hydrogen and hydrogen derivatives.
https://usa-germany-cep.org/fileadmin/usa/Documents/1612_Ger...
https://www.bundeswirtschaftsministerium.de/Redaktion/EN/Pre...