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> As of 2021, German primary energy consumption amounted to 12,193 Petajoule, with more than 75% coming from fossil sources, 6.2% from nuclear energy and 16.1%

> As of 2021, German primary energy consumption amounted to 12,193 Petajoule, with more than 75% coming from fossil sources, 6.2% from nuclear energy and 16.1% from renewables. You might offset that 6% nuclear that is going away with renewables if you really put your hearts into it, but probably not. Won't be economical.

ZeroGravitas 5y ago
Most primary energy is wasted as heat when turning it into electricity. The German electrification program means they'll only need about a third of that power from renewables to travel the same distance in cars or heat the same homes.
- recuter 5y ago
  Waste heat from a power plant in one part of the country can't be sent to heat homes in another. That's the very heart of the matter. If you could magically get the angry pixies into all the forthcoming electric cars directly with no waste, sure. It is very nice milestone that the top line numbers are there already, but way too early to declare victory.
  - yayachiken 5y ago
    By definition, the primary energy input and electrical energy output are equal for renewable sources that don't require fuel. So the point is that transitioning from thermal electricity generation to sources like solar and wind already reduces the primary energy use. Electrifying traffic further reduces the primary energy use, as 100% of primary energy from gas turn into something like 40% of power which can be used to drive the car forward. An electric engine is a lot more efficient. This is just math and doesn't yet include efficiency gains through insulation, heat pumps etc.
    - imtringued 5y ago
      > By definition, the primary energy input and electrical energy output are equal for renewable sources that don't require fuel. When you think about it, this is unfairly disadvantaging renewables due to an unfortunate choice of primary energy. For renewables, the primary energy is solar radiation! Suddenly the primary energy of solar panels would go up 5 fold just because of changing the definition of primary energy. Then everyone would be talking how unfair primary energy is to fossil fuels.
      - yayachiken 5y ago
        You can go even further. All "natural" processes are completely excluded from primary energy use. If you include the energy used by agriculture (as in: photosynthesis) you will get a number that human energy use is something like 99% powered by the sun. If you include ambient heat, non-solar energy sources become a rounding error. This may seem obvious and silly, but especially in residential heating using the ambient heat with heat-pumps, solar collectors, large sun-facing triple insulated window fronts, will be key for energy usage reduction. I would recommend the books by Professor Volker Quaschning (well-known climate scientist in Germany), he goes into lots of stuff like this in detail.

ZeroGravitas 5y ago

Most primary energy is wasted as heat when turning it into electricity. The German electrification program means they'll only need about a third of that power from renewables to travel the same distance in cars or heat the same homes.

recuter 5y ago
Waste heat from a power plant in one part of the country can't be sent to heat homes in another. That's the very heart of the matter. If you could magically get the angry pixies into all the forthcoming electric cars directly with no waste, sure. It is very nice milestone that the top line numbers are there already, but way too early to declare victory.
- yayachiken 5y ago
  By definition, the primary energy input and electrical energy output are equal for renewable sources that don't require fuel. So the point is that transitioning from thermal electricity generation to sources like solar and wind already reduces the primary energy use. Electrifying traffic further reduces the primary energy use, as 100% of primary energy from gas turn into something like 40% of power which can be used to drive the car forward. An electric engine is a lot more efficient. This is just math and doesn't yet include efficiency gains through insulation, heat pumps etc.
  - imtringued 5y ago
    > By definition, the primary energy input and electrical energy output are equal for renewable sources that don't require fuel. When you think about it, this is unfairly disadvantaging renewables due to an unfortunate choice of primary energy. For renewables, the primary energy is solar radiation! Suddenly the primary energy of solar panels would go up 5 fold just because of changing the definition of primary energy. Then everyone would be talking how unfair primary energy is to fossil fuels.
    - yayachiken 5y ago
      You can go even further. All "natural" processes are completely excluded from primary energy use. If you include the energy used by agriculture (as in: photosynthesis) you will get a number that human energy use is something like 99% powered by the sun. If you include ambient heat, non-solar energy sources become a rounding error. This may seem obvious and silly, but especially in residential heating using the ambient heat with heat-pumps, solar collectors, large sun-facing triple insulated window fronts, will be key for energy usage reduction. I would recommend the books by Professor Volker Quaschning (well-known climate scientist in Germany), he goes into lots of stuff like this in detail.