We spend $25bn/year to produce 1% of our energy usage by renewables.
In 2015, the total power generation in Germany was 559 TWh. Renewables amount to about 121 TWh, i.e. about 22%. [0]
Newbuild house prices have increased by 40% in the last ten years
That sounds like a lot. From what I can find, construction prices have increased by about 20% since 2005 -- that goes for virtually all kinds of construction, including road construction[1][2]. Must be all the heat exchangers in those new roads... I'm not sure if that figure is corrected for overall inflation, it doesn't appear to be (cumulative inflation in Germany since 2005 is about 15%[3]).
Yeah you get nice numbers if you ignore the total energy usage. The numbers you gave are only one fifth of Germanys total energy consumption. I was off by 2% though, 3% is covered by renewables. We are not only talking electric, but total energy: heat, oil etc.
Renewable energy is usually only framed in terms of electrical power generation, but taking a wider perspective is sensible.
Primary energy is 3704 TWh[0], so 3% jives with the numbers I gave (so you were off by a factor of 3). 27% of that is heating, 39% transportation. The key to reducing those is gains in efficiency, ie. things like insulation, combined heat and power, renewable heat on the one hand, more efficient cars and more public transportation on the other hand.
http://m.welt.de/debatte/kommentare/article156130737/Energie...