2 ms·

I don't believe that amount takes in consideration that there are many and many days in Germany when the sun doesn't shine almost at all. I live nearby (in Czec

I don't believe that amount takes in consideration that there are many and many days in Germany when the sun doesn't shine almost at all. I live nearby (in Czechia) and the solar arrays here are very widespread - so much that both the biologists and the public already hate them and don't want any more - and yet it all generates only a few percents of our energy. The cost of these projects was enormous too. Czechia will be building new nuclear power sources soon and decommission some of the arrays, thankfully people here are not like Germans. I also don't think we should aim to generate the same amount of energy. We want more and better manufacturing, and if that should be done cleanly, it needs a lot of electricity, way more than the "renewables" could ever bring.

adrianN 6y ago
You can do the math yourself. Solar panels have around 150W/m^2. In Germany they produce a little more than 10% of peak output if you average over one year. The average German uses about 48000kWh per year (primary energy), so around 350m^2 per person. That's around 8% of Germany's land area, or two percentage points more than what we currently use for energy crops. Since primary energy includes heat and transportation, both of which can be done much more efficient with electricity (e.g. a car is maybe 30% efficient, and a heat pump gets you 2-5J of heat per Joule of electricity) you can very conservatively cut that in half. I'm reasonably sure that it also includes power plant inefficiencies (another 40%?) but let's not account for those. That gets you down to about 4%. Wind power is more efficient per m^2 than solar in Germany, and a lot can be produced offshore. That gets you down to the 2-3% range. And of course a lot of solar can be installed on rooftops and such where it doesn't consume any additional land at all.

adrianN 6y ago

You can do the math yourself. Solar panels have around 150W/m^2. In Germany they produce a little more than 10% of peak output if you average over one year. The average German uses about 48000kWh per year (primary energy), so around 350m^2 per person. That's around 8% of Germany's land area, or two percentage points more than what we currently use for energy crops. Since primary energy includes heat and transportation, both of which can be done much more efficient with electricity (e.g. a car is maybe 30% efficient, and a heat pump gets you 2-5J of heat per Joule of electricity) you can very conservatively cut that in half. I'm reasonably sure that it also includes power plant inefficiencies (another 40%?) but let's not account for those. That gets you down to about 4%. Wind power is more efficient per m^2 than solar in Germany, and a lot can be produced offshore. That gets you down to the 2-3% range. And of course a lot of solar can be installed on rooftops and such where it doesn't consume any additional land at all.