One of the reasons some people are skeptical about Desertec is that they don’t understand why that project is necessary.
If the goal is only to get to 100% renewable electricity in Germany, I agree, that could be easily done with local resources.
Even if the goal is only to get to 100% renewable energy in Germany (a more ambitious one), I would be optimistic.
But I think Desertec is still necessary to counter global warming.
For one, Europe is producing around 3,200 TWh a year of electricity, with more than half of that generated from fossil fuel. That’s a lot of energy. Germany got 123.5 TWh from renewable energy last year, which is nice, but still leaves a long way to go compared to the demand in all of Europe.
Also, speed matters. Eventually we might get to 100% from local renewable sources everywhere. But reducing carbon emissions is an urgent task. Every bit of renewable energy everywhere is necessary for that.
So while it may be true that Germany can get 100% energy from local renewables, that is not necessarily true of all Europe, and even if it is, it would take longer.