Natural gas is a fossil fuel, as is coal more or less. The natural gas we're currently using comes with Oil. Methane doesn't...
They build over 100 windmills near where i live. >_> to ship the power to california.
Destroying Yellowstone isn't the only issue, what happens if in this persuit you cause Yellowstone to irrupt.
The Sahara is unstable with as much sand as it has, one day you'd have solar panels the next they'd be burried in sand, a lot of it.
To the North and South Poles... that's pratically impossible as they only get sunlight for 3 months a year, and the rest is blowing snow and Ice, and the dark...
And the space station idea, one problem Political and monetary support... Very few with money care, and those in government care even less... thus no money...
not sure what you mean about Masdar type cities...
the Thermal coupling would work in such areas as Montana where it turned from hot to very cold... if you use it like what happens to your sidewalks... yeah.... however requires.... money and research...