Let's compare solar energy and coal, and try to do it without using any math. Let's compare the land that would be consumed by solar energy versus the amount of land consumed by mountaintop removal, leaving out all the other types of coal mining.
By 2012, mountaintop removal will consume 2,200 square miles of the best land in the Eastern US, an area the size of Delaware. That's 2,200 sq miles of the East Coast rivers' headwaters, and the mine waste will send poisons through the nations water supplies from the Chesapeake Bay to the Gulf of Mexico for centuries to come. It's not sustainable - that land is won't give any more energy, food, or water ever again.
Meanwhile, it is estimated that roughly a 100 by 100 mile square (10,000 sq mile) of American desert devoted to solar power could supply all of America's electricity.
And the EU proposes to produce electricity for the EU, Middle East, and North Africa using 0.3% of the Sahara. How small that area is can be seen on this site.
The DOE says that concentrated solar energy plants using reflectors and boilers could provide us with as much power as we need for substantially less than nukes. The numbers I am seeing for the area of CSP are consistent with estimates of land needed for solar energy that I've been seeing for about 15 years. In America, if an area equivalent to several large counties were used to collect solar energy, we would have all the electricity we need. Not that it all has to be in one place - it can include military bases, old strip mines, highway easements, power line right of ways and a lot of areas that are already degraded to some degree. This DOE report is recent and very detailed.
The EU's ambitious project, called TREC (The Trans-Mediterranean Renewable Energy Cooperation), proposes to use concentrating solar power (CSP), which uses reflectors to heat pipes full of fluid (probably water.) The design will probably be reflective parabolic troughs. Because these units can store heat, they can provide power at night (unlike photovoltaics), but because CSP operates at higher temperatures, they need to be in the desert. CSP would be complemented by wind along the coast and other renewable power sources.
Basically, a solar farm the size of Sicily would provide electricity for the entire EU. An area the size of Ireland would power the entire world.
This seems like a lot of land, but remember, we are already on our way to strip mining an area the size of Delaware and it will just keep getting larger and larger.The amount of area we are strip mining for coal continues to grow, our watersheds are being devastated and the damage is permanent. A similar fate is in store for the Rockies in pursuit of oil shale. These areas are slated for permanent destruction on the scale of a nuclear war.
It's tough to compare the projected costs of different technologies, and the hidden cost of fossil fuels is rarely included. But when you look at the area of land permanently destroyed for a jolt of fossil fuels that only supplies part of our needs, versus the area for solar energy to supply all our energy, it becomes a lot clearer. A picture is worth a thousand words, and if its CSP versus mountaintop removal, solar is going to be the clear winner.