An article on the electrical grid, and it's vulnerability to various stressors. This has implications for future transmission of electricity, regardless of how it is generated.
An important point:
In August 2003, a tree branch in Ohio caused the largest blackout in North America's history, for a fairly simple reason: the electrical grid is so complex, and running so close to capacity, that even small problems can cascade into catastrophic breakdowns. As with most problems of complexity beyond the point of diminishing returns, the question of what finally pushed the system over the edge is much less important than the question of what made the system of complex that it became vulnerable to something so small in the first place.