Baseload is concept of a 20th century grid run by monopoly utilities with a vested financial interest in operating certain inflexible power plants at maximum output. If I have a paid-off coal or nuclear power plant, of course I want it to run at max output 24/7! And because I'm the monopoly utility (true in 30 U.S. states), I get to prioritize output from my power plant. Winner winner chicken dinner!
In truth, our power system already has a helluva lot of capacity built to accommodate variability from energy USERS (supply = demand at all times or system crashes), and it can also be used to manage variability from energy PRODUCERS, like wind. It's not an extra cost, it's built in until the level of variability far exceeds current situations (except in isolated geographic areas of the grid, or island power networks).
In the long run, we will need a power system with more flexible sources of generation or storage to manage higher levels of variability associated with wind and solar power. But for now, on most power grids? Not even close.
And guess what, fossil fuels aren't without variability, either? What if you can't get a coal train to a coal power plant? http://www.marketplace.org/top...