I assume that you are referring to the situation in the USA. Do you have any knowledge / opinion on the situation with wind in places like Spain and Denmark, where there are so many windmills and in many places with an almost "always on" wind, so that both countries are on their way to getting 30% of their electricity form wind? I guess that whether one can make that much electricity doesn't automatically mean that one is making it when or where it is most needed...
"the wind can cause certain nodes to go to THOUSANDS of dollars/MWhr because of congestion on the grid"
Am I correct to take that to mean that when their electricity is not needed they produce so little that the investment (the windmill) is just sitting there losing value and producing no return on investment?
Ok, so wind is never "always on". Even in coastal locations like Spain, Portugal and Denmark, while it may seem like a steady breeze, I assure you the generation is varying from 10% to 100%. The turbines actually have brakes on them so they don't overspeed. The brakes are there for another reason as well: when the wind power is too high, it pushes too much power onto the transmission system. Wind is often not located near load centers. When there is too much power on one side of the grid and equipment is at risk, price signals are used to try to rebalance the generation and protect the transmission network.
This means that the wind points get negative prices (eg. they are paying money to the grid to generate power), while units that are hundreds if not thousands of miles away get very strong positive price signals to 'turn on'. These are usually high heat rate gas turbines (GT's) that don't really want to run, but they will if prices get high enough. Thus the consumer actually loses out because of this congestion on the grid; the consumer ends up eventually paying for the 'uplift' and 'balancing' charges for out-of-merit dispatch of units.
As for suggestions that the USA should upgrade it's grid, well, #1, the USA has one of the best electrical grids in the entire world. How many 765kv lines do you have in the UK? Or look at Japan, with it's very weird mix of 50hz/60hz split grid. We have upgraded in the USA, for example, in Texas (the state with the most wind power), they build new 345kv lines to take power to the load centers. This *helps* but it isn't a total solution.
Finally, we haven't talked about regulation. Because there is no or very little storage of electricity, the load and the generation must always be in balance and equal. The difference between load and generation is called the ACE (area control error) and needs to stay within certain bounds. Therefore you can use units which ramp fast to regulate the wind units. If you look at the generation profile of a wind unit, it is not a flat line. It is very peaky and has lots of spikes. So when the wind is blowing, great, but as soon as it slacks off, something has to pick up the drop in generation, and that unit has to be able to respond fast. Which means NOT coal, because running a boiler takes 20-30 minutes to ramp up or down, so you need to run gas or diesel units to regulate the wind generation.