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U.S. states can reach grid parity by 2014, energy experts say

Another way of defining "grid parity" is that 1 KWH of power from a coal plant would cost you 31 cents - and thjat would be the same costs as from a wind farm, solar farm, wave farm, hydro etc. Right now most of those others (except hyrdo) cost anywhere from 4 to 15 times more than a coal plant - the difference is in subsidies paid to those firms to use those methods by state and Federal Governments. Oregon will pay out around $110 million per year (over 5 years) to get people to put up wind farms. Oh, and Oregon raised income taxes on a select group of people of $550 million due to budget shortfalls in this last year . . . funny how that worked out

From what I can see, grid parity just looks at the cost of producing a KWH without considering overall costs of providing that KWH to customers 24/7.

Unfortunately, if you have a solar panel which is at "grid parity" with coal, it's probably costlier in terms of overall costs. For example, with solar you have to provide costly energy storage for nighttime (nobody even knows what that will be). You have to worry about cloudy days and have some mix of extra capacity or extra storage which will be overkill on sunny days. This increases the cost of actually relying on solar as a primary power source.

With wind there are similar issues. The wind doesn't blow when and where you want it. That means building much more turbine capacity than you need in the hope that statistically you'll have enough turbines turning somewhere to provide the needed electricity and/or building some sort of expensive energy storage. If you have to install double the turbines you actually need to meet this statistical certainty, you've basically doubled the cost of wind even though technically you have reached grid parity.

With both wind and solar you can never guarantee that at any time you will be getting the optimum output from your devices. With conventional "grid power" achieving maximum output is totally under the control of the electric utilities. This makes planning vastly simpler and effectively reduces the cost, but this is not covered in the concept of "grid parity". Or do the promoters of grid parity assume that somewhere there will be conventional grid power sources such as coal to take up the slack times of wind and solar? If so, then the concept of grid parity is a cheat that does not fully consider the true costs.

The article also mentions government subsidies to renewable power. Technically, I don't think these are counted in the concept of "grid parity", but mentioning them in this context just confuses things.

In short, grid parity is a bit like achieving "break even" in nuclear fusion. It's a necessary point for success, but by itself does not mean we are at a commercially viable point of replacing conventional grid power. Don't get your hopes up on the basis of "grid parity".