Regarding comments about wind integration, I recommend this article from the IEEE Power & Energy Magazine, "Wind Myths Debunked."
Regarding power rates in Europe compared to the US, a key difference is taxes. European electric rates, just like in the US, are complicated and opaque. But here is a handy source of data, from the EU --
It says indeed that residential rates are highest in Denmark and Germany. But also notes that "the highest proportion of taxes in the final price of electricity for [residential] consumers was recorded in Denmark, where more than half (55.8 %) of the final price was made up of VAT, taxes and levies; Germany (44.9 %) and Portugal (43.2 %) had the next highest shares.
Most US states do not tax electricity sales.
This chart breaks out the components, showing "energy and supply" costs in Denmark are only 6.8 cents of the total 29.8 cent price.
Total prices in the UK are half of that in Denmark, but largely because power is untaxed. The "energy and supply" cost in the UK is 11.7 cents.
It's also interesting to note that industrial power costs in Denmark and Germany are just average in the EU. This is partly due to the fact that most German industries don't pay the EEG surcharge; it is charged to residential consumers. So pointing only to residential rates, and ignoring the components of the rates, intentionally exaggerates the supposed effect of renewables.
Regarding comments on storage, let me paste in a passage from the IEEE article "Wind Myths Debunked", from 2009 --
Does Wind Need Storage?
The fact that “the wind doesn’t always blow” is often used to suggest the need for dedicated energy storage to handle fluctuations in the generation of wind power. Such viewpoints, however, ignore the realities of both grid operation and the performance of a large, spatially
diverse wind-generation resource.
Historically, all other variation (for example, that due to system loads, generation-commitment and dispatch changes, and network topology changes) has been handled systemically. This is because the diversity of need leads to much lower costs when variability is aggregated before being balanced. Storage is almost never “coupled” with any single energy source—it is most economic when operated to maximize the economic benefit to an entire system.
Storage is nearly always beneficial to the grid, but this benefit must be weighed against its cost. With more than 26 GW of wind power currently operating in the United States and more than 65 GW of wind energy operating in Europe (as of the date of this writing), no additional storage has been added to the systems to balance wind. Storage has value in a system without wind, which is the reason why about 20 GW of pumped hydro storage was built in the United States and 100 GW was built worldwide, decades before wind and solar energy were considered as viable electricity generation tech- nologies. Additional wind could increase the value of energy storage in the grid as a whole, but storage would continue to provide its services to the grid—storing energy from a mix of sources and responding to variations in the net demand, not just wind...
You can read more at http://www.ieee-pes.org/images/pdf/open-access-milligan.pdf.
All of the experts cite the technical, policy and political challenges of a total transformation of the power system.
The technical challenges are looking increasingly solvable, as real world experience shows systems surviving with very high levels of renewables for short periods of time (Germany, Denmark, Colorado). And a steady stream of innovation and progress in PV, wind, batteries, and other technologies suggest it will be easier going forward.
The policy questions are the subject of America's Power Plan, a study of policy barriers to a high-renewable future in the US. The Plan is featured in a regular series of articles on this site, and is available at www.americaspowerplan.org.
The politics issue seems the hardest for now, as incumbent industries are pushing back. But as the market matures, more investors and politicians will see it as an opportunity instead of a threat, and we will hit a tipping point of support.