Back in 2008, or 2009, I forget, I was posting the "original Million Dollar Way" blog. If you think the current MDW blog has problems, that one really had problems. I loved it; my readers didn't. All three of them. So, one night, in a decision I regret, I deleted the entire blog with one keystroke. There were some great posts in that blog.
In the original blog I tracked electric rates. One of the sites I linked was this one:
Michael Blue Jay's "Saving Electricity." I see that blog is still around, and this particular link has not been updated since 2004. But I don't think electric rates in this country have changed a whole lot. All-source electricity in this country is probably about 8 cents/kWh depending on the make-up of the source: coal, natural gas, nuclear, solar. So, let's call it a dime/kWh.
Look at
what the Germans are willing to pay for going solar: about thirty cents/kWh.
The Japanese appear to have just announced, if I understand the story correctly, that "they" will be paying about 53 cents/kWh for solar, again, compared to a dime in the US for electricity generated from all sources.
I see that
the site I used to follow all the time for solar energy is still posting. These are their rates for solar. In North Dakota, a sunny climate state, solar would cost about three dimes/kWh; in a cloudy state like Washington State, it might cost up to six dimes. (Washington State has "dirt-cheap" hydroelectric power, but I digress.)
The following is from SolarBuzz, linked above.

The price, 18.7 cents per kilowatt hour, is similar to the price
National Grid agreed to pay when it signed a contract in 2010 to
purchase half the power generated by Cape Wind. NStar will purchase
27.5 percent of the wind farm’s total output.
The utilities pay about 8 cents per kilowatt hour for electricity
and NStar originally balked at becoming a Cape Wind customer, arguing
the wind farm’s cost was just too high. That position changed last
month when, after nearly a year of negotiations, state energy officials
agreed to endorse a proposed merger between NStar and Connecticut-based
Northeast Utilities if NStar made several concessions, including buying
power from Cape Wind.
I always get in trouble when I talk about things I don't know a whole lot about, and when I talk in averages and generalities, but this is how I understand it.
Electricity from natural gas must be down to four or five cents/kWh, here in the US (a lot higher overseas), and Japan is willing to spend over 50 cents/kWh using solar power. Japan needs to ask Spain how solar power / wind power worked out for them.
Spain suspended all renewable energy projects earlier this year.