The renewable energy markets are maturing quite rapidly.

The solar sector, in particular, is showing signs of advancement as clear leaders are emerging every day. What we're seeing is a shift in the way the market as a whole views this industry.

Much of the initial guesswork and hype associated with solar technology stocks is beginning to wane. And fair valuation is being applied to companies based on their margins, earnings and outputs—not just on the next big idea or promise.

With that in mind, I want to go over some recent solar stock earnings to illustrate my point. When finished, you'll have a better idea of how the solar industry is moving, and how to profit from it as it grows.

Solar Technology Stocks: A Look Beyond Earnings

To get a clear picture of what's going on, we first have to go back to March.

Having recently returned from a Piper Jaffray renewable energy finance forum in late February, I had a good idea of how the solar industry was going to shake out over the next few months.

Some of the established players were building and opening new manufacturing plants, putting upward pressure on megawatt output numbers, but also driving up capital costs, which were obviously needed to put steel in the ground.

There also was (and is) a shaky silicon supply issue, causing heartache for some and fortune for others.

The winners were going to be the companies that could ramp up output and efficiency while maintaining relatively low costs and decent margins.

Seems simple enough.

From what I heard at that forum, I had a fairly good idea of which companies could provide nice returns in the near future. And, if you remember, many solar technology stocks had gone down with the broader market early in the year—so there were bargains to be had anyway.

And so I set the traps.

First up was Solarfun Power Holdings (NASDAQ: SOLF). Badly battered for the first two months of the year, SOLF was trading astoundingly low at under $10 per share.

The company's fourth quarter 2007 earnings had been delayed for some accounting issues, but were due out the last week of March. I recommended buying SOLF at $9.40 per share to members of the Alternative Energy Speculator on March 17^th.

Earnings came out on March 27^th. Earnings per share beat The Street estimate by a penny. And revenue beat predictions by $20.1 million.

By the end of the first week of April, SOLF was trading at $15.70. And members of the Alternative Energy Speculator were sitting on gains of 67%.  Take a look:

Before March 27^th, it didn't matter that SOLF was negotiating polysilicon contracts with Hoku Scientific (NASDAQ: HOKU). Or that their founder is a major name in the Chinese utility business, which will provide a good climate for negotiating grid-connected installations.

All professional investors wanted to see were the numbers. And the numbers were good.

More Recent Solar Technology Stock Earnings

More recently, we saw the third quarter (quarterly reports depend on the company's fiscal year) earnings of Energy Conversion Devices (NASDAQ: ENER) on May 8^th.

Analysts were expecting a loss of $0.06 per share on revenues of $66.7 million.

Boy were they wrong.

Revenue came in close, at $70 million. But the surprise came in the form of profitability. Instead of the predicted loss of 6 cents per share, the company turned a profit of $7 million, or $0.17 per share.

The day before the earnings, ENER was trading at $34.81. On May 8^th, shares climbed to $49.91, a 43% one-day run. Now, shares are trading even higher, around $54 per share.  Check that one out:

And finally, today we saw the first quarter earnings release of Canadian Solar (NASDAQ: CSIQ).

Analysts were predicting earnings per share of $0.31 on revenues of $151.9 million.

The actual numbers were earnings per share of $0.61 on revenues of $171.2 million.

CSIQ also lifted second quarter guidance above Street expectations.

You can guess what happened. The stock soared nearly 30% in one day, gaining around $10.  Take a look:

The Next Solar Stock Earnings

I've got my eye on two other solar technology companies reporting earnings this week as well.

One is already in the Alternative Energy Speculator portfolio.

I'm recommending the other one today.

You've seen through the previous three examples how these earnings are moving share prices. The winners in this industry are starting to emerge, and more attention is being paid to them from all investors—not just those interested in green investing.

That just makes it more profitable for us.

I believe this next company will move in much the same way the others have on Thursday when it reports its earnings.

But you need to be a member of the Alternative Energy Speculator to profit. If you buy in before this company releases earnings, the nominal fee for the service can more than pay for itself.

Call it like you see it,

Nick