Throughout the last winter and spring, solar stocks fell deeper and deeper out of favor. Investors fretted about a sharp slowdown in government subsidies right at a time when many companies were expanding their factories to boost output. Prices for solar panels and other components were in freefall as inventories piled up. But industry executives in China had a hunch that they could find ample demand for their rising output. They were right. Demand is better than many had expected, and this sector is now in rally mode.

In the last three months, Jinko Solar (NYSE: JKS), Solarfun (NYSE: SLF), ReneSola (NYSE: SOL) and Trina Solar (NYSE: TSL) have all risen by at least +40%. If you missed those moves, ample opportunities remain for some of the other industry players.

Jinko sets the tone
Little-known Jinko Solar has single-handedly established a more bullish tone for the entire sector. The May, 2010 IPO was flat-lining around $10 two months ago, but has since surged nearly +150% thanks to recent blowout earnings. The company turns re-processed and virgin silicon into solar panels and can handle all phases of the manufacturing process, from wafers to modules to panels. That vertical integration has helped the company to become a low-cost manufacturer, which is essential in this price-competitive business.

Earlier this week, Jinko Solar reported its first-ever results as a publicly-traded company, and they were nothing short of spectacular. Earnings per share (EPS) of $1.39 were more than double the consensus forecast as sales were nicely ahead of plan and gross margins were firmer than most had expected. Analysts now think the company can earn close to $3.50 a share next year, nearly $1 more than they thought just a week ago. Shares, which recently traded hands for around $25, could approach $30 in coming months, but most of the sharp gains have been made in this stock as it is no longer a well-kept secret.

Where to turn?
Some Chinese solar stocks still trade at very low valuations. JA Solar (Nasdaq: JASO), for example, trades for less than seven times projected 2010 and 2011 profits. This former highflyer traded above $25 back in 2008, but can now be had for less than $6. Sales have been surging, from $34 million in the first quarter of 2009 to $351 million in the second quarter of 2010. But profit growth has not been as robust and actually fell back on a sequential basis in the most recent quarter, thanks to profit margin pressures.

However, recent additions to manufacturing capacity have led analysts to start boosting profit forecasts, despite expectations that pricing and profit margins will stay under pressure. It’s unlikely that shares will re-visit those 2008 heights any-time soon, as investors are no longer willing to slap very high multiples on these stocks as the industry matures. Yet shares could move up to $8 or $9 if the company can meet or exceed recently-boosted forecasts. That translates into a +30% to +50% gain from current levels.

A contrarian play
After a series of missteps, Canadian Solar (Nasdaq: CSIQ) is deeply out of favor right now. Shares have fallen more than -40% in the past six months after a string of weak profit reports and an announcement that an SEC investigation would likely lead to a re-statement of 2010 fourth quarter results. But later today, investor concerns might start to see a resolution as the company will hold a conference call after the market closes to update recent results.

Canadian Solar was once a highflyer, too: sales at this solar panel maker had zoomed from $20 million in 2005 to $700 million by 2008. And although sales flattened last year, recent capacity additions should push sales north of $1 billion this year. Equally important, the bottom-line should rebound in 2011, with EPS bumping back up to $1.50. Shares trade for less than eight times that forecast. (Profits are being constrained this year while industry demand catches up with supply — a situation expected to reverse in coming quarters.)

Today’s conference call will be crucial to get shares moving up again. Management has lost a great deal of credibility and they will have to be forthright about the issues regarding the SEC investigation. They will have to make a clear case of why profits will rebound so sharply in 2011 — as is currently expected. If they can clear the decks, this solar laggard could be the next rebound candidate.

Action to Take –> As a note of caution, it appears that investors will need to see considerable upside to further boost shares of any sector stock that had already had a good run. For example, shares of Yingli Green Energy (NYSE: YGE), which had risen more than +20% in the past three months, barely budged in Thursday trading, despite the announcement of estimate-topping results earlier in the day. Instead, investors may want to focus on the still-weak names like JA Solar and Canadian Solar, both of which carry very low expectations.